A new dihydroindole alkaloidal glycoside, aspidospermidose, has been isolated from the leaves of Rhazya stricta, and has been assigned structure (1) on the basis of spectral studies. Rhazya stricta Decaisne (Apocynaceae) is a small, glabrous, erect shrub which is widely distributed in Western Asia and Pakistan. It has long been used for the treatment of various diseases; the anti-cancer activity of some of its alkaloids has also been reported. Continuing our investigations on the leaves of R. stricta, we report here the isolation and structure determination of a new dihydroindole alkaloid (1) which bears a glycosidic linkage (with the sugar in an oxidised state on Nₐ). Alkaloidal glycosides with oxidised sugar units have not, to our knowledge, been previously reported in Nature. The structure of aspidospermidose has been elucidated by extensive n.m.r. studies, including 2D n.m.r., nuclear Overhauser enhancement (n.o.e.) measurements, homodecoupling, and ¹³C-n.m.r. [broad band and gated spin echo (GASPE)] experiments.