Articles de revues : « Flavonoid luteolin »

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Muruganathan, Nandakumar, Anand Raj Dhanapal, Venkidasamy Baskar, Pandiyan Muthuramalingam, Dhivya Selvaraj, Husne Aara, Mohamed Zubair Shiek Abdullah et Iyyakkannu Sivanesan. « Recent Updates on Source, Biosynthesis, and Therapeutic Potential of Natural Flavonoid Luteolin : A Review ». Metabolites 12, n^o 11 (20 novembre 2022) : 1145. http://dx.doi.org/10.3390/metabo12111145.

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Nature gives immense resources that are beneficial to humankind. The natural compounds present in plants provide primary nutritional values to our diet. Apart from food, plants also provide chemical compounds with therapeutic values. The importance of these plant secondary metabolites is increasing due to more studies revealing their beneficial properties in treating and managing various diseases and their symptoms. Among them, flavonoids are crucial secondary metabolite compounds present in most plants. Of the reported 8000 flavonoid compounds, luteolin is an essential dietary compound. This review discusses the source of the essential flavonoid luteolin in various plants and its biosynthesis. Furthermore, the potential health benefits of luteolins such as anti-cancer, anti-microbial, anti-inflammatory, antioxidant, and anti-diabetic effects and their mechanisms are discussed in detail. The activity of luteolin and its derivatives are diverse, as they help to prevent and control many diseases and their life-threatening effects. This review will enhance the knowledge and recent findings regarding luteolin and its therapeutic effects, which are certainly useful in potentially utilizing this natural metabolite.

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Uehara, Ayumi, Junichi Kitajima, Goro Kokubugata et Tsukasa Iwashina. « Further Characterization of Foliar Flavonoids in Crossostephium chinense and their Geographic Variation ». Natural Product Communications 9, n^o 2 (février 2014) : 1934578X1400900. http://dx.doi.org/10.1177/1934578x1400900207.

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Foliar flavonoids of Crossostephium chinense in Japan and Taiwan were isolated and further characterized. Eighteen flavonoid aglycones, luteolin, apigenin, hispidulin, chrysoeriol, 5,7,4′-trihydroxy-6,3′,5′-trimethoxyflavone, jaceosidin, cilsimaritin, quercetin 3-methyl ether, axillarin, chrysosplenol-D, cirsiliol, apometzgerin, 5,7,3′-trihydroxy-6,4′,5′-trimethoxyflavone, luteolin 3′,4′-dimethyl ether, cirsilineol, eupatilin, nepetin and 5,7,3′,4′-tetrahydroxy-6,5′-dimethoxyflavone, were identified by UV, 1H and 13C NMR spectroscopic, LC-MS and HPLC comparisons with authentic samples. The compounds existed on the leaf surface. Four flavonoid glycosides, quercetin 3,7-di- O-glucoside, quercetin 3- O-rutinoside, luteolin 7- O-glucoside and apigenin 7- O-rutinoside, were also isolated as the intracellular flavonoids. It was shown by HPLC survey that variation of the species’ flavonoids occurs among the collection sites.

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Uehara, Ayumi, Shinobu Akiyama et Tsukasa Iwashina. « Foliar Flavonoids from Tanacetum vulgare var. boreale and their Geographical Variation ». Natural Product Communications 10, n^o 3 (mars 2015) : 1934578X1501000. http://dx.doi.org/10.1177/1934578x1501000307.

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Foliar flavonoids of Tanacetum vulgare var. boreale were isolated. Eight flavonoid glycosides, 7- O-glucosides of apigenin, luteolin, scutellarein and 6-hydroxyluteolin, and 7- O-glucuronides of apigenin, luteolin, chrysoeriol and eriodictyol were identified. Moreover, eight flavonoid aglycones, apigenin, luteolin, hispidulin, nepetin, eupatilin, jaceosidin, pectolinarigenin and axillarin were also isolated and identified. The flavonoid composition of two varieties of T. vulgare, i.e. var. boreale and var. vulgare, were compared. All samples of var. boreale and one sample of var. vulgare had the same flavonoid pattern, and could be distinguished from almost all the samples of var. vulgare. Thus, the occurrence of chemotypes, which are characterized by either the presence or absence of scutellarein 7- O-glucoside, eriodictyol 7- O-glucuronide and pectolinarigenin was shown in T. vulgare sensu lato.

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Theoharides, Theoharis C. « Luteolin : The wonder flavonoid ». BioFactors 47, n^o 2 (mars 2021) : 139–40. http://dx.doi.org/10.1002/biof.1729.

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Stich, K., et G. Forkmann. « Enzymatic Synthesis of 4′-and 3′, 4′ -Hydroxylated Flavanones and Flavones with Flower Extracts of Sinningia cardinalis ». Zeitschrift für Naturforschung C 42, n^o 11-12 (1 décembre 1987) : 1193–99. http://dx.doi.org/10.1515/znc-1987-11-1210.

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Flowers of Sinningia (syn. Rechsteineria) cardinalis contain glycosides of the flavones apigenin (4′-OH) and luteolin (3′,4′-OH) respectively, and of the related 3-deoxyanthocyanidins apigeninidin and luteolinidin. Studies on substrate specificity of the key enzyme of flavonoid biosynthesis, chalcone synthase, revealed that the 3′,4′-hydroxylated flavonoids are formed by hydroxylation of flavonoid compounds rather than by incorporation of caffeoyl-CoA into the flavonoid skeleton during the condensation reaction. In fact, flavonoid 3′-hydroxylase activity could be demonstrated in the microsomal fraction of the flower extracts. The enzyme catalyses hydroxylation of naringenin and apigenin in the 3′-position to eriodictyol and luteolin, respectively, with NADPH as cofactor. Besides flavanone 3′-hydroxylase a further NADPH-dependent enzyme activity (flavone synthase II) was observed in the microsomal fraction catalysing the oxidation of naringenin to apigenin and of eriodictyol to luteolin. The Cytochrome P-450 inhibitor ancymidol was found to abolish completely flavone synthase II activity, whereas flavonoid 3′-hydroxylase activity was not impaired.

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Nikolova, M., et S. Ivancheva. « Distribution of Surface Flavonoids in Bulgarian Plants ». Natural Product Communications 1, n^o 11 (novembre 2006) : 1934578X0600101. http://dx.doi.org/10.1177/1934578x0600101119.

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The review describes the distribution of surface flavonoids in Bulgarian plants. More than 100 species of Asteraceae, Lamiaceae, Scrophulariaceae, Geraniaceae and other families have been checked for external flavonoid aglycones. The flavonoid profiles of Asteraceae species are composed of a wide array of flavones and flavonols, mainly based upon 6-substituted derivatives. Flavone aglycones are predominant in the exudates of Lamiaceae species. Apigenin, luteolin and their derivatives were most commonly found in the studied species of Scropulariaceae and Lamiaceae. It has been shown that species of Geraniaceae, Ranunculaceae, and Solanaceae contain flavonoids of the flavonol class as surface constituents. Surface distributed flavonoids appear to have been well studied and useful for chemotaxonomy. If there is not too much infraspecific variation, flavonoid profiles can be used as taxonomic characters to distinguish species. Correlations between external flavonoid formation and local environment are apparent.

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Tomás, Francisco, Luis Hernández, Francisco A. T. Barberán et Federico Ferreres. « Flavonoid Glycosides from Thymus membranaceus ». Zeitschrift für Naturforschung C 40, n^o 7-8 (1 juillet 1985) : 583–84. http://dx.doi.org/10.1515/znc-1985-7-824.

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Abstract Thymus membranaceus is an endemism of southeastern Spain, which belongs to section Pseudothymbra of genus Thymus. In this work we have achieved an investigation of the flavonoid glycosides present in the aerial parts of this plant. Among the compounds identified are the rare luteolin-7-0-β-D-xyloside, luteolin-7-0-β-D-[rhamnosyl (1→2)glucoside] and luteolin-7-0-β-D-[xylosyl (1→2)glucoside] previously not known to occur in the Labiatae.

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Kasaj, Denata, Liselotte Krenn, Christina Gschnell et Brigitte Kopp. « Flavonoid Glycosides from Achillea roseo-albax ». Scientia Pharmaceutica 69, n^o 2 (30 juin 2001) : 211–17. http://dx.doi.org/10.3797/scipharm.aut-01-22.

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In the first detailed study of the flavonoid pattern of Achillea roseo-alba rutin, apigenin-7-O-ß-glucopyranoside, luteolin-7-O-ß-glucopyranoside, isorhamnetin-3-O-rutinoside, schaftoside, luteolin-4’-O-ß-glucopyranoside and 6-OH-luteolin-7-O-ß-glucopyranosid were proven in the methanolic extract of aerial parts of the plant. Additionally quercetin-3-O-[ß-apiofiranosyl-(1′′′→2′′)-ß-glucopyranoside] was identified for the first time in the genus Achillea.

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Cao, Jie, Ying Zhang, Wei Chen et Xiujuan Zhao. « The relationship between fasting plasma concentrations of selected flavonoids and their ordinary dietary intake ». British Journal of Nutrition 103, n^o 2 (14 septembre 2009) : 249–55. http://dx.doi.org/10.1017/s000711450999170x.

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Epidemiological studies suggest that a diet high in flavonoids protects against chronic diseases such as CVD and cancer. The objective of the present study was to evaluate the relationship between the intake of quercetin, kaempferol, isorhamnetin, apigenin and luteolin and their corresponding plasma concentrations, and further to explore whether these flavonoids can serve as biomarkers of their intake. Flavonoid intake and their plasma concentrations were analysed in ninety-two subjects consuming their habitual diet. Flavonoid intake was estimated with 7-d dietary records using available data on the flavonoid content of food. Plasma flavonoid concentrations were quantified by HPLC. In addition, we undertook a dietary intervention study to investigate plasma apigenin concentration after the consumption of celery leaf. The mean intake estimates of quercetin, kaempferol, isorhamnetin, apigenin and luteolin amounted to 13·58, 14·97, 12·31, 4·23 and 8·08 mg/d, respectively. The corresponding mean plasma concentrations were 80·23, 57·86, 39·94, 10·62 and 99·90 nmol/l. The mean 7 d intake of five flavonoids was positively correlated to their corresponding plasma concentrations, with correlation coefficients ranging from 0·33 to 0·51 (P < 0·05). In the dietary intervention study, the plasma apigenin concentration rose after celery leaf ingestion, and fell within 28 h to below the limit of detection (2·32 nmol/l). The present results suggest that quercetin, kaempferol, isorhamnetin, apigenin and luteolin are bioavailable from the diet. The levels of fasting plasma flavonoids seem to be suitable biomarkers of short-term intake. The combination of plasma flavonoids with their intake may prove useful when the possible health-protective effects of flavonoids are studied.

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Peck, Melicent C., Robert F. Fisher et Sharon R. Long. « Diverse Flavonoids Stimulate NodD1 Binding to nod Gene Promoters in Sinorhizobium meliloti ». Journal of Bacteriology 188, n^o 15 (1 août 2006) : 5417–27. http://dx.doi.org/10.1128/jb.00376-06.

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ABSTRACT NodD1 is a member of the NodD family of LysR-type transcriptional regulators that mediates the expression of nodulation (nod) genes in the soil bacterium Sinorhizobium meliloti. Each species of rhizobia establishes a symbiosis with a limited set of leguminous plants. This host specificity results in part from a NodD-dependent upregulation of nod genes in response to a cocktail of flavonoids in the host plant's root exudates. To demonstrate that NodD is a key determinant of host specificity, we expressed nodD genes from different species of rhizobia in a strain of S. meliloti lacking endogenous NodD activity. We observed that nod gene expression was initiated in response to distinct sets of flavonoid inducers depending on the source of NodD. To better understand the effects of flavonoids on NodD, we assayed the DNA binding activity of S. meliloti NodD1 treated with the flavonoid inducer luteolin. In the presence of luteolin, NodD1 exhibited increased binding to nod gene promoters compared to binding in the absence of luteolin. Surprisingly, although they do not stimulate nod gene expression in S. meliloti, the flavonoids naringenin, eriodictyol, and daidzein also stimulated an increase in the DNA binding affinity of NodD1 to nod gene promoters. In vivo competition assays demonstrate that noninducing flavonoids act as competitive inhibitors of luteolin, suggesting that both inducing and noninducing flavonoids are able to directly bind to NodD1 and mediate conformational changes at nod gene promoters but that only luteolin is capable of promoting the downstream changes necessary for nod gene induction.

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Kusano, Katsumi, Tsukasa Iwashina, Junichi Kitajima et Tamaki Mishio. « Flavonoid Diversity of Saussurea and Serratula Species in Tien Shan Mountains ». Natural Product Communications 2, n^o 11 (novembre 2007) : 1934578X0700201. http://dx.doi.org/10.1177/1934578x0700201115.

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Nine Saussurea species, S. alberti, S. elegans, S. gnaphalodes, S. involucrata, S. konuroba, S. kuschakewiczii, S. leucophylla, S. schanginiana and S. sordida, and Serratula lyratifolia from the Tien Shan Mountains and adjacent area were chemically characterized for flavonoids. Thirty-one flavonoids and one hydroquinone were isolated from the leaves of these species and identified from mass spectrometric, UV, 1H and 13C NMR spectroscopic data, by characterization of hydrolyzates, and direct TLC and HPLC comparisons with authentic samples as kaempferol 3-O-rutinoside (1), quercetin 3-O-rutinoside (2), isorhamnetin 3-O-rutinoside (3), quercetin 3-O-glucoside (4), quercetin 3-O-galactoside (5), kaempferol 5-O-glucoside (6), kaempferol 7-O-glucoside (7), quercetin 5-O-glucoside (8), quercetin 7-O-glucoside (9), isorhamnetin 5-O-glucoside (10), luteolin (11), hispidulin (12), nepetin (13), selagin 7-methyl ether (14), selagin (15), velutin (16), luteolin 7-methyl ether (17), jaceosidin (18), apigenin 7-O-rutinoside (19), apigenin 7-O-glucoside (20), luteolin 7-O-rutinoside (21), luteolin 7-O-glucoside (22), luteolin 7-O-galactoside (23), luteolin 7-O-glucuronide (24), hispidulin 7-O-glucoside (25), nepetin 7-O-glucoside (26), luteolin 5-O-glucoside (27), isovitexin (28), apigenin 6,8-di-C-glycoside (29), isoorientin (30), luteolin 8-C-glycoside (31), and arbutin (32). The nine surveyed Saussurea species differed in their flavonoid composition. It was shown that the genus is not only morphologically, but also chemically diversified.

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Uehara, Ayumi, et Tsukasa Iwashina. « Flavonoids from the Japanese Monotypic Genus, Nipponanthemum ». Natural Product Communications 7, n^o 8 (août 2012) : 1934578X1200700. http://dx.doi.org/10.1177/1934578x1200700811.

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Foliar flavonoids of Nipponanthemum, which is a monotypic genus and consists of only one Japanese endemic species, N. nipponicum, were isolated for the first time. Fifteen flavonoids, i.e. six glycosides, quercetin 3,7-di- O-glucoside, vicenin-2, quercetin 3- O-glucoside, luteolin 7- O-glucoside, kaempferol 3- O-glucoside and apigenin 7- O-glucoside, and nine aglycones, luteolin, nepetin, quercetin 3-methyl ether, axillarin, apigenin, hispidulin, chrysoeriol, jaceosidin and sudachitin were identified. Of these compounds, the flavonoid aglycones existed on the leaf surface.

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Topcu, Zeki, Bintug Ozturk, Ozlem Kucukoglu et Emrah Kilinc. « Flavonoids in Helichrysum pamphylicum Inhibit Mammalian Type I DNA Topoisomerase ». Zeitschrift für Naturforschung C 63, n^o 1-2 (1 février 2008) : 69–74. http://dx.doi.org/10.1515/znc-2008-1-213.

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DNA topoisomerases are important targets for cancer chemotherapy. We investigated the effects of a methanolic extract of Helichrysum pamphylicum on mammalian DNA topoisomerase I via in vitro plasmid supercoil relaxation assays. The extracts manifested a considerable inhibition of the enzyme’s activity in a dose-dependent manner. We also performed a HPLC analysis to identify the flavonoid content of the H. pamphylicum extract and tested the identified flavonoids; luteolin, luteolin-4-glucoside, naringenin, helichrysinA and isoquercitrin, on DNA topoisomerase I activity. The measurement of the total antioxidant capacity of the flavonoid standards suggested that the topoisomerase inhibition might be correlated with the antioxidant capacity of the plant.

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Joshi, Kunjani. « Leaf Flavonoid Patterns in the Species of Stemonoporus (Dipterocarpaceae) and Their Taxonomic Significance ». Journal of Natural History Museum 24 (9 octobre 2009) : 146–55. http://dx.doi.org/10.3126/jnhm.v24i1.2291.

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During the chemotaxonomic study of 16 species of Stemonoporus, three flavonoid aglycones (flavonol quercetin, flavonol kaempferol and flavone apigenin) and glycosides (quercetin 3- glucoside, quercetin 3-rutinoside and apigenin 5-glucoside) were isolated while flavonol myricetin, flavone luteolin and proanthcyanidin were not detected in any of the species surveyed. The isolated flavonoids can be used as chemotaxonomic markers. The species of Stemonoporus can be regarded as advanced in flavonoid pattern because of the absence of myricetin and loss of proanthocyanidins. The data of the flavonoid patterns and the outcome of cluster analysis are taxonomically useful to resolve the controversies over the systematic arrangement of the species and suggest the need for a revision of classification of the genus Stemonoporus. Key words: Dipterocarpaceae; Flavonols; Chemotaxonomy; Cluster analysis. Journal of Natural History MuseumVol. 24, 2009Page: 146-155

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Huang, Lei, Mi-Yeon Kim et Jae Youl Cho. « Immunopharmacological Activities of Luteolin in Chronic Diseases ». International Journal of Molecular Sciences 24, n^o 3 (21 janvier 2023) : 2136. http://dx.doi.org/10.3390/ijms24032136.

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Flavonoids have been shown to have anti-oxidative effects, as well as other health benefits (e.g., anti-inflammatory and anti-tumor functions). Luteolin (3′, 4′, 5,7-tetrahydroxyflavone) is a flavonoid found in vegetables, fruits, flowers, and herbs, including celery, broccoli, green pepper, navel oranges, dandelion, peppermint, and rosemary. Luteolin has multiple useful effects, especially in regulating inflammation-related symptoms and diseases. In this paper, we summarize the studies about the immunopharmacological activity of luteolin on anti-inflammatory, anti-cardiovascular, anti-cancerous, and anti-neurodegenerative diseases published since 2018 and available in PubMed or Google Scholar. In this review, we also introduce some additional formulations of luteolin to improve its solubility and bioavailability.

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Wang, Bixia, Jipeng Qu, Siyuan Luo, Shiling Feng, Tian Li, Ming Yuan, Yan Huang, Jinqiu Liao, Ruiwu Yang et Chunbang Ding. « Optimization of Ultrasound-Assisted Extraction of Flavonoids from Olive (Olea europaea) Leaves, and Evaluation of Their Antioxidant and Anticancer Activities ». Molecules 23, n^o 10 (30 septembre 2018) : 2513. http://dx.doi.org/10.3390/molecules23102513.

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Olea europaea leaves are the major byproduct of olive farming. In this study, ultrasound-assisted extraction of flavonoids from olive leaves was optimized using response surface methodology, and the flavonoid compounds and their antioxidant and anticancer activities were investigated by high performance liquid chromatography. The results showed that the optimized conditions for achieving the maximum yield of flavonoids (74.95 mg RE/g dm) were 50 °C temperature, 270 W power, 50 min time, and 41 mL/g liquid-solid ratio. There was a significant difference in the total flavonoid content between the aged and young leaves harvested in April and July, and six main components were quantified. Among them, luteolin-4’-O-glucoside was the most predominant flavonoid compound, followed by apigenin-7-O-glucoside and rutin. Olive leaves also contained small amounts of luteolin, apigenin, and quercetin. Additionally, excellent antioxidant activity was exhibited when tested with the DPPH assay; superoxide radical-scavenging ability and reducing power was also tested. The anticancer activity of the flavonoids was assessed using HeLa cervical cancer cells, and it was observed that increasing concentrations of olive leaf flavonoids resulted in decreased cancer cell viability. These results suggest that the flavonoids from olive leaves could be used as a potential source of natural antioxidants for the pharmaceutical and food industries.

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CHOWDHURY, Arnab Roy, Shalini SHARMA, Suparna MANDAL, Anindya GOSWAMI, Sibabrata MUKHOPADHYAY et Hemanta K. MAJUMDER. « Luteolin, an emerging anti-cancer flavonoid, poisons eukaryotic DNA topoisomerase I ». Biochemical Journal 366, n^o 2 (1 septembre 2002) : 653–61. http://dx.doi.org/10.1042/bj20020098.

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Luteolin, a naturally occurring flavonoid, is abundant in our daily dietary intake. It exhibits a wide spectrum of pharmacological properties, but little is known about its biochemical targets other than the fact that it induces topoisomerase II-mediated apoptosis. In the present study, we show that luteolin completely inhibits the catalytic activity of eukaryotic DNA topoisomerase I at a concentration of 40μM, with an IC50 of 5μM. Preincubation of enzyme with luteolin before adding a DNA substrate increases the inhibition of the catalytic activity (IC50 = 0.66μM). Treatment of DNA with luteolin before addition of topoisomerase I reduces this inhibitory effect. Subsequent fluorescence tests show that luteolin not only interacts directly with the enzyme but also with the substrate DNA, and intercalates at a very high concentration (>250μM) without binding to the minor groove. Direct interaction between luteolin and DNA does not affect the assembly of the enzyme–DNA complex, as evident from the electrophoretic mobility-shift assays. Here we show that the inhibition of topoisomerase I by luteolin is due to the stabilization of topoisomerase-I DNA-cleavable complexes. Hence, luteolin is similar to camptothecin, a class I inhibitor, with respect to its ability to form the topoisomerase I-mediated ‘cleavable complex'. But, unlike camptothecin, luteolin interacts with both free enzyme and substrate DNA. The inhibitory effect of luteolin is translated into concanavalin A-stimulated mouse splenocytes, with the compound inducing SDS–K+-precipitable DNA–topoisomerase complexes. This is the first report on luteolin as an inhibitor of the catalytic activity of topoisomerase I, and our results further support its therapeutic potential as a lead anti-cancer compound that poisons topoisomerases.

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Campos, Maria G., Rosemary F. Webby et Kenneth R. Markham. « The Unique Occurrence of the Flavone Aglycone Tricetin in Myrtaceae Pollen ». Zeitschrift für Naturforschung C 57, n^o 9-10 (1 octobre 2002) : 944–46. http://dx.doi.org/10.1515/znc-2002-9-1031.

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In pollen, flavonoids are usually found as glycosides and in particular, flavonol 3-O-diglycosides. However, in members of the Myrtaceae, subfamily Leptospermoideae, the rare flavone aglycone tricetin, along with other flavonoid aglycones including 3-O-methyl quercetin and luteolin, have been found to comprise a significant portion of the constituent flavonoids.

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Hendriks, Jerome J. A., Jacqueline Alblas, Susanne M. A. van der Pol, Eric A. F. van Tol, Christine D. Dijkstra et Helga E. de Vries. « Flavonoids Influence Monocytic GTPase Activity and Are Protective in Experimental Allergic Encephalitis ». Journal of Experimental Medicine 200, n^o 12 (20 décembre 2004) : 1667–72. http://dx.doi.org/10.1084/jem.20040819.

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In the chronic disabling disease multiple sclerosis (MS), migration of monocytes across the blood-brain barrier is a crucial step in the formation of new lesions in the central nervous system (CNS). Infiltrating monocyte-derived macrophages secrete inflammatory mediators such as oxygen radicals, which contribute to axonal demyelination and damage, resulting in neurological deficits. Flavonoids are compounds occurring naturally in food, which scavenge oxygen radicals and have antiinflammatory properties. To investigate whether they might suppress clinical symptoms in MS, we treated rats sensitized for acute and chronic experimental allergic encephalomyelitis, an experimental model of MS, with flavonoids. We demonstrated that the flavonoid luteolin substantially suppressed clinical symptoms and prevented relapse when administered either before or after disease onset. Luteolin treatment resulted in reduced inflammation and axonal damage in the CNS by preventing monocyte migration across the brain endothelium. Luteolin influenced migration by modulating the activity of Rho GTPases, signal transducers involved in transendothelial migration. Oral administration of luteolin also significantly reduced clinical symptoms.

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Yuan, Erdong, Benguo Liu, Qingyi Wei, Jiguo Yang, Lei Chen et Qiong Li. « Structure Activity Relationships of Flavonoids as Potent α-Amylase Inhibitors ». Natural Product Communications 9, n^o 8 (août 2014) : 1934578X1400900. http://dx.doi.org/10.1177/1934578x1400900829.

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The effects of three flavonoids (quercetin, luteolin, diosmetin) on α-amylase were examined by enzymatic kinetics and fluorescence spectroscopy. The three test flavonoids were non-competitive inhibitors of the enzyme. Addition of flavonoids led to fluorescence quenching of α-amylase. The quenching was initiated from the formation of a complex between the flavonoids and the enzyme, corresponding to a static quenching process. An α-amylase molecule provides a binding site for the test flavonoid. The main binding force was hydrophobic. The decreasing order of inhibition of α-amylase by flavonoids and the binding force was luteolin, diosmetin, and quercetin. It is demonstrated that hydroxylation in ring C and methylation of the hydroxyl group in ring B of flavonoids may weaken the binding affinities to α-amylase.

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Abdul-Qader, Ziena M., Kareem M. Rabie et Huda S. Husni. « Efficacy of Bio-fertilizer and Chemical Fertilization on Flavonoids Distribution in Different Plant Parts of Stevia rebaudiana (Bertoni.) ». Bionatura 7, n^o 2 (15 mai 2022) : 1–9. http://dx.doi.org/10.21931/rb/2022.07.02.20.

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This study aims to investigate the effect of the biological and chemical fertilizers on the content of the flavonoid compounds distributed within the different plant parts (leaves, stems, branches, and roots) of Stevia rebaudiana (Bertoni.) grown in Iraq. The results showed that the treatments of the biological fertilizers, including Mycorrhiza (C2) achieved the highest content of the most flavonoids in different parts of the plant. The treatment C2 recorded a rise of the flavonoid compounds Naringin, Naringenin and Luteolin 7-glucose in the leaves, Naringin, Rutin, and Acacetin7-neorutinoside in the stems and branches, and Apiening6-rhamnose8- glucose, Apigenin7-o neohespiroside, Kampferol3-7dirmmoside, Quercetrin, Narengenin, Acacetin7-neorutinoside, Kampferol, and Luteolin 7-glucose in the roots. On the other hand, treatment C1 recorded the highest content of Quercetin in the leaves, Quercetrin3-O glucose in the stems and branches, and Quercetrin3-O glucose, Naringenin, and Acacetin7-neorutinoside in the leaves . Keywords. Flavonoid, Stevia, Mycorrhiza and chemical Fertilization

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Kusriani, Raden Herni, Shinta Maulida Rosandhy et Elfahmi Elfahmi. « Luteolin, a flavonoid from Syzygium myrtifolium Walp. » Current Research on Biosciences and Biotechnology 1, n^o 1 (30 août 2019) : 31–33. http://dx.doi.org/10.5614/crbb.2019.1.1/fkan4064.

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A flavonoid, luteolin, was isolated from the leaves of Syzygium myrtifolium. The compound was purified using vacuum liquid chromatography with the help of a specific guidance for the flavonoid isolation. The chemical structure of this compound was determined based on measurements of UV, IR and NMR spectroscopic data. The occurrence of luteolin in S. myrtifolium is firstly reported from this study.

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Myagchilov, Aleksey Viktorovich, Petr Grigor'yevich Gorovoy et Larisa Ivanovna Sokolova. « FLAVONOIDS OF SERRATULA KOMAROVII ILJIN (FAMILY ASTERACEAE) ». chemistry of plant raw material, n^o 1 (5 mars 2020) : 141–48. http://dx.doi.org/10.14258/jcprm.2020016301.

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In the Far East of Russia the genus Serratula L. (family Asteraceae) is represented by 2 species - Serratula manshurica Kitag. and Serratula komarovii Iljin, which can be potential sources of biologically active compounds (phytoecdysteroids). For the first time in the aerial part (leaves, stems, inflorescences) of Serratula komarovii 6 flavonoid compounds (luteolin-7-O-β-D-glucuronopyranoside, apigenin-7-O-β-D-glucuronopyranoside, chrysoeriol-7-O-β-D-glucuronopyranoside, quercetin, luteolin, 3-methylquercetin) were identified by liquid extraction (70% ethyl alcohol) and reverse phase liquid chromatography (RP HPLC). The structure of compounds (luteolin-7-O-β-D-glucuronopyranoside, apigenin-7-O-β-D-glucuronopyranoside, chrysoeriol-7-O-β-D-glucuronopyranoside), isolated by preparative column chromatography on silica gel in a gradient elution with a mixture of solvents (carbon tetrachloride and ethyl alcohol) was proved by UV and NMR-1H, -13C, 1H-,13C-HMBC spectroscopy. It was noted that the dominant flavonoid in Serratula komarovii is luteolin-7-O-β-D-glucuronopyranoside (in the leaves – 4.92±0.98% and in the stems – 1.23±0.25%), and in inflorescences – apigenin-7-O-β-D-glucuronopyranoside (1.10±0.22%). The method of differential spectrophotometry was used to determine the sum of flavonoids in the aerial organs of Serratula komarovii which varies from 1.96 to 9.04%. The maximum content of flavonoids was detected in the leaves – 9.04±0.71%, and the minimum in the stems of the plant – 1.96±0.20%. Thus, Serratula komarovii can be a promising and constantly renewable source of not only phytoecdysteroids, but also flavonoids necessary for the pharmaceutical industry.

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Hennebelle, Thierry, Sevser Sahpaz, Henry Joseph et François Bailleul. « Phenolics and Iridoids of Lippia Alba ». Natural Product Communications 1, n^o 9 (septembre 2006) : 1934578X0600100. http://dx.doi.org/10.1177/1934578x0600100906.

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The phytochemical investigation of polar extracts of Lippia alba led to the isolation of a new acetylated flavonoid, apigenin-7-O-[(3-O-acetyl)β-D-glucopyranuronyl(1→2)]-β-D-glucopyranuronide, and of seventeen known compounds: seven iridoids (theveside, geniposidic acid, shanzhiside methyl ester, caryoptoside, 8-epi-loganin, mussaenoside and geniposide), six phenylpropanoids (cistanoside F, forsythoside B, calceolarioside E, acteoside, isoacteoside and 2-acetylacteoside) and four flavonoids (apigenin-7-O-glucuronide, luteolin-7-O-glucuronide, apigenin-7-O-diglucuronide and luteolin-7-O-diglucuronide).

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Ioannou, Irina, Leila Chekir et Mohamed Ghoul. « Effect of Heat Treatment and Light Exposure on the Antioxidant Activity of Flavonoids ». Processes 8, n^o 9 (1 septembre 2020) : 1078. http://dx.doi.org/10.3390/pr8091078.

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The application of food processes can lead to a modification of both the structure and the activities of flavonoids. In this article, the effect of heat treatment and exposure to light on the antioxidant activity of 6 model flavonoid solutions (rutin, naringin, eriodictyol, mesquitol, luteolin, and luteolin 7-O-glucoside) was studied. The evolution of the antioxidant activity measured after heat treatment of 130 °C at 2 h and an exposure to visible light for 2 weeks is measured by the ABTS (2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt) method and represented by a new parameter called ΔTEAC. The model solution of Mesquitol showed the highest increase in ΔTEAC after a heat treatment, a value of 200 mM was obtained. The increase in ΔTEAC is always greater with thermal treatment than with light exposure. Thus, temperature and light lead to different degradation pathways of the flavonoid. In vivo measurements were carried out with solutions of naringin, erodictyol, and luteolin 7-O-glucoside. Heated solutions of flavonoids do not exhibit toxicity on cells. The specific activities of superoxide dismutase and glutathione peroxide have been determined and have shown an increased impact on the potential anti-cancer of these solutions by enhancing their cellular antioxidant activity, as well as modulation of the oxidative stress.

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BROWN, E. Jonathan, Hicham KHODR, C. Robert HIDER et Catherine A. RICE-EVANS. « Structural dependence of flavonoid interactions with Cu2+ ions : implications for their antioxidant properties ». Biochemical Journal 330, n^o 3 (15 mars 1998) : 1173–78. http://dx.doi.org/10.1042/bj3301173.

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The flavonoids constitute a large group of polyphenolic phytochemicals with antioxidant properties in vitro. The interactions of four structurally related flavonoids (quercetin, kaempferol, rutin and luteolin) with Cu2+ ions were investigated in terms of the extent to which they undergo complex formation through chelation or modification through oxidation, as well as in their structural dependence. The ortho 3ʹ,4ʹ-dihydroxy substitution in the B ring is shown to be important for Cu2+-chelate formation, thereby influencing the antioxidant activity. The presence of a 3-hydroxy group in the flavonoid structure enhances the oxidation of quercetin and kaempferol, whereas luteolin and rutin, each lacking the 3-hydroxy group, do not oxidize as readily in the presence of Cu2+ ions. The results also demonstrate that the reactivities of the flavonoids in protecting low-density lipoprotein (LDL) against Cu2+ ion-induced oxidation are dependent on their structural properties in terms of the response of the particular flavonoid to Cu2+ ions, whether chelation or oxidation, their partitioning abilities between the aqueous compartment and the lipophilic environment within the LDL particle, and their hydrogen-donating antioxidant properties.

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Çetinkaya, Melisa, et Yusuf Baran. « Therapeutic Potential of Luteolin on Cancer ». Vaccines 11, n^o 3 (27 février 2023) : 554. http://dx.doi.org/10.3390/vaccines11030554.

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Cancer is a global concern, as the rate of incidence is increasing each year. The challenges related to the current chemotherapy drugs, such as the concerns related to toxicity, turn to cancer therapeutic research to discover alternative therapy strategies that are less toxic to normal cells. Among those studies, the use of flavonoids—natural compounds produced by plants as secondary metabolites for cancer therapy—has been a hot topic in cancer treatment. Luteolin, a flavonoid that has been present in many fruits, vegetables, and herbs, has been identified to exhibit numerous biological activities, including anti-inflammatory, antidiabetic, and anticancer properties. The anticancer property of Luteolin has been extensively researched in many cancer types and has been related to its ability to inhibit tumor growth by targeting cellular processes such as apoptosis, angiogenesis, migration, and cell cycle progression. It achieves this by interacting with various signaling pathways and proteins. In the current review, the molecular targets of Luteolin as it exerts its anticancer properties, the combination therapy that includes Luteolin with other flavonoids or chemotherapeutic drugs, and the nanodelivery strategies for Luteolin are described for several cancer types.

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Rajhard, Saša, Lucija Hladnik, Filipa A. Vicente, Stanko Srčič, Miha Grilc et Blaž Likozar. « Solubility of Luteolin and Other Polyphenolic Compounds in Water, Nonpolar, Polar Aprotic and Protic Solvents by Applying FTIR/HPLC ». Processes 9, n^o 11 (30 octobre 2021) : 1952. http://dx.doi.org/10.3390/pr9111952.

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In recent years, flavonoids have become a highly researched topic due to their health beneficial effects. Since flavonoids’ solubility plays a significant role in their use in pharmaceutical, food, biological, and chemical areas, the determination of suitable solvents is crucial. Fourier transform infrared (FTIR) analysis was used to characterize functional groups of several flavonoids and phenolic compounds, namely luteolin, hesperidin, quercetin, naringenin, gallic acid and tannic acid. Concentration dependence on transmittance was evaluated for these compounds in ethanol. Afterwards, luteolin was chosen as a model flavonoid, with its concentration correlated with transmittance using 15 solvents with different polarities. Luteolin solubility was further corroborated with high-performance liquid chromatography (HPLC). These results shed light on using FTIR as a semi-quantitative method for the initial screening of solvents and the solubility of different compounds while saving time and solvents. Hence, HPLC would only be needed as a final step for the most promising solvents.

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Zhao*, Xin, Janice E. Young, Ted Carey et Weiqun Wang. « Total Phenolic and Flavonoid Contents of Organically and Conventionally Grown Lettuce, Collards and Chinese Cabbage ». HortScience 39, n^o 4 (juillet 2004) : 863C—863. http://dx.doi.org/10.21273/hortsci.39.4.863c.

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Organic vegetables have been suggested to produce higher levels of phytochmemicals, which play active roles in disease prevention. We measured total phenolic and aglycone flavonoid (apigenin, kaempferol, luteolin, and quercetin) contents in leaves of organically- and conventionally-grown lettuce (`Kalura' and `Red Sails'), collards (`Top Bunch') and Pak Choi (`Mei Qing') greens during spring and summer trials, using the Folin assay and HPLC, respectively. Postharvest changes in phenolic contents of organic and conventional lettuce were also investigated after 17-day storage at 4 °C. Production system did not cause a significant difference in total phenolic levels of lettuce and collards in either trial, but total phenolics were significantly higher in organic Pak Choi in the summer trial, possibly due to greater flea beetle damage in the organic plots. Organic production did not affect the aglycone flavonoid levels of lettuce and collards in the spring trial except that apigenin increased in organic samples. In the summer trial, however, concentrations of kaempferol, luteolin and quercetin tended to increase in organic lettuce and collards; only luteolin showed promising increase in Pak Choi. Species and cultivars both had significant effects on total phenolic and flavonoid contents. After 17-day storage, total phenolic content significantly increased in both organic and conventional lettuce although the concentrations of aglycone flavonoids remained relatively constant. Total phenolic content was higher in organic `Red Sails' at a marginal significance level after storage, while it did not differ between organic and conventional `Kalura'. We noted a dominant presence of glycoside flavonoids in lettuce before and after storage, which warrants further study.

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Caporali, Sabrina, Alessandro De Stefano, Cinzia Calabrese, Alfredo Giovannelli, Massimo Pieri, Isabella Savini, Manfredi Tesauro, Sergio Bernardini, Marilena Minieri et Alessandro Terrinoni. « Anti-Inflammatory and Active Biological Properties of the Plant-Derived Bioactive Compounds Luteolin and Luteolin 7-Glucoside ». Nutrients 14, n^o 6 (9 mars 2022) : 1155. http://dx.doi.org/10.3390/nu14061155.

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Flavonoids are interesting molecules synthetized by plants. They can be found abundantly in seeds and fruits, determining the color, flavor, and other organoleptic characteristics, as well as contributing to important nutritional aspects. Beyond these characteristics, due to their biochemical properties and characteristics, they can be considered bioactive compounds. Several interesting studies have demonstrated their biological activity in different cellular and physiological processes in high-order organisms including humans. The flavonoid molecular structure confers the capability of reacting with and neutralizing reactive oxygen species (ROS), behaving as scavengers in all processes generating this class of molecules, such as UV irradiation, a process widely present in plant physiology. Importantly, the recent scientific literature has demonstrated that flavonoids, in human physiology, are active compounds acting not only as scavengers but also with the important role of counteracting the inflammation process. Among the wide variety of flavonoid molecules, significant results have been shown by investigating the role of the flavones luteolin and luteolin-7-O-glucoside (LUT-7G). For these compounds, experimental results demonstrated an interesting anti-inflammatory action, both in vitro and in vivo, in the interaction with JAK/STAT3, NF-κB, and other pathways described in this review. We also describe the effects in metabolic pathways connected with inflammation, such as cellular glycolysis, diabetes, lipid peroxidation, and effects in cancer cells. Moreover, the inhibition of inflammatory pathway in endothelial tissue, as well as the NLRP3 inflammasome assembly, demonstrates a key role in the progression of such phenomena. Since these micronutrient molecules can be obtained from food, their biochemical properties open new perspectives with respect to the long-term health status of healthy individuals, as well as their use as a coadjutant treatment in specific diseases.

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Kicel, Agnieszka, et Monika Anna Olszewska. « Evaluation of Antioxidant Activity, and Quantitative Estimation of Flavonoids, Saponins and Phenols in Crude Extract and Dry Fractions of Medicago lupulina Aerial Parts ». Natural Product Communications 10, n^o 3 (mars 2015) : 1934578X1501000. http://dx.doi.org/10.1177/1934578x1501000326.

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This study was designed to evaluate the flavonoid, saponin (TSC) and phenolic (TPC) contents and in vitro antioxidant activity of the crude (CME) and dry extracts and fractions of Medicago lupulina L. aerial parts. A validated RP-HPLC method led to quantitation of flavonols (kaempferol, quercetin and myricetin) and flavones (apigenin and luteolin) in the hydrolyzed extract. TSC and TPC were assayed spectrophotometrically at 560 and 760 nm, respectively. The antioxidant activity of the CME and the dry fractions were followed in vitro by DPPH free radical and ferric reducing antioxidant power (FRAP) methods. The flavonoid content of CME was 1.27 mg/g dw. The prevailing flavonoids were luteolin and myricetin, at concentrations of 0.37 and 0.36 mg/g dw, respectively. TSC and TPC were detected in CME at the level of 90.4 mg ESE/g dw, and 12.9 mg GAE/g dw, respectively. In the DPPH and FRAP tests, the CME exhibited antioxidant capacity with TEAA and FRAP values of 45.4 μmol Trolox®/g dw and 0.2 mmol Fe2+/g dw, respectively. The diethyl ether dry fraction was the most valuable one, showing the highest antioxidant activity (TEAA = 726.1 μmol Trolox®/g dw, FRAP = 2349.4 μmol Fe2+/g dw) that was in accordance with its high TPC (162.4 mg/g dw).

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Seelinger, Günter, Irmgard Merfort, Ute Wölfle et Christoph Schempp. « Anti-carcinogenic Effects of the Flavonoid Luteolin ». Molecules 13, n^o 10 (22 octobre 2008) : 2628–51. http://dx.doi.org/10.3390/molecules13102628.

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Lodhi, Santram. « Luteolin : A potential flavonoid for cancerous diseases ». Advance Pharmaceutical Journal 3, n^o 3 (août 2018) : 74–75. http://dx.doi.org/10.31024/apj.2018.3.3.1.

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Wang, Qian, Ji Zhang, Man Liu, Jian Yang, Xiang-ming Zhang, Lei Zhou, Lang Cao et Xia-li Liao. « Modified Syntheses of the Dietary Flavonoid Luteolin ». Journal of Chemical Research 39, n^o 9 (septembre 2015) : 550–52. http://dx.doi.org/10.3184/174751915x14404221529907.

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Papaliodis, D., W. Boucher, D. Kempuraj et T. C. Theoharides. « The flavonoid luteolin inhibits niacin-induced flush ». British Journal of Pharmacology 153, n^o 7 (avril 2008) : 1382–87. http://dx.doi.org/10.1038/sj.bjp.0707668.

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Zhang, Luyao, Yitong Cai, Lishuang Li, Chen Chen, Hanyu Zhao, Zehui Zhang, Yaochuan Liu, Yingyu Wang, Chunlian Tian et Mingchun Liu. « Effects of Luteolin on Biofilm of Trueperella pyogenes and Its Therapeutic Effect on Rat Endometritis ». International Journal of Molecular Sciences 23, n^o 22 (21 novembre 2022) : 14451. http://dx.doi.org/10.3390/ijms232214451.

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Trueperella pyogenes is an opportunistic pathogen that causes suppurative infections in animals. The development of new anti-biofilm drugs will improve the current treatment status for controlling T. pyogenes infections in the animal husbandry industry. Luteolin is a naturally derived flavonoid compound with antibacterial properties. In this study, the effects and the mechanism of luteolin on T. pyogenes biofilm were analyzed and explored. The MBIC and MBEC of luteolin on T. pyogenes were 156 μg/mL and 312 μg/mL, respectively. The anti-biofilm effects of luteolin were also observed by a confocal laser microscope and scanning electron microscope. The results indicated that 312 μg/mL of luteolin could disperse large pieces of biofilm into small clusters after 8 h of treatment. According to the real-time quantitative PCR detection results, luteolin could significantly inhibit the relative expression of the biofilm-associated genes luxS, plo, rbsB and lsrB. In addition, the in vivo anti-biofilm activity of luteolin against T. pyogenes was studied using a rat endometritis model established by glacial acetic acid stimulation and T. pyogenes intrauterine infusion. Our study showed that luteolin could significantly reduce the symptoms of rat endometritis. These data may provide new opinions on the clinical treatment of luteolin and other flavonoid compounds on T. pyogenes biofilm-associated infections.

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Lebot, V., F. Lawac, S. Michalet et L. Legendre. « Characterization of taro [Colocasia esculenta (L.) Schott] germplasm for improved flavonoid composition and content ». Plant Genetic Resources 15, n^o 3 (9 décembre 2015) : 260–68. http://dx.doi.org/10.1017/s1479262115000581.

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The starchy corms of taro (Colocasia esculenta) are consumed throughout the tropics and are essential for food security in many developing countries. Taro corms are increasingly processed into fries, chips, flours or flakes in urban areas, and varieties with attractive corm flesh colours are now needed. The identification of flavonoids in taro corms would add value to this crop. The present study developed a high-performance thin layer chromatography (HPTLC) protocol for the high-throughput screening of flavonoids in taro germplasm. Overall, 350 different accessions were analysed including 259 varieties from Vanuatu, one from Vietnam, eight from Thailand, eight from the Philippines, six from Malaysia, two from Japan and 18 from Indonesia. Forty-eight breeding lines (hybrids) including 21 from Vanuatu, 21 from Samoa, four from Hawaii and two from Papua New Guinea were also analysed. Ten flavones, namely luteolin-6-C-hexoside-8-C-pentoside, schaftoside, luteolin-3′,7-di-O-glucoside, homoorientin, isovitexin, orientin, luteolin-4′-O-glucoside, luteolin-7-O-glucoside, vitexin and apigenin-7-O-glucoside, were successfully detected in the corm and are responsible for the attractive yellow colour of the flesh and fibres. Quantitatively, luteolin-6-C-hexoside-8-C-pentoside and schaftoside were the most important of all the detected flavonoids. However, only 18% of the varieties analysed presented these two compounds and 80% presented poor flavonoid composition. No geographical structure of the variation was detected and the most flavone-rich varieties originated from Vanuatu, Thailand, the Philippines, Malaysia and Indonesia. The compounds detected in the present study were significantly and positively correlated, suggesting that there is potential for fast improvement through controlled crosses, subsequent evaluation of full-sib progenies and cloning of elite individuals.

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Vijayalakshmi, A., S. Jayakumari et K. Masilamani. « In-vitro antioxidant potential of the flavonoid glycosides from Cassia tora linn. Leaves ». International Journal of Engineering Technology and Sciences 3, n^o 1 (30 juin 2016) : 19–26. http://dx.doi.org/10.15282/ijets.5.2016.1.3.1042.

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The present study aimed to study the anti-oxidant potential of isolated flavonoids from the ethanol extract (70%v/v) of Cassia tora leaves. Three flavonoids were isolated viz Luteolin-7-O-β-glucopyranoside (I), quercetin-3-O-β-d-glucuronide (II) and Formononetin-7-O-β-D-Glucoside (III) from the ethanol extract (70%v/v) of Cassia tora leaves in the previous study. A comprehensive study on the phytochemical contents - total phenolic content and flavonoid content was accessed using Folin-Denis and AlCl3 method respectively. The antioxidant potential of the samples was evaluated using inhibition of hydroxyl radical, 2,2-diphenyl-1-picrylhydrazyl (DPPH), and nitric oxide scavenging methods. The total phenolic content and flavonoid content was found to be 18.60 % w/w and 9.5% w/w respectively. The IC50 values of ethanol extract against hydroxyl, DPPH and nitric oxide radical were found to be 270 µg/mL, 190 µg/mL and 130 µg/mL respectively. The radical scavenging activity of the isolated flavonoids decreased in the following order: quercetin (IC50 values 15, 14, 18 µg/mL) >formononetin (IC50 values 19, 21, 14 µg/mL) > luteolin (IC50 values 20, 23, 18 µg/mL) respectively.

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Liu, Chang, Jie Pan, Zhi-Gang Yin, Tingting Feng, Jiehong Zhao, Xiu Dong et Ying Zhou. « Integrated transcriptome and metabolome analyses revealed regulatory mechanisms of flavonoid biosynthesis in Radix Ardisia ». PeerJ 10 (29 juin 2022) : e13670. http://dx.doi.org/10.7717/peerj.13670.

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Background Radix Ardisia (Jab Bik Lik Jib) is a common Miao medicine and is widely distributed in the Guizhou region of southern China. The botanical origin of Radix Ardisia includes the dry root and rhizome of Ardisia Crenata Sims (ACS) or Ardisia Crispa (Thunb.) A.DC. (AC), which are closely related species morphologically. However, the secondary metabolites in their roots are different from one another, especially the flavonoids, and these differences have not been thoroughly explored at the molecular level. This project preliminarily identified regulatory molecular mechanisms in the biosynthetic pathways of the flavonoids between ACS and AC using a multi-omics association analysis. Methods In this study, we determined the total levels of saponin, flavonoid, and phenolic in Radix Ardisia from different origins. Integrated transcriptome and metabolome analyses were used to identify the differentially expressed genes (DEGs) and differentially expressed metabolites (DEM). We also performed conjoint analyses on DEGs and DEMs to ascertain the degree pathways, and explore the regulation of flavonoid biosynthesis. Results The total flavonoid and phenolic levels in ACS were significantly higher than in AC (P < 0.05). There were 17,685 DEGs between ACS vs. AC, 8,854 were upregulated and 8,831 were downregulated. Based on this, we continued to study the gene changes in the flavonoid biosynthesis pathway, and 100 DEGs involving flavonoid biosynthesis were differentially expressed in ACS and AC. We validated the accuracy of the RNA-seq data using qRT-PCR. Metabolomic analyses showed that 11 metabolites were involved in flavonoid biosynthesis including: Naringenin, Luteolin, Catechin, and Quercetin. A conjoint analysis of the genome-wide connection network revealed the differences in the types and levels of flavonoid compounds between ACS and AC. The correlation analysis showed that Naringenin, Luteolin, Catechin, and Quercetin were more likely to be key compounds in the flavonoid biosynthesis pathway also including 4CL, AOMT, CHS, CHI, DFR, F3’5’H, FLS, and LAR. Conclusions This study provides useful information for revealing the regulation of flavonoid biosynthesis and the regulatory relationship between metabolites and genes in the flavonoid biosynthesis pathway in Radix Ardisia from different origins.

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Myagchilov, Aleksey Viktorovich, Larisa Ivanovna Sokolova et Petr Grigor'yevich Gorovoy. « FLAVONOIDS OF THE EAST ASIAN SPECIES SERRATULA MANSHURICA KITAG. » chemistry of plant raw material, n^o 1 (16 mars 2021) : 167–73. http://dx.doi.org/10.14258/jcprm.2021018269.

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One of the poorly studied and widespread plants in the Russian Far East is the Manchurian saw-wort (Serratula manshurica Kitag.). It is known that this plant is rich in phytoecdysteroids, which have high biological activity (anabolic, adaptogenic, cardiotropic, immunomodulatory effects). Two biologically active compounds of the flavonoid class were isolated from the aerial part of Serratula manshurica Kitag. Growing in the Primorsky Kray of the Far East of Russia by liquid extraction and recrystallization methods: quercetin-4'-O-β-D-glucuronopyranoside and apigenin-7-O-β-D-glucuronopyranoside. The structure of the isolated compounds was proved by UV-, NMR-spectroscopy and mass spectrometry with electrospray ionization. The quantitative content of flavonoids in the aerial part of the Serratula manshurica plant in different phenological phases of plant development (luteolin-4'-O-β-D-glucuronopyranoside, quercetin-4'-O-β-D-glucuronopyranoside, apigenin-7-O-β-D-glucuronopyranoside, 3-methylquercetin-4'-O-β-D-glucuronopyranoside, quercetin, apigenin, 3-methylquercetin, luteolin, isokaempferide) was determined by the method of reversed phase liquid chromatography (RP HPLC). It was shown that the maximum content of flavonoid aglycones in plants was observed during the beginning of the growing season and in the budding phase, and their glycosides - during the flowering phase. Thus, to obtain plant material with the maximum content of flavonoid aglycones (quercetin, 3-methylquercetin, luteolin) the collection of vegetative mass should be carried out during the beginning of the growing season, and their glycosides - during the flowering period. Serratula manshurica Kitag., which grows abundantly on the territory of Primorsky Krai, can be considered a constantly renewable and promising source for obtaining flavonoids.

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Sangeetha, R. « Luteolin in the Management of Type 2 Diabetes Mellitus ». Current Research in Nutrition and Food Science Journal 7, n^o 2 (12 juin 2019) : 393–98. http://dx.doi.org/10.12944/crnfsj.7.2.09.

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Diabetes is an increasing pandemic and several million people are affectedbythis disease worldwide. The treatment of diabetes includes lifestyle modifications, oral antidiabetic drugs and insulin. The chronic use of oral antidiabetic drugs produces undesirable side effects. Hence safe alternative medicines are always sought after. Plant phytochemicals are the best alternatives as they possess a wide spectrum of pharmacological activities. Flavonoids are an important class of phytocomponent which is commonly present in fruits and vegetables. Luteolin belongs toflavone class of flavonoid which has multiple health benefitslike antioxidant, antidiabetic,anti-inflammatory and anti-cancer properties. Luteolin mediates several pharmacological actions of which the role of luteolin in the treatment of diabetes is well studied. In thisreview, the use of flavonoids as antidiabetic agents is discussed, with special reference to luteolin.Luteolin mediates its anti-diabetic potential by maintaining blood glucose levels and improving the sensitivity of body cells to insulin and these mode of actions have been discussed here.

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Castano-Duque, Lina, Matthew D. Lebar, Carol Carter-Wientjes, David Ambrogio et Kanniah Rajasekaran. « Flavonoids Modulate Aspergillus flavus Proliferation and Aflatoxin Production ». Journal of Fungi 8, n^o 11 (16 novembre 2022) : 1211. http://dx.doi.org/10.3390/jof8111211.

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Aflatoxins are carcinogenic mycotoxins produced by Aspergillus flavus. They contaminate major food crops, particularly corn, and pose a worldwide health concern. Flavonoid production has been correlated to resistance to aflatoxin accumulation in corn. The effects of flavonoids on fungal proliferation and aflatoxin production are not well understood. In this study, we performed bioassays, fluorescence and scanning electron microscopy, and total antioxidant analysis to determine the effects of three flavonoids (apigenin, luteolin, and quercetin) on proliferation and aflatoxin production in A. flavus NRRL 3357. Results showed that concentrations of apigenin and luteolin modulated fungal proliferation and aflatoxin production in a dose-dependent manner, leading to inhibition or promotion of proliferation and toxin production. Microscopy studies of fungi exposed to flavonoids showed mycelial cell wall disruption, abnormal cell wall invaginations, and tears. Fluorescent enhancement of apigenin and luteolin using Naturstoff reagent A showed that these chemicals localized in sphere-like structures on the mycelia surface. Fungi exposed to low concentrations of apigenin, luteolin, and quercetin lowered the total antioxidant capacity in the environment compared to controls. Our results indicate that flavonoids disrupt cell wall integrity and may localize in vesicle-like structures. We hypothesize that flavonoids could act as potential signaling molecules at low concentrations and change the oxidative state of the microenvironment, either or both of which may lead to reduction of fungal proliferation and aflatoxin production.

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Abidin, Lubna, Mohammad Mujeeb et Showkat R. Mir. « Maximized Extraction of Flavonoid Luteolin from V.negundo L. Leaves : Optimization Using Box-Behnken Design ». Current Bioactive Compounds 15, n^o 3 (7 mai 2019) : 343–50. http://dx.doi.org/10.2174/1573407214666180731120014.

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Background: Luteolin is a flavonoid unveiling various therapeutic activities, found in Vitex negundo L. Thus, there is a need to present process parameters at which maximum amount of luteolin can be extracted from V. negundo L. leaves in “one-run”. Objective: Response surface methodology (RSM) was employed for optimizing the process parameters for the extraction of luteolin from V. negundo L. leaves. The study also compared the efficacy of various traditional and modern extraction methods for luteolin extraction. Methods: Extraction conditions (solvent to drug ratio, extraction temperature and extraction time) were optimized by RSM, Box-Behnken Design (BBD). Quantification of luteolin in various extracts was done through High Performance Liquid Chromatography (HPLC). Results: Hot solvent extraction by reflux technique stood out to be the best technique and methanol was found to be the most effective solvent for luteolin extraction.Through the use of BBD, the optimal conditions for luteolin extraction were established as: solvent to drug ratio- 17.7 mL/g, extraction temperature- 55.5°C and extraction time-2.04 hours. Under such conditions 7.32 %w/w of luteolin was yielded which was close to predicted value of 7.29 %w/w. Conclusion: Reflux technique stood out to be the best among all the studied modes of extraction and methanol proved to be the most effective solvent. Moreover, all the three variables significantly affected the luteolin extraction. Our study shows the applicability of a statistical technique, RSM in phytocompound extraction field. This makes the optimization technique cheap and less laborious than the traditional optimization method.

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Kaluzhskiy, Leonid, Pavel Ershov, Evgeniy Yablokov, Tatsiana Shkel, Irina Grabovec, Yuri Mezentsev, Oksana Gnedenko et al. « Human Lanosterol 14-Alpha Demethylase (CYP51A1) Is a Putative Target for Natural Flavonoid Luteolin 7,3′-Disulfate ». Molecules 26, n^o 8 (13 avril 2021) : 2237. http://dx.doi.org/10.3390/molecules26082237.

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Widespread pathologies such as atherosclerosis, metabolic syndrome and cancer are associated with dysregulation of sterol biosynthesis and metabolism. Cholesterol modulates the signaling pathways of neoplastic transformation and tumor progression. Lanosterol 14-alpha demethylase (cytochrome P450(51), CYP51A1) catalyzes one of the key steps in cholesterol biosynthesis. The fairly low somatic mutation frequency of CYP51A1, its druggability, as well as the possibility of interfering with cholesterol metabolism in cancer cells collectively suggest the clinical importance of CYP51A1. Here, we show that the natural flavonoid, luteolin 7,3′-disulfate, inhibits CYP51A1 activity. We also screened baicalein and luteolin, known to have antitumor activities and low toxicity, for their ability to interact with CYP51A1. The Kd values were estimated using both a surface plasmon resonance optical biosensor and spectral titration assays. Unexpectedly, in the enzymatic activity assays, only the water-soluble form of luteolin—luteolin 7,3′-disulfate—showed the ability to potently inhibit CYP51A1. Based on molecular docking, luteolin 7,3′-disulfate binding suggests blocking of the substrate access channel. However, an alternative site on the proximal surface where the redox partner binds cannot be excluded. Overall, flavonoids have the potential to inhibit the activity of human CYP51A1 and should be further explored for their cholesterol-lowering and anti-cancer activity.

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Wollenweber, Eckhard, Marion Dörr, Matthias Beyer, James N. Roitman et Christopher F. Puttoek. « Rare Flavonoids from Odixia and Ozothamnus spp. (Asteraceae, Gnaphalieae) ». Zeitschrift für Naturforschung C 52, n^o 9-10 (1 octobre 1997) : 571–76. http://dx.doi.org/10.1515/znc-1997-9-1003.

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Representatives of the genera Odixia and Ozothamnus, Australian Asteraceae belonging to the tribe Gnaphalieae, have been analyzed for the presence of flavonoid aglycones accumulated on leaf and stem surfaces. Fiftytwo more or less lipophilic flavonoids have been identified. Methyl ethers of apigenin, luteolin, kaempferol and quercetin are abundant, while rare methyl ethers of isoscutellarein, 8-hydroxy galangin, herbacetin and gossypetin appear to be characteristic. The distribution of rare flavonoids is discussed

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& et al., Abbas. « EVALUATION OF MYRTUS COMMUNIS FLAVONOID AS ANTIDER-MATOPHTIC AND KERATINASE INHIBITIOR ». IRAQI JOURNAL OF AGRICULTURAL SCIENCES 51, n^o 6 (23 décembre 2020) : 1525–33. http://dx.doi.org/10.36103/ijas.v51i6.1180.

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This study was applied for extraction flavonoid compounds from Myrtus communis (aerial part)and detection of its effectiveness on growth of one of dermatiphytic isolates and keratinase activity, Trichophyton mentagrophytes was the most common isolates which was obtained with frequency (66%), the identification and quantitation of flavonoids was carried out by thin layer and high performance liquid chromatography. The results showed that each 100 g of aerial part of the plant contained 850 mg total flavonoids as rutin).The HPLC chromatogram for M. communis flavonoid extract revealed that, M. communis flavonoid extract contained Rutin, Quercetin, Apigenin, Kaempferol, Luteolin . The inhibitory effect of flavonoid against Trichophyton mentagrophytes and keratinase activity was evaluted. The higher effect was observed at concentration 10 mg/ml against fungal isolate .The minimum inhibiter concentration was at 3mg/ml while the higher inhibition of keratinase activity was obtained at concentration 5mg/ml with 25% remaining enzyme activity.

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Hurtová, Martina, David Biedermann, Zuzana Osifová, Josef Cvačka, Kateřina Valentová et Vladimír Křen. « Preparation of Synthetic and Natural Derivatives of Flavonoids Using Suzuki–Miyaura Cross-Coupling Reaction ». Molecules 27, n^o 3 (31 janvier 2022) : 967. http://dx.doi.org/10.3390/molecules27030967.

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Herein, we report the use of the Suzuki–Miyaura cross-coupling reaction for the preparation of a library of synthetic derivatives of flavonoids for biological activity assays. We have investigated the reactivity of halogenated flavonoids with aryl boronates and with boronyl flavonoids. This reaction was used to prepare new synthetic derivatives of flavonoids substituted at C-8 with aryl, heteroaryl, alkyl, and boronate substituents. The formation of flavonoid boronate enabled a cross-coupling reaction with halogenated flavones yielding biflavonoids connected at C-8. This method was used for the preparation of natural compounds including C-8 prenylated compounds, such as sinoflavonoid NB. Flavonoid boronates were used for the preparation of rare C-8 hydroxyflavonoids (natural flavonoids gossypetin and hypolaetin). A series of previously unknown derivatives of quercetin and luteolin were prepared and fully characterized.

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Ojong, Peter B., Victor Njiti, Zibao Guo, Ming Gao, Samuel Besong et Sandra L. Barnes. « Variation of Flavonoid Content Among Sweetpotato Accessions ». Journal of the American Society for Horticultural Science 133, n^o 6 (novembre 2008) : 819–24. http://dx.doi.org/10.21273/jashs.133.6.819.

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The objective of this study was to characterize and quantify five commonly occurring flavonoids (quercetin, luteolin, apigenin, myricetin, and kaempferol) in storage roots and leaves of 10 sweetpotato [Ipomoea batatas L. (Lam.)] accessions: SC1149, ‘Excel’, ‘Vardaman’, ‘Hernandez’, ‘Picadito’, ‘Porto Rico’, ‘GA90-16’, PI531116, NC98-608 (Covington), and ‘Beauregard’ (B94-14-G2). The flavonoids were present in varying amounts (quercetin comprised greater than 79% and 55% of the mean flavonoid content in sweetpotato leaf and root samples, respectively) and were found to be more concentrated in the leaves (0.65% to 2.76% dry weight) than in the storage roots (0.27% to 1.69% dry weight). The results indicate significant variability in flavonoid content among different sweetpotato accessions, suggesting that there is the potential for genetic manipulation of sweetpotato to influence flavonoid content and profile through traditional breeding or biotechnological approaches.

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Adiji, Olubu A., Maite L. Docampo-Palacios, Anislay Alvarez-Hernandez, Giulio M. Pasinetti, Xiaoqiang Wang et Richard A. Dixon. « UGT84F9 is the major flavonoid UDP-glucuronosyltransferase in Medicago truncatula ». Plant Physiology 185, n^o 4 (28 janvier 2021) : 1617–37. http://dx.doi.org/10.1093/plphys/kiab016.

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Abstract Mammalian phase II metabolism of dietary plant flavonoid compounds generally involves substitution with glucuronic acid. In contrast, flavonoids mainly exist as glucose conjugates in plants, and few plant UDP-glucuronosyltransferase enzymes have been identified to date. In the model legume Medicago truncatula, the major flavonoid compounds in the aerial parts of the plant are glucuronides of the flavones apigenin and luteolin. Here we show that the M. truncatula glycosyltransferase UGT84F9 is a bi-functional glucosyl/glucuronosyl transferase in vitro, with activity against a wide range of flavonoid acceptor molecules including flavones. However, analysis of metabolite profiles in leaves and roots of M. truncatula ugt84f9 loss of function mutants revealed that the enzyme is essential for formation of flavonoid glucuronides, but not most flavonoid glucosides, in planta. We discuss the use of plant UGATs for the semi-synthesis of flavonoid phase II metabolites for clinical studies.

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Jang, Chan, Nayoung Moon, Jisun Oh et Jong-Sang Kim. « Luteolin Shifts Oxaliplatin-Induced Cell Cycle Arrest at G0/G1 to Apoptosis in HCT116 Human Colorectal Carcinoma Cells ». Nutrients 11, n^o 4 (2 avril 2019) : 770. http://dx.doi.org/10.3390/nu11040770.

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Certain antioxidative flavonoids are known to activate nuclear factor E2-related factor 2 (Nrf2), a transcription factor that regulates cellular antioxidants and detoxifying response and is reportedly highly activated in many types of cancers. Few studies on the potential undesired effects of flavonoid intake during chemotherapy have been conducted, yet Nrf2 activators could favor cancer cell survival by attenuating chemotherapeutic efficiency. This study aimed to examine if luteolin, an Nrf2 activator, hinders chemotherapeutic activity of oxaliplatin, a potent anticancer agent for colorectal cancer, in HCT116 cells. Luteolin treatment strongly increased the transcriptional activity of the antioxidant response element in HCT116 cells and induced the protein expression of heme oxygenase-1, which were indicative of its Nrf2-inducing potential. Intriguingly, 25 μM luteolin reduced cell viability through apoptotic induction, which was intensified in p53-expressing cells while 1 μM oxaliplatin caused cell cycle arrest at G0/G1-phase via the p53/p21-dependent mechanism. Moreover, luteolin treatment was found to reduce oxaliplatin-treated p53-null cell viability and colony counts further, thereby demonstrating an additional effect of luteolin in the killing of human colorectal tumor HCT116 cells not expressing functional p53 protein. The findings suggest that luteolin can induce p53-mediated apoptosis regardless of oxaliplatin treatment and may eliminate oxaliplatin-resistant p53-null colorectal cells.

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