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: The results suggest that suppression of ROS‐mediated COX‐2 expression by isovitexin is beneficial in reducing inflammation and carcinogenesis.
Abstract: Isovitexin, isolated from rice hull of Oryza sativa, has been characterized as a potent antioxidant. Its antioxidant activity, determined on the basis of inhibition of lipid peroxidation by the Fenton reaction, was comparable with that of alpha-tocopherol, a well-established antioxidant. Isovitexin was able to reduce the amount of hydrogen peroxide production induced by lipopolysaccharide (LPS) in mouse macrophage RAW264.7 cells. In this study, we assessed its effects on the production of tumor necrosis factor alpha (TNF-alpha), prostaglandin E2 (PGE2), and the expression of cyclooxygenase-2 (COX-2) in LPS-activated RAW 264.7 macrophages. Isovitexin inhibited the release of TNF-alpha, a proinflammatory cytokine, upon LPS activation with a 50% inhibitory concentration (IC50) of 78.6 microM. Isovitexin markedly reduced LPS-stimulated PGE2 production in a concentration-dependent manner, with an IC50 of 80.0 microM. The expression of COX-2 was also inhibited by isovitexin treatment. Our results suggest that suppression of ROS-mediated COX-2 expression by isovitexin is beneficial in reducing inflammation and carcinogenesis.
44 citations
TL;DR: Results suggest that flavonoid derivatives from Colocasia esculenta (L.) Schott represent potential compounds for the prevention and/or treatment of diabetic complications.
Abstract: The goal of this study was to determine the rat lens aldose reductase-inhibitory effects of 95% ethanol extracts from the leaves of C. esculenta and, its organic solvent soluble fractions, including the dichloromethane (CH2Cl2), ethyl acetate (EtOAc), n-butanol (BuOH) and water (H2O) layers, using dl-glyceraldehyde as a substrate. Ten compounds, namely tryptophan (1), orientin (2), isoorientin (3), vitexin (4), isovitexin (5), luteolin-7-O-glucoside (6), luteolin-7-O-rutinoside (7), rosmarinic acid (8), 1-O-feruloyl-d-glucoside (9) and 1-O-caffeoyl-d-glucoside (10) were isolated from the EtOAc and BuOH fractions of C. esculenta. The structures of compounds 1–10 were elucidated by spectroscopic methods and comparison with previous reports. All the isolates were subjected to an in vitro bioassay to evaluate their inhibitory activity against rat lens aldose reductase. Among tested compounds, compounds 2 and 3 significantly inhibited rat lens aldose reductase, with IC50 values of 1.65 and 1.92 μM, respectively. Notably, the inhibitory activity of orientin was 3.9 times greater than that of the positive control, quercetin (4.12 μM). However, the isolated compounds showed only moderate ABTS+ [2,29-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)] activity. These results suggest that flavonoid derivatives from Colocasia esculenta (L.) Schott represent potential compounds for the prevention and/or treatment of diabetic complications.
44 citations
TL;DR: The phytochemical study on the aerial parts of Cyperus rotundus L. led to the isolation of a fructose-amino acid conjugate, N-(1-deoxy-α-D-fructos-1-yl)-L-tryptophan, which was elucidated on the basis of spectroscopic methods.
44 citations
TL;DR: High-performance liquid chromatography coupled to positive ion electrospray ionization tandem mass spectrometry (MS) and diode array detection was employed to identify the polyphenol C-glycosides in the extract of Swertia franchetiana.
Abstract: High-performance liquid chromatography coupled to positive ion electrospray ionization tandem mass spectrometry (MS) and diode array detection was employed to identify the polyphenol C-glycosides in the extract of Swertia franchetiana, a traditional Chinese/Tibetan herb. The neutral loss scan of the extract of S. franchetiana using the characteristic losses of 120 and 150 u provided a detailed profile of the polyphenol C-glycosides in the complex mixture. On-line UV spectroscopy along with MS-MS and MS-MS-MS mass spectra analysis produced with and without in-source collision induced dissociation was contributed to discriminate and identify the polyphenol C-glycosides. Three xanthone C-glycosides (i.e., mangiferin, isomangiferin, and 1,6,7-trihydroxyl-2-C-glucosexanthone) and three flavone C-glycosides (i.e., isoorientin, isovitexin, and swertisin) were tentatively identified. Isomangiferin and 1,6,7-trihydroxyl-2-C-glucosexanthone were for the first time found in this plant.
43 citations
TL;DR: In this article, 2-hydroxy-4-6-dimethoxyacetophenone (4) was glycosylated with O-(2,3,4,6-tetra-Obenzyl-α-D-glucopyranosyl) trichloroacetimidate and trimethylsilyl triflate as promoter to yield directly the C-glycoside 6.
Abstract: 2-Hydroxy-4,6-dimethoxyacetophenone (4) was glycosylated with O-(2,3,4,6-tetra-O-benzyl-α-D-glucopyranosyl) trichloroacetimidate (5) and trimethylsilyl triflate as promoter to yield directly the C-glycoside 6. Construction of the flavone system by application of a Baker-Venkataraman-type rearrangement followed by deprotection yielded isoembigenin (2). Glycosylation of 4,6-bis(tert-butyldimethylsilyloxy)-2-hydroxyacetophenone (17) with the trichloroacetimidate 5 afforded the O-glycoside intermediate 18 which was converted via Fries rearrangement into the C-glycoside 21. Applying again the Baker-Venkataraman rearrangement and cyclization gave isovitexin and vitexin derivatives 25 and 26, which were completely deprotected to yield isovitexin (1b) and vitexin (1a), respectively.
43 citations