Stereoselective synthesis and osteogenic activity of subglutinols A and B.

Since clinically approved immunosuppressive drugs (e.g., cyclosporin A, FK506) possess dose-dependent biphasic effects that cause undesirable side effects on bone structure, including osteopenia, osteoporosis, and increased incidence of bone fractures, considerable effort has been devoted to the identification of immunosuppressive drugs that promote bone formation in a dose-dependent manner. Herein, we report the stereoselective synthesis of subglutinols A and B and present initial biological data showing the significant potential of subglutinol A as an immunosuppressive drug with dose-dependent osteogenic activity. We also show that activating protein 1 (AP-1) family transcription factors could be one of the key regulators for the anabolic activity of subglutinol A. Such drugs with dose-dependent osteogenic activity might help reduce bone-associated side effects and be clinically useful for bone tissue transplantation.