lipid and flavonoidal constituents of Herniaria nemistemon J.gay and their biological activity

The LIPID content of Herniaria nemistemon grown in Egypt was studied. The unsaponifiable fraction was identified by GLC. A series of hydrocarbons ranging from C[20]-C[32], in addition to cholesterol, campasterol, stigmasterol, beta-sitosterol, and the triterpenoid alpha-amyrin, as well as fatty alcohol fraction ranging from C[31]-C[38] were identified. The fatty acid fraction revealed the presence of the 14 fatty acids in which palmitic acid [21.62%] represented the major constituent. The flavonoidal constituents isolated from the chloroform and ethyl acetate fractions of aqueous alcoholic extract of H. nemistemon were identified as kaempferol, quercetin-3-O-glucoside-7-O-rhamnoside, kaempferol 7-O-rhamnoglucosyl, vitexin and kaempferol 4'-methyl ether, using PC, TLC, UV,[1] H-NMR and MS analysis. The different extracts and isolated compounds were evaluated for antioxidant activity against [DPPH]. The ethyl acetate extract possessed the highest antioxidant activity followed by chloroform extract, and the fraction containing triterpene and sterols presented a relatively strong antioxidant effect, also it was found that all the isolated flavonoidal compounds showed high activity. The different extracts and isolated compounds of the plant exhibited no cytotoxic activity against Ehrlich-ascites carcinoma cell line at the tested concentrations

Stimulation of rosmarinic acid, essential oil and anthocyanin biosynthesis of in vitro cultures of lemon basil [ocimum americanum L.] in response to different cultural conditions

Shoot-tip explants of germinated plantlets of O. americanum were inoculated aseptically on MS-medium hormone-free and MS supplemented with different concentrations of NAA and/or BA. Stimulation of rosmarinic acid synthesis in leaf, stem and root derived calli in response to increasing levels of NaCl as salt stress in the culture media was examined. The proliferated shoots, roots and the stressed callus tissues were subjected to rosmarinic acid analysis by HPLC. However, leaf-derived callus was investigated under light and dark conditions and increasing levels of 2,4-D in the culture media for essential oil content, composition and anthocyanin accumulation. The obtained results indicated that both in vitro produced shoots and roots of all treatments accumulated high rosmarinic acid content than intact plant. Increasing NaCl concentration in the culture media up to 0.3% caused a reduction in rosmarinic acid content of leaf and stem derived callus tissues. Moreover, callus tissues incubated under dark condition showed higher values of volatile oil [%] as compared with callus tissues grown under illumination. The sesquiterpenes content of the essential oil were the best under light condition, while monoterpene hydrocarbons and oxygenated monoterpene were higher under dark condition. The higher values of anthocyanins was recorded with callus tissues grown under light condition. It is observed that anthocyanin synthesis is influenced by levels of 2,4-D added to the culture media