Structure Elucidation of Roselipins, Inhibitors of Diacylglycerol Acyltransferase Produced by Gliodadium roseum KF-1040

Abstract

The structures of roselipins 1A, IB, 2A and 2B were elucidated by spectroscopic studies including ¹H-¹H COSY, ¹³C-¹H COSY, ¹³C-¹H HMQC and ¹³C-¹H HMBC NMR experiments, and degradation experiments. They have the common skeleton of 2, 4, 6, 8, 10, 12, 14, 16, 18-nonamethyl-5, 9, 13-trihydroxy-2E, 6E, 10E-icosenoic acid modified with a D-mannose and a D-arabinitol. Roselipin A and B groups were stereoisomers at the arabinitol moiety, which esterified the fatty acid from the different terminal hydroxy residue. Roselipin 2 group was 6′′-O-acetyl roselipin 1 group.