A novel biflavone di-C-glucoside, 6,6″-di-C-β-D-glucopyranoside-methylene-(8,8″)- biapigenin (1), was isolated from the leaves of Jatropha curcas L. (Euphorbiaceae), together with six known compounds; apigenin 7-O-β-D-neohesperidoside (2), apigenin 7-O-β-Dgalactoside (3), orientin (4), vitexin (5), vicenin II (6), and apigenin (7). Their structures were determined on the basis of extensive chemical and spectroscopic analyses (UV, NMR and HRESI-MS). The immunomodulatory effect of an 80% aqueous methanol extract (AME) and compounds 1 - 5 (0.25 mg/kg body wt) to one-day-old specific pathogen-free (SPF) chicks was determined. Stimulation of both humoral and cell-mediated seroresponse was observed, especially those of AME and compound 1. Remarkable effective increases of the antibody titers, lymphocyte and macrophage cells, in blood were recorded. SPF chicks treated with the tested samples exhibited protection against Newcastle disease challenge virus after being vaccinated.

Two new flavonol glycosides, myricetin 4'-O-α-L-rhamnopyranoside (1) and quercetin 3'-O-α-L-rhamnopyranoside (2), together with a novel biflavonol compound, speciin (3), as well as eleven phenolic metabolites, namely myricitrin (4), europetin 3-O-α-L-¹C₄-rhamnopyranoside (5), quercitrin (6), hyperin (7), rhamnetin 3-O-β-galacto-pyranoside (8), caffeic acid (9), caffeic acid methyl ester (10), chlorogenic acid (11), chlorogenic acid methyl ester (12), gallic acid (13) and gallic acid methyl ester (14), were identified from the 80 % methanol extract of the aerial parts (leaves and stems) of Oenothera speciosa Nutt. (Onagraceae). In addition myricetin (15), quercetin (16) and ellagic acid (17) were identified from the chloroform extract. The structures were established depending on their chemical and physical analyses (UV, HR-ESIMS, 1D and 2D NMR). It was found that 80 % aqueous methanol extract of O. speciosa is non-toxic to mice up to 5 g kg^-1b.wt. The investigated extract exhibited significant antihyperglycaemic and anti-inflammatory activities in a dose dependant manner. Also, the 80 % methanol extract, myricitrin(4) and hyperin(7) showed potent antioxidant activity in vitro using 1,1-diphenyl 2-picryl hydrazyl (DPPH) radical assay.