LABELLED STEROIDAL SAPOGENINS AND HYDROCARBONS FROMTRIGONELLA FOENUMGRAECUMBY ACETATE, MEVALONATE AND CHOLESTEROL FEEDS TO SEEDS

Abstract

The formation of steroidal sapogenins from plant sterols involves oxidation at Cia, C22 and C27 and ring closure, a theory put forward as early as 1952 (T s c h es c h e and K o rte). Cholesterol is the main candidate sterol following the work of J o l y et al. in 1969 (a) and its biosynthesis from acetate via mevalonate and squalene is established. The evidence for the above route to spirostans comes from experiments with radioactive compounds. However, uptake of the label into sapogenin is frequently lower than one would like. Contributing to the low incorporation are such factors as the biosynthetic activity of the plant tissue during the experiment, the nature of the precursor, and the method of introduction of the latter into the plant.

Elicitation of diosgenin production in Trigonella foenum-graecum L. seedlings by heavy metals and signaling molecules

“…Trigonella foenum-graecum is one of the several plant sources that produce diosgenin (Evans 1996). Seedlings of the plant are also reported to produce diosgenin (Hardman and Fazli 1972;Bhavsar et al 1980;Ortuno et al 1999). Previously we have studied the role of ethylene on diosgenin production in T. foenum-graecum seedlings (De and De 2003) and in Dioscorea floribunda (De and De 2005).…”

Sterol Side Chain Reductase 2 Is a Key Enzyme in the Biosynthesis of Cholesterol, the Common Precursor of Toxic Steroidal Glycoalkaloids in Potato

“…In addition to SGAs in solanaceous plants, spirostan and/or furostan saponins such as dioscin in yam (Dioscorea spp; order Liliales) and trigoneosides in fenugreek (Trigonella spp; order Fabales) could also be biosynthesized via cholesterol as an intermediate (Bennett and Heftmann, 1965;Hardman and Fazli, 1972). Whether these plants have any genes homologous to DHCR24 is unknown.…”