Topic
Isovitexin
About: Isovitexin is a research topic. Over the lifetime, 526 publications have been published within this topic receiving 11525 citations. The topic is also known as: 6-Glucosylapigenin & Isovitexin.
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TL;DR: This study provided a new bacterial resource for the cleavage of C-glycosidic bond of flavone C- glycosides and reported the carbon nutrition sources reduction induced deglycosylation for the first time.
Abstract: Flavone C-glycosides are difficult to be deglycosylated using traditional chemical methods due to their solid carbon–carbon bond between sugar moieties and aglycones; however, some bacteria may easily cleave this bond because they generate various specific enzymes. A bacterial strain, named W12-1, capable of deglycosylating orientin, vitexin, and isovitexin to their aglycones, was isolated from human intestinal bacteria in this study and identified as Enterococcus faecalis based on morphological examination, physiological and biochemical identification, and 16S rDNA sequencing. The strain was shown to preferentially deglycosylate the flavone C-glycosides on condition that the culture medium was short of carbon nutrition sources such as glucose and starch, and its deglycosylation efficiency was negatively correlated with the content of the latter two substances. This study provided a new bacterial resource for the cleavage of C-glycosidic bond of flavone C-glycosides and reported the carbon nutrition sources reduction induced deglycosylation for the first time.
14 citations
TL;DR: Results support the competition model previously proposed to explain the dominance relationship between gG and gX, which was based on the assumptions that both the xylosyl- and the glucosyltransferase work at saturating isovitexin concentration.
Abstract: In a hybrid swarm of Melandrium dioicum and Melandrium album, a plant was found in which the genes gG and gX, controlling an isovitexin 7-O-glucosyltransferase, respectively an isovitexin 7-O-xylosyltransferase, were co-dominant. In earlier experiments, gene gG was always dominant over its allele gX. Genetical and biochemical analysis revealed that this co-dominance was caused by an allele of gX, further designated gX′. Comparison of the enzyme-kinetic properties of the gX′ controlled xylosyltransferase with the gX controlled xylosyltransferase revealed no difference in substrate affinity for UDP-xylose nor for isovitexin. However, the maximal activity of the gX′ controlled transferase was 8+9 times higher than the gX controlled activity. These results support the competition model previously proposed to explain the dominance relationship between gG and gX. This model was based on the assumptions that 1) both the xylosyl- and the glucosyltransferase work at saturating isovitexin concentration and that 2) the lower Vmax of the xylosyltransferase, makes this enzyme a poorer competitor for isovitexin than the glucosyltransferase.
14 citations
TL;DR: In a leaf flavonoid survey of 15 Brazilian orchid species from the subtribe Ornithocephalinae, flavone C-glycosides were found to be the major constituents in all except two OrnithOcephalus taxa, which could be distinguished from all the other taxa studied by the absence of methylated C- glycosylflavones and presence of isovitexin.
13 citations
TL;DR: The antioxidant activity results showed that quercetin, kaemferol, and rutin displayed excellent antioxidant activity in the DPPH radical scavenging test, and their IC50 value was calculated as 5.60, 16.85 and 32.85 µg/mL, respectively.
Abstract: The purpose of this study was to investigate the major flavonoids content and bioactivities of Tartary buckwheat sprouts. The crude methanol extract (ME) of Tartary buckwheat sprouts was abundant in flavonoids, and six major flavonoids, including isoorientin, vitexin, isovitexin, rutin, quercetin, and kaemferol were successfully determined from the sprouts by the high-performance liquid chromatography (HPLC) method. Generally, the flavonoid content of buckwheat sprouts was in the order of rutin > quercetin > isovitexin > vitexin> isoorientin > kaemferol. The highest rutin content of the ME and sprout cultures was 89.81 mg/g and 31.50 mg/g, respectively. Antibacterial activity results indicated the ME displayed notable inhibitory activity against the five tested bacteria, and its minimum inhibitory concentration (MIC) values ranged from 0.8 mg/mL to 3.2 mg/mL. Among the six flavonoids, quercetin was the most active compound, which exhibited strong activity against all tested bacteria except for E. coli and S. epidermidis, with its MIC values ranging from 0.2 mg/mL to 0.4 mg/mL. For the antifungal activity assay, the ME of Tartary buckwheat sprouts and four flavonoids could significantly inhibit the spore germination of two pathogenic fungi, and their inhibitory efficiency was concentration dependent. Quercetin was the most active one, which significantly inhibited the spore germination of F. oxysporum f. sp. vasinfectum and F. oxysporum f. sp. cucumerinum, and its median effective inhibitory concentration (IC50) value was 42.36 and 32.85 µg/mL, respectively. The antioxidant activity results showed that quercetin, kaemferol, and rutin displayed excellent antioxidant activity in the DPPH radical scavenging test, and their IC50 value was calculated as 5.60, 16.23, and 27.95 µg/mL, respectively. This is the first report on the antimicrobial activity of the crude extract of Tartary buckwheat sprouts. These results indicated that the methanol extract of Tartary buckwheat sprouts could be used as a potential antimicrobial or antioxidant agent in the future.
13 citations
TL;DR: In this article, phenylalanine-1-14 C-labeled vitexin (I) and isovitexins (II) were obtained from Spirodela species cultured on a medium containing phenYLalanine 1- 14 C, and were introduced in separate experiments into the growth media for Lemna minor plants, a species which normally produces both of these C -glycosylflavones.
13 citations