6-Butyryl-5-hy­droxy-4-phenyl­seselin

In the title coumarin compound (systematic name: 6-butyryl-5-hy­droxy-8,8-dimethyl-4-phenyl-2H,8H-benzo[1,2-b;3,4-b′]dipyran-2-one), C24H22O5, also known as mammea A/AC cyclo D, the chromene and pyran rings are almost coplanar with a maximum deviation from the mean plane of 0.295 (2) Å. The attached phenyl group is inclined at 53.49 (8)° with respect to the chromene ring. The mol­ecular structure is stabilized by an intra­molecular O—H⋯O hydrogen bond. In the crystal, mol­ecules are linked into sheets parallel to (101) by inter­molecular C—H⋯O hydrogen bonds. Adjacent sheets are sustained by inter­molecular C—H⋯π and π–π [centroid–centroid distance = 4.471 (2) Å] inter­actions

Identification of highly potent α-glucosidase inhibitory and antioxidant constituents from Zizyphus rugosa bark: enzyme kinetic and molecular docking studies with active metabolites

Context: Previous studies have shown that extracts of Zizyphus rugosa Lam. (Rhamnaceae) bark contained phytoconstituents with antidiabetic potential to lower blood glucose levels in diabetic rats. However, there has been no report on the active compounds in this plant as potential antidiabetic inhibitors. Objective: We evaluated the α-glucosidase inhibitory and antioxidant activities of Z. rugosa extract. Moreover, the active phytochemical constituents were isolated and characterized. Materials and methods: The α-glucosidase inhibition of crude ethanol extract obtained from the bark of Z. rugosa was assayed as well as the antioxidant activity. Active compounds (1–6) were isolated, the structures were determined, and derivatives (2a–2 l) were prepared. All compounds were tested for their α-glucosidase inhibitory (yeast and rat intestine) and antioxidant (DPPH) activities. Results: The active α-glucosidase inhibitors (1–6) were isolated from Z. rugosa bark and 12 derivatives (2a–2 l) were prepared. Compound 2 showed the most powerful yeast α-glucosidase inhibitory activity (IC50 16.3 μM), while compounds 3 and 4 display only weak inhibition toward rat intestinal α-glucosidase. Moreover, compound 6 showed the most potent antioxidant activity (IC50 42.8 μM). The molecular docking results highlighted the role of the carboxyl moiety of 2 for yeast α-glucosidase inhibition through H-bonding. Discussion and conclusions: These results suggest the potential of Z. rugosa bark for future application in the treatment of diabetes and active compounds 1 and 2 have emerged as promising molecules for therapy

A novel pyrrole alkaloid from the fruit peels of <i>Strychnos nux</i>-<i>blanda</i>

<p>A novel pyrrole alkaloid, strychnuxin (<b>1</b>), along with five known compounds (<b>2</b>–<b>6</b>) was isolated from the fruit peels of <i>Strychnos nux</i>-<i>blanda</i>. The structures of all the isolated compounds (<b>1</b>–<b>6</b>) were fully characterised using spectroscopic data, as well as comparison with the previous literature data. Moreover, all isolated compounds were assessed for their <i>α</i>-glucosidase and acetylcholinesterase inhibitory activities.</p

Reactive Radical Scavenging And Xanthine Oxidase Inhibition Of Proanthocyanidins From Carallia Brachiata

Antioxidant-guided separation of Carralia brachiata bark led to a new A-type trimeric proanthocyanidin named carallidin (1), along with mahuannin A (2) and p-hydroxy benzoic acid (3). The structure of 1 was fully characterized by interpretation of spectroscopic data and chemical means. Compounds 1 and 2 exhibited radical scavenging against DPPH (IC50 102 and 182 μM) and superoxide radical (IC50 1.47 and 9.74 μM). In addition, 1 and 2 also inhibited xanthine oxidase with IC50 values of 12.9 and 16.0 μM. Copyright © 2006 John Wiley & Sons, Ltd

Dalvelutinoside, a new isoflavone glycoside from the methanol extract of <i>Dalbergia velutina</i> roots

<p>A new isoflavone glycoside, dalvelutinoside (<b>1</b>), together with one known isoflavone (<b>2</b>) and five known isoflavone glycosides (<b>3–7</b>) were isolated from the methanol extract of the roots of <i>Dalbergia velutina</i>. Their structures were determined by spectroscopic analysis. All isolated compounds were evaluated for their cytotoxicity against KB and HeLa cell lines.</p