Purpactins, new inhibitors of acyl-CoA:cholesterol acyltransferase produced by Penicillium purpurogenum. II. Structure elucidation of purpactins A, B and C.

The structure of purpactins, novel acyl-CoA:cholesterol acyltransferase (ACAT) inhibitors, was determined by spectroscopic analyses. Purpactin A was deduced to be 3-1'-acetoxy-11-hydroxy-4-methoxy-9-methyl-3'-methylbutyl-5H, 7H-dibenzo[b,g]-1,5-dioxocin-5-one, purpactin B was 5-1''-acetoxy-6'-hydroxymethyl-4-methoxy-4'-methyl-3''-methylbutyl-spiro [benzofuran-2,1'-cyclohexa-3',5'-diene]-2',3(2H)-dione and purpactin C was 5-1''-acetoxy-6'-formyl-4-methoxy-4'-methyl-3''-methylbutyl-spiro [benzofuran-2,1'-cyclohexa-3',5'-diene]-2',3(2H)-dione. Purpactin A was attributed to 1'-O-acetylpenicillide.