title: Three new α-glucosidase inhibitors from guggul, the oleogum resin of Commiphora wightii.
abstract: Three new compounds; epi-mukulin, (Z)-Δ(1,2) dehydroguggulsterone and Δ(6,7)dehydro-20-hydroxygugglsterone were isolated from the n-hexane-soluble fraction (HSF) of the methanol extract of guggul, the oleogum resin of Commiphora wightii together with six known compounds: diasesartemin, (+)-epi-magnolin, (+)-diayangambin, gugglsterol I, (E)-guggulsterone and (Z)-guggulsterone. Their structures were elucidated on the basis of different spectroscopic data. α-Glucosidase inhibitory effects of HSF and the isolated compounds were evaluated calorimetrically. The HSF showed significant α-glucosidase inhibitory effect [IC(50) value of 140 µg mL(-1) (p < 0.05)]. Under the assay conditions, diasesartemin (IC(50) = 60.6 ± 0.01 µM) was found to be more potent than the positive control, acarbose (IC(50) = 92.94 ± 0.01 µM); a known α-glucosidase inhibitor (p < 0.05). The IC(50) values of epi-mukulin and (Z)-guggulsterone were found to be 159.33 and 132.14 µM, respectively. Other compounds showed weak α-glucosidase inhibitory effects, <30% inhibition of the enzyme activity at 0.1 mg mL(-1).
authors.affiliation: Department of Chemistry of Natural Compounds, Division of Pharmaceutical Sciences and Drug Industries, and Centre of Excellence for Advanced Sciences, National Research Centre, Dokki 12622 , Egypt. saheg.2011@gmail.com
authors.forename: Sahar
authors.initials: S
authors.lastname: El-Mekkawy
authors.forename: Meselhy R
authors.initials: MR
authors.lastname: Meselhy
authors.forename: Nolitha
authors.initials: N
authors.lastname: Nkobole
authors.forename: Namrita
authors.initials: N
authors.lastname: Lall
mesh_terms: D000704:Analysis of Variance; D029744:Commiphora / Q000737:chemistry*; D065089:Glycoside Hydrolase Inhibitors; D006586:Hexanes; D007194:India; D020128:Inhibitory Concentration 50; D000432:Methanol; D015394:Molecular Structure; D010840:Phytosterols / Q000032:analysis* / Q000302:isolation & purification / Q000494:pharmacology; D010936:Plant Extracts / Q000032:analysis* / Q000302:isolation & purification / Q000494:pharmacology; D053149:Plant Gums / Q000032:analysis* / Q000302:isolation & purification / Q000494:pharmacology; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet
chemical_list: D065089:Glycoside Hydrolase Inhibitors; D006586:Hexanes; D010840:Phytosterols; D010936:Plant Extracts; D053149:Plant Gums; C026385:n-hexane; C018562:guggulu extract; D000432:Methanol