From 5 kg of the skins of the bulbs of Alllum glganteum Rgl. (family Alliaceae),collected at the stage of the end of fruit-bearing (Turkmen SSR, district of the village of Morgunovka),by extraction with methanol, we obtained 500 g of combined substances giving a positive reaction for steroid saponins [1]. Part of the total material isolated (40 g) was washed with acetone, and the insoluble residue (30 g) was chromatographed on a column of SiO 2. Elution was performed by the gradient method using chloroform with increasing proportions of methanol. Chloroform-methanol (90 : 1) and (80 : 1) yielded 2 g of a crystalline compound C27H4405, mp 269-270"C (methanol), [~]~-76.0 ° (c 1.45 chloroform), which we have called neoapigenin (I). The mass spectrum of {I) contained, in addition to the peak of the molecular ion with m/e 488, peaks with m/e 389, 379, 376, 334, 319, 305, 139, 115, which are characteristic for steroid sapogenins [2]. The IR spectrum of the genin (I) had absorption bands characteristic for sapogenins with the 25S configuration (858, 910<930, 975 cm -~) [3] and for an OH group (3200-3500 cm-l). The acetylation of the sapogenln (I) with acetic anhydride in pyridine (25"C, four days) gave the triacetate, C33Hs008, mp 118-122°C (methanol), [~]}~-117.3 ° (c 1.76; chloroform), tool. wt. 574 (mass spectrometry). The IR spectrum of the triacetate of the gentn had absorption characteristic for an ester grouping (1740 cm-l),and there was no absorption in the region of hydroxy groups.The genin that we have isolated of the neo-(25S) series with three acetylatable hydroxy groups has constants differing from those of the 25S-trihydroxysapogenins described in the literature.