Spirostanol saponins from the bulbs of Lilium candidum

Abstract

in this plant. Bulbs of Lilium candidum L. were extracted with EtOH and concentrated in vacuo. The crude ethanolic extract was dissolved in 1% H 2 SO 4 and extracted with diethyl ether. The water portion after extraction was alkalized with NH 3 and extracted with CHCl 3 . During extraction, a foam-like interphase was created. This interphase was chromatographed over silica gel with a mixture of CHCl 3 and MeOH to give compounds 1 and 2. Additional HPLC separation of compound 1 (S5ODS2 column, mobile system MeOH–H 2 O, gradient 30:70% MeOH/60 min, flow 0.6 mL/min, detection 210 nm) resulted in the isolation of compounds 1a, 1b, and 1c. The structures of the 25R (compound 1a) and 25S (compound 1b) isomers of 3--L-rhamnopyranosyl-12D-glucopyranosyloxyspirost-5-en-27-ol were elucidated on the basis of spectroscopic analysis, including two-dimensional NMR spectroscopic techniques. The presence of the 25R isomer was described in Lilium brownii var. colchesteri 4, while the 25S isomer was isolated from Lilium candidum L. 5. Their mutual presence and separation have not described in the genus Lilium until now. Compound 1c represents the 3-hydroxy-3-methylglutaryl ester of the isolated 25R isomer, and compound 2 is the glucosidic derivative of compound 1c. These compounds are known in several Lilium species [6, 7], but their presence in Lilium candidum L. is described for the first time.