Special metabolites isolated from Urochloa humidicola (Poaceae)

ABSTRACT This study aims to identify special metabolites in polar extracts from Urochloa humidicola (synonym Brachiaria humidicola) that have allelopathic effects and induce secondary photosensitization in ruminants. The compounds were isolated and identified via chromatographic and spectroscopic techniques. The compounds 4-hydroxy-3-methoxy-benzoic acid, trans-4-hydroxycinnamic acid, and p-hydroxy-benzoic acid; the flavonols isorhamnetin-3-O-β-d-glucopyranoside and methyl quercetin-3-O-β-d-glucuronate; and kaempferitrin, quercetin-3-O-α-l-rhamnopyranoside, and tricin were identified in the extract from the leaves of Urochloa humidicola. Two furostanic saponins, namely, dioscin and 3-O-α-l-rhamnopyranosyl-(1-4)-[α-l-rhamnopyranosyl-(1-2)]-β-d-glucopyranosyl-penogenin, as well as catechin-7-O-β-d-glucopyranoside were identified in the methanolic extract obtained from the roots of this plant. This species features a range of metabolites that may be toxic for animals if used in food and may interfere with the growth medium, thereby inhibiting the development of other species.

Bulk copolymerization of acrylamide and crotonic acid

Bulk copolymerization of acrylamide and crotonic acid has been carried out. The results indicate that both monomers form copolymer in all monomeric ratios. The induction period is 40 minutes. The increasing concentration of acrylamide and benzoyl peroxide and increase in temperature and time enhance the rate of formation of copolymer. Monomer reactivity ratios of acrylamide and crotonic acid are determined experimentally using the rearranged form of copolymer composition equation. Molecular weight of the copolymer samples show that the copolymer of low molecular weight may be prepared at high temperature. All copolymer samples are white crystalline substances that become light brown at 200-210°C and burn when temperature reaches to 270°C