Glycosides of Calotropis procera R.Br. Glycosides and aglycones. 320

From the latex of Calotropis procera, HESSEet al. [2] had isolated free calotropagenin (8) and six of its glycosides. We now obtained three additional compounds: uzarigenin (4), syriogenin [10] (a 3 β, 14α, x-trihydroxy-card-(20:22)-enolide) and proceroside. The latter is a new glycoside containing a sugar moiety identical or stereoisomeric with those present in gomphoside, calactin and calotropin. Its aglycone, not yet known in free form, contains one (probably secondary) hydroxyl group more than calotropagenin and is most probably a 2α, 3β, 14β, x-tetrahydroxy-card-(20:22)-enolide.