Rubiothiazepine a Novel Unusual Cytotoxic Alkaloid from Ixora undulata Roxb. Leaves

Magdy M. D. Mohammed, Nabaweya

Abstract

Leaves of Ixora undulata Roxb. were investigated phytochemically for the first time for its alkaloidal content, which resulted in the isolation of a novel unusual thiazepine alkaloid glycoside identified as 7-[(β-D-glucopyranosyl)oxy]-6-hydroxy-2-methoxy-4,5-dihydro-1,3-thiazepine and trivially named as Rubiothiazepine. Its structure was determined on the basis of 1D and 2D NMR (1H-, 13C-NMR, 1H-1H COSY, 1H-13C HETCOR, 1H-13C HMBC, 1H-15N HMBC and DIFNOE), high resolution ESI-CID-MS/MS, UV and IR spectroscopy. The isolated compound showed cytotoxic activity against EL4 (Murine Leukemia) with IC50 >100 μg/mL, and also showed cytotoxic and HIV-1 activity against MT-4 and HIV-1IIIB with CC50 >100 μg/mL and EC50 >100 μg/mL, respectively