title: Inhibition of human lanosterol synthase by the constituents of Colocasia esculenta (taro).
abstract: Ethanol extracts of lyophilized vegetables were tested for inhibition of human lanosterol synthase (hOSC) in order to find the compounds to suppress cholesterol biosynthesis. Of 130 samples tested, twelve samples showed significant inhibition. Among them, Colocasia esculenta (taro) showed the highest inhibition (55% inhibition at 300 microg/ml). Examination of activity variation among eight taro cultivars indicated that "Aichi-wase" and "Yatsugashira" had the most potent activity for hOSC inhibition. In order to identify the active constituent of taro, ethanol extracts of "Aichi-wase" were partitioned with hexane and aqueous methanol, and fractionated by silica gel column chromatography. Inhibitory activity was concentrated in two major active fractions. Further purification of these fractions by preparative HPLC gave three monogalactosyldiacylglycerols and five digalactosyldiacylglycerols as active compounds that showed 28 to 67% inhibitory activities at the concentration 300 microg/ml.
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Sakano
authors.forename: Motoh
authors.initials: M
authors.lastname: Mutsuga
authors.forename: Rie
authors.initials: R
authors.lastname: Tanaka
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Suganuma
authors.forename: Takahiro
authors.initials: T
authors.lastname: Inakuma
authors.forename: Masatake
authors.initials: M
authors.lastname: Toyoda
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Goda
authors.forename: Masaaki
authors.initials: M
authors.lastname: Shibuya
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Ebizuka
mesh_terms: D031060:Colocasia; D004791:Enzyme Inhibitors / Q000302:isolation & purification / Q000494:pharmacology; D006801:Humans; D019751:Intramolecular Transferases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D010936:Plant Extracts; D019751:Intramolecular Transferases; C021924:lanosterol synthase