Monoterpene Indole Alkaloids from Anthocephalus cadamba Fruits Exhibiting Anticancer Activity in Human Lung Cancer Cell Line H1299

Abstract Two new monoterpene indole alkaloids, Vincosamide‐ N ‐oxide ( 1 ) and isodihydroamino cadambine ( 2 ) along with seven known alkaloids and triterpenoids vincosamide ( 3 ), vallesiachotamine ( 4 ), iso‐vallesiachotamine ( 5 ), dihydrocadambine ( 6 ), cadambine ( 7 ), ursolic acid ( 8 ) and oleanolic acid ( 9 ) were isolated from the fruits of Anthocephalus cadamba (Roxb) Miq. (Family: Rubiaceae). The chemical structures of the isolated molecules were determined using a combination of InfraRed (IR) and one dimensional (1D) and two dimensional (2D) Nuclear Magnetic Resonance (NMR) spectroscopy and High Resolution‐Electronspray Ionisation Mass Spectrometry (HR‐ESIMS). The molecules were evaluated for their in‐vitro antiproliferative activity against human lung cancer cell line H1299. Cytotoxic profile was studied in mouse macrophage RAW 264.7 cell line and induction of apoptosis in MCF‐7 cells. Compounds 4 and 5 were found to exhibit potent anticancer activity with IC 50 values of 4.24 and 3.79 μM respectively. Both compounds demonstrated significant fragmentation in the chromatin within the nucleus cells as a result of apoptosis. In addition none of the purified compounds showed any toxic effect on normal cells.