Neokotalanol, a potent α-glucosidase inhibitor isolated from Salacia reticulata, was synthesized through a key coupling reaction between a perbenzylated thiosugar and an appropriately protected perseitol triflate derived from D-mannose. This key step was found to be quite temperature dependent, and a simultaneous cyclization of the triflate leading to a characteristic 2,4,7-trioxabicyclo[4.2.1]nonane system was detected.
Enzyme Inhibitors ; chemical synthesis ; chemistry ; Glycoside Hydrolase Inhibitors ; Plant Extracts ; chemical synthesis ; chemistry ; Salacia ; chemistry

Nine compounds were isolated from the 90% ethanol extract of Salacia polysperma by silica gel, Sephadex LH-20 column chromatography, together with preparative HPLC methods. Based on HR-ESI-MS, MS, 1D and 2D NMR spectral analyses, the structures of the nine compounds were identified as 28-hydroxy wilforlide B(1), wilforlide A(2), 1β,3β-dihydroxyurs-9(11),12-diene(3),(-)-epicatechin(4),(+)-catechin(5),(-)-4'-O-methyl-ent-galloepicatechin(6), 3-hydroxy-1-(4-hydroxy-3-methoxy-phenyl)propan-1-one(7),(-)-(7S,8R)-4-hydroxy-3,3',5'-trimethoxy-8',9'-dinor-8,4'-oxyneoligna-7,9-diol-7'-aldehyde(8), and vanillic acid(9). Compound 1 is a new oleanane-type triterpene lactone. Compounds 1, 3, 4, 7-9 were isolated from the Salacia genus for the first time. All compounds were assayed for their α-glucosidase inhibitory activity. The results suggested that compound 8 exhibited moderate α-glucosidase inhibitory activity, with an IC_(50) value of 37.2 μmol·L~(-1), and the other compounds showed no α-glucosidase inhibitory activity.
Salacia/chemistry* ; alpha-Glucosidases ; Triterpenes/pharmacology* ; Magnetic Resonance Spectroscopy ; Ethanol ; Molecular Structure

Chemical constituents of the roots and stem of Salacia hainanensis Chun et How were isolated and purified with column chromatography on silica gel, Sephadex LH-20 and preparative HPLC. Their structures were elucidated based on physicochemical and spectral spectroscopic analysis. Depending on the activities of anti-alpha-glucosidase and inhibiting AGEs (advanced glycation end products, AGEs) formation in vitro, nine compounds were identified as 26, 27-dihydroxy-7, 24-tirucalladien-3-one (1), abruslactone A (2), lupeol (3), 21alpha, 30-dihydroxy-D: A-friedooleanan-3-one (4), 15alpha-hydroxyfriedelan-3-one (5), friedelin (6), mangiferin (7), epicatechin (8) and beta-sitosterol (9), separately. Among them, compound 1 is a new compound, and compound 2 was isolated from the Salacia genus for the first time, while, compounds 3, 4, 5, 8 were obtained from this plant for the first time.
Catechin ; analogs & derivatives ; chemistry ; isolation & purification ; Molecular Structure ; Pentacyclic Triterpenes ; chemistry ; isolation & purification ; Plant Roots ; chemistry ; Plant Stems ; chemistry ; Plants, Medicinal ; chemistry ; Salacia ; chemistry ; Steroids ; chemistry ; isolation & purification ; Triterpenes ; chemistry ; isolation & purification ; Xanthones ; chemistry ; isolation & purification