Isolation and synthesis of a novel immunosuppressive 17 alpha-substituted dammarane from the flour of the Palmyrah palm (Borassus flabellifer)

The novel triterpene 1 with a dammarane skeleton and a hitherto unknown 17 alpha-substitution pattern has been isolated from the Palmyrah palm in low yield and prepared by synthesis in larger quantities. 1 was shown to be an extremely potent immunosuppressant in vitro (MLR; IC50 = 10 ng/ml) and in v ivo (DTH; ED50 = 0.01 mg/kg p.o.). A glucocorticoid like activity is exclud ed. (C) 1999 Elsevier Science Ltd. All rights reserved.