Ultraviolet rays are the main cause of skin aging. Isoflavone structures are good anti-ultraviolet natural compounds and have an especially strong anti-ultraviolet B (UVB) effect. However, the anti-ultraviolet A (UVA) effect of isoflavones is more controversial.
View Article and Find Full Text PDFIn continual study on the heartwood of Rhamnus nakaharai, a new alaternin-8-O-glucoside, namely 1,2,6,8-tetrahydroxy-3-methylanthraquinone-8-O-β-glucopyranoside (1), together with some known compounds were further isolated and characterised by 1-D, 2-D NMR and other spectral evidences. The free radical scavenging and antityrosinase activities of the isolates, including alaternin (1a), emodin (2a), emodin-8-O-β-glucopyranoside (2), 6-methoxysorigenin-8-O-β-glucopyranoside (3) and 6-methoxysorigenin (3a) were tested. Alaternin (1a) exhibited to be mild DPPH radical scavenger with half as potent as vitamin C, while both alaternin (1a) and emodin-8-O-β-glucopyranoside (2) exhibited stronger SOD-like activity than that of BHA.
View Article and Find Full Text PDFTwenty-four compounds, including the previously unknown artoxanthocarpuone A, artoxanthocarpuone B, hydroxylakoochin A, methoxylakoochin A, epoxylakoochin A, and artoxanthol, were isolated and characterized spectroscopically. Among them, artoxanthol is stilbene oligomer presumably constructed in a 5,11,12-triphenyl hexahydrochrysene scaffold by a Diels-Alder type of reaction, for which a biosynthetic pathway is proposed. Artoxanthol, alboctalol, steppogenin, norartocarpetin, resveratrol, oxyresveratrol, and chlorophorin potently inhibited mushroom tyrosinase activity with IC50 values from 0.
View Article and Find Full Text PDFIn this study, we examined the potential of synthetic isoflavones for application in cosmeceuticals. Twenty-five isoflavones were synthesized and their capacities of free-radical-scavenging and mushroom tyrosinase inhibition, as well as their impact on cell viability of B16F10 murine melanoma cells and HaCaT human keratinocytes were evaluated. Isoflavones that showed significant mushroom tyrosinase inhibitory activities were further studied on reduction of cellular melanin formation and antityrosinase activities in B16F10 melanocytes in vitro.
View Article and Find Full Text PDFContext: Consumption of medicinal mushrooms for disease prevention and maintaining health has a very long history in Asia. Grifola frondosa (Fr) S.F.
View Article and Find Full Text PDFThis study examined the inhibitory effects of Grifola frondosa (GF), a medicinal mushroom popularly consumed in traditional medicine and health food, on digestive enzymes related to type 2 diabetes; chemical profiles and inhibitory kinetics of its bioactive fractions were also analyzed. Results showed that all GF extracts showed weak anti-α-amylase activity; however, strong anti-α-glucosidase activity was noted on GF n-hexane extract (GF-H). Further fractionation confirmed that compared with acarbose (a commercial α-glucosidase inhibitor), the nonpolar fraction of GF possessed a stronger anti-α-glucosidase activity but a weaker anti-α-amylase activity.
View Article and Find Full Text PDFArtoxanthochromane (1), a DielsAlder-type conjugation product of 4-isopropenylresorcinol and oxyresveratrol, was isolated from the heartwood of Artocarpus xanthocarpus and characterized. The structure of 1 was elucidated as 2-(2,4-dihydroxyphenyl)-3-(3,5-dihydroxyphenyl)-7-hydroxy-4,4-dimethylchromane by 1D- and 2D-NMR spectroscopy, and other spectral evidences. A plausible metabolic mechanism was proposed to illustrate the biosynthetic pathway of artoxanthochromane.
View Article and Find Full Text PDFGrifola frondosa (GF), a high value medicinal mushroom in China and Japan, is popularly consumed as traditional medicines and health foods, especially for enhancing immune functions. In this study, our aim was to examine the immunomodulatory activities of GF and its bioactive compound ergosterol peroxide (EPO) in lipopolysaccharide (LPS)-induced human monocytic (THP-1) cells. At low concentrations, EPO but not other extracts showed a full protection against LPS-induced cell toxicity.
View Article and Find Full Text PDFDeoxybenzoins are potent antioxidants and tyrosinase inhibitors with potential to be developed as food preservatives and cosmetic ingredients. To explore the potential in cardiovascular protection, 25 polyphenolic deoxybenzoins were synthesized and evaluated for inhibitory effects on KCl-induced porcine coronary arterial contraction. The results revealed deoxybenzoins are significant inhibitors of KCl-induced arterial contraction.
View Article and Find Full Text PDFDeoxybenzoins (DOBs) are one-pot synthetic precursors of isoflavones with feature analogous to those beneficial polyphenols such as resveratrol (stilbene) and phloretin (dihydrochalcone). In this study, seventeen polyphenolic DOBs were synthesized and evaluated by various antioxidant assays and tyrosinase inhibitory effect in vitro. Results displayed that these DOBs are powerful antioxidants; for example, 2,3,4-trihydroxy-3',4'-dimethoxydeoxybenzoin possesses an excellent anti-lipid peroxidation activity (IC(50)=0.
View Article and Find Full Text PDFThree new ent-kaurane type diterpenes, broussonetones A-C (1-3), were isolated from leaves of Broussonetia papyrifera, together with seven known compounds, and their structures determined by 1D and 2D NMR and MS methods. Compounds 1-3 were marginal inhibitors of tyrosinase. Antioxidant assays showed them also to be inhibitors of xanthine oxidase.
View Article and Find Full Text PDFThe objective of this study was to prepare sodium nonivamide acetate (SNA) microemulsion for topical administration. Microemulsions consisted of a mixed surfactant of Tween 80 and Span 20 as surfactant, ethanol as cosurfactant, isopropyl myristate (IPM) as an oil phase and water as an external phase. The effect of composition of microemulsion including the ratio of oil phase/surfactant/aqueous phase, various cosurfactant and polymer on the character and permeability of microemulsion were evaluated.
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