Journal articles: 'Flavonoids – Synthesis'

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Li, Chengshuai, Lijing Zhang, Decao Niu, Shuzhen Nan, Xiumei Miao, Xiaowei Hu, and Hua Fu. "Investigation of flavonoid expression and metabolite content patterns during seed formation of Artemisia sphaerocephala Krasch." Seed Science Research 31, no. 2 (June 2021): 136–48. http://dx.doi.org/10.1017/s096025852100012x.

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AbstractFlavonoids are a group of phenolic secondary metabolites in plants that have important physiological, ecological and economic value. In this study, using the desert plant Artemisia sphaerocephala Krasch. as the sample material, the content and components of the total flavonoids in its seeds at seven different developmental stages were determined. In addition, the genes involved in flavonoid metabolism were identified by full-length transcriptome sequencing (third-generation sequencing technology based on PacBio RS II). Their expression levels were analysed by RNA-seq short reading sequencing, to reveal the patterns and regulation mechanisms of flavonoid accumulation during seed development. The key results were as follows: the content of total flavonoids in mature seeds was 15.05 mg g−1, including five subclasses: flavonols, chalcones, flavones, flavanones and proanthocyanidins, among which flavonols accounted for 45.78%. The period of rapid accumulation of flavonoids was 40–70 d following anthesis. The high expression of phenylalanine ammonia-lyase (PAL), 4-coumarate-CoA ligase (4CL) and UDP-glucose:flavonoids 3-o-glucosyltransferase (UF3GT) promoted the accumulation of total flavonoids, while the high expression of flavonoids 3′-hydroxylase (F3′H) and flavonols synthase (FLS) made flavanols the main component. Transcription factors such as the MYB-bHLH-WDR (MBW) complex and Selenium-binding protein (SBP) directly regulated the structural genes of flavonoid metabolism, while C2H2-type zinc finger (C2H2), Zinc-finger transcription factor (GATA), Dehydration-responsive element binding (DREB), Global Transcription factor Group E protein (GTE), Trihelix DNA-binding factors (Trihelix) and Phytochrome-interacting factor (PIF) indirectly promoted the synthesis of flavonoids through hormones such as brassinoidsteroids (BRs) and abscisic acid (ABA). These results provided valuable resources for the application of related genes in genetics and breeding.

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Fardoun, Manal Muin, Dina Maaliki, Nabil Halabi, Rabah Iratni, Alessandra Bitto, Elias Baydoun, and Ali H. Eid. "Flavonoids in adipose tissue inflammation and atherosclerosis: one arrow, two targets." Clinical Science 134, no. 12 (June 2020): 1403–32. http://dx.doi.org/10.1042/cs20200356.

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Abstract Flavonoids are polyphenolic compounds naturally occurring in fruits and vegetables, in addition to beverages such as tea and coffee. Flavonoids are emerging as potent therapeutic agents for cardiovascular as well as metabolic diseases. Several studies corroborated an inverse relationship between flavonoid consumption and cardiovascular disease (CVD) or adipose tissue inflammation (ATI). Flavonoids exert their anti-atherogenic effects by increasing nitric oxide (NO), reducing reactive oxygen species (ROS), and decreasing pro-inflammatory cytokines. In addition, flavonoids alleviate ATI by decreasing triglyceride and cholesterol levels, as well as by attenuating inflammatory mediators. Furthermore, flavonoids inhibit synthesis of fatty acids and promote their oxidation. In this review, we discuss the effect of the main classes of flavonoids, namely flavones, flavonols, flavanols, flavanones, anthocyanins, and isoflavones, on atherosclerosis and ATI. In addition, we dissect the underlying molecular and cellular mechanisms of action for these flavonoids. We conclude by supporting the potential benefit for flavonoids in the management or treatment of CVD; yet, we call for more robust clinical studies for safety and pharmacokinetic values.

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Yang, Yun, Mengjiao Chen, Yaxin Liu, Huanhuan Ding, Hongyan Du, Zhiqiang Sun, and Jingle Zhu. "Metabolome and Transcriptome Analyses Reveal Different Flavonoid Biosynthesis and Chlorophyll Metabolism Profiles between Red Leaf and Green Leaf of Eucommia ulmoides." Forests 12, no. 9 (September 16, 2021): 1260. http://dx.doi.org/10.3390/f12091260.

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Flavonoids are natural antioxidants in plants that affect the color of plant tissues. Flavonoids can be divided into eight subgroups, including flavonols, anthocyanins, and proanthocyanidins. The mechanisms of flavonoid synthesis in model plants have been widely studied. However, there are a limited number of reports on the synthesis of flavonoids in the red leaf varieties of woody plants. In this study, we combined morphological observation, pigment content determination, metabolomics, and transcriptomics to investigate the metabolites and gene regulation present in the red and green leaves of Eucommia ulmoides Oliv. The results showed that the red leaves have a lower chlorophyll content and a higher anthocyanin content. Metabonomic analysis identified that the relative content of most flavonoids is up-regulated in red leaves based on UPLC-ESI-MS/MS, which included the apigenin class, quercetin class, kaempferol class, and procyanidins. Transcriptome data suggested that the differentially up-regulated genes are enriched in flavonoid and anthocyanin synthesis pathways, ABC transport, and GST pathways. The integrative analysis of the transcriptome and metabolome showed that the up-regulation of flavonoid metabolism and a high expression of chlorophyll degradation with the down-regulation of chlorophyll biosynthesis genes are detected in E. ulmoides red leaves compared with green leaves. In addition, the co-expression networks implied that cyanidin 3-5-O-diglucoside, EuDR5, EuPAL2, EuDFR11, Eu3MaT1, and EuF3′H are likely associated with the red leaf coloration of E. ulmoides. In summary, this research provided a reference for studying the mechanism of red leaf coloration in woody plants and the use of E. ulmoides red leaves as feedstock for bioactive products.

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Ma, Dawei, Hao Tang, Michael Reichelt, Eerik-Mikael Piirtola, Juha-Pekka Salminen, Jonathan Gershenzon, and C. Peter Constabel. "Poplar MYB117 promotes anthocyanin synthesis and enhances flavonoid B-ring hydroxylation by up-regulating the flavonoid 3′,5′-hydroxylase gene." Journal of Experimental Botany 72, no. 10 (March 12, 2021): 3864–80. http://dx.doi.org/10.1093/jxb/erab116.

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Abstract Flavonoids, such as anthocyanins, proanthocyanidins, and flavonols, are widespread plant secondary metabolites and important for plant adaptation to diverse abiotic and biotic stresses. Flavonoids can be variously hydroxylated and decorated; their biological activity is partly dependent on the degree of hydroxylation of the B-ring. Flavonoid biosynthesis is regulated by MYB transcription factors, which have been identified and characterized in a diversity of plants. Here we characterize a new MYB activator, MYB117, in hybrid poplar (Populus tremula×tremuloides). When overexpressed in transgenic poplar plants, MYB117 enhanced anthocyanin accumulation in all tissues. Transcriptome analysis of MYB117-overexpressing poplars confirmed the up-regulation of flavonoid and anthocyanin biosynthesis genes, as well as two flavonoid 3′,5′-hydroxylase (F3′5′H) genes. We also identified up-regulated cytochrome b5 genes, required for full activity of F3′5′H . Phytochemical analysis demonstrated a corresponding increase in B-ring hydroxylation of anthocyanins, proanthocyanidins, and flavonols in these transgenics. Similarly, overexpression of F3′5′H1 directly in hybrid poplar also resulted in increased B-ring hydroxylation, but without affecting overall flavonoid content. However, the overexpression of the cytochrome b5 gene in F3′5′H1-overexpressing plants did not further increase B-ring hydroxylation. Our data indicate that MYB117 regulates the biosynthesis of anthocyanins in poplar, but also enhances B-ring hydroxylation by up-regulating F3′5′H1.

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Trifunschi, Svetlana, and Melania Florina Munteanu. "Synthesis, Characterization and Antioxidant Activity of Cooper-Quercetin Complex and Iron-Quercetin Complex." Revista de Chimie 69, no. 10 (November 15, 2018): 2621–24. http://dx.doi.org/10.37358/rc.18.10.6593.

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Complexes of cooper (II) and iron (II) with flavonoid quercetin have been synthesized. The structure of compounds has been confirmed by means of UV-Vis and FTIR spectroscopic techniques. The antioxidant activity of the flavonoid complexes has been evaluated by using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method. These complexes of flavonoids are much more effective free radical scavengers than the free flavonoids, an aspect which recommends them for further studies on possible therapeutic applications.

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Wang, Tao, Qingjun Zou, Qiaosheng Guo, Feng Yang, Liwei Wu, and Wenyan Zhang. "Widely Targeted Metabolomics Analysis Reveals the Effect of Flooding Stress on the Synthesis of Flavonoids in Chrysanthemum morifolium." Molecules 24, no. 20 (October 14, 2019): 3695. http://dx.doi.org/10.3390/molecules24203695.

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Chrysanthemum morifolium. cv “Hangju” is an important medicinal material with many functions in China. Flavonoids as the main secondary metabolites are a major class of medicinal components in “Hangju” and its composition and content can change significantly after flooding. This study mimicked the flooding stress of “Hangju” during flower bud differentiation and detected its metabolites in different growth stages. From widely targeted metabolomics data, 661 metabolites were detected, of which 46 differential metabolites exist simultaneously in the different growth stages of “Hangju”. The top three types of the 46 differential metabolites were flavone C-glycosides, flavonol and flavone. Our results demonstrated that the accumulation of flavonoids in different growth stages of “Hangju” was different; however, quercetin, eriodictyol and most of the flavone C-glycosides were significantly enhanced in the two stages after flooding stress. The expression of key enzyme genes in the flavonoid synthesis pathway were determined using RT-qPCR, which verified the consistency of the expression levels of CHI, F3H, DFR and ANS with the content of the corresponding flavonoids. A regulatory network of flavonoid biosynthesis was established to illustrate that flooding stress can change the accumulation of flavonoids by affecting the expression of the corresponding key enzymes in the flavonoid synthesis pathway.

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Khater, Mai, Divyashree Ravishankar, Francesca Greco, and Helen MI Osborn. "Metal complexes of flavonoids: their synthesis, characterization and enhanced antioxidant and anticancer activities." Future Medicinal Chemistry 11, no. 21 (November 2019): 2845–67. http://dx.doi.org/10.4155/fmc-2019-0237.

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Flavonoids are polyphenolic compounds of natural origin. They are extensively studied within drug discovery programs due to their wide ranging biological activities such as antimicrobial, antioxidant, antitumor, neuroprotective and cardioprotective properties. The ability of flavonoids to coordinate with metal atoms has provided new leads for drug discovery programs, with better pharmacological activities and clinical profiles than the parent flavonoids. In this review, the enhanced antioxidant and anticancer activities of flavonoid metal complexes versus the parent flavonoids are discussed. Possible mechanisms of action for the metal complexes, such as DNA binding and apoptosis induction, are also presented alongside an overview of the synthesis of the metal complexes, and the different techniques used for their characterization.

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Różańska, Dorota, and Bożena Regulska-Ilow. "The importance of flavonoids in reducing blood pressure - selected aspects." Postępy Higieny i Medycyny Doświadczalnej 73 (March 27, 2019): 173–81. http://dx.doi.org/10.5604/01.3001.0013.1437.

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Hypertension is an independent risk factor for the development of cardiovascular disease. Therapy requires modifying the diet and lifestyle in order to reduce body weight. The role of flavonoids in reducing blood pressure also seems interesting. Flavonoids are plant compounds. The main classes of flavonoids are flavons, isoflavons, flavonols, flavanols, flavanones, and anthocyanins. Numerous epidemiological studies have reported that a higher intake of flavonoids in a diet is associated with a decreased risk of hypertension. One of the mechanisms by which flavonoids can help to reduce blood pressure is their activity as angiotensin-converting enzyme (ACE) inhibitors. Various flavonoids have a different ability to inhibit ACE, which is dependent on their chemical structure. The ACE inhibitor activity is associated with three structural elements of flavonoids: the catechol group on the B-ring, C2-C3 double bond and the cetone group in C4 at the C-ring. Flavonoids may exhibit ACE inhibitor activity because of compete with the substrate (competitive inhibition). One of the studies showed that flavonoid activity, as an ACE inhibitor, may be dependent on the ACE genotype (I/I, I/D, D/D). The vasodilatory properties of flavonoids can help lower blood pressure. Authors of numerous studies have shown that these properties are associated with different mechanisms, e.g. activation of potassium channels, regulation of extracellular and intracellular Ca2+ level, stimulation of nitric oxide synthase and increased synthesis of nitric oxide. Based on the studies presented in this paper, it can be concluded that flavonoids may play an important role both in preventing hypertension and in supporting its treatment.

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Zhu, Saijie, Junjun Wu, Guocheng Du, Jingwen Zhou, and Jian Chen. "Efficient Synthesis of Eriodictyol from l-Tyrosine in Escherichia coli." Applied and Environmental Microbiology 80, no. 10 (March 7, 2014): 3072–80. http://dx.doi.org/10.1128/aem.03986-13.

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ABSTRACTThe health benefits of flavonoids for humans are increasingly attracting attention. Because the extraction of high-purity flavonoids from plants presents a major obstacle, interest has emerged in biosynthesizing them using microbial hosts. Eriodictyol is a flavonoid with anti-inflammatory and antioxidant activities. Its efficient synthesis has been hampered by two factors: the poor expression of cytochrome P450 and the low intracellular malonyl coenzyme A (malonyl-CoA) concentration inEscherichia coli. To address these issues, a truncated plant P450 flavonoid, flavonoid 3′-hydroxylase (tF3′H), was functionally expressed as a fusion protein with a truncated P450 reductase (tCPR) inE. coli. This allowed the engineeredE. colito produce eriodictyol froml-tyrosine by simultaneously coexpressing the fusion protein with tyrosine ammonia lyase (TAL), 4-coumarate-CoA ligase (4CL), chalcone synthase (CHS), and chalcone isomerase (CHI). In addition, metabolic engineering was employed to enhance the availability of malonyl-CoA so as to achieve a new metabolic balance and rebalance the relative expression of genes to enhance eriodictyol accumulation. This approach made the production of eriodictyol 203% higher than that in the control strain. By using these strategies, the production of eriodictyol froml-tyrosine reached 107 mg/liter. The present work offers an approach to the efficient synthesis of other hydroxylated flavonoids froml-tyrosine or even glucose inE. coli.

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Barron, Denis, and Ragai K. Ibrahim. "Synthesis of Flavonoid Sulfates. III. Synthesis of 3′,4′-ortho Disulfates Using Sulfur Trioxide-trimethylamine Complex, and of 3′-SuIfates Using Aryl Sulfatase." Zeitschrift für Naturforschung C 43, no. 9-10 (October 1, 1988): 631–35. http://dx.doi.org/10.1515/znc-1988-9-1002.

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Abstract A number of flavonoid 3′,4′-disulfates were synthesized from the corresponding 4′-sulfate esters, using sulfur trioxide-trimethylamine complex. Desulfation of the sulfate esters using aryl sulfatase demonstrated that the rate of hydrolysis of the 3′-sulfate group was slower than either the 7- or 4′ groups, thus allowing the specific synthesis of flavonol 3,3′-disulfates. The effects of ortho-disulfation on the 13C NMR spectra of flavonoids, and the regative FAB-MS spectra of diand trisulfated flavonoids are discussed.

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Jin, Lu, Meng-Ling Wang, Yao Lv, Xue-Yi Zeng, Chao Chen, Hai Ren, Heng Luo, and Wei-Dong Pan. "Design and Synthesis of Flavonoidal Ethers and Their Anti-Cancer Activity In Vitro." Molecules 24, no. 9 (May 6, 2019): 1749. http://dx.doi.org/10.3390/molecules24091749.

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Flavonoids are well-characterized polyphenolic compounds with pharmacological and therapeutic activities. However, most flavonoids have not been developed into clinical drugs, due to poor bioavailability. Herein, we report a strategy to increase the drugability of flavonoids by constructing C(sp2)-O bonds and stereo- as well as regioselective alkenylation of hydroxyl groups of flavonoids with ethyl-2,3-butadienoate allenes. Twenty-three modified flavonoid derivatives were designed, synthesized, and evaluated for their anti-cancer activities. The results showed that compounds 4b, 4c, 4e, 5e, and 6b exhibited better in vitro inhibitory activity against several cancer cell lines than their precursors. Preliminary structure–activity relationship studies indicated that, in most of the cancer cell lines evaluated, the substitution on position 7 was essential for increasing cytotoxicity. The results of this study might facilitate the preparation or late-stage modification of complex flavonoids as anti-cancer drug candidates.

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Zhang, Aiai, Jing Zheng, Xuemiao Chen, Xueyin Shi, Huaisong Wang, and Qiushi Fu. "Comprehensive Analysis of Transcriptome and Metabolome Reveals the Flavonoid Metabolic Pathway Is Associated with Fruit Peel Coloration of Melon." Molecules 26, no. 9 (May 10, 2021): 2830. http://dx.doi.org/10.3390/molecules26092830.

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The peel color is an important external quality of melon fruit. To explore the mechanisms of melon peel color formation, we performed an integrated analysis of transcriptome and metabolome with three different fruit peel samples (grey-green ‘W’, dark-green ‘B’, and yellow ‘H’). A total of 40 differentially expressed flavonoids were identified. Integrated transcriptomic and metabolomic analyses revealed that flavonoid biosynthesis was associated with the fruit peel coloration of melon. Twelve differentially expressed genes regulated flavonoids synthesis. Among them, nine (two 4CL, F3H, three F3′H, IFS, FNS, and FLS) up-regulated genes were involved in the accumulation of flavones, flavanones, flavonols, and isoflavones, and three (2 ANS and UFGT) down-regulated genes were involved in the accumulation of anthocyanins. This study laid a foundation to understand the molecular mechanisms of melon peel coloration by exploring valuable genes and metabolites.

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Sajid, Moon, Chaitanya N. Channakesavula, Shane R. Stone, and Parwinder Kaur. "Synthetic Biology towards Improved Flavonoid Pharmacokinetics." Biomolecules 11, no. 5 (May 18, 2021): 754. http://dx.doi.org/10.3390/biom11050754.

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Flavonoids are a structurally diverse class of natural products that have been found to have a range of beneficial activities in humans. However, the clinical utilisation of these molecules has been limited due to their low solubility, chemical stability, bioavailability and extensive intestinal metabolism in vivo. Recently, the view has been formed that site-specific modification of flavonoids by methylation and/or glycosylation, processes that occur in plants endogenously, can be used to improve and adapt their biophysical and pharmacokinetic properties. The traditional source of flavonoids and their modified forms is from plants and is limited due to the low amounts present in biomass, intrinsic to the nature of secondary metabolite biosynthesis. Access to greater amounts of flavonoids, and understanding of the impact of modifications, requires a rethink in terms of production, more specifically towards the adoption of plant biosynthetic pathways into ex planta synthesis approaches. Advances in synthetic biology and metabolic engineering, aided by protein engineering and machine learning methods, offer attractive and exciting avenues for ex planta flavonoid synthesis. This review seeks to explore the applications of synthetic biology towards the ex planta biosynthesis of flavonoids, and how the natural plant methylation and glycosylation pathways can be harnessed to produce modified flavonoids with more favourable biophysical and pharmacokinetic properties for clinical use. It is envisaged that the development of viable alternative production systems for the synthesis of flavonoids and their methylated and glycosylated forms will help facilitate their greater clinical application.

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Kicinska, Anna, and Wieslawa Jarmuszkiewicz. "Flavonoids and Mitochondria: Activation of Cytoprotective Pathways?" Molecules 25, no. 13 (July 4, 2020): 3060. http://dx.doi.org/10.3390/molecules25133060.

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A large number of diverse mechanisms that lead to cytoprotection have been described to date. Perhaps, not surprisingly, the role of mitochondria in these phenomena is notable. In addition to being metabolic centers, due to their role in cell catabolism, ATP synthesis, and biosynthesis these organelles are triggers and/or end-effectors of a large number of signaling pathways. Their role in the regulation of the intrinsic apoptotic pathway, calcium homeostasis, and reactive oxygen species signaling is well documented. In this review, we aim to characterize the prospects of influencing cytoprotective mitochondrial signaling routes by natural substances of plant origin, namely, flavonoids (e.g., flavanones, flavones, flavonols, flavan-3-ols, anthocyanidins, and isoflavones). Flavonoids are a family of widely distributed plant secondary metabolites known for their beneficial effects on human health and are widely applied in traditional medicine. Their pharmacological characteristics include antioxidative, anticarcinogenic, anti-inflammatory, antibacterial, and antidiabetic properties. Here, we focus on presenting mitochondria-mediated cytoprotection against various insults. Thus, the role of flavonoids as antioxidants and modulators of antioxidant cellular response, apoptosis, mitochondrial biogenesis, autophagy, and fission and fusion is reported. Finally, an emerging field of flavonoid-mediated changes in the activity of mitochondrial ion channels and their role in cytoprotection is outlined.

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Serafini, Mauro, Ilaria Peluso, and Anna Raguzzini. "Flavonoids as anti-inflammatory agents." Proceedings of the Nutrition Society 69, no. 3 (June 23, 2010): 273–78. http://dx.doi.org/10.1017/s002966511000162x.

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Epidemiological evidence suggests that a high intake of plant foods is associated with lower risk of chronic diseases. However, the mechanism of action and the components involved in this effect have not been identified clearly. In recent years, the scientific community has agreed to focus its attention on a class of secondary metabolites extensively present in a wide range of plant foods: the flavonoids, suggested as having different biological roles. The anti-inflammatory actions of flavonoids in vitro or in cellular models involve the inhibition of the synthesis and activities of different pro-inflammatory mediators such as eicosanoids, cytokines, adhesion molecules and C-reactive protein. Molecular activities of flavonoids include inhibition of transcription factors such as NF-κB and activating protein-1 (AP-1), as well as activation of nuclear factor-erythroid 2-related factor 2 (Nrf2). However, the in vitro evidence might be somehow of limited impact due to the non-physiological concentrations utilized and to the fact that in vivo flavonoids are extensively metabolized to molecules with different chemical structures and activities compared with the ones originally present in the food. Human studies investigating the effect of flavonoids on markers of inflammation are insufficient, and are mainly focused on flavonoid-rich foods but not on pure molecules. Most of the studies lack assessment of flavonoid absorption or fail to associate an effect on inflammation with a change in circulating levels of flavonoids. Human trials with appropriate placebo and pure flavonoid molecules are needed to clarify if flavonoids represent ancillary ingredients or key molecules involved in the anti-inflammatory properties of plant foods.

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Rauter, Amélia P., Marcus Ennis, Karl-Heinz Hellwich, Bernardo J. Herold, Derek Horton, Gerard P. Moss, and Ida Schomburg. "Nomenclature of flavonoids (IUPAC Recommendations 2017)." Pure and Applied Chemistry 90, no. 9 (September 25, 2018): 1429–86. http://dx.doi.org/10.1515/pac-2013-0919.

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Abstract Flavonoid structures, found in nature or obtained by synthesis, may be very complex. These Recommendations provide a guide for flavonoid aglycone names. This will also allow the construction of the names for their polyglycosylated species with clarity and conciseness. A joint working party of IUPAC/IUBMB members has prepared these recommendations, which establish rules for the general nomenclature of flavonoids, providing examples of acceptable trivial names, and names derived from trivial names, together with semi-systematic and fully systematic names that follow the published IUPAC recommendations.

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Matvieieva, N. A., O. A. Havryliuk, and L. S. Yastremska. "Effect of short-term cold stress on flavonoid accumulation in Artemisia vulgaris and Artemisia annua “hairy” root cultures." Faktori eksperimental'noi evolucii organizmiv 23 (September 9, 2018): 302–7. http://dx.doi.org/10.7124/feeo.v23.1032.

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Aim. The aim of the work was to investigate the effect of short-term cold stress (+10°С) on the growth, flavonoid synthesis and antioxidant activity in Artemisia vulgaris L. and A. annua L. “hairy“ root cultures. Methods. Transgenic roots were cultivated during the first 1, 2 and 5 days at +10°C on Murashige and Skoog basal medium with twice reduced macrosalt content. The total flavonoids content in Rutin equivalent was determined using alcohol extract reaction with alumunium chloride. Antioxidant activity was studied using the DPPH method. Results. Short-term cold stress resulted in a reduction of mass increment by 12–76 %. The total flavonoid content in «hairy» roots ranged from 32.0±3.13 to 187.0±21.04 mg RE/g dry weight. Decrease of temperature has led to decrease of the flavonoids content in No. 1, No. 2 A. vulgaris root lines and No. 5 A. annua line by 18–33 %. The reaction of No. 3 A. vulgaris and No. 4 A. annua root lines was expressed in stimulation flavonoid synthesis by 62 % and 56.5 %. Cultivation of «hairy» roots under short-term cold stress has led to decrease of the antioxidant activity in all roots lines by 4–40 %. Conclusions. Сold stress had negative effect the “hairy“ roots growth, stimulated flavonoids accumulation only in two “hairy” root lines and reduced the level of antioxidant activity. Keywords: «hairy» roots culture, Artemisia spp., cold stress, flavonoids, antioxidant activity.

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Línzembold, Ildikó, Dalma Czett, Katalin Böddi, Tibor Kurtán, Sándor Balázs Király, Gergely Gulyás-Fekete, Anikó Takátsy, et al. "Study on the Synthesis, Antioxidant Properties, and Self-Assembly of Carotenoid–Flavonoid Conjugates." Molecules 25, no. 3 (February 1, 2020): 636. http://dx.doi.org/10.3390/molecules25030636.

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Flavonoids and carotenoids possess beneficial physiological effects, such as high antioxidant capacity, anticarcinogenic, immunomodulatory, and anti-inflammatory properties, as well as protective effects against UV light. The covalent coupling of hydrophobic carotenoids with hydrophilic flavonoids, such as daidzein and chrysin, was achieved, resulting in new amphipathic structures. 7-Azidohexyl ethers of daidzein and chrysin were prepared in five steps, and their azide-alkyne [4 + 2] cycloaddition with pentynoates of 8′-apo-β-carotenol, zeaxanthin, and capsanthin afforded carotenoid–flavonoid conjugates. The trolox-equivalent antioxidant capacity against ABTS•+ radical cation and self-assembly of the final products were examined. The 1:1 flavonoid–carotenoid hybrids generally showed higher antioxidant activity than their parent flavonoids but lower than that of the corresponding carotenoids. The diflavonoid hybrids of zeaxanthin and capsanthin, however, were found to exhibit a synergistic enhancement in antioxidant capacities. ECD (electronic circular dichroism) and UV-vis analysis of zeaxanthin–flavonoid conjugates revealed that they form different optically active J-aggregates in acetone/water and tetrahydrofuran/water mixtures depending on the solvent ratio and type of the applied aprotic polar solvent, while the capsanthin derivatives showed no self-assembly. The zeaxanthin bis-triazole conjugates with daidzein and with chrysin, differing only in the position of a phenolic hydroxyl group, showed significantly different aggregation profile upon the addition of water.

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Xu, Sherry L., Cathy W. C. Bi, Roy C. Y. Choi, Kevin Y. Zhu, Abudureyimu Miernisha, Tina T. X. Dong, and Karl W. K. Tsim. "Flavonoids Induce the Synthesis and Secretion of Neurotrophic Factors in Cultured Rat Astrocytes: A Signaling Response Mediated by Estrogen Receptor." Evidence-Based Complementary and Alternative Medicine 2013 (2013): 1–10. http://dx.doi.org/10.1155/2013/127075.

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Neurotrophic factors are playing vital roles in survival, growth, and function of neurons. Regulation of neurotrophic factors in the brain has been considered as one of the targets in developing drug or therapy against neuronal disorders. Flavonoids, a family of multifunctional natural compounds, are well known for their neuronal beneficial effects. Here, the effects of flavonoids on regulating neurotrophic factors were analyzed in cultured rat astrocytes. Astrocyte is a major secreting source of neurotrophic factors in the brain. Thirty-three flavonoids were screened in the cultures, and calycosin, isorhamnetin, luteolin, and genistein were identified to be highly active in inducing the synthesis and secretion of neurotrophic factors, including nerve growth factor (NGF), glial-derived neurotrophic factor (GDNF), and brain-derived neurotrophic factor (BDNF). The inductions were in time- and dose-dependent manners. In cultured astrocytes, the phosphorylation of estrogen receptor was triggered by application of flavonoids. The phosphorylation was blocked by an inhibitor of estrogen receptor, which in parallel reduced the flavonoid-induced expression of neurotrophic factors. The results proposed the role of flavonoids in protecting brain diseases, and therefore these flavonoids could be developed for health food supplement for patients suffering from neurodegenerative diseases.

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Marais, Jannie P. J., Daneel Ferreira, and Desmond Slade. "Stereoselective synthesis of monomeric flavonoids." Phytochemistry 66, no. 18 (September 2005): 2145–76. http://dx.doi.org/10.1016/j.phytochem.2005.03.006.

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Nay, Bastien, Jean-Pierre Monti, Alain Nuhrich, Gérard Deffieux, Jean-Michel Mérillon, and Joseph Vercauteren. "Methods in synthesis of flavonoids." Tetrahedron Letters 41, no. 47 (November 2000): 9049–51. http://dx.doi.org/10.1016/s0040-4039(00)01649-x.

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Mills, Chavonda J., Nelly N. Mateeva, and Kinfe K. Redda. "Synthesis of novel substituted flavonoids." Journal of Heterocyclic Chemistry 43, no. 1 (January 2006): 59–64. http://dx.doi.org/10.1002/jhet.5570430109.

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Yan, Shiqiang, Mingxian Xie, Yujie Wang, Qiang Xiao, Ning Ding, and Yingxia Li. "Semi-synthesis of a series natural flavonoids and flavonoid glycosides from scutellarin." Tetrahedron 76, no. 8 (February 2020): 130950. http://dx.doi.org/10.1016/j.tet.2020.130950.

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Awouafack, Maurice Ducret, Pierre Tane, Michael Spiteller, and Jacobus Nicolaas Eloff. "Eriosema (Fabaceae) Species Represent a Rich Source of Flavonoids with Interesting Pharmacological Activities." Natural Product Communications 10, no. 7 (July 2015): 1934578X1501000. http://dx.doi.org/10.1177/1934578x1501000749.

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Many flavonoids have so far been isolated as main secondary metabolites in plant species of the genus Eriosema (Fabaceae), which contains approximately 160 species. A total of 52 flavonoids including isoflavones, dihydroflavonols, flavonols, flavanones, dihydrochalcones, isoflavanone and their pyrano or glucoside derivatives were isolated and characterized from the five species of this genus investigated to date. Total synthesis and semi-synthesis (acetylation, methylation, hydrogenation, and cyclization) of some isolated flavonoids were reported. Due to several significant pharmacological properties (antimicrobial, cytotoxicity, anti-mycobacterial, antioxidant, antiviral, erectile-dysfunction, vasodilatory and hypoglycemic) of the isolated flavonoids and derivatives, more scientists should be interested in investigating Eriosema species. The present review is the first to document all flavonoids that have been reported from the genus Eriosema to date together with their synthetic and semi-synthetic derivatives, and their pharmacological properties. Dihydrochalcones, which are precursors of other classes of flavonoids, are very rare in natural sources and their isolation from Eriosema species may explain the large number of flavonoids found in this genus. It appears that isoflavone could be a marker for species in this genus. The 83 flavonoids (1–83) documented include 52 isolates, 31 semi-synthetic and 3 totally synthetic derivatives. Data were obtained from Google scholar, Pubmed, Scifinder, Sciencedirect, and Scopus. With 52 different flavonoids isolated from only 5 of the approximately 160 species it shows the remarkable chemical diversity of this genus. This compilation of the biological activities and chemical composition may renew the interest of pharmacologists and phytochemists in this genus.

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Pchelovska, S. A., S. V. Litvinov, Yu V. Shylina, K. V. Lystvan, V. V. Zhuk, D. O. Sokolova, L. V. Tonkal, A. G. Salivon, and O. G. Nesterenko. "Presowing radiation exposure of Chamomilla recutita L. seeds affects on flavonoid accumulation." Faktori eksperimental'noi evolucii organizmiv 22 (September 9, 2018): 311–17. http://dx.doi.org/10.7124/feeo.v22.967.

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Aim. Presowing radiation exposure of seeds is offered to apply as modification factor of secondary metabolites accumulation in medicinal plants. Aim of studying was to choose doses of both gamma- and X-ray exposure of Chamomilla recutita L. seeds that would lead to increasing synthesis of secondary metabolites and biomass. Methods. Both X- and gamma-radiation exposure of seeds, extraction of flavonoids, spectrophotometry assessment of flavonoid extracts, qualitative and semi-quantitative high effective liquid chromatography. Results. Presowing radiation exposure of Chamomilla recutita L. seeds increased both flavonoid production over control and yield of pharmacologically valuable raw material – inflorescence number per square. Chromatographical analyses indicated stable qualitative composition of Chamomilla recutita L. ethanol extracts; the exposure did not lead to synthesis of de novo components. Conclusions. Obtained data validate approach to apply presowing radiation exposure of Chamomilla recutita L. seeds (5–50 Gy dose rate) as modification factor increasing both its productivity and pharmaceutical value of medicinal plants. Keywords: Chamomilla recutita L., stimulating productivity, flavonoids, presowing exposure.

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Ullah, Asad, Sidra Munir, Syed Lal Badshah, Noreen Khan, Lubna Ghani, Benjamin Gabriel Poulson, Abdul-Hamid Emwas, and Mariusz Jaremko. "Important Flavonoids and Their Role as a Therapeutic Agent." Molecules 25, no. 22 (November 11, 2020): 5243. http://dx.doi.org/10.3390/molecules25225243.

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Flavonoids are phytochemical compounds present in many plants, fruits, vegetables, and leaves, with potential applications in medicinal chemistry. Flavonoids possess a number of medicinal benefits, including anticancer, antioxidant, anti-inflammatory, and antiviral properties. They also have neuroprotective and cardio-protective effects. These biological activities depend upon the type of flavonoid, its (possible) mode of action, and its bioavailability. These cost-effective medicinal components have significant biological activities, and their effectiveness has been proved for a variety of diseases. The most recent work is focused on their isolation, synthesis of their analogs, and their effects on human health using a variety of techniques and animal models. Thousands of flavonoids have been successfully isolated, and this number increases steadily. We have therefore made an effort to summarize the isolated flavonoids with useful activities in order to gain a better understanding of their effects on human health.

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Zhu, Wei, Zhuoheng Zhong, Shengzhi Liu, Bingxian Yang, Setsuko Komatsu, Zhiwei Ge, and Jingkui Tian. "Organ-Specific Analysis of Morus alba Using a Gel-Free/Label-Free Proteomic Technique." International Journal of Molecular Sciences 20, no. 2 (January 16, 2019): 365. http://dx.doi.org/10.3390/ijms20020365.

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Morus alba is an important medicinal plant that is used to treat human diseases. The leaf, branch, and root of Morus can be applied as antidiabetic, antioxidant, and anti-inflammatory medicines, respectively. To explore the molecular mechanisms underlying the various pharmacological functions within different parts of Morus, organ-specific proteomics were performed. Protein profiles of the Morus leaf, branch, and root were determined using a gel-free/label-free proteomic technique. In the Morus leaf, branch, and root, a total of 492, 414, and 355 proteins were identified, respectively, including 84 common proteins. In leaf, the main function was related to protein degradation, photosynthesis, and redox ascorbate/glutathione metabolism. In branch, the main function was related to protein synthesis/degradation, stress, and redox ascorbate/glutathione metabolism. In root, the main function was related to protein synthesis/degradation, stress, and cell wall. Additionally, organ-specific metabolites and antioxidant activities were analyzed. These results revealed that flavonoids were highly accumulated in Morus root compared with the branch and leaf. Accordingly, two root-specific proteins named chalcone flavanone isomerase and flavonoid 3,5-hydroxylase were accumulated in the flavonoid pathway. Consistent with this finding, the content of the total flavonoids was higher in root compared to those detected in branch and leaf. These results suggest that the flavonoids in Morus root might be responsible for its biological activity and the root is the main part for flavonoid biosynthesis in Morus.

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Pi, Erxu, Chengmin Zhu, Wei Fan, Yingying Huang, Liqun Qu, Yangyang Li, Qinyi Zhao, et al. "Quantitative Phosphoproteomic and Metabolomic Analyses Reveal GmMYB173 Optimizes Flavonoid Metabolism in Soybean under Salt Stress." Molecular & Cellular Proteomics 17, no. 6 (March 1, 2018): 1209–24. http://dx.doi.org/10.1074/mcp.ra117.000417.

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Salinity causes osmotic stress to crops and limits their productivity. To understand the mechanism underlying soybean salt tolerance, proteomics approach was used to identify phosphoproteins altered by NaCl treatment. Results revealed that 412 of the 4698 quantitatively analyzed phosphopeptides were significantly up-regulated on salt treatment, including a phosphopeptide covering the serine 59 in the transcription factor GmMYB173. Our data showed that GmMYB173 is one of the three MYB proteins differentially phosphorylated on salt treatment, and a substrate of the casein kinase-II. MYB recognition sites exist in the promoter of flavonoid synthase gene GmCHS5 and one was found to mediate its recognition by GmMYB173, an event facilitated by phosphorylation. Because GmCHS5 catalyzes the synthesis of chalcone, flavonoids derived from chalcone were monitored using metabolomics approach. Results revealed that 24 flavonoids of 6745 metabolites were significantly up-regulated after salt treatment. We further compared the salt tolerance and flavonoid accumulation in soybean transgenic roots expressing the 35S promoter driven cds and RNAi constructs of GmMYB173 and GmCHS5, as well as phospho-mimic (GmMYB173S59D) and phospho-ablative (GmMYB173S59A) mutants of GmMYB173. Overexpression of GmMYB173S59D and GmCHS5 resulted in the highest increase in salt tolerance and accumulation of cyaniding-3-arabinoside chloride, a dihydroxy B-ring flavonoid. The dihydroxy B-ring flavonoids are more effective as anti-oxidative agents when compared with monohydroxy B-ring flavonoids, such as formononetin. Hence the salt-triggered phosphorylation of GmMYB173, subsequent increase in its affinity to GmCHS5 promoter and the elevated transcription of GmCHS5 likely contribute to soybean salt tolerance by enhancing the accumulation of dihydroxy B-ring flavonoids.

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Tanaka, Toshio, Atsuhiko Iuchi, Hiroshi Harada, and Shoji Hashimoto. "Potential Beneficial Effects of Wine Flavonoids on Allergic Diseases." Diseases 7, no. 1 (January 15, 2019): 8. http://dx.doi.org/10.3390/diseases7010008.

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Wine, a widely consumed beverage, comprises several biophenols that promote health. Flavonoids, majorly present in red wine, have been shown to have antioxidant, anti-inflammatory, anticancer, and immunomodulatory activities. Regular consumption of red wine (100 mL/day) is estimated to provide an average of 88 mg of flavonoids, whereas recent epidemiological studies indicate that wine is one of the major sources of flavonoid intake amongst wine lovers in European countries (providing an average intake of 291–374 mg/day of flavonoids). In addition to being antioxidants, in vitro studies suggest that flavonoids also have anti-allergic activities that inhibit IgE synthesis, activation of mast cells and basophils or other inflammatory cells, and production of inflammatory mediators, including cytokines. Furthermore, they affect the differentiation of naïve CD4+ T cells into effector T cell subsets. Moreover, several studies have reported the benefits of flavonoids in allergic models such as atopic dermatitis, asthma, anaphylaxis, and food allergy; however, evidence in humans is limited to allergic rhinitis and respiratory allergy. Although further evaluation is required, it is expected that an appropriate intake of flavonoids may be beneficial in preventing, and eventually managing, allergic diseases.

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Uyama, Hiroshi. "Artificial Polymeric Flavonoids: Synthesis and Applications." Macromolecular Bioscience 7, no. 4 (April 10, 2007): 410–22. http://dx.doi.org/10.1002/mabi.200700005.

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Tlegenov, R. T., and A. Aitmambetov. "Synthesis of Lupinine Derivatives of Flavonoids." Russian Journal of Bioorganic Chemistry 31, no. 5 (September 2005): 495–98. http://dx.doi.org/10.1007/s11171-005-0067-8.

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Kumar, Rajesh, Nitya Sharma, and Om Prakash. "Hypervalent Iodine Reagents in the Synthesis of Flavonoids and Related Compounds." Current Organic Chemistry 24, no. 18 (November 18, 2020): 2031–47. http://dx.doi.org/10.2174/1385272824999200420074551.

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Hypervalent iodine compounds have proved to be very useful reagents to bring about various oxidative transformations including (i) α-functionalization of carbonyl compounds, (ii) oxidation of phenols, and (iii) oxidative rearrangement of ketones and α,β- unsaturated ketones. These reactions find interesting applications in the development of newer and convenient approaches for the synthesis of flavonoids. This review focuses on the use of most common three hypervalent compounds, namely iodobenzene diacetate, [hydroxy(tosyloxy)iodo]benzene, and [bis-trifluoroacetoxy(iodo)]benzene in the synthesis of cis/trans-3-hydroxyflavanones, 3-hydroxyflavones (flavonols), flavones, isoflavones and related compounds.

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Zhang, Ying, Yuanyuan Li, and Shunxing Guo. "Effects of the mycorrhizal fungus Ceratobasidium sp. AR2 on growth and flavonoid accumulation in Anoectochilus roxburghii." PeerJ 8 (January 16, 2020): e8346. http://dx.doi.org/10.7717/peerj.8346.

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Background Anoectochilus roxburghii is a traditional Chinese medicine with potent medicinal activity owing to the presence of secondary metabolites, particularly flavonoids. A. roxburghii also maintains a symbiotic relationship with mycorrhizal fungi. Moreover, mycorrhizal fungi can induce metabolite synthesis in host plants. However, little is known about the role of mycorrhizal fungi in promoting the accumulation of flavonoid metabolites in A. roxburghii. Methods A. roxburghii and the isolated fungus Ceratobasidium sp. AR2 were cocultured. The portion of A. roxburghii above the medium treated with or without AR2 was studied by transcriptome and target metabolome analyses. Results AR2 promoted the growth and development of A. roxburghii. The contents of total flavonoid, rutin, isorhamnetin, and cyanidin-3-glucoside chloride were increased compared with those in uninoculated cultures. Transcriptome analysis suggested that 109 unigenes encoding key enzymes were potentially associated with changes in flavonoids. Quantitative real-time polymerase chain reaction of fourteen flavonoid-related unigenes showed that most flavonoid biosynthetic genes were significantly differentially expressed between inoculated and uninoculated plantlets. Conclusion The isolate AR2 could significantly promote the growth and development of A. roxburghii and the accumulation of flavonoids. Overall, our findings highlighted the molecular basis of the effects of mycorrhizal fungi on flavonoid biosynthesis in A. roxburghii and provided novel insights into methods to improve the yield and quality of A. roxburghii.

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Justyna, Nawrocka, Szczech Magdalena, and Małolepsza Urszula. "Trichoderma atroviride enhances phenolic synthesis and cucumber protection against Rhizoctonia solani." Plant Protection Science 54, No. 1 (November 24, 2017): 17–23. http://dx.doi.org/10.17221/126/2016-pps.

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The treatment of cucumber plants with Trichoderma atroviride TRS25 (TRS25) provided protection against infection by Rhizoctonia solani. In plants inoculated with the pathogen, nontreated with Trichoderma, disease symptoms were observed on the roots, shoots, and leaves while in plants treated with TRS25 the spread of the disease was limited. The induction of systemic defence response in cucumber against R. solani infection seemed to be strongly related to the enhanced synthesis of phenolic compounds in plants. HPLC analysis indicated remarkable increases in the concentrations of 23 phenolics belonging to hydroxybenzoic acids, cinnamic acids, catechins, flavonols, flavons, and flavanons in the plants without systemic disease symptoms. We suggest that the accumulation of phenolic acids, flavonoids and de novo synthesis of catechins may strongly contribute to cucumber protection against R. solani.

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Hao, Gangping, Xihua Du, Renjiu Shi, Jianmei Wang, and Lei Feng. "Involvement of nitric oxide in ultraviolet B-induced activation of phenylalanine ammoniumlyase and stimulation of flavonoid biosynthesis in Ginkgo biloba leaves." Australian Journal of Botany 57, no. 1 (2009): 56. http://dx.doi.org/10.1071/bt08067.

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Previous studies have shown that ultraviolet B (UV-B) irradiation can stimulate biosynthesis of secondary metabolites. Several other studies have demonstrated that nitric oxide (NO) is an important signal molecule that plays a key role in plant defence responses to UV-B irradiation. However, the signalling mechanism of NO involvement in UV-B-induced secondary-metabolite synthesis is unclear. The purpose of the present study is to investigate the role of NO in the accumulation UV-B-induced secondary metabolite in the leaves of Ginkgo biloba. Our results showed that UV-B irradiation induced multiple biological responses in the leaves of G. biloba, including increases in both NO production and nitric oxide synthase (NOS) activity, and subsequent activation of phenylalanine ammoniumlyase (PAL) and synthesis of flavonoids. Application of NO via the donor sodium nitroprusside (SNP) enhanced UV-B-induced PAL activity and increased accumulation of flavonoids in G. biloba leaves. Both the NOS inhibitor N(G)-nitro-l-arginine methyl ester (L-NAME) and the NO scavenger 2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide (c-PTIO) reduced the production of NO. Moreover, UV-B-induced increase in PAL activity and flavonoid accumulation were suppressed by L-NAME and c-PTIO. These findings suggest a causal relationship between NO release and both PAL activity and flavonoid accumulation under UV-B irradiation. In addition, the results also indicate that NO, produced via NOS-like activity in ginkgo leaves subjected to UV-B irradiation, might act as an essential signal molecule for triggering the activation of PAL and synthesis of flavonoids.

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IINUMA, MUNEKAZU, TOSHIYUKI TANAKA, KAZUHIRO ITO, and MIZUO MIZUNO. "Flavonoids syntheses. V. Synthesis of flavonoids with three hydroxy and four methoxy groups and their spectral properties." CHEMICAL & PHARMACEUTICAL BULLETIN 35, no. 2 (1987): 660–67. http://dx.doi.org/10.1248/cpb.35.660.

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Li, Zhiyuan, Hong Jiang, Huizhuan Yan, Xiumei Jiang, Yan Ma, and Yong Qin. "Carbon and nitrogen metabolism under nitrogen variation affects flavonoid accumulation in the leaves of Coreopsis tinctoria." PeerJ 9 (September 10, 2021): e12152. http://dx.doi.org/10.7717/peerj.12152.

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Flavonoids are phytochemicals present in medicinal plants and contribute to human health. Coreopsis tinctoria, a species rich in flavonoids, has long been used in traditional medicine and as a food resource. N (nitrogen) fertilization can reduce flavonoid accumulation in C. tinctoria. However, there is limited knowledge regarding N regulatory mechanisms. The aim of this study was to determine the effect of N availability on flavonoid biosynthesis in C. tinctoria and to investigate the relationship between C (carbon) and N metabolism coupled with flavonoid synthesis under controlled conditions. C. tinctoria seedlings were grown hydroponically under five different N levels (0, 0.625, 1.250, 2.500 and 5.000 mM). The related indexes of C, N and flavonoid metabolism of C. tinctoria under N variation were measured and analysed. N availability (low and moderate N levels) regulates enzyme activities related to C and N metabolism, promotes the accumulation of carbohydrates, reduces N metabolite levels, and enhances the internal C/N balance. The flavonoid content in roots and stalks remained relatively stable, while that in leaves peaked at low or intermediate N levels. Flavonoids are closely related to phenylalanine ammonia-lyase (PAL), cinnamate 4-hydroxylase (C4H), 4-coumarate: coenzyme A ligase (4CL), and chalcone-thioase (CHS) activity, significantly positively correlated with carbohydrates and negatively correlated with N metabolites. Thus, C and N metabolism can not only control the distribution of C in amino acid and carbohydrate biosynthesis pathways but also change the distribution in flavonoid biosynthesis pathways, which also provides meaningful information for maintaining high yields while ensuring the nutritional value of crop plants.

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Taleghani, Akram, and Zahra Tayarani-Najaran. "Potent Cytotoxic Natural Flavonoids: The Limits of Perspective." Current Pharmaceutical Design 24, no. 46 (April 26, 2019): 5555–79. http://dx.doi.org/10.2174/1381612825666190222142537.

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Background:Besides the numerous biologic and pharmacologic functions in the human body that act as potent antioxidants, flavonoids (flavones, flavanones, flavonols, flavanols and isoflavones) are noted as cancer preventive or therapeutic agents.Methods:This review summarizes the published data using PubMed, Science Direct, and Scopus.Results:In this context, recognition and introduction of the most active cytotoxic flavonoids as promising agents for cancer therapy gives insight for further evaluations. However, there are some critical points that may affect the entering of flavonoids as active cytotoxic phytochemicals in the clinical phase. Issues such as the abundance of active species in nature, the methods of extraction and purification, solubility, pharmacokinetic profile, presence of the chiral moieties, method of synthesis, and structure modification may limit the entry of a selected compound for use in humans. Although plenty of basic evidence exists for cytotoxic/antitumor activity of the versatility of flavonoids for entry into clinical trials, the above-mentioned concerns must be considered.Conclusion:This review is an effort to introduce cytotoxic natural flavonoids (IC50< 10 µM) that may have the potential to be used against various tumor cells. Also, active constituents, molecular mechanisms, and related clinical trials have been discussed as well as the limitations and challenges of using flavonoids in clinic.

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Wang, Huiling, Wei Wang, Weidong Huang, and Haiying Xu. "Effect of Salicylic Acid on the Gene Transcript and Protein Accumulation of Flavonoid Biosynthesis-related Enzymes in Vitis vinifera Cell Suspension Cultures." HortScience 52, no. 12 (December 2017): 1772–79. http://dx.doi.org/10.21273/hortsci12515-17.

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Salicylic acid (SA) as a plant signal molecule plays an important regulatory role in stimulating the accumulation of plants’ defensive compounds. Numerous studies have shown its regulating effects on the biosynthesis of flavonoids. However, the controlling mechanism needs to be made clear further. Here, Vitis vinifera L. ‘Cabernet Sauvignon’ cell suspension cultures were treated with SA and its synthesis inhibitor paclobutrazol (Pac) to investigate their effects on flavonoid biosynthesis. The accumulation of gene transcripts and proteins of flavonoid biosynthesis pathway enzymes, including chalcone synthase (VvCHS), chalcone isomerase (VvCHI), dihydroflavonol 4-reductase (VvDFR), and anthocyanidin synthase (VvANS), were detected using real-time polymerase chain reaction (RT-PCR), quantitative polymerase chain reaction (qPCR), and western-blotting techniques. The results showed that treatment with exogenous SA at the proper concentration enhanced the production of flavonoids such as anthocyanins and proanthocyanidins (PAs) inside the suspension-cultured cells. The induction of anthocyanins and PAs was found to be time course-dependent. The mRNA and protein accumulation of VvCHS, VvCHI, VvDFR, and VvANS in the treatment system were enhanced too, and the changes were observed concomitantly. Treatment of Pac inhibited the induction of the accumulation of gene transcripts and proteins in accordance with the decreased accumulation of flavonoids. These results suggest that exogenous SA could induce both transcript and protein accumulation of flavonoid biosynthesis-related enzymes and in turn enhance the accumulation of flavonoid compounds such as anthocyanins and PAs in suspension-cultured grape cells.

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Ardissone, Silvia, K. Dale Noel, Mitchell Klement, William J. Broughton, and William J. Deakin. "Synthesis of the Flavonoid-Induced Lipopolysaccharide of Rhizobium Sp. Strain NGR234 Requires Rhamnosyl Transferases Encoded by Genes rgpF and wbgA." Molecular Plant-Microbe Interactions® 24, no. 12 (December 2011): 1513–21. http://dx.doi.org/10.1094/mpmi-05-11-0143.

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In the presence of flavonoids, Rhizobium sp. strain NGR234 synthesizes a new lipopolysaccharide (LPS), characterized by a rhamnan O-antigen. The presence of this rhamnose-rich LPS is important for the establishment of competent symbiotic interactions between NGR234 and many species of leguminous plants. Two putative rhamnosyl transferases are encoded in a cluster of genes previously shown to be necessary for the synthesis of the rhamnose-rich LPS. These two genes, wbgA and rgpF, were mutated. The resulting mutant strains synthesized truncated rough LPS species rather than the wild-type rhamnose-rich LPS when grown with flavonoids. Based on the compositions of these purified mutant LPS species, we inferred that RgpF is responsible for adding the first one to three rhamnose residues to the flavonoid-induced LPS, whereas WbgA is necessary for the synthesis of the rest of the rhamnan O-antigen. The NGR234 homologue of lpsB, which, in other bacteria, encodes a glycosyl transferase acting early in synthesis of the core portion of LPS, was identified and also mutated. LpsB was required for all the LPS species produced by NGR234, in the presence or absence of flavonoids. Mutants (i.e., of lpsB and rgpF) that lacked any portion of the rhamnan O-antigen of the induced LPS were severely affected in their symbiotic interaction with Vigna unguiculata, whereas the NGRΩwbgA mutant, although having very few rhamnose residues in its LPS, was able to elicit functional nodules.

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González, M. E., F. Martínez-Abarca, and L. Carrasco. "Flavonoids: Potent Inhibitors of Poliovirus RNA Synthesis." Antiviral Chemistry and Chemotherapy 1, no. 3 (June 1990): 203–9. http://dx.doi.org/10.1177/095632029000100304.

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Wen, Lingrong, Yueming Jiang, Jiali Yang, Yupeng Zhao, Miaomiao Tian, and Bao Yang. "Structure, bioactivity, and synthesis of methylated flavonoids." Annals of the New York Academy of Sciences 1398, no. 1 (April 24, 2017): 120–29. http://dx.doi.org/10.1111/nyas.13350.

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NABAEI-BIDHENDI, G., and N. R. BANNERJEE. "ChemInform Abstract: Convenient Synthesis of Polyhydroxy Flavonoids." ChemInform 22, no. 29 (August 23, 2010): no. http://dx.doi.org/10.1002/chin.199129172.

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TANAKA, TOSHIYUKI, KAZUSHI UMEMURA, MUNEKAZU IINUMA, and MIZUO MIZUNO. "Synthesis of Flavonoids in Scutellaria baicalensis. (1)." YAKUGAKU ZASSHI 107, no. 4 (1987): 315–17. http://dx.doi.org/10.1248/yakushi1947.107.4_315.

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Theunis, Mart, Hajime Kobayashi, William J. Broughton, and Els Prinsen. "Flavonoids, NodD1, NodD2, and Nod-Box NB15 Modulate Expression of the y4wEFG Locus That Is Required for Indole-3-Acetic Acid Synthesis in Rhizobium sp. strain NGR234." Molecular Plant-Microbe Interactions® 17, no. 10 (October 2004): 1153–61. http://dx.doi.org/10.1094/mpmi.2004.17.10.1153.

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Flavonoids secreted by host plants activate, in conjunction with the transcriptional activator NodD, nod gene expression of rhizobia resulting in the synthesis of Nod factors, which trigger nodule organogenesis. Interestingly, addition of inducing flavonoids also stimulates the production of the phytohormone indole-3-acetic acid (IAA) in several rhizobia. Here, the molecular basis of IAA synthesis in Rhizobium sp. NGR234 was investigated. Mass spectrometric analysis of culture supernatants indicated that NGR234 is capable of synthesizing IAA via three different pathways. The production of IAA is increased strongly by exposure of NGR234 to daidzein in a NodD1-, NodD2-, and SyrM2-dependent manner. This suggests that the y4wEFG locus that is downstream of nod-box NB15 encodes proteins involved in IAA synthesis. Knockout mutations in y4wE and y4wF abolished flavonoid-inducible IAA synthesis and a functional y4wF was required for constitutive IAA production. The promoter activity of NB15 and IAA production both were enhanced by introduction of a multicopy plasmid carrying nodD2 into NGR234. Surprisingly, the y4wE mutant still nodulated Vigna unguiculata and Tephrosia vogelii, although the nodules contained less IAA and IAA conjugates than those formed by the wild-type bacterium.

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Margna, U., L. Laanest, E. Margna, and T. Vainjärv. "ʟ-Tyrosine as a Precursor of Flavonoids in Buckwheat Cotyledons." Zeitschrift für Naturforschung C 40, no. 3-4 (April 1, 1985): 154–59. http://dx.doi.org/10.1515/znc-1985-3-402.

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Abstract Exogenous ʟ-tyrosine was incorporated 13 -14 times less effectively than exogenous L-phenylalanine into flavonoids in excised cotyledons of 3 days old buckwheat seedlings but proved to be an only 5 times poorer precursor when the experiments were carried out with 5 days old material. Simultaneous administration of ʟ-phenylalanine markedly reduced incorporation of ʟ-tyrosine into flavonoids. A similar decrease in the utilization of exogenous ʟ-tyrosine for flavonoid bio synthesis occurred in kinetin-treated cotyledons. However, in cotyledons treated with high doses of glyphosate, an inhibitor of the shikimic acid pathway, an increase in the formation of flavonoids from exogenously supplied ʟ-tyrosine was observed. Under all conditions the relative incorporation rate of exogenous L-tyrosine was highest for anthocyanins and lowest for C-glycosylflavones while within the latter class of compounds the luteolinic derivatives orientin and isoorientin incorporated more label than their apigeninic analogues vitexin and isovitexin. PAL and TAL activities were found to be present in the cotyledons in a ratio of 50:1. The possible role of ʟ-tyrosine as an alternative natural precursor for the biosynthesis of flavonoids and other related polyphenols is discussed.

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AL-Ishaq, Abotaleb, Kubatka, Kajo, and Büsselberg. "Flavonoids and Their Anti-Diabetic Effects: Cellular Mechanisms and Effects to Improve Blood Sugar Levels." Biomolecules 9, no. 9 (September 1, 2019): 430. http://dx.doi.org/10.3390/biom9090430.

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Diabetes mellitus (DM) is a prevailing global health metabolic disorder, with an alarming incidence rate and a huge burden on health care providers. DM is characterized by the elevation of blood glucose due either to a defect in insulin synthesis, secretion, binding to receptor, or an increase of insulin resistance. The internal and external factors such as obesity, urbanizations, and genetic mutations could increase the risk of developing DM. Flavonoids are phenolic compounds existing as secondary metabolites in fruits and vegetables as well as fungi. Their structure consists of 15 carbon skeletons and two aromatic rings (A and B) connected by three carbon chains. Flavonoids are furtherly classified into 6 subclasses: flavonols, flavones, flavanones, isoflavones, flavanols, and anthocyanidins. Naturally occurring flavonoids possess anti-diabetic effects. As in vitro and animal model’s studies demonstrate, they have the ability to prevent diabetes and its complications. The aim of this review is to summarize the current knowledge addressing the antidiabetic effects of dietary flavonoids and their underlying molecular mechanisms on selected pathways: Glucose transporter, hepatic enzymes, tyrosine kinase inhibitor, AMPK, PPAR, and NF-κB. Flavonoids improve the pathogenesis of diabetes and its complications through the regulation of glucose metabolism, hepatic enzymes activities, and a lipid profile. Most studies illustrate a positive role of specific dietary flavonoids on diabetes, but the mechanisms of action and the side effects need more clarification. Overall, more research is needed to provide a better understanding of the mechanisms of diabetes treatment using flavonoids.

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Syrchin, S. O., О. M. Yurieva, L. T. Nakonechna, F. V. Muchnyk, and I. M. Kurchenko. "Total Phenolic and Flavonoid Content, Antioxidant Activity of Talaromyces funiculosus Strains." Mikrobiolohichnyi Zhurnal 82, no. 5 (October 17, 2020): 48–57. http://dx.doi.org/10.15407/microbiolj82.05.048.

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Microscopic fungi synthesize a wide range of phenolic compounds that play an important role in cell wall formation, as well as perform signaling and protective functions. One of the important functions of phenolic compounds, primarily polyphenols, is antioxidant activity. The most active polyphenols are flavonoids, their synthesis in microscopic fungi has not been studied enough. The aim of the study was to determine the total phenols and flavonoids content and antioxidant activity of Talaromyces funiculosus strains isolated from different econiches. Methods. 20 strains of the microscopic fungus T. funiculosus – 10 endophytes and 10 saprotrophs were used in the experiments. Cultivation of filamentous fungi was performed under submerged conditions with shaking at 210–230 rpm in Erlenmeyer flasks containing 200 ml of Czapek liquid medium at a temperature 26±2°C for 6 days. The biomass of the strains was filtered, dried at 70°C and extracted with 95% methanol (1:50 w/v). The total phenols content was determined using Folin-Ciocalteu reagent by the method of Arora, Chandra (2010) with some modifications and expressed as mg of gallic acid equivalents (GAE) per g of dry weight mycelium. Flavonoids in each extract were determined spectrophotometrically with AlCl3 and expressed as mg of quercetin equivalents (QE) per g of dry weight mycelium. Antioxidant activity of methanolic extracts was measured as radical scavenging activity by the percentage inhibition of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. Results. The total phenolic content of methanolic extracts of T. funiculosus strains ranged from 0.12±0.007 to 1.97±0.150 mg GAE/g. The highest level of phenolic compounds was found for saprotroph UCM F-16790 (1.97±0.150) and endophyte UCM F-16795 (1.71±0.137 mg GAE/g). The flavonoid content in methanolic extracts of the studied strains varied in the range of 0.02±0.001–0.39±0.041 mg QE/g. All studied strains of T. funiculosus showed antioxidant activity against DPPH radical, which was 12.19±2.34–60.37±7.24% inhibition. Statistical analysis revealed a strong positive correlation between the total phenols and flavonoids content (Pearson’s correlation coefficient r=0.92); between antioxidant activity, phenols (r=0.82) and flavonoids (r=0.81) content in methanol extracts of T. funiculosus strains. The total content of phenols and flavonoids and antioxidant activity did not depend on the trophic group of the studied strains. The moderate correlation between flavonoids content and antioxidant activity of methanolic extracts of endophytic T. funiculosus strains (r=0.46) may be related to their ability to synthesize a wider range of polyphenolic compounds with antioxidant activity. Conclusions. The studied T. funiculosus strains have the ability to synthesize phenolic compounds and flavonoids in different concentrations. Correlation analysis revealed strong correlations between total phenolic and flavonoid contents and antioxidant activity. The reason for phenomenon of moderate correlation (r=0.46) between flavonoid content and antioxidant activity in endophytic strains may be the synthesis of other compounds by individual strains. The determination of individual components synthesized by the most active strains is of scientific interest for further study. T. funiculosus UСM F-16795 and UСM F-16790 strains had a quite high level of phenols and flavonoids. Obtained data may be promising for the search for phenolic compounds with antioxidant properties to increase plant resistance to negative impacts of environmental stress factors.

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IINUMA, MUNEKAZU, TOSHIYUKI TANAKA, KOJI HAMADA, MIZUO MIZUNO, and FUJIO ASAI. "Flavonoids syntheses. VI. Synthesis and spectral properties of 4-arylcoumarins (neoflavones)." CHEMICAL & PHARMACEUTICAL BULLETIN 35, no. 9 (1987): 3909–13. http://dx.doi.org/10.1248/cpb.35.3909.

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Dangrit, Darin, and Kanokporn Sompornpailin. "Enhancing Biosynthesis of Flavonol Protective Biomaterials Using FLS Transgenic Plants." Applied Mechanics and Materials 866 (June 2017): 29–32. http://dx.doi.org/10.4028/www.scientific.net/amm.866.29.

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Flavonol synthase (FLS) gene encodes an enzyme that is involved in conversion substrates into flavonols, quercetin and kaempferol. These substances are a subgroup of flavonoids which have an important role in both plant and human health. Many environmental factors such as temperature, pH and UV-A radiation have been studied and presented relationship with flavonoid synthesis. In this experiment, the combination of visible and UV-A lights was used as factors for elevating flavonoid biosynthesis of wild type (WT) plant and two lines of FLS transgenic plant under tissue culture condition. Both transgenic lines significantly enhanced the accumulation of quercetin and kaempferol substances nearly one fold higher than WT plant did. The photosynthetic pigment levels of chlorophyll A, chlorophyll B and carotenoid in transgenic lines are in the range 45.20-46.88, 16.34-17.04 and 13.63-13.46, while those of WT plants are 35.93, 13.18 and 10.55 (µg/g FW), respectively. Therefore, FLS transgenic plants containing high flavonol content showed a better in the protection photosynthetic pigments by less reductions of chlorophyll and carotenoid pigments.

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Journal articles on the topic 'Flavonoids – Synthesis'

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