Identification and Preliminary SAR Studies of (+)-Geodin as a Glucose Uptake Stimulator for Rat Adipocytes

(+)-Geodin (1) was isolated from Penicillium glabrum AJ117540 with activity that stimulates glucose uptake by rat adipocytes. Unlike insulin it is active in the presence of wortmannin. Dihydrogeodin (2) and sulochrin (3) which are the precursors of (+)-geodin biosynthesis were also isolated from the same fungus. Preliminary SAR studies of 1 showed some analogues had enhanced activity. Especially, the activities of racemic geodin and dibromo analogue (7a) were comparable to that of the natural product.