title: Bio-assay guided isolation of alpha-glucosidase inhibitory constituents from Eclipta alba.
abstract: Eclipta alba (L.) Hassk is used traditionally in diabetes mellitus in India and the plant extract is reported to possess anti-diabetic activity. A bioactivity-guided isolation approach based on alpha-glucosidase inhibition was used to identify the constituents contributing towards the inhibition of the enzyme and probably contributing towards its anti-diabetic activity. Four echinocystic acid glycosides were thus isolated, of which eclalbasaponin VI, isolated from the n-butanol fraction, was found to be the most potent (IC50 54.2 +/- 1.3 microM). The compound is an uncompetitive type of inhibitor with Ki 26.1 microM. A quantitative estimation of the constituents was established using RP-HPLC.
authors.affiliation: National Institute of Pharmaceutical Education and Research, 4, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India.
authors.forename: Deepak
authors.initials: D
authors.lastname: Kumar
authors.forename: Raghuvir H
authors.initials: RH
authors.lastname: Gaonkar
authors.forename: Rina
authors.initials: R
authors.lastname: Ghosh
authors.forename: Bikas C
authors.initials: BC
authors.lastname: Pal
mesh_terms: D002851:Chromatography, High Pressure Liquid; D036601:Eclipta / Q000737:chemistry*; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000494:pharmacology*; D065089:Glycoside Hydrolase Inhibitors; D006027:Glycosides / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D004791:Enzyme Inhibitors; D065089:Glycoside Hydrolase Inhibitors; D006027:Glycosides