Novel ursane-type triterpene from the fresh leaves of Carissa carandas and evaluation of cytotoxicity

One novel ursolic acid derivative sabiracin 1 (11,25-epoxy-3β-hydroxy-urs-12-en-28-oic acid) was isolated from the leaves of Carissa carandas, together with five known compounds para hydroxy benzaldehyde (2), ursolic acid (3), carissin (4), 22α-hydroxyursolic acid (5) and β-sitosterol-3-O-β-D-glucopyranoside (6). Compounds 2 and 5 were isolated for the first time from this genus. Structure elucidation was done by the help of spectroscopic techniques. Compounds 1-3, 5 and 6 were examined against oral cancer (CAL-27) and lung cancer (NCI-H460) cell lines. 6 showed good activity against oral cancer (IC₅₀ 18.69 µM), moderate activity against lung cancer (IC₅₀ 63.34 µM) and no cytotoxicity against normal cell lines.

Keywords: Carissa carandas; 11,25-epoxyursolic acid; Apocynaceae; cytotoxicity; novel ursolic acid derivative.