Isolation and structure elucidation of pyridine alkaloids from the aerial parts of the Mongolian medicinal plant Caryopteris mongolica Bunge

Abstract

Abstract The seven pyridine alkaloids 1–7, the flavonoid acacetin (8), and L-proline anhydride (9) have been isolated from the aerial parts of the Mongolian medicinal plant Caryopteris mongolica Bunge. The structures of the natural products 1–9 have been assigned by MS, as well as IR, 1D NMR (1H, 13C, DEPT), and 2D NMR (COSY, HSQC, HMBC, NOESY) spectroscopic methods. The compounds 2 and 4–7 represent new chemical structures. Acacetin (8) and L-proline anhydride (9) have been obtained from C. mongolica for the first time.