Isolation and 1H/13C-NMR Studies on 19,20-Dihydrocondylocarpine: An Alkaloid from the Leaves of Ervatamia coronaria and Alstonia scholaris

Studies on the alkaloidal constituents of the leaves of ERVATAMIA CORONARIA Stapf and ALSTONIA SCHOLARIS have resulted in the isolation of (20 S)-19,20-dihydrocondylocarpine which has not been previously reported from these plants. The stereochemistry at C-20 was established with the help of n. O. e. difference measurements. (13)C-NMR assignments have been made by polarisation transfer techniques.