Analysis of Steroidal Sapogenins from Amber Fenugreek (<i>Trigonella foenum-graecum</i>) by Capillary Gas Chromatography and Combined Gas Chromatography/Mass Spectrometry

Abstract

Mixtures of steroidal sapogenins isolated from the seed and combined aerial parts (foliage) of fenugreek (cultivar Amber) have been examined by capillary column gas chromatography with mass spectral and flame ionization detectors. Diosgenin [(25 R )-spirost-5-en-3β-ol] was the major component in seed and foliage extracts hydrolyzed with hydrochloric acid. Yamogenin also appeared to be present. Tigogenin, neotigogenin, smilagenin, and sarsasapogenin were identified in the extracts. Dihydroxy steroidal sapogenins, tentatively identified as yuccagenin, gitogenin, and neogitogenin, were detected as minor components in hydrolyzed extracts from seed. A gas chromatographic method based on the use of an internal standard and a column of HP-5MS was developed to determine diosgenin in Amber fenugreek. Expressed on a dry weight basis, mean levels of diosgenin in seed were 0.54%. In field-grown foliage sampled during a season at 9, 15, and 19 weeks postseeding, diosgenin levels were 0.16, 0.07, and 0.07%, respectively. Keywords: Steroidal sapogenins; spirostanols; fenugreek; diosgenin; quantitation; seed; foliage