New pregnane glycoside derivative from Caralluma retrospiciens (Ehrenb).

Retrospinoside (1) is a new polyoxy pregnane glycoside which was isolated and characterised from the aerial parts of Caralluma retrospiciens (Ehrenb.) N. E. Br., family Apocynaceae. The structure was established as 3-O-[ß-D-glucopyranosyl-(1 â†’ 4)-ß-D-(3-O-methyl-6-desoxygalactopyranosy)]-14,15,20-trihydroxy-4ß-pregnane. Its structural elucidation was performed through extensive spectroscopic measurements including 1D- and 2D-NMR, and HRMS, in addition to chemical methods.