0000000000352126
AUTHOR
Simon Gibbons
30-Norfriedelane triterpenes from the stem bark ofCaloncoba glauca
Abstract The stem bark of Caloncoba glauca has yielded three friedelane triterpenes of which two are characterized by the loss of C-30 and the presence of a C-27, C-15 lactone. They were identified, with considerable use of long-range C H coupling studies, as the known compound trichadonic acid (3-oxofriedelan-27-oic acid) and two new 30-norfriedelane derivatives, 3,27-dioxo-30-norfriedelan-20(29)-en-27,15α-lactone (caloncobalactone) and 3,27-dioxo-21β-hydroxy-30-norfriedelan-20(29)-en-17,15α-lactone (21β-hydroxycaloncoba lactone).
Friedelane triterpenes from the stem bark of Caloncoba glauca
Further investigation of the stem bark of Caloncoba glauca has yielded three minor (D:A)-friedo-oleanane derivatives. These have been identified, on the basis of NMR studies, as the known compound kokoonol [3-oxo-(D:A)-friedo-olean-27-ol] and the novel natural products kokoonal [3-oxo-(D:A)-friedo-olean-27- al] and 3β,21β-dihydroxy-30-nor-(D:A)-friedo-olean-27-oic acid.