Academic literature on the topic 'Apigenin di-C-glycoside'

Anthocyanins and other flavonoids were isolated from the flowers of eleven Centaurea species, C. macrocephala, C. rupestotilis and C. suaveolens, which produce yellow flowers, and C. achtarovii, C. dealbata, C. montana, C. nigra, C. scabiosa, C. simplicicaulis, C. hypoleuca and C. triumfetti, which have cyanic flowers. Four anthocyanins, cyanidin 3,5-di- O-glucoside, cyanidin 3- O-(6″-malonylglucoside)-5- O-glucoside, cyanidin 3- O-(6″-succinylglucoside)-5- O-glucoside and cyanidin glycoside, were detected in the cyanic flowers of seven Centaurea species. Of these anthocyanins, the first two were found as major anthocyanins. In the cyanic species, four other flavonoids, apigenin 7- O-glucuronide-4′- O-glucoside, malonylated apigenin 7,4′-di- O-glucoside, apigenin 7- O-glucuronide and kaempferol glycoside, were also isolated. On the other hand, nine flavonols and four flavones were isolated from the three yellow-flowered species, and identified as quercetagetin, quercetagetin 7- O-glucoside, quercetagetin 3′-methyl ether 7- O-glucoside, patuletin, patuletin 7- O-glucoside, quercetin 7- O-glucoside, kaempferol 3-methyl ether, kaempferol 3-methyl ether 4′- O-glucuronide and isorhamnetin 3- O-galactoside, and apigenin, apigenin 7- O-glucuronide, luteolin 7- O-glucoside and apigenin 6,8-di- C-glucoside (vicenin-2). Of these flavonoids, the former five flavonols are “yellow flavonols”, and it was shown that their flower colors are due to these compounds.

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.

Abstract Objectives This study was carried out to evaluate the effects of flavonoids present in leaves of Passiflora edulis fruit on complications induced by diabetes in rats. Methods The extract of P. edulis leaf was obtained by 70% ethanol maceration. From the dry extract, the fractions were obtained by consecutive liquid–liquid partition with hexane, ethyl acetate and n-butanol. The content of isoorientin of ethyl acetate and n-butanol fractions was determined by ultra-performance liquid chromatography coupled with electrospray and triple quadrupole ionization (TQD) analysis in tandem mass spectrometry (UPLC–ESI-Tq-MS). Only Fr-BuOH was used to treat diabetic or not Wistar rats. Biochemical parameters, platelet aggregation and production of reactive species were evaluated. Key findings The UPLC–ESI-Tq-MS analysis revealed the presence of several flavonoids, among which we identified five possible flavonoids c-heterosides (luteolin-7-O-pyranosyl-3-O-glucoside, apigenin-6-8-di-C-glycoside, apigenin-6-C-arabinoside-8-C-glycoside, isoorientin, isovitexin). The diabetic rats (treated intraperitoneally with alloxan, 150 mg/kg) treated with Fr-BuOH (20 mg/kg/day for 90 days) presented improvement in blood glucose, serum levels of fructosamine, lipid profile and urea. Furthermore, the Fr-BuOH reduced both platelet aggregation and the production of oxidant species in diabetic animals. Conclusions These results suggested that flavonoid C-glycosides present in the Fr-BuOH may be beneficial for the diabetic state, preventing complications induced by diabetes.

One of the plants used in Indonesian traditional medicine, namely, Patiwala (Lantana camara), is traditionally used to treat some diseases, including itching, wounds, ulcers, swelling, eczema, tetanus, malaria, tumors, rheumatism, and headaches. This study aimed to characterize the compound nonpolar fraction of Patiwala leaf capable of scavenging free radicals. The characterization of compound was carried out using the Ultra-Performance Liquid Chromatography–tandem Mass Spectrometry (UPLC-MS/MS) with positive ion method, while the antioxidant testing was carried out using the radical DPPH (2,2-diphenyl-1-picrylhidrazyl) and FRAP (ferric reducing antioxidant power) methods. The results showed that the nonpolar fraction of the methanol extract of L. camara leaves was very strong toward DPPH radicals (IC50 34.65 ± 1.26 μg/mL and 40.23 ± 0.18 μg/mL), and FRAP radical (IC50 4.93 ± 0.22 μg/mL and 12.79 ± 0.09 μg/mL). Nineteen compounds identified by UPLC-MS/MS method were Resveratrol dimer, iso-humolones, oleuropein glucoside, quercetin-3-O-glycoside, myricetin, oleuropein, 12-deoxy-16-hydroxy-phorbol, aloeresin A, humulones, ursolic acid, viniferin, Epicatechin, oleanolic acid, 5-hydroxy-3′,4′,7-trimerthoxy-flavanone, Apigenin-6,8-di-C-β-D-glucoside, procyanidin A2, caffeoyl-O-hexoside, tansihnone IIA, and phillyrin. The methanolic extract of L. camara leaves can be developed as a source of antioxidants from natural ingredients.

Background: Diabetes mellitus is the most common disease in Egypt. In this context, Beta vulgaris subspecies cicla L. var. flavescens is an edible plant that has been used in traditional medicine as a therapy for treating some diseases. Objective: The current study was performed to evaluate the antibacterial and potential anti-diabetic activities of different extracts and isolated flavone C-glycoside compounds isolated from Beta vulgaris subspecies cicla L. var. flavescens leaves. Methods: Phytochemical investigation of n-butanol extract led to the isolation of five phytoconstituents. Their structures were determined by spectroscopic tools, including 1D-NMR (1H- & 13C-NMR) and 2D-NMR (HMQC & HMBC) besides the comparison of the data with the literature. The extracts and phytoconstituents were evaluated in vitro for their activity against some bacterial pathogens, which represent prominent human pathogens, particularly in hospital settings. The antibacterial activity was examined against three Gram-positive bacterial strains (Staphylococcus aureus, Staphylococcus epidermidis & Enterococcus faecalis) and five Gram-negative ones (Pseudomonas aeruginosa, Proteus vulgaris, Klebsiella pneumoniae, Proteus mirabilis & Salmonella typhimurium) relative to Ciprofloxacin as a reference drug. Furthermore, the in vitro antidiabetic activity (Type II) was evaluated using the alpha-glucosidase inhibitory assay. Results: Five flavone C-glycosides namely; Apigenin 8-C-β-D-glucopyranoside (vitexin) (1), 2''-Oxylopyranosylvitexin (2), acacetin 8-C-β-D-glucopyranoside (3), acacetin 8-C-α-L-rhamnoside (4), and 6,8-di-C-β-D-glucopyranosylapigenin (vecinin-II) (5) were isolated from n-butanol extract of B. vulgaris subspecies cicla L. var. flavescens. Compound 1 showed a promising antibacterial activity against most of the test bacterial strains with respect to the minimum inhibitory concentration values (MIC) ranged from 1.95 to 15.63 µg ml-1. On the other hand, compounds 1 and 3 demonstrated superior antidiabetic activities with IC50 values of 35.7 and 42.64 µg ml-1, respectively, while an inferior potential antidiabetic activity was recorded for compound 4 (IC50 = 145.5 µg ml-1) in comparison with Acarbose as a reference drug. Conclusion: B. vulgaris L. is an edible plant, which could be used as a natural source of antibiotic and hypoglycemic drugs.

AbstractFlavone C-arabinosides/xylosides are plant-originated glycoconjugates with various bioactivities. However, the potential utility of these molecules is hindered by their low abundance in nature. Engineering biosynthesis pathway in heterologous bacterial chassis provides a sustainable source of these C-glycosides. We previously reported bifunctional C-glucosyl/C-arabinosyltransferases in Oryza sativa japonica and O. sativa indica, which influence the C-glycoside spectrum in different rice varieties. In this study, we proved the C-arabinosyl-transferring activity of rice C-glycosyltransferases (CGTs) on the mono-C-glucoside substrate nothofagin, followed by taking advantage of specific CGTs and introducing heterologous UDP-pentose supply, to realize the production of eight different C-arabinosides/xylosides in recombinant E. coli. Fed-batch fermentation and precursor supplement maximized the titer of rice-originated C-arabinosides to 20–110 mg/L in an E. coli chassis. The optimized final titer of schaftoside and apigenin di-C-arabinoside reached 19.87 and 113.16 mg/L, respectively. We demonstrate here the success of de novo bio-production of C-arabinosylated and C-xylosylated flavones by heterologous pathway reconstitution. These results lay a foundation for further optimal manufacture of complex flavonoid compounds in microbial cell factories.

Colour is an important determinant of quality and customer appeal for Asian noodles that are made from bread wheat (Triticum aestivum L.). The Asian noodle market represents approximately one third of wheat exports from Australia and as a consequence maintaining and improving colour for noodles is an important research and breeding objective. The focus of this project is yellow alkaline noodles (YAN) prepared using wheat flour and alkaline salts, sodium and potassium carbonate, and for which a bright yellow colour is desired. Xanthophylls, primarily lutein, and apigenin di-Cglycosides (ACGs) have been shown to be important components of this yellow colour. ACGs were of particular interest since, in contrast to lutein, the content in flour could be increased without adverse effects on colour of other end-products. There was little information either on the genetic variation for ACG content or the mechanism and genetic control of biosynthesis which was surprising in view of their putative role in a wide range of plant processes, food colour and flavour, and possibly human health. The aims of this project were to provide new information on the role of ACGs in YAN colour and genetic regulation of their biosynthesis. To achieve this aims: genetic variation in grain ACG traits in bread wheat and related species was surveyed, the quantitative contribution of ACG to the yellow colour of YAN was determined and compared to lutein, QTL for ACG content and composition were located, and candidate genes associated with variation in ACG composition identified. Substantial variation in both grain ACG content and the ratio, ACG1/ACG2, were identified within bread wheat cultivars and related species. Genotype controlled the major portion of the variation. ACG content appeared to be a multigenic trait whereas variation in ACG1/ACG2 was associated with a limited number of chromosomes, in particular chromosomes 1B, 7B and 7D. In the absence of chromosome 7B (Chinese Spring 7B nullisomics) there was a substantial increase in ACG1/ACG2, i.e. a relative increase in the glucose-containing isomer, possibly indicating the presence of a Cglycosyltransferase on 7B with specificity for UDP-galactose. A similar phenotype observed in some wheat cultivars could be explained by a deletion or mutation of a gene controlling this enzyme. The results suggest that it should be possible to manipulate both ACG content and composition through breeding. Only 30% of ACG (means 19.3 µg/g) is recovered in flour, which contributed to 1 to 3 CIE b* units to the part of the yellow colour of yellow alkaline noodles (YAN) that develops specifically in the presence of alkali. The relatively low recovery of ACG in flour contrasts with the high recovery of lutein (90%, with means 1.011 µg/g). Since the difference between white salted noodles (WSN) and YAN is approximately 6 b* units, this would indicate that another unidentified compound(s) is responsible for the difference. Potential for ACG0-based improvement of bread wheat cultivars for YAN yellowness is likely to be limited by the range of genetic variation, the location of ACG in grain tissues that are largely discarded during milling and the lack of correlation between grain and flour ACG content. Moreover, the observed variation in ACG recovery in small scale milling was not reflected in larger scale milling anticipated to better represent commercial practice. The improvement in flour recovery and the amount of ACG recovered in the flour were not significant and not enough to achieve the yellowness of commercial noodles. Selection that requires larger scale milling is costly, time consuming and not applicable to early generation screening. In this context, further work on QTL associated with variation in ACG content and development of marker-assisted-selection would be very useful. Addition of thirteen new markers to the QTL region for ACG trait on chromosome 7BS in a Sunco/Tasman doubled haploid population reduced the size of the QTL interval from 28.8cM to approximately 5.5cM. In this revised 7BS map, the major QTL for ACG1 and ACG2 content as well as ACG1/ACG2 ratio were detected within 4.7cM of SSR marker Xwmc76. The QTL region linked to Xwmc76 was shown to be syntenic with a region in rice chromosome 6S between AP005387 and AP005761 and a region on Brachypodium chromosome 1. Based on these comparisons, the most likely candidate gene associated with variation in ACG composition appeared to be a glycosyltransferase. Alternate alleles at the 7BS QTL may be associated with amino acid changes within the C glycosyltransferase that shift the substrate specificity from galactose (ACG2, Tasman) to glucose (ACG1, Sunco). Alternatively, based on a comparison of Chinese Spring nullisomic-tetrasomic lines where nullisomic 7B was associated with a phenotype similar to Sunco, it is possible that Sunco contains a null allele. Other candidate genes located on the same chromosome that could potentially be involved in ACG biosynthesis were identified and included a sugar transporter, which could determine the relative sizes of the available pools of UDP-glucose and UDPgalactose, an epimerase required for inter-conversion of these sugars, other glycosyltransferases and a flavone-2-hydroxylase (F2H) involved in the first committed step in the pathway to ACG. Research approaches that could be used to validate the role of the candidate gene are discussed along with other options for improving the colour of wheat cultivars for the YAN market. Options for utilizing ACG as yellow pigment of noodles might include incorporating the embryo or seed coat materials (pollard and bran) into the flour after milling and genetic modification of bread wheat to achieve ACG expression in the starchy endosperm.
Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2012