Zaragozic acids: a family of fungal metabolites that are picomolar competitive inhibitors of squalene synthase.
Three closely related fungal metabolites, zaragozic acids A, B, and C, that are potent inhibitors of squalene synthase have been isolated and characterized. Zaragozic acids A, B, and C were produced from an unidentified sterile fungal culture, Sporormiella intermedia, and Leptodontium elatius, respectively. The structures of the zaragozic acids and their trimethyl esters were determined by a combination of physical and chemical techniques. The zaragozic acids are characterized by a novel 2,8-dioxobicyclo[3.2.1]octane-4,6,7- trihydroxyl-3,4,5-tricarboxylic acid core and differ from each other in the structures of the 6-acyl and 1-alkyl side chains. They were found to be potent competitive inhibitors of rat liver squalene synthase with apparent Ki values of 78 pM, 29 pM, and 45 pM, respectively. They inhibited cholesterol synthesis in Hep G2 cells, and zaragozic acid A was an inhibitor of acute hepatic cholesterol synthesis in the mouse (50% inhibitory dose of 200 micrograms/kg of body weight). Inhibition of squalene synthase in cells and in vivo was accompanied by an accumulation of label from [3H]mevalonate into farnesyl diphosphate, farnesol, and organic acids. These data indicate that the zaragozic acids are a previously unreported class of therapeutic agents with potential for the treatment of hypercholesterolemia.
Bergstrom
J D
JD
Department of Biochemical Regulation, Merck Research Laboratories, Rahway, NJ 07065-0900.
Kurtz
M M
MM
Rew
D J
DJ
Amend
A M
AM
Karkas
J D
JD
Bostedor
R G
RG
Bansal
V S
VS
Dufresne
C
C
VanMiddlesworth
F L
FL
Hensens
O D
OD
D000818:Animals; D001203:Ascomycota / Q000378:metabolism*; D001643:Bridged Bicyclo Compounds / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D019086:Bridged Bicyclo Compounds, Heterocyclic; D002784:Cholesterol / Q000096:biosynthesis; D002851:Chromatography, High Pressure Liquid; D013186:Farnesyl-Diphosphate Farnesyltransferase / Q000037:antagonists & inhibitors*; D005260:Female; D005285:Fermentation; D006801:Humans; D007700:Kinetics; D008055:Lipids / Q000096:biosynthesis*; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D003904:Mitosporic Fungi / Q000378:metabolism*; D015394:Molecular Structure; D014233:Tricarboxylic Acids / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D001643:Bridged Bicyclo Compounds; D019086:Bridged Bicyclo Compounds, Heterocyclic; D008055:Lipids; D014233:Tricarboxylic Acids; C079090:zaragozic acid C; C075117:squalestatin 1; C079089:zaragozic acid B; D002784:Cholesterol; D013186:Farnesyl-Diphosphate Farnesyltransferase