Artykuły w czasopismach na temat „Chlorophyll”
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Vaňková, Kateřina, Ivana Marková, Jana Jašprová, Aleš Dvořák, Iva Subhanová, Jaroslav Zelenka, Iva Novosádová i in. "Chlorophyll-Mediated Changes in the Redox Status of Pancreatic Cancer Cells Are Associated with Its Anticancer Effects". Oxidative Medicine and Cellular Longevity 2018 (2.07.2018): 1–11. http://dx.doi.org/10.1155/2018/4069167.
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Nutritional factors which exhibit antioxidant properties, such as those contained in green plants, may be protective against cancer. Chlorophyll and other tetrapyrrolic compounds which are structurally related to heme and bilirubin (a bile pigment with antioxidant activity) are among those molecules which are purportedly responsible for these effects. Therefore, the aim of our study was to assess both the antiproliferative and antioxidative effects of chlorophylls (chlorophylla/b, chlorophyllin, and pheophytina) in experimental pancreatic cancer. Chlorophylls have been shown to produce antiproliferative effects in pancreatic cancer cell lines (PaTu-8902, MiaPaCa-2, and BxPC-3) in a dose-dependent manner (10–125 μmol/L). Chlorophylls also have been observed to inhibit heme oxygenase (HMOX) mRNA expression and HMOX enzymatic activity, substantially affecting the redox environment of pancreatic cancer cells, including the production of mitochondrial/whole-cell reactive oxygen species, and alter the ratio of reduced-to-oxidized glutathione. Importantly, chlorophyll-mediated suppression of pancreatic cancer cell viability has been replicated inin vivoexperiments, where the administration of chlorophyllaresulted in the significant reduction of pancreatic tumor size in xenotransplanted nude mice. In conclusion, this data suggests that chlorophyll-mediated changes on the redox status of pancreatic cancer cells might be responsible for their antiproliferative and anticancer effects and thus contribute to the decreased incidence of cancer among individuals who consume green vegetables.
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Putra, Bayu Taruna Widjaja, Risky Setiawan Purwoko, Indarto Indarto i Peeyush Soni. "An investigation of copper chlorophyllin solution for low-cost optical devices calibration in chlorophyll measurement". International Journal of Metrology and Quality Engineering 10 (2019): 10. http://dx.doi.org/10.1051/ijmqe/2019009.
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Chlorophylls and turbidity are related parameters deemed important in predicting water quality, especially in the freshwater fisheries sector. In other hand, chlorophyll contents in vegetation are often used as a measure for estimating plant health. To ensure the chlorophyll content, appropriate analysis techniques are needed, which include, yet not limited to, dimethylsulfoxide (DMSO), acetone extraction analysis, and measuring turbidity using expensive equipment. Measurements using these methods are still not reliable, especially for smallholders. In addition, calibration of a digital camera for these purposes requires several efforts of preparing a series of chemical analyses and the qualities of newly developed cameras have increased. Thus, calibration needs to be taken into account for improving the accuracy in estimating chlorophyll contents. This study posits fundamental findings germane to the potential use of chlorophyllin for calibrating the optimal instrument, like consumer-grade cameras. Sodium copper chlorophyllin is commonly used as food additive and ingredients, and medical treatments. However, we can gain another benefit of chlorophyllin, particularly for developing low-cost optical instruments for estimating chlorophyll content through hydro-color-based with promising accuracy.
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Li, Yaqiong, i Min Chen. "Novel chlorophylls and new directions in photosynthesis research". Functional Plant Biology 42, nr 6 (2015): 493. http://dx.doi.org/10.1071/fp14350.
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Chlorophyll d and chlorophyll f are red-shifted chlorophylls, because their Qy absorption bands are significantly red-shifted compared with chlorophyll a. The red-shifted chlorophylls broaden the light absorption region further into far red light. The presence of red-shifted chlorophylls in photosynthetic systems has opened up new possibilities of research on photosystem energetics and challenged the unique status of chlorophyll a in oxygenic photosynthesis. In this review, we report on the chemistry and function of red-shifted chlorophylls in photosynthesis and summarise the unique adaptations that have allowed the proliferation of chlorophyll d- and chlorophyll f-containing organisms in diverse ecological niches around the world.
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Li, Yaqiong, Nicholas Scales, Robert E. Blankenship, Robert D. Willows i Min Chen. "Extinction coefficient for red-shifted chlorophylls: Chlorophyll d and chlorophyll f". Biochimica et Biophysica Acta (BBA) - Bioenergetics 1817, nr 8 (sierpień 2012): 1292–98. http://dx.doi.org/10.1016/j.bbabio.2012.02.026.
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Wood, Lindsay W. "Chloroform–Methanol Extraction of Chlorophyll a". Canadian Journal of Fisheries and Aquatic Sciences 42, nr 1 (1.01.1985): 38–43. http://dx.doi.org/10.1139/f85-005.
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Chloroform–methanol (2:1, v/v) extracts significantly more (P < 0.001) chlorophyll a from algal cultures and from freshwater and seawater microcosms than does dimethyl sulfoxide, methanol, absolute methanol with hydrogen sulfide, or 90% acetone. For chlorophyte cultures it yields 97% or more of the chlorophyll a within a 4-h steeping period without grinding. It can be used with both calibrated spectrophotometry and fluorometric instrumentation. Sample filtration onto MgCO3-coated filters is recommended to ensure buffering of the extraction mixture. Holding the filters in chloroform–methanol at 4 °C or room temperature in the dark prevents loss of chlorophyll a for at least 10 d. More refined analyses of phaeophytin and other chlorophylls require the use of chloroform–methanol–water (2:2:1.8, by volume) and placement in a separatory funnel. After 24 h the lower (chloroform) layer contains all of the chlorophyll. Strict pH control is required for pheophytin determinations.
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Loughlin, Patrick C., Robert D. Willows i Min Chen. "Hydroxylation of the C132 and C18 carbons of chlorophylls by heme and molecular oxygen". Journal of Porphyrins and Phthalocyanines 19, nr 09 (wrzesień 2015): 1007–13. http://dx.doi.org/10.1142/s1088424615500571.
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Following extraction from photosynthetic organisms, chlorophylls are prone to reactions including demetalation, dephytylation and specific oxidations of the exocyclic ring E, termed allomerizations. Allomerization of chlorophylls has been well-characterized in methanol and to a lesser extent in aqueous solution. Here we detail novel allomerization-like reactions of chlorophyll a and chlorophyll b. In the presence of heme, detergent-solubilized chlorophyll a is hydroxylated at its C 132 position in ring E and, surprisingly, the C 18 position in ring D. Two major oxidation products are synthesized — a C 132- OH and a C 132- OH , C 18- OH derivative of chlorophyll a. We track the origin of the oxygen atoms added in these hydroxylated chlorophylls using 18 O 2 labeling and demonstrate that the additional oxygen atoms are derived from molecular oxygen. A similar heme-catalyzed reaction is also observed using chlorophyll b as a substrate. These results highlight the need for care when dealing with extracted chlorophylls and demonstrate an unusual hydroxylation of the C 18 position of chlorophylls in the presence of heme.
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Costa, Junet F. da, Ferry F. Karwur i Leenawaty Limantara. "Efek Beta Karoten dan Agregasi Klorofil Pada Fotostabilitas Klorofil a dalam Pelarut Aseton". Jurnal Natur Indonesia 11, nr 2 (20.11.2012): 115. http://dx.doi.org/10.31258/jnat.11.2.115-123.
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Chlorophyll as photosynthetic pigment has many benefits to human such as antioxidant, antibacterial, color additive,immunity, and photosensitizer. Concerning to these applications, chlorophyll a will react with oxygen and light andreduce its effectiveness. It is then important to understand the stability of chlorophyll a on oxygen and light.Stability of chlorophyll a in the presence of beta-carotene (1:1) in acetone was studied for various waterconcentrations. Each solution was exposed to red light (ë e” 630 nm) for 0.5; 1.0; 2.5; 5.0; 10; 20; 30; 40; 50; and 60minutes and their spectrum were analysed. When water was added (8.33; 16.67; 25; 33.33; 41.67; 50; 58.33; 66.67;75; and 83.33 percent) to the acetone solution of chlorophyll a, the chlorophylls aggregate, and in the presence ofbeta-carotene, the chlorophyll more stable. The water shifts the chlorophyll a spectrum toward red duringillumination with or without the presence of carotene. The formation of oligomeric chlorophyll a aggregate occurswithin 10-20 minutes after the water was applied. This strategy of aggregating the chlorophylls to dissipateexcess energy captured from light does not support the photostability of chlorophyll as much as beta-carotene.Surprisingly, when beta carotene was mixed with 66.7% and 75.0% of water, the chlorophyll a degraded 5.56% and9.71% respectively. In conclusion, the aggregate form of chlorophyll a and the presence of beta-carotene increasephotostability of chlorophyll a in acetone solution.
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Chaicharoenaudomrung, Nipha, Anant Oonsivilai i Ratchadaporn Oonsivilai. "Chlorophylls Contents in Echinocactus grusonii Extract". Advanced Materials Research 931-932 (maj 2014): 1507–11. http://dx.doi.org/10.4028/www.scientific.net/amr.931-932.1507.
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Currently, Golden Barrel cactus extract is formulated in dietary supplements, on account of its powerful weight loss profit and antioxidant activity. Golden Barrel cactus grusonii (Echinocactus grusonii), a Thai cultivar Golden Barrel cactus which is known as the golden barrel Golden Barrel cactus was therefore investigated for total chlorophylls with the aim of developing as a dietary supplement in future. The chlorophyll contents of 3 and 6 years Echinocactus grusonii extracts were evaluated by High Performance Liquid Chromatography with a Grace-Vydac 201TP54 reversed-phase polymeric C18 column. The results showed that chlorophyll a and chlorophyll b are the main components of Echinocactus grusonii crude extracts also at higher level at age 3 years. It was found that the main chlorophylls contents are chlorophyll a and chlorophyll b at 2.94±0.55μg/ml and 1.63±0.14 μg/ml for 3 years Echinocactus grusonii. In addition, the amount of chlorophyll a and chlorophyll b show lower content at 1.11±0.25μg/ml and 0.67±0.01μg/ml for 6 years Echinocactus grusonii. In conclusion, Echinocactus grusonii age 3 years crude extracts showed total chlorophylls contents higher than at age 6 years. The phytochemical profile study of Echinocactus grusonii age 3 years and 6 years crude extracts are planned in the near future.
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Mińkowski, Karol, Monika Bartosiak i Dariusz Ciemiński. "Effect of extraction and refining of rapeseed oil on profile and content of chlorophyll pigments". Zywnosc Nauka Technologia Jakosc/Food Science Technology Quality 119, nr 2 (2019): 95–109. http://dx.doi.org/10.15193/zntj/2019/119/288.
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The objective of the research study was to determine the effect of industrial extraction and refining of rapeseed oil on the profile and content of chlorophyll pigments, where those processes were carried out under industrial conditions with the use of a modernized production line. The material to be analysed were samples of oil collected at various stages of the rapeseed oil extraction and refining processes. The content of chlorophyll pigments was determined using a reversed phase high-performance liquid chromatography with fluorometric detection. It was found that the industrial method of extracting rapeseed oil affected the profile and content of chlorophyll pigments. The content of chlorophyll pigments in the extracted oil was 40 % higher than that in the pressed oil. The chlorophyll pigments analysed mainly contained pheophytin and phyropheophytin, and only small amounts of chlorophylls a and b. The thermal treatment of oil performed prior to the refining caused the chlorophylls to fully transform. The phyropheophytin to pheophytin ratio changed from 0.7 to 3.8 : 1. The crude oil contained chlorophylls derivatives only. The acid-degumming and neutralisation processes of oil caused the total content of chlorophyll pigments to slightly decrease and their profile to change a little. The effectiveness of reducing chlorophyll pigments after bleaching was 98.5 %. Compared to the chlorophyll b derivatives, the chlorophyll a derivatives were more easily removed from the oil with the use of bleaching clay. In some batches of the bleached oil the phyropheophytin b was still present and its amount was of 0.09 mg/kg.
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Miyachi, Shigetoh, Kerstin Strassdat, Hideaki Miyashita i Horst Senger. "Quantum Requirement of Photosynthesis in the Primarily Chlorophyll d Containing Prokaryote Acaryochloris marina". Zeitschrift für Naturforschung C 52, nr 9-10 (1.10.1997): 636–38. http://dx.doi.org/10.1515/znc-1997-9-1010.
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The recently isolated and characterized unicellular photosynthetic prokaryote Acaryochloris marina (Miyashita et al., 1996) contains chlorophylls a, d , and traces of a chlorophyll c-like pigment as well as phycocyanin. a type of allophycocyanin, zeaxanthin and cx-carotene, chlorophyll d being the predominant chlorophyll component. Quantum requirement measurements of the photosynthetic oxygen evolution resulted in about 12 quanta for excitation of chlorophylls a and d and 18 for phycocyanin. The data also revealed that these pigments are involved in energy absorption for photosynthetic oxygen evolution. Energy is transferred efficiently and equally well between the chlorophylls. Light absorbed by phycocyanin which is organized in phycobiliprotein aggregates (M arquardt et al., 1997), results in a less efficient energy transfer to the reaction center chlorophylls
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Ribeiro, Flávia Santana, Lorena Gabrielle Fernandes Alves, Marcio Rosa, Narcisa Silva Soares i Carlos André Gonçalves. "Pigmentos fotossintéticos como descritores de resposta a adubação organomineral em cana-de-açúcar (Saccharum Officinarum L.)". Revista Agraria Academica 5, nr 2 (1.03.2022): 103–10. http://dx.doi.org/10.32406/v5n2/2022/103-110/agrariacad.
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Sugarcane (Saccharum officinarum L.) comes from the Asian continent. Culture is of enormous importance to the Brazilian economy, being explored throughout the country, with the Southeast, Northeast and South as the largest production centers today. With the growing population, it has been increasingly sought to increase productivity and profitability with the cultivation of sugarcane with the help of agricultural and managerial techniques. Plant productivity is related to photosynthetic efficiency. One of the factors linked to this efficiency is the chlorophyll content, due to its direct connection with the absorption and transfer of light energy. However, the concentration of chlorophylls can be influenced by fertility and fertilization. The objective of this work was to compare the use of chlorophyll meter (Minolta SPAD® 502 and Falker ClorofiLOG® 17 1030) and spectrophotometer for chlorophyll determination in sugarcane fertilized with organominerals and industrial sewage sludge. The experiment was conducted in randomized blocks, with five replications per treatment. The characteristics evaluated were: Cla (chlorophyll a), Clb (chlorophyll b), Car (carotenoids), Clt (total chlorophylls), Cla/Clb (ratio between chlorophyll a and chlorophyll b). All equipment used showed similar responses in terms of chlorophyll concentration in response to fertilization. It was found that, regardless of the treatments, the concentrations of photosynthetic pigments did not vary.
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Trukhachev, V. I., I. I. Seregina, S. L. Belopukhov, I. I. Dmitrevskaya, T. I. Fomina, O. A. Zharkikh i D. M. Akhmetzhanov. "The effect of stressful ecological conditions on chlorophyll content in the leaves of spring wheat plants". IOP Conference Series: Earth and Environmental Science 981, nr 3 (1.02.2022): 032093. http://dx.doi.org/10.1088/1755-1315/981/3/032093.
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Abstract In short-term vegetative experiment studied the effect of the different combinations of nitrogen and zinc fertilizers on the chlorophyll content in the leaves of spring wheat plants of the Zlata variety. It is established that application of nitrogen fertilizers together with zinc in most combinations contributed to stabilization of synthesis processes of chlorophyll grains in the leaves of wheat. It is shown that in conditions of optimal water supply and in the conditions of ecological stress caused by drought the most optimal combinations were ammonium sulfate with zinc and urea with zinc. With optimal water supply in variants where were applied ammonium sulfate with zinc and urea with zinc was obtained an increase of the amount of chlorophyll (a + b) compared with control variant without zinc, as a result of the growth of the content of both chlorophylls a and chlorophyll b. In the conditions of named ecological stress, the amount of chlorophyll (a+b) was increased in the variant with the addition of ammonium sulfate mainly due to chlorophyll a. In the variant where was applied urea with zinc the amount of chlorophylls (a+b) increased as a result of growth of chlorophyll a and chlorophyll b. It is shown that in conditions of drought in the specified variants had been increasing the ratio og chlorophyll a and chlorophyll b due to growth of chlorophyll b which indicates about improvement of water balance inside of the plant cells and increasing a photosynthetic activity due to normalization of processes of photolysis of water.
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Kusmita, Lia, i Leenawaty Limantara. "THE INFLUENCE OF STRONG AND WEAK ACID UPON AGGREGATION AND PHEOPHYTINIZATION OF CHLOROPHYLL A AND B". Indonesian Journal of Chemistry 9, nr 1 (20.06.2010): 70–76. http://dx.doi.org/10.22146/ijc.21564.
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Chlorophyll is green pigment that can be found in plant chloroplast. Higher plants usually have two kinds of chlorophylls, chlorophyll a and b. These green pigments are easily degraded by temperature, light intensity, oxygen, acid, and water. Water causes aggregation of chlorophyll, while acid causes pheophytinization of chlorophyll. Aggregation and pheophytinization process of chlorophyll are influenced by solvents. This study was conducted to observe the spectral difference of aggregated chlorophyll in acetone and methanol upon pheophytinization by strong (HCl) and weak acid (CH3COOH), in comparison to the non-aggregated chlorophyll. Observation of spectral pattern was carried out using double beam spectrophotometer CARY 50 at 350-1100 nm. The result shows that pheophytinization of chlorophyll a and b causes hypsochromic shift, particularly at Soret band. There are new peak formations in Qx region, specifically at 506 and 535 nm for pheophytinized-chlorophyll a, and at 371, 435, 526 and 599 nm for pheophytinized-chlorophyll b. Keywords: aggregation, chlorophyll a and b, pheophytinization
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Chen, Guangyu E., Andrew Hitchcock, Philip J. Jackson, Roy R. Chaudhuri, Mark J. Dickman, C. Neil Hunter i Daniel P. Canniffe. "Two Unrelated 8-Vinyl Reductases Ensure Production of Mature Chlorophylls in Acaryochloris marina". Journal of Bacteriology 198, nr 9 (22.02.2016): 1393–400. http://dx.doi.org/10.1128/jb.00925-15.
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ABSTRACTThe major photopigment of the cyanobacteriumAcaryochloris marinais chlorophylld, while its direct biosynthetic precursor, chlorophylla, is also present in the cell. These pigments, along with the majority of chlorophylls utilized by oxygenic phototrophs, carry an ethyl group at the C-8 position of the molecule, having undergone reduction of a vinyl group during biosynthesis. Two unrelated classes of 8-vinyl reductase involved in the biosynthesis of chlorophylls are known to exist, BciA and BciB. The genome ofAcaryochloris marinacontains open reading frames (ORFs) encoding proteins displaying high sequence similarity to BciA or BciB, although they are annotated as genes involved in transcriptional control (nmrA) and methanogenesis (frhB), respectively. These genes were introduced into an 8-vinyl chlorophylla-producing ΔbciBstrain ofSynechocystissp. strain PCC 6803, and both were shown to restore synthesis of the pigment with an ethyl group at C-8, demonstrating their activities as 8-vinyl reductases. We propose thatnmrAandfrhBbe reassigned asbciAandbciB, respectively; transcript and proteomic analysis ofAcaryochloris marinareveal that bothbciAandbciBare expressed and their encoded proteins are present in the cell, possibly in order to ensure that all synthesized chlorophyll pigment carries an ethyl group at C-8. Potential reasons for the presence of two 8-vinyl reductases in this strain, which is unique for cyanobacteria, are discussed.IMPORTANCEThe cyanobacteriumAcaryochloris marinais the best-studied phototrophic organism that uses chlorophylldfor photosynthesis. Unique among cyanobacteria sequenced to date, its genome contains ORFs encoding two unrelated enzymes that catalyze the reduction of the C-8 vinyl group of a precursor molecule to an ethyl group. Carrying a reduced C-8 group may be of particular importance to organisms containing chlorophylld. Plant genomes also contain orthologs of both of these genes; thus, the bacterial progenitor of the chloroplast may also have contained bothbciAandbciB.
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Chen, Min, Martin Schliep, Robert D. Willows, Zheng-Li Cai, Brett A. Neilan i Hugo Scheer. "A Red-Shifted Chlorophyll: Fig. 1". Science 329, nr 5997 (19.08.2010): 1318–19. http://dx.doi.org/10.1126/science.1191127.
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Chlorophylls are essential for light-harvesting and energy transduction in photosynthesis. Four chemically distinct varieties have been known for the past 60 years. Here we report isolation of a fifth, which we designate chlorophyll f. Its in vitro absorption (706 nanometers) and fluorescence (722 nanometers) maxima are red-shifted compared to all other chlorophylls from oxygenic phototrophs. On the basis of the optical, mass, and nuclear magnetic resonance spectra, we propose that chlorophyll f is [2-formyl]-chlorophyll a (C55H70O6N4Mg). This finding suggests that oxygenic photosynthesis can be extended further into the infrared region and may open associated bioenergy applications.
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Huh, Man Kyu. "Effect of Chlorophyll in Garlic Chives (Allium tuberosum) Leaves by Drought and pH". European Journal of Agriculture and Food Sciences 4, nr 3 (13.06.2022): 66–69. http://dx.doi.org/10.24018/ejfood.2022.4.3.508.
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Allium tuberosum Rotter (garlic chives) is a species of plant native to the Chinese province and naturalized elsewhere in Asia and around the world. In Korea, chives are boiled and used as seasoned vegetables or as soup ingredients, and are also used for chive kimchi and cucumber pickles. This paper describes experimental results for chlorophyll content and efficiency with drought stress and soil acidity on garlic chives. Analytical determination of total chlorophyll (a, b) was performed with spectrophotometer. Chlorophyll fluorescence analysis was used to measure photosynthetic parameters with the Imaging-PAM Chlorophyll Fluorometer. The content of total chlorophyll was 0.711 at 80% moisture. The content for chlorophylls a, b, and total were 0.333, 0.151, and 0.390 at 10% moisture, respectively. The simple type of regression showed the relation between chlorophylls as a function of acidity. The slope factors for chlorophyll content (a, b, and total) were 0.866, 0.903, and 0.910, respectively. The current fluorescence yield (Ft) was increased to the decrease of water in soils. The maximal PSII quantum yield, Fv/Fm was the highest at 70% moisture among nine moisture percentage stages. The slope factors of Ft, Fm (maximum fluorescence yield), Fv (quenched state), and Fv/Fm for chlorophyll efficient indicators were -0.873, 0.977, 969, and 0.897, respectively. Water stress decreased chlorophyll a, chl b, chl (a + b) contents, and the chl a/b ratio in the A. tuberosum. Low soil pH also affected the chlorophyll content and efficiency of A. tuberosum.
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Liu, Man-Hai, Yi-Fen Li i Bing-Huei Chen. "Preparation of Chlorophyll Nanoemulsion from Pomelo Leaves and Its Inhibition Effect on Melanoma Cells A375". Plants 10, nr 8 (12.08.2021): 1664. http://dx.doi.org/10.3390/plants10081664.
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Pomelo (Citrus grandis), an important fruit crop grown in tropical and subtropical areas, is cultivated mainly in Asian countries. The dominant pigment in pomelo leaves, chlorophyll, has been reported to possess many biological activities such as antioxidant, anti-inflammation and anticancer. The objectives of this study were to determine chlorophylls in Pomelo leaves by high-performance liquid chromatography-mass spectrometry (HPLC-MS) and to encapsulate the isolated chlorophylls from preparative column chromatography into a nanoemulsion system for elucidating the inhibition mechanism on the growth of melanoma cells A375. The results showed that chlorophyll a and chlorophyll b could be separated within 25 min by using a C18 column and a gradient ternary mobile phase of acetone, acetonitrile and methanol. Pomelo leaves mainly contained chlorophyll a (2278.3 μg/g) and chlorophyll b (785.8 μg/g). A highly stable chlorophyll nanoemulsion was prepared with the mean particle size being 13.2 nm as determined by a dynamic light scattering (DLS) method. The encapsulation efficiency of chlorophyll nanoemulsion was 99%, while the zeta potential was −64.4 mV. In addition, the chlorophyll nanoemulsion possessed high thermal stability up to 100 °C and remained stable over a 90-day storage period at 4 °C. Western blot analysis revealed that chlorophyll nanoemulsion and extract could upregulate p53, p21, cyclin B and cyclin A as well as downregulate CDK1 and CDK2 in a concentration-dependent manner for inhibition of melanoma cells A375. Furthermore, chlorophyll nanoemulsion and extract could upregulate Bax and cytochrome C and downregulate Bcl-2, leading to activation of caspase-9, caspase-8 and caspase-3 for the induction of cell apoptosis. Compared to chlorophyll extract, chlorophyll nanoemulsion was more effective in inhibiting the growth of melanoma cells A375.
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Porra, R. J., W. Schäfer, E. Cmiel, Ingrid Katheder i H. Scheer. "The Unexpected Reduction of the Vinyl Group of Chlorophyll b by Sodium Borohydride in Methanolic Extracts of Maize Leaves and Its Inhibition by 8-Hydroxyquinoline". Zeitschrift für Naturforschung C 48, nr 9-10 (1.10.1993): 745–48. http://dx.doi.org/10.1515/znc-1993-9-1011.
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Abstract During rapid extraction of chlorophylls from maize leaves under reducing conditions with methanol containing NaBH4, chlorophyll a remained unchanged but chlorophyll b yielded [7-hydroxymethyl]-chlorophyll b. The 3-vinyl group of chlorophyll b was also reduced forming significant am ounts, up to 60%, of [3-ethyl]-[7-hydroxymethyl]-chlorophyll b. This was unexpected since this reduction of the 3-vinyl group does not occur when isolated chlorophyll b is treated in an identical manner with methanolic borohydride. The vinyl-group of chlorophyll a is not reduced during the same extraction conditions suggesting that the presence of a formyl or hydroxyethyl group at C-7 is necessary. The presence of 8-hydroxyquinoline and NaBH4 in equimolar (16.5 m M) concentrations strongly inhibits the reduction of the 3-vinyl group of chlorophyll b in leaf extracts
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Guo, Hai Rong, Shao Ying Ma, Xiao Fei Wang, Er Fang Ren i Yuan Yuan Li. "Microwave-Assisted Extraction of Chlorophyll from Filter Mud of Sugercane Mill and Component Analysis". Advanced Materials Research 518-523 (maj 2012): 430–35. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.430.
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Microwave-assisted extraction (MAE) was used to extract chlorophylls from filter mud. Ethanol was used as the solvent. The optimal conditions for the MAE of chlorophylls were concluded from the study as the irradiation time, 50 s, the ratio of liquid to solid, 8:1 (mL/g), the extraction temperature, 40 °C, and the extraction time, 60 min. Compared with conventional extraction, the MAE of chlorophylls from the filter mud was more effective. The extraction time for MAE was 60 min with 0.277 mg/g chlorophyll yield, while conventional extraction needed 240 min with only about 0.259 mg/g chlorophyll yield. The Ultraviolet Absorption Spectra of the extracted chlorophylls showed that there was a strong absorption peak at about 663 nm. C=N, Mg-N and C-N was not seen existed from the infrared spectroscopy probably because that the mixed extracts were not purified and the chlorophyll content was less.
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Nürnberg, Dennis J., Jennifer Morton, Stefano Santabarbara, Alison Telfer, Pierre Joliot, Laura A. Antonaru, Alexander V. Ruban i in. "Photochemistry beyond the red limit in chlorophyll f–containing photosystems". Science 360, nr 6394 (14.06.2018): 1210–13. http://dx.doi.org/10.1126/science.aar8313.
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Photosystems I and II convert solar energy into the chemical energy that powers life. Chlorophyll a photochemistry, using red light (680 to 700 nm), is near universal and is considered to define the energy “red limit” of oxygenic photosynthesis. We present biophysical studies on the photosystems from a cyanobacterium grown in far-red light (750 nm). The few long-wavelength chlorophylls present are well resolved from each other and from the majority pigment, chlorophyll a. Charge separation in photosystem I and II uses chlorophyll f at 745 nm and chlorophyll f (or d) at 727 nm, respectively. Each photosystem has a few even longer-wavelength chlorophylls f that collect light and pass excitation energy uphill to the photochemically active pigments. These photosystems function beyond the red limit using far-red pigments in only a few key positions.
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Etinski, Mihajlo, Milena Petkovic i Miroslav Ristic. "A study of the low-lying singlet and triplet electronic states of chlorophyll A and B". Journal of the Serbian Chemical Society 78, nr 11 (2013): 1775–87. http://dx.doi.org/10.2298/jsc130806096e.
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Chlorophylls have been extensively investigated both experimentally and theoretically owing to the fact that they are essential for photosynthesis. We have studied two forms of chlorophyll, chlorophyll a and chlorophyll b, by means of density functional theory. Optimization of S0, S1 and T1 states was performed with the B3-LYP functional. The computed fluorescence lifetimes show good agreement with the available experimental data. The electronic adiabatic energies of S1 and T1 states are 2.09/2.12 and 1.19/1.29 eV for chlorophyll a and chlorophyll b respectively. We discussed the implications of this results on the triplet formation. Also, the calculated vertical ionization potentials shows good agreement with the experimental results.
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Drążkiewicz, Maria, i Zbigniew Krupa. "The participation of chlorophyllase in chlorophyll metabolism". Acta Societatis Botanicorum Poloniae 60, nr 1-2 (2014): 139–54. http://dx.doi.org/10.5586/asbp.1991.012.
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Although the breakdown of chlorophylls can easily be visually recognized, the fate of these photosynthetic pigments as well as their catabolism is still largely unknown. In the past, the enzyme called "chlorophyllase" (chlorophyll-chlorofillido-hydrolase, EC 3.1.1.14) had been thought to participate both in the biosynthesis and in the degradation of chlorophylls. It is, however, clear at present that in vivo this enzyme is involved rather in the first steps of chlorophyll degradation.
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Siebke, Katharina, i Marilyn C. Ball. "Non-destructive measurement of chlorophyll b:a ratios and identification of photosynthetic pathways in grasses by reflectance spectroscopy". Functional Plant Biology 36, nr 11 (2009): 857. http://dx.doi.org/10.1071/fp09201.
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Equations for non-destructive determination of chlorophyll b : a ratios in grasses were developed from reflectance spectra of intact leaves of barley (Hordeum vulgare L.) and two barley mutants: clorina f2, which lacks chlorophyll b and clorina f104, which has a low chlorophyll b content. These plants enabled separation of effects of chlorophyll composition on reflectance spectra due to differential light absorption by chlorophylls a and b and to measure the effects of chlorophyll b on the contribution of fluorescence emitted by chlorophyll a to the reflectance spectra. Indices developed from these data were then tested on growth chamber-grown leaves from six C3 and 17 C4 grass species (7 NAD-ME and 10 NADP-ME subtypes). We used the chlorophyll b : a ratio because the data were less skewed than the chlorophyll a : b ratio. The best index for determination of the chlorophyll b : a ratio utilised wavelengths affected by chlorophyll absorbance: [R626 – 0.5 (R603 + R647)]/[R552– R626]. The chlorophyll b : a ratio was significantly lower in the C4 than C3 grasses, but was not sufficient in itself to separate these two functional groups. However, because of differences in fluorescence characteristics, C3 and C4 species could be distinguished by an index based on wavelengths affected by chlorophyll fluorescence: [R696 to 709/R545 to 567].
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Yang, Yu Jie, Bi Ru Hu, Zhi Ming Liu i Wen Jian Wu. "Preparation of Photostable Chlorophyll/PVA Film". Advanced Materials Research 239-242 (maj 2011): 2707–10. http://dx.doi.org/10.4028/www.scientific.net/amr.239-242.2707.
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Based on the principle that chlorophyll’s photodegradation occurs in the presence of oxygen, high-oxygen-barrier polyvinyl alcohol (PVA) films comprising chlorophyll are prepared without photodegradation of chlorophyll by a facile procedure. The photostability of the films are characterized by the absorption spectra. The result shows that the chlorophyll in the films can keep photostable at least for six months whereas the photostability of chlorophyll in ethanol is less than one day. The absorption maxima of chlorophyll/PVA films at red band, which are at 668nm due to the chlorophyll and consist with that of chlorophyll in ethanol (666 nm), shift blue after the sunlight treatment. The shift extent increases with the time of sunlight treatment and decreases with the content of chlorophyll in samples. The method proposed in the study could greatly improve the photostability of chlorophyll and can be used in the field of photocatalysis.
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Minocha, Rakesh, Gabriela Martinez, Benjamin Lyons i Stephanie Long. "Development of a standardized methodology for quantifying total chlorophyll and carotenoids from foliage of hardwood and conifer tree species". Canadian Journal of Forest Research 39, nr 4 (kwiecień 2009): 849–61. http://dx.doi.org/10.1139/x09-015.
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Despite the availability of several protocols for the extraction of chlorophylls and carotenoids from foliage of forest trees, information regarding their respective extraction efficiencies is scarce. We compared the efficiencies of acetone, ethanol, dimethyl sulfoxide (DMSO), and N, N-dimethylformamide (DMF) over a range of incubation times for the extraction of chlorophylls and carotenoids using small amounts of unmacerated tissue. Of the 11 species studied, comparable amounts of chlorophyll were extracted by all four solvents from three species and by ethanol and DMF from nine species. In four species, acetone, ethanol, and DMF extracted comparable chlorophyll amounts, while in another two species comparable amounts were extracted by ethanol, DMSO, and DMF. In one species, ethanol extracted significantly greater amounts of chlorophyll compared with all other solvents. The brown coloration of DMSO extracts for some species compromised the calculations of chlorophylls and carotenoids, making DMSO a poor choice. Overall, extraction efficiencies of ethanol and DMF were comparable for analyzing chlorophyll concentrations. However, because DMF is more toxic than ethanol, we recommend ethanol as the better option of these two for chlorophyll extractions. On the other hand, DMF is the most efficient solvent among the four tested for the extraction of carotenoids from these species. The results presented will facilitate the design of multispecies local- and regional-scale ecological studies to evaluate forest health. Additionally, they will enable reliable comparisons of results from multiple laboratories and (or) studies that used different solvents and help validate chlorophyll estimates obtained by remote sensing.
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Herrera, Marta, Isabel Viera i María Roca. "HPLC–MS2 Analysis of Chlorophylls in Green Teas Establishes Differences among Varieties". Molecules 27, nr 19 (20.09.2022): 6171. http://dx.doi.org/10.3390/molecules27196171.
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Green teas are nonfermented teas, the quality of which is measured by the green color. However, this category encompasses a high number of tea varieties that differ in cultivation and processing. For example, leaf or stem/bubble tea, plants cultivated under a light or shadow regime, powdered or unpowdered tea, etc. These variables determine the different qualities among green teas (Matcha, Sencha, Gyokuro, etc.) and consequently their different values on the market. Our purpose is to determine if these variables can exert an influence on the chlorophyll profile and to establish a characteristic profile for specific green teas. With such an aim, we analyzed the chlorophyll profiles of 6 different green tea varieties via HPLC-hr ESI/APCI–MS2 and identified up to 17 different chlorophyll compounds. For the first time, 132-hydroxy-chlorophylls, 132-hydroxy-pheophytins, and 151-hydroxy-lactone-pheophytins have been identified in green teas. Shadow teas (Matcha and Sencha) and light-regimen green teas can be statistically differentiated by the total chlorophyll content and the a/b ratio. However, only Matcha tea contains a higher proportion of chlorophylls a and b among the green tea varieties analyzed, justifying the higher quality and price of this variety. Other chlorophyll metabolites (pheophytins, pyropheophytins, and oxidized chlorophylls) are indicative of the various processing and storage conditions.
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Zvezdanović, Jelena, Sanja Petrović i Aleksandar Lazarević. "Nickel(II) interactions with chlorophylls in solution: impact to degradation induced by UV-irradiation". Chemia Naissensis 5, nr 2 (2022): 1–17. http://dx.doi.org/10.46793/chemn5.2.01z.
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Chlorophylls and metal substituted complexes of chlorophylls with known photosensitizing abilities can be used in many types of biological and solar energy applications; thus, it is important to analyze their basic properties when they are treated by visible light and/or UV radiation. Nickel(II) can replace central magnesium from chlorophyll (Chl) molecule to form a metal substituted, “central” Ni-Chl complex. So, the possible formation of nickel-chlorophyll complexes in 95% ethanol at 40 °C was studied by UHPLC-DAD chromatography (UltraHigh Performance Liquid Chromatography–Diode Array Detector). Nickel(II)-chlorophylls interactions in the reaction solutions at 40 °C lead not only to the formation of the Ni-related Chls, Ni-Chl complexes but several oxidation and demetalation products of chlorophylls. On the other hand, the influence of nickel(II) – chlorophyll interactions on chlorophylls solutions stability under continual UV-A, -B, and -C irradiation in 95% ethanol, was followed by UV-Vis spectrophotometry. Chlorophylls as well as their reaction solutions with nickel(II) undergo photochemical degradation obeying first- order kinetics. In general, the degradation is “energy-dependent”, i.e. proportional to the UV photons energy input. Chlorophylls are less stable than their reaction solutions with nickel(II), probably due to the higher stability of Ni-chlorophylls complexes, to all three subranges of UV- irradiation.
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Bobkov, Sergey, i Ivan Bychkov. "CONTENT OF PHOTOSYNTHETIC PIGMENTS IN ONTOGENESIS OF WILD AND CULTURAL PEA". Vestnik of Kazan State Agrarian University 16, nr 4 (15.02.2021): 10–14. http://dx.doi.org/10.12737/2073-0462-2021-10-14.
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The objective consisted in study of wild pea representatives on chlorophyll and carotenoid content for use in producing new varieties with high photosynthetic efficiency and optimal assimilate distribution. The research was conducted in 2016‑2017 in Federal Scientific Center of Legumes and Groat Crops (Orel). Plants were grown on experimental field with density 1.2 million plants/ha on triplicated plots 1 m2. Wild pea accessions k-5322 (asiaticum), k-3370 (elatius), k-4014 (elatius) from VIR collection and varieties Temp and Stabil were used. Wild accessions k-3370 and k-5322 had more chlorophyll a, chlorophyll b and carotenoids then leafy Temp variety on 24.5 %, 28.2 %, 41.5 % and 13.3 %, 2.7 %, 18.7 % respectively. Unlike the cultivated pea, accessions k-3370 and k-5322 retain high level of chlorophylls a and b in ontogenesis longer time. After transition from bud formation to the beginning of seed filling content of chlorophylls a and b in accession k-3370 was at the same level (11.71 mg/g и 11.1 mg/g respectively), in accession k-5322 it decreased insignificantly from 11.31 mg/g to 9.72 mg/g. Nevertheless, in variety Temp content of chlorophylls a and b significantly decreased on 34.1 % after transition from bud formation to the seed filling. Wild accession k-3370 like pea varieties had low chlorophyll a/b ratio (2.92), but accession k-5322 had the highest value (3.26) of the ratio. In wild accession k-3370 and k-5322 the chlorophyll a/b ratio was changed in ontogenesis that is no-typical for Temp variety. Pea wild accessions can be considered as sources of valuable alleles determining the high level of chlorophylls and carotenoids
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Vu, Do Van, Nguyen Hong Nguyen i Tri Ly Minh Nguyen. "DETERMINING OPTIMIZED CONDITIONS FOR REMOVAL OF CHLOROPHYLL IN EXTRACTED LIQUID FROM NEEM LEAVES BY DISTILLED WATER BY RESPONSE SURFACE METHOD". Science and Technology Development Journal 14, nr 4 (30.12.2011): 36–42. http://dx.doi.org/10.32508/stdj.v14i4.2046.
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Chlorophyll content in liquid ethanol extract of neem’s leaves has bad effect on quality and storage time of the extract. In this study, we tried to remove remaining chlorophyll in the liquid ethanol extract of neem’s leaves by distilled water. The results showed that after chlorophyll removing, the liquid extract still retained almost all the biological activity ingredients (limonoid). Three effecting factors, i.e., (i) The time to cool to precipitate chlorophyll in the extracted liquid, (ii) The initial content of chlorophyll; (iii) The ratio between the extracted liquid and distilled water added all affect chlorophyll removal efficiency, have been studied. The Response Surface Method (RSM) showed that, the optimal conditions for removing chlorophyll process, the ratio between extracted liquid and distilled water respectively is 16.8 μg/ml and 1.3 (13:10; v:v). The time to cool to precipitate chlorophyll in the extracted liquid didi not have significantly affect on the performance of the removing chlorophyll’s contents.
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AROYEHUN, Fisayo S., Amos M. MAKINDE i Musibau O. ISA. "Comparative Extraction of Chlorophylls in Selected Forest and Savanna Mosses Using Dimethylsulphoxide and Acetone". Notulae Scientia Biologicae 8, nr 3 (22.09.2016): 347–53. http://dx.doi.org/10.15835/nsb839877.
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The present study compared the extraction of chlorophylls from selected forest mosses (Hyophila involuta and Thuidium gratum) and derived savanna moss (Archidium ohioense) using dimethylsulphoxide (DMSO) and 80% acetone. The mosses were collected from natural populations found in the Central Campus of the Obafemi Awolowo University, Ile-Ife, Nigeria. The chlorophyll extractions process followed standard methods and the absorbance of the extracts were read on spectrophotometer at wavelengths of 645 nm and 663 nm respectively. The data obtained were later subjected to appropriate statistical analysis. The results showed that DMSO was a better chlorophyll extractant for mosses than 80% acetone. Although there were significant differences in the chlorophyll a, chlorophyll a/b ratio and total chlorophyll accumulation within all three species using DMSO and 80% acetone as extractant (P < 0.05), there was no significant difference in the chlorophyll b accumulation of all the three species (P > 0.05).
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Kaspary, Tiago Edu, Luan Cutti, Cristiano Bellé, Gabriele Casarotto, Mártin Zanchett Groth, Gerarda Beatriz Pinto Da Silva i Adalin Cezar Moraes De Aguiar. "Non-destructive analysis of photosynthetic pigments in Avena strigosa and Avena sativa". 2019 13, (03) 2019 (20.05.2019): 354–59. http://dx.doi.org/10.21475/ajcs.19.13.03.p1149.
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Chlorophylls and carotenoids are the main photosynthetic pigments in plants. The photosynthetic potential of crop plants is used to determine the correct rate of nitrogen fertilization. To date, no studies have been conducted to understand the relationship between different methods of measurement of photosynthetic pigments in oats. The objective of this study was to quantify and compare the levels of photosynthetic pigments in Avena strigosa and A. sativa using two different methods, the extraction method and portable chlorophyll meter, and to determine whether the results of these two methods showed a significant correlation. Photosynthetic pigments were measured using both methods in a greenhouse and the laboratory at four developmental stages: tillering [28 days after sowing (DAS)], vegetative stage I (55 DAS), vegetative stage II (75 DAS), and reproductive stage (120 DAS). The same leaves were used to measure the relative chlorophyll content using a portable chlorophyll meter and extractable chlorophyll using the laboratory extraction method. The readings of the chlorophyll index differed for each developmental stage of both A. sativa and A. strigosa. The contents of chlorophyll a, chlorophyll b, and carotenoids determined using the extraction method showed high coefficients of correlation with the total chlorophyll index determined using the portable chlorophyll meter. Thus, the measurement of chlorophyll using the portable chlorophyll meter can be used for the accurate evaluation of the photosynthetic potential of oats, thus saving time and reagents.
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Dewi, Eko Nurcahya, Lukita Purnamayati i Irwandi Jaswir. "Effects of thermal treatments on the characterisation of microencapsulated chlorophyll extract of Caulerpa racemosa". International Food Research Journal 29, nr 6 (6.12.2022): 1279–92. http://dx.doi.org/10.47836/ifrj.29.6.05.
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Caulerpa racemosa is a macroalga that has a green pigment, that is, chlorophyll. Chlorophyll is highly sensitive to damage during heat processing. In the present work, C. racemosa chlorophyll extract was microencapsulated with fish gelatine and Arabic gum coatings, using a freeze-drying technique, to protect against heat damage. The microcapsules were subjected to high temperatures (120, 140, and 160°C) for 5 h. The protective effect of microcapsules on chlorophyll stability was assessed by measuring chlorophylls a and b degradation, total phenolic content, antioxidant activity, functional group analysis, colour, particle size, and morphology via scanning electron microscopy. Chlorophyll b significantly decreased by 87.78% in comparison with chlorophyll a (61.49%) during heating; the characteristic green colour of chlorophyll changed to brownish-green following heat exposure. However, chlorophyll was still present in the microcapsules as detected by the presence of the functional group C=O bond at 1600 nm wavelength. The heat treatment did not affect microcapsule particle size and morphology. Particle size distribution ranged from 91.58 to 112.51 µm, and the microcapsule was flake-shaped. The activation energy of chlorophyll a was 19336.96 kJ/mol·K; this was higher than that of chlorophyll b, which was 1780.53 kJ/mol·K. Based on the results, microcapsules produced using fish gelatine and Arabic gum as coating materials were able to protect chlorophyll in C. racemosa extract from heat damage.
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Obukhov, Yu N., K. V. Neverov, Yu V. Maleeva i M. S. Kritsky. "CHLOROPHYLL <i>A</i> DIMERS HARBORED BY WATER-SOLUBLE PROTEIN BoWSCP PHOTOSENSITIZE REDUCTION OF CYTOCHROME <i>C</i>". Доклады Российской академии наук. Науки о жизни 509, nr 1 (1.03.2023): 191–95. http://dx.doi.org/10.31857/s2686738922600790.
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When bound to water-soluble proteins of the WSCP family, chlorophyll molecules form dimers structurally similar to “special pair” of chlorophylls (bacteriochlorophylls) in photosynthetic reaction centers. Being exposed to red light (λ ≥ 650 nm) in oxygen-free solutions, chlorophyll a dimers harbored by BoWSCP holoproteins (from Brassica oleracea var. botrytis) have sensitized the reduction of cytochrome c. According to absorption and circular dichroism spectroscopy data, the photochemical process did not significantly impair the structure of chlorophyll a molecules as well as their dimers harbored by BoWSCP protein. Adding tris(hydroxymethyl)aminomethane as an electron donor for chlorophyll recovery stimulated the photoreduction of cytochrome c.
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Nakashima, Satoru, i Eri Yamakita. "In Situ Visible Spectroscopic Daily Monitoring of Senescence of Japanese Maple (Acer palmatum) Leaves". Life 13, nr 10 (9.10.2023): 2030. http://dx.doi.org/10.3390/life13102030.
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The degradation of green leaves in autumn after their photosynthetic activities is associated with decreases in chlorophylls and increases in anthocyanins. However, the sequential orders of these processes are not well understood because of a lack of continuous monitoring of leaves in the same positions. Therefore, the senescence processes of Japanese maple (Acer palmatum) leaves were followed daily in the same positions for approximately 60 days using visible spectroscopy with an original handheld visible–near-infrared spectrometer. The obtained reflection spectra were converted to absorption spectra and band areas of chlorophyll a and anthocyanins were determined. Decreases in the chlorophyll a band area with time show two-step exponential decreases corresponding to slow and fast first-order decrease rates. A rapid decrease in chlorophyll a started after an increase in anthocyanin. Therefore, the leaf senescence started through a slow decrease in chlorophyll a (20–30 days), followed by a rapid increase in anthocyanins (~20 days), followed by a rapid decrease in chlorophyll a (10–20 days). The formation of anthocyanins has been proposed to protect leaf cells from losing chlorophylls through solar radiation damage. The obtained sequential changes of pigments support this light screen hypothesis. (199 words < 200 words)
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Zhang, Chenlu, Sha Liang, Yilin Wang, Sha Luo, Weijia Yao, Hao He, Yuxiao Tian, Huanxiu Li, Fen Zhang i Bo Sun. "Variation of chlorophyll and carotenoids in different varieties and organs of Chinese kale". Quality Assurance and Safety of Crops & Foods 14, nr 4 (15.10.2022): 136–45. http://dx.doi.org/10.15586/qas.v14i4.1077.
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The concentrations of chlorophyll and carotenoids were analyzed in two organs (leaves and bolting stems) of 19 varieties of Chinese kale (including four maturity periods and two flower colors). Two chlorophylls and four carotenoids were identified in Chinese kale. The concentrations of chlorophyll and carotenoids varied widely in different organs and varieties. JL-03 was a good candidate for the future breeding programs, since it contained the highest concentrations of chlorophyll and carotenoids (except violaxanthin) in leaves. Lutein was the main component of carotenoids and accounted for approximately 50% of total carotenoids. The concentrations of chlorophyll and carotenoids in leaves significantly exceeded those in bolting stems. Principal component analysis showed that organ was the main source of differences of chlorophyll and carotenoid concentrations in different varieties of Chinese kale, while the maturity and flower color have little effect. Correlation analysis identified a significantly positive correlation between chlorophyll and carotenoids in Chinese kale. These results provided evidence for improving human dietary nutrition and breeding of Chinese kale.
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Renkova, A. G., V. R. Habibrakhmanova, O. P. Gurjanov, E. I. Galeeva, D. F. Rakhmatullina i F. V. Minibayeva. "PHOTOSYNTHETIC ACTIVITY AND CHLOROPHYLLS CONTENT IN THE MOSS HYLOCOMIUM SPLENDENS HEDW. UNDER TEMPERATURE STRESS". ÈKOBIOTEH 6, nr 4 (30.12.2023): 227–35. http://dx.doi.org/10.31163/2618-964x-2023-6-4-227-235.
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Mosses are an attractive model for studying the mechanisms of plant adaptation to unfavorable environmental conditions. There is little information in the literature on the pigment composition and its role in stress resistance of mosses, although this topic is quite widely covered for higher vascular plants. Unfavorable environmental temperature is one stress factors with the strongest effect on plants, since photosynthesis, the main energy-supplying producing process in plants, is sensitive to temperature and often inhibited before other cellular functions are impaired. Chlorophyll is known to play a central role in the process of photosynthesis. In this regard, the aim of the present work was to study the response of the moss Hylocomium splendens Hedw. to temperature stress. The chlorophyll content and chlorophyll a fluorescence parameters in H. splendens shoots were investigated. Results showed that both elevated and negative temperatures decreased the content of chlorophyll a significantly, while, on the contrary, the content of chlorophyll b increased. It is interesting to note that the decrease in chlorophyll a under temperature stress was accompanied by an increase in the content of pheophytin a. The content of chlorophylls in the post-stress period did not recover to the control level. Temperature stress did not affect the maximum photochemical efficiency of photosynthesis, but the rate of electron transfer significantly decreased under the influence of low temperature. Thus, significant changes in the pigment composition of chlorophylls are not always accompanied by changes in fluorescence parameters to the same extent.
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Zamzam, Noura, Rafal Rakowski, Marius Kaucikas, Gabriel Dorlhiac, Sefania Viola, Dennis J. Nürnberg, Andrea Fantuzzi, A. William Rutherford i Jasper J. van Thor. "Femtosecond visible transient absorption spectroscopy of chlorophyll-f-containing photosystem II". Proceedings of the National Academy of Sciences 117, nr 37 (31.08.2020): 23158–64. http://dx.doi.org/10.1073/pnas.2006016117.
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The recently discovered, chlorophyll-f-containing, far-red photosystem II (FR-PSII) supports far-red light photosynthesis. Participation and kinetics of spectrally shifted far-red pigments are directly observable and separated from that of bulk chlorophyll-a. We present an ultrafast transient absorption study of FR-PSII, investigating energy transfer and charge separation processes. Results show a rapid subpicosecond energy transfer from chlorophyll-a to the long-wavelength chlorophylls-f/d. The data demonstrate the decay of an ∼720-nm negative feature on the picosecond-to-nanosecond timescales, coinciding with charge separation, secondary electron transfer, and stimulated emission decay. An ∼675-nm bleach attributed to the loss of chl-a absorption due to the formation of a cation radical, PD1+•, is only fully developed in the nanosecond spectra, indicating an unusually delayed formation. A major spectral feature on the nanosecond timescale at 725 nm is attributed to an electrochromic blue shift of a FR-chlorophyll among the reaction center pigments. These time-resolved observations provide direct experimental support for the model of Nürnberg et al. [D. J. Nürnberg et al., Science 360, 1210–1213 (2018)], in which the primary electron donor is a FR-chlorophyll and the secondary donor is chlorophyll-a (PD1 of the central chlorophyll pair). Efficient charge separation also occurs using selective excitation of long-wavelength chlorophylls-f/d, and the localization of the excited state on P720* points to a smaller (entropic) energy loss compared to conventional PSII, where the excited state is shared over all of the chlorin pigments. This has important repercussions on understanding the overall energetics of excitation energy transfer and charge separation reactions in FR-PSII.
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Mohd Amin, Siti Faridah, Roselina Karim, Yus Aniza Yusof i Kharidah Muhammad. "Effects of Metal Concentration, pH, and Temperature on the Chlorophyll Derivative Content, Green Colour, and Antioxidant Activity of Amaranth (Amaranthus viridis) Purees". Applied Sciences 13, nr 3 (19.01.2023): 1344. http://dx.doi.org/10.3390/app13031344.
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The thermal process of green amaranth leads to the partial or complete degradation of chlorophyll pigments and loss of green colour due to the formation of chlorophyll derivatives. This study aimed to evaluate a stabilisation process utilising metal ions to obtain a stable green colour of metal-chlorophyll derivative complexes. In this study, the effects of CuSO4 (0–240 ppm), ZnCl2 (0–1800 ppm) ions, pH (4–9), and temperature (60–100 °C) on green amaranth purees with a constant time of 15 min were investigated. In tapered leaf amaranths, the sample depicted higher contents of chlorophyll a (0.33 mg/g), chlorophyll b (0.34 mg/g), and total chlorophyll (0.68 mg/g) than round leaf amaranths (chlorophyll a = 0.28 mg/g, chlorophyll b = 0.29 mg/g, and total chlorophyll = 0.58 mg/g). A higher chlorophyll derivative content (0.62 mg/g), DPPH scavenging activity (93 mM TE/g), and FRAP value (54 mM TE/g) of Cu-amaranth purees were successfully achieved using 210 ppm of CuSO4 after heating at pH 6 and 80 °C. Zn-amaranth purees were produced using 1500 ppm of ZnCl2 at pH 8 and 90 °C for 15 min with chlorophyll derivative content of 0.39 mg/g, DPPH scavenging activity of 79 mM TE/g, and FRAP value of 57 mM TE/g. In HPLC chromatograms, two major peaks were identified as chlorophylls a and b in fresh amaranths. Nevertheless, these two peaks disappeared in Cu- and Zn-amaranth purees, presumably due to the formation of metallo-chlorophyll derivatives.
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Sarkar, Debisri, Archana Sharma i Geeta Talukder. "Chlorophyll and chlorophyllin as modifiers of genotoxic effects". Mutation Research/Reviews in Genetic Toxicology 318, nr 3 (grudzień 1994): 239–47. http://dx.doi.org/10.1016/0165-1110(94)90017-5.
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Ouameur, A. Ahmed, R. Marty i H. A. Tajmir-Riahi. "Human serum albumin complexes with chlorophyll and chlorophyllin". Biopolymers 77, nr 3 (2005): 129–36. http://dx.doi.org/10.1002/bip.20173.
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BUMBAC, MARIUS, CRISTINA MIHAELA NICOLESCU, RADU LUCIAN OLTEANU, OLGA TIRON, ELENA ELISABETA MANEA, COSTEL BUMBAC, LAURA MONICA GORGHIU i in. "UV-VIS ANALYSIS OF GRANULAR ACTIVATED ALGAE CHLOROPHYLL CONTENT". Journal of Science and Arts 21, nr 4 (30.12.2021): 1111–20. http://dx.doi.org/10.46939/j.sci.arts-21.4-b06.
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Chlorophyll-a is the pigment whose concentration is an important indicator for the development of microalgae biomass. This study aims at evaluating the concentration of chlorophylls in the biomass of granular activated algae, using acetone and 90% ethanol for the extraction procedures applied. Concentrations of chlorophyll a, b and c were determined by applying three calculation types: methods proposed by Jeffrey and Humphrey for the extracts in acetone, Ritchie method for ethanolic extracts, and monochromatic method with acidification for ethanolic extracts. Experimental findings show that the solvent 90% ethanol is more efficient than acetone for extracting chlorophyll from biomass of granular activated algae. Also, by comparing results obtained by the two methods proposed for ethanolic extracts, it was found that the values obtained through the acidification method are influenced by the volume of hydrochloric acid added to the organic chlorophylls extract.
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Sokolova, G. G., I. A. Kondrateva i M. V. Kalgina. "Dynamics of chlorophyll concentration in the birch (Betula pendula) leaves under the conditions of technogenic pollution in the city of Biysk". Проблемы ботаники Южной Сибири и Монголии 22, nr 1 (3.07.2023): 355–59. http://dx.doi.org/10.14258/pbssm.2023068.
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The article considers the results of biochemical studies of chlorophyll content in leaves of birch growing in different conditions in the city of Biysk: control, parks, squares, highways, petrol stations, factories, thermal power plants. In park areas, compared with the control, the content of chlorophylls a and b and the a / b ratio are lower. The best conditions for the growth of birch trees (closeness of crowns, distance from highways, and lower frequency of attendance) contribute to an increase in the content of chlorophyll a and b in the leaves. The sparse location of trees in squares and their intensive visits, emissions from industrial enterprises, cars and thermal power plants lead to a decrease in the content of chlorophyll a and b in the leaves. Regardless of the growing conditions, a regular increase in the content of chlorophyll a is observed during the growing season. A change in the content of chlorophyll a in birch leaves has been revealed; in the city of Biysk, it is changing downward in the following row of growing places: control -> parks -> squares -> highways -> petrol stations -> factories -> CHP. In dynamics by month, a slight increase in the concentration of chlorophylls in July was detected in all places of birch growth, and then its decrease in August.
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Li, Qin, Shuangzhen Zhou, Wenyu Liu, Zhensheng Zhai, Yitian Pan, Changchang Liu, Mawsheng Chern i in. "A chlorophyll a oxygenase 1 gene ZmCAO1 contributes to grain yield and waterlogging tolerance in maize". Journal of Experimental Botany 72, nr 8 (11.02.2021): 3155–67. http://dx.doi.org/10.1093/jxb/erab059.
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Abstract Chlorophylls function in photosynthesis, and are critical to plant developmental processes and responses to environmental stimuli. Chlorophyll b is synthesized from chlorophyll a by chlorophyll a oxygenase (CAO). Here, we characterize a yellow-green leaf (ygl) mutant and identify the causal gene which encodes a chlorophyll a oxygenase in maize (ZmCAO1). A 51 bp Popin transposon insertion in ZmCAO1 strongly disrupts its transcription. Low enzyme activity of ZmCAO1 leads to reduced concentrations of chlorophyll a and chlorophyll b, resulting in the yellow-green leaf phenotype of the ygl mutant. The net photosynthetic rate, stomatal conductance, and transpiration rate are decreased in the ygl mutant, while concentrations of δ-aminolevulinic acid (ALA), porphobilinogen (PBG) and protochlorophyllide (Pchlide) are increased. In addition, a ZmCAO1 mutation results in down-regulation of key photosynthetic genes, limits photosynthetic assimilation, and reduces plant height, ear size, kernel weight, and grain yield. Furthermore, the zmcao1 mutant shows enhanced reactive oxygen species production leading to sensitivity to waterlogging. These results demonstrate the pleiotropy of ZmCAO1 function in photosynthesis, grain yield, and waterlogging tolerance in maize.
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Huh, Man Kyu, i Byeongryong Lee. "The Change of Chlorophyll Content and Chlorophyll Efficiency in Epipremnum aureum by Water and pH". European Journal of Botany 1, nr 2 (2.09.2022): 1–5. http://dx.doi.org/10.24018/ejbotany.2022.1.2.12.
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Epipremnum aureum (pothos) is an herbaceous species and is originated to tropical or subtropical South East Asia and Solomon islands. This study investigated the effect of excessive moisture on chlorophyll content and photosynthesis efficiency on E. aureum. The chlorophyll a, b, and total (chlorophyll a + b) contents were measured by using spectrophotometer. Fluorescence analysis for chlorophyll efficiency was measured with the PAM Chlorophyll Fluorometer. The chlorophyll content increases when moisture increases to 30%, but gradually decreases when it exceeds 40%. When the soil moisture was 80%, the values of chlorophyll a and b were 0.317 mg/g and 0.126 mg/g, respectively. This decreased the chlorophyll a, b, and total contents by 38.1%, 46.6%, and 36.8%, respectively, compared to 30% in 80% moisture. The chlorophyll content was highest at pH 6.5 of the soil. The content for chlorophylls a, b, and total were 0.471, 0.219, and 0.446 mg/g at pH 6.5, respectively. The correlation coefficients were subjected of the chlorophyll efficiency as a function of moistures. The change of chlorophyll efficiency in the quenched state (Fv) was also increased at 30% of moisture and then decreased steeply. The maximal possible value for fluorescence (Fm) was varied from 4310 (40% moisture) to 4220 (80% moisture). The Fm was varied from 4098 (pH 4.0) to 4356 (pH 6.5). The maximum quantum yield of photosynthesis (Fv/Fm) was varied from 0.798 (30% moisture) to 0.810 (60% moisture). The slope factors of Fo, Fm, Fv, and Fv/Fm for chlorophyll efficient indicators were 0.938, -0.806, 0.013, and 0.846, respectively. Excess watering decreased chlorophyll a, chl b, and chl (a + b) contents, and the chl a/b ratio in the E. aureum. The growth of this species was not as sensitive to pH compared to moisture.
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Sun, Danni, Songlin Wu, Xiaohui Li, Baosheng Ge, Chengxu Zhou, Xiaojun Yan, Roger Ruan i Pengfei Cheng. "The Structure, Functions and Potential Medicinal Effects of Chlorophylls Derived from Microalgae". Marine Drugs 22, nr 2 (27.01.2024): 65. http://dx.doi.org/10.3390/md22020065.
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Microalgae are considered to be natural producers of bioactive pigments, with the production of pigments from microalgae being a sustainable and economical strategy that promises to alleviate growing demand. Chlorophyll, as the main pigment of photosynthesis, has been widely studied, but its medicinal applications as an antioxidant, antibacterial, and antitumor reagent are still poorly understood. Chlorophyll is the most important pigment in plants and algae, which not only provides food for organisms throughout the biosphere, but also plays an important role in a variety of human and man-made applications. The biological activity of chlorophyll is closely related to its chemical structure; its specific structure offers the possibility for its medicinal applications. This paper reviews the structural and functional roles of microalgal chlorophylls, commonly used extraction methods, and recent advances in medicine, to provide a theoretical basis for the standardization and commercial production and application of chlorophylls.
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Jain, M., S. Tiwary i R. Gadre. "Sorbitol-induced changes in various growth and biochemici parameters in maize". Plant, Soil and Environment 56, No. 6 (3.06.2010): 263–67. http://dx.doi.org/10.17221/233/2009-pse.
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Treatment of maize seedlings with different concentrations of sorbitol decreased the rate of germination substantially. Root and shoot length was also reduced by sorbitol treatment, however, decrease in root length was lower than shoot length. Incubation of leaf segments from maize seedlings grown in continuous light with sorbitol decreased the fresh weight and increased the dry weight in a concentration-dependent manner. Sorbitol treatment also reduced the total chlorophylls, chlorophyll a as well as chlorophyll b; the decrease in chlorophyll 'b' being more prominent than chlorophyll 'a', however, carotenoid content was declined marginally. Supply of sorbitol decreased the protein and RNA content; however, proline content and in vivo nitrate reductase activity (NRA) were increased. The results demonstrate an inhibitory effect of sorbitol-induced stress on overall growth in maize. Amongst the biochemical parameters analysed, chlorophyll, protein and RNA contents were declined, while proline content and nitrate reductase activity were enhanced with sorbitol treatment.
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Susanto, Fahmi, Hosokawa i Miyashita. "Variation in Lipid Components from 15 Species of Tropical and Temperate Seaweeds". Marine Drugs 17, nr 11 (6.11.2019): 630. http://dx.doi.org/10.3390/md17110630.
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The present study describes the variation in lipid components from 15 species of seaweeds belonging to the Chlorophyta, Ochrophyta, and Rhodophyta phyla collected in tropical (Indonesia) and temperate (Japan) areas. Analyses were performed of multiple components, including chlorophylls, carotenoids, n-3 and n-6 polyunsaturated fatty acids (PUFAs), and alpha tocopherol (α-Toc). Chlorophyll (Chl) and carotenoid contents varied among phyla, but not with the sampling location. Chl a and b were the major chlorophylls in Chlorophyta. Chl a and Chl c were the main chlorophylls in Ochrophyta, while Chl a was the dominant chlorophylls in Rhodophyta. β-Carotene and fucoxanthin were detected as major seaweed carotenoids. The former was present in all species in a variety of ranges, while the latter was mainly found in Ochrophyta and in small quantities in Rhodophyta, but not in Chlorophyta. The total lipids (TL) content and fatty acids composition were strongly affected by sampling location. The TL and n-3 PUFAs levels tended to be higher in temperate seaweeds compared with those in tropical seaweeds. The major n-3 PUFAs in different phyla, namely, eicosapentaenoic acid (EPA) and stearidonic acid (SDA) in Ochrophyta, α-linolenic acid (ALA) and SDA in Chlorophyta, and EPA in Rhodophyta, accumulated in temperate seaweeds. Chlorophylls, their derivatives, and carotenoids are known to have health benefits, such as antioxidant activities, while n-3 PUFAs are known to be essential nutrients that positively influence human nutrition and health. Therefore, seaweed lipids could be used as a source of ingredients with health benefits for functional foods and nutraceuticals.
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Kalmykova, Elena, Kristina Mel'nik i Petr Kuz'min. "Species differences in the content of photosynthetic pigments in plants of arid territories of the South of Russia". Agrarian Bulletin of the 232, nr 03 (27.03.2023): 32–42. http://dx.doi.org/10.32417/1997-4868-2023-232-03-32-42.
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Abstract. The purpose is to study the features of adaptive reactions of the pigment system of plants in the stress conditions of the Astrakhan region. In the role of diagnosing the state of plants, physiological and biochemical indicators are used, which reflect the body's ability to adapt to changing environmental conditions. Methods. In the studies, methods of observation, description of the objects of study, spectrophotometric determination of the quantitative content of photosynthetic pigments, methods of statistical analysis were used. Results. Features in the quantitative content of chlorophyll a and b, carotenoids, as well as the ratio of the values of chlorophyll a and b, the amount of chlorophylls to carotenoids were revealed. The calculation of the linear Pearson correlation coefficient between the content of chlorophylls and carotenoids in leaves and the average daily temperature and daylight hours was carried out. It was established that the maximum content of chlorophyll a was observed in tamarix, the minimum amount was noted in saxaul. The largest amount of chlorophyll b was noted in the leaves of teresken, and the smallest in saxaul. The highest amount of carotenoids was observed in tamarix (0.59 mg/g dry weight), a little less was noted in teresken (0.54), its minimum content in saxaul (0.12) and juzgun (0.29). In the studied species, the ratio of chlorophylls ranged from 2.9 to 6.5, the maximum was in saxaul, and the minimum was in juzgun. The potential of photochemical activity decreases in the series saxaul > tamarix > teresken > juzgun. It was revealed that the maximum value for the ratio between the amount of chlorophylls and carotenoids in saxaul (2.9). Scientific novelty. New knowledge was obtained on resistance to adverse external factors in the stress conditions of the Astrakhan region in terms of the ratio of physiological and biochemical parameters – between chlorophyll, carotenoids in leaves and the average daily temperature and daylight hours, which made it possible to assess the potential of plants and compile the following series of studied species: saxaul > juzgun > teresken > tamarix.
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De Mesquita Alves, Jackson, Alex Serafim De Lima, Francisco Romário Andrade Figueiredo, Toshik Iarley Da Silva, Lourival Ferreira Cavalcante, Francisco De Oliveira Mesquita, Evandro Franklin De Mesquita i Cesenildo De Figueiredo Suassuna. "Chlorophyll a fluorescence and development of zucchini plants under nitrogen and silicon fertilization". Agronomía Colombiana 38, nr 1 (1.01.2020): 45–52. http://dx.doi.org/10.15446/agron.colomb.v38n1.79172.
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Zucchini (Cucurbita pepo L.) has a great economic and productive potential in the semi-arid region of Brazil, due to the wide acceptance by consumers and quick financial return. The nitrate (NO3-) assimilation process in C3 plants such as zucchini is related to photorespiration, and Si accumulated near the stomata reduces the transpiration rate, making the photosynthesis cycle more efficient. The objective of this study was to evaluate the interaction between nitrogen and silicon fertilization ongrowth, chlorophyll index, and chlorophyll a fluorescence of zucchini plants. The treatments were distributed in a split-plot scheme in a randomized block design with three replicates. The plot was arranged by silicon levels (0 and 6 g/plant) and the subplots constituted by five nitrogen levels (30, 60, 90, 120 and 150 kg ha-1). Leaf, stem and total dry masses, chlorophylla, chlorophyll b, total chlorophyll, chlorophyll a/b ratio and chlorophyll a fluorescence were evaluated. The highest dry matter productions in zucchini were obtained in treatments without Si. Si and N application together positively influences the chlorophyll a/b ratio of zucchini plants. The interaction between Si and N positively influences the maximum fluorescence, variable fluorescence and quantum yield of photosystemII of zucchini plants.
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Phothilimthana, Phitchaya Mangpo, Tikhon Jelvis, Rohin Shah, Nishant Totla, Sarah Chasins i Rastislav Bodik. "Chlorophyll". ACM SIGPLAN Notices 49, nr 6 (5.06.2014): 396–407. http://dx.doi.org/10.1145/2666356.2594339.
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