Afromontoside. A new cytotoxic principle from Dracaena afromontana

A new cytotoxic principle, steroidal saponin afromontoside (1), has been isolated from a methanolic extract of the twigs of Dracaena afromontana. It was shown to be (25R)-furost-5-ene-3β,22α,26-triol 26-O-α-L-rhamnopyranoside 3-O-([O-α-L-rhamnopyranosyl(1→4)]-β-D-glucopyranoside) by spectral and chemical methods. The aglycone of afromontoside, diosgenin, as well as dihydrodiosgenin and several structurally related compounds have been shown to be cytotoxic to cultured KB cells.