Isolation of solasodine and other steroidal alkaloids and sapogenins by direct hydrolysis-extraction of Solanum plants or glycosides therefrom

Abstract

Concomitant extraction and hydrolysis of Solanum steroidal glycoalkaloids in a two-phase system containing an aqueous mineral acid and an organic water immiscible solvent, and having a boiling point under 100 oC, is described. It is essentially a “one-pot” process, combining direct acid hydrolysis of the glycosides in the plant material and in situ extraction of the released aglycones after alkali treatment, in a single step, the various ingredients being added simultaneously or sequentially, as required. Application of the process to fruits, leaves, and tissue cultures of Solanum khasianum Clarke plants, either fresh or in dried, finely ground form, using a two-phase aqueous hydrochloric acid-toluene system, proved to be very suitable for continuous production of pure solasodine which is a valuable raw steroid for the preparation of steroidal drugs. Pure Solanum glycoalkaloids were also prepared and hydrolysed accordingly. The process has analytical applications too, and could be extended in a general way to glycosides in other series for preparation of their related aglycones.