Sablacaurin A and B, two 19-nor-3,4-seco-lanostane-type triterpenoids from Sabal causiarum and Sabal blackburniana, respectively

In search for bioactive compounds from Sabal species, sablacaurin A [25-ethyl,23-methyl-19-nor-24-methylene-3,4-,seco-4(28)-lanosten-10,3-olide] and sablacaurin B [24-ethyl,24-methyl-19-nor-3,4-,seco-4(28),25(26)-lanostadiene-10,3-olide], the first 19-nor lanostane derivatives of the 3,4-seco type with a spiro element, have been isolated front the leaves of Sabal causiarum and Sabal blackburniana respectively, together with the known squalene (S. blackburniana) and beta-sitosterol (S. causiarum). From leaves of Sabal peregrina, the known triterpenes 3-oxo-24-methylenecycloartane and 24-methylcycloart-25(26)-en-3-one were isolated. The structures of these compounds were established from spectroscopic studies. (C) 2004 Elsevier Ltd. All rights reserved.