Objective: To study the chemical constituents from the ethyl acetate portion of an ethanolic extractive of the leaves of Aeschynanthus mengxinensis.
Method: The column chromatographic techniques were applied to isolate constituents. A combination of IR, ESI-MS, NMR and 2D-NMR spectroscopy was used to identify structures.
Result: Four compounds were isolated from the ethyl acetate fraction of this plant, and the structure of them have identified as 2alpha, 3beta, 19beta-trihydroxyolean-12-ene-23,28-dioic acid (1), 2alpha, 3beta, 21beta-trihydroxyolean-12-ene-28-oic acid (2), 2alpha, 3beta, 23-trihydroxyurs-12-ene-28-oic acid (3) and stigmast-5 (6), 22 (23)-diene-3beta-ol (4).
Conclusion: The NMR data of compound 1 was completely assigned by 2D-NMR techniques, including HMBC and HMQC. Compounds 1-4 were isolated for the first time from Gesneriaceae.