title: 2,3,22,23-tetrahydroxyl-2,6,10,15,19,23-hexamethyl-6,10,14,18-tetracosatetraene, an acyclic triterpenoid isolated from the seeds of Alpinia katsumadai, Inhibits acyl-CoA : cholesterol acyltransferase activity.
abstract: In order to isolate a cholesterol-lowering compound from Alpinia katsumadai, an inhibitor for acyl-CoA : cholesterol acyltransferase (ACAT), an enzyme responsible for the cholesterol ester formation in liver, was purified, its chemical structure was determined, and in vivo and in vitro inhibition activities were performed. In a high fat diet mouse model, we discovered that the ethanol extract of Alpinia katsumadai reduced plasma cholesterol, triglyceride, and low density lipoprotein (LDL) levels. An acyclic triterpenoid showing ACAT inhibitory activity was isolated from the extract of seeds of A. katsumadai. By NMR spectroscopic analysis of its (1)H-NMR, (13)C-NMR, (1)H-(1)H correlation spectroscopy, heteronuclear multiple bond connectivity (HMBC), hetero multiquantum coherence (HMQC) and nuclear Overhauser effect, chemical structure of 2,3,22,23-tetrahydroxyl-2,6,10,15,19,23-hexamethyl-6,10,14,18-tetracosatetraene (1), were elucidated. The acyclic triterpenoid was found to be responsible for the ACAT inhibition activities of rat liver microsomes with IC(50) values of 47.9 µM. It also decreased cholesteryl ester formation with IC(50) values of 26 µM in human hepatocyte HepG2 cell. The experimental study revealed that the ethanol extract of A. katsumadai has a hypolipemic effect in high fat diet mice, and the isolated acyclic triterpenoid has ACAT inhibition activity, showing a potential novel therapeutic approach for the treatment of hyperlipidemia and atherosclerosis.
authors.affiliation: Department of Biological Science and Biotechnology, Hannam University, Daejeon 305–811, Korea.
authors.forename: Soon-Yong
authors.initials: SY
authors.lastname: Choi
authors.forename: Moon Hee
authors.initials: MH
authors.lastname: Lee
authors.forename: Jung Ho
authors.initials: JH
authors.lastname: Choi
authors.forename: Young Kook
authors.initials: YK
authors.lastname: Kim
mesh_terms: D032429:Alpinia; D000818:Animals; D002784:Cholesterol / Q000097:blood; D002788:Cholesterol Esters / Q000378:metabolism; D059305:Diet, High-Fat; D005233:Fatty Alcohols / Q000494:pharmacology*; D005260:Female; D056945:Hep G2 Cells; D006801:Humans; D000960:Hypolipidemic Agents / Q000494:pharmacology*; D051379:Mice; D008813:Mice, Inbred ICR; D008862:Microsomes, Liver / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology*; D012639:Seeds; D002785:Sterol O-Acyltransferase / Q000037:antagonists & inhibitors*; D014280:Triglycerides / Q000097:blood
chemical_list: C579427:2,3,22,23-tetrahydroxyl-2,6,10,15,19,23-hexamethyl-6,10,14,18-tetracosatetraene; D002788:Cholesterol Esters; D005233:Fatty Alcohols; D000960:Hypolipidemic Agents; D010936:Plant Extracts; D014280:Triglycerides; D002784:Cholesterol; D002785:Sterol O-Acyltransferase