Saponins and Sapogenins

The seeds of Luffa aegyptica Mill, locally known as "ghia torai" (family Cucurbitaceae), have earlier been studied for the saponin and sapogenin contents and found to contain a mixture of colourless saponins which on hydrolysis yields two acid and a neutral sapogenin. The acetates of the two acid genins melted at 266-268" and 176-181" while the neutral genin acetate melted at 262-264O.l The acid genin acetate, m.p. 266-26S0, has earlier been identified as oleanolic acid acetate.l The presence of only oleanolic acid has been reported in other specie^^?^ while Luffa operculata* from South America has been reported to contain gypsogenin and an unidentified neutral genin for which no physical constants are found in the literature. It has been found that the second aoid genin acetate, m.p. 176-181°, in the process of recrystallization from methanol slowly and successively transforms into a product, m.p. 262-264", identical with the neutral genin acetate. The acid genin acetate and the neutral genin acetate have ultimately been identified as acetyl gypsogenin and acetyl gypsogenin lactone by transformation of both of these into oleanolic acid and hederagenin through Wolff-Kishner and sodium borohydride reduction respectively. Finally, direct comparison of the acid genin acetate was made with a sample of gypsogenin acetate kindly provided by Dr. K. Schaffner. Ruzicka and Giacomello5 have reported the transformation of gypsogenin into its lactone.