Investigation of saponin content and lipoidal matter in two aerva species growing in Egypt

ABSTRACT

The study included the investigation of saponin contents in Aerva lanata [L.] Juss ex. Schult and Aerva javanica [Burm. fil] growing in Egypt. The crude saponin mixture was prepared and purified by MgO method, further purification of the isolates was carried out by column chromatography followed by centrifugally accelerated rotatory TLC. Three glycosides were isolated. Hydrolysis of glycoside 1 afforded beta-sitosterol and glucose, saponin glycoside, yielded lupeol, galactose and glucose, while saponin glucoside, gave oleanolic acid, galactose, glucose and rhamnose. The genins were identified on the basis of mp, mmp, chromatographic behavior IR, 1HMR and EI-mass spectra. The sugar moieties of the glycosides were identified by PC and GLC analysis. Quantitative estimation of saponin applying the hemolytic index method revealed that it is higher in A. javanica [0.09%] than in A. lanata [0.014%]. Identification of the hydrocarbons, sterols and triterpenes was achieved by chromatographic as well as GC-MS analysis. beta-Sitosterol, campesterol, stigmasterol, stigmasterol acetate and lupeol were identified in both species. Olean-12-en-28 oic acid 3,16 dioxomethyl ester and ergosterol were identified in A. lanata, while oleanolic acid methyl ester was identified only in A. javanica. The total fatty acids of the two species were methylated and analyzed by GLC. The results revealed the presence of lauric, myristic, myrstoleic, palmitolleic, stearic, oleic and linoleic acids in the two aerva species. Palmitic acid was found only in A. javanica