Basic and Applied Studies on the Chemical Conistituents and Bioactivity of Argel (Solenostemma argel Del Hayne).

Abstract

At the present work extraction, fractionation, phytochemical screening and biological activity of the extract for the stems of Solenostemma argel (S. argel) were studied. The results showed that S. argel contains medicinal species such as phytosterols, triterpenoids, alkaloids, flavonoids, and saponins. Chemical research of the stems showed the presence of some minerals, micro element: Fe (1.055%), Zn (0.052%), Mn (0.059%), Ca (21.10%), Mg (29.95%), and Cu (0.014%), and macro elements: N (1.96%), P(0.48%), S (0.050%) and K (0.816%), by using atomic absorption spectrophotometer (AAS) to determine heavy metal concentrations. The aqueous extract of the stem of S. argel and its other organic fractions were tested against the activity of third larvae of Tribolium castaneum. Among these, the chloroform extract (CHCl3) showed high activity. Its activity was investigated further, using the diffusion method, against the growth of four types of bacteria (two Gram-positive and two Gram-negative), and two types of fungi. These experiments proved that the CHCl3 extract of S. argel had a high antimicrobial activity. Fractionation of the CHCl3 extract was done by column chromatography (CC), thin layer chromatography (TLC), and further purification of semi-pure compounds was achieved using preparative thin-layer chromatography (PTLC) to obtain pure compounds. Isolated compounds were characterized using nuclear magnetic resonance (1H- NMR, 13C- NMR, HMBC combined with HSQC NMR), mass spectroscopy (MS) and infrared (IR) for structure elucidation. From the structure elucidation, it was obvious that the two compounds were phytosterols, which were identified as novel compounds, named stigma sterol glucoside and beta sitosterol glucoside, and another compound was triterpenoids that was identified as novel compound, named beta amyrin.