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

The novel triterpene 1 with a dammarane skeleton and a hitherto unknown 17α-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 vivo (DTH; ED50=0.01 mg/kg p.o.). A glucocorticoid like activity is excluded.