Determination of antioxidant and antimicrobial activities of the extracts of aerial parts of Portulaca quadrifida.

Background: The extracts from the aerial parts of Portulaca quadrifida have been reported to show the total flavonoid content, antioxidant and antibacterial activities.

Results: Our results revealed that the total flavonoid content of methanol and chloroform extracts is 2.335 ± 0.

Determination of antioxidant and antimicrobial activities of leaf extracts of Otostegia integrifolia.

Background: The extracts from the leaves of Otostegia integrifolia have been reported to show phytochemical analysis, total flavonoid content, antioxidant and antibacterial activities.

Results: Our results revealed that the total flavonoid content of methanol and ethyl acetate extracts is 416.5 + 0.

Three new isoflavonoids from Erythrina caffra.

Three new isoflavonoids, 5,7-dihydroxy-2',4'-dimethoxy-5'-(3-methylbut-2-enyl) isoflavanone (erycaffra A) (1), 5,7-dihydroxy-2',4'-dimethoxy-5'-(2-hydroxy-3-methylbut-3-enyl)isoflavanone (erycaffra B) (2), and 5,7-dihydroxy-6,8-di-(2-hydroxy-3-methylbut-3-enyl)isoflavone (erycaffra C) (3), were isolated from the stem bark of E. caffra Thunb., along with eight known compounds, namely, alpinumisoflavone (4), isoerysenegalensein E (5), beta-amyrin (6), oleanolic acid (7), octacosyl-E-ferulate (8), triacontyl-4-hydroxycinnamate (9), n-tetracosyl p-coumarate (10) and octacosan-1-ol (11).

New flavonoids from the stem bark of Erythrina caffra Thunb.

Three new flavonoids 5,7-dihydroxy-2',4'-dimethoxy-5'-formylisoflavanone (erycaffra E) (1), 5,7-dihydroxy-3'-(2″-hydroxy-3″-methylbut-3-enyl)-5'-(3‴-hydroxy-3‴-methyl-trans-but-1-enyl)-4'-methoxyflavanone (erycaffra D) (2) and 5,7-dihydroxy-4'-methoxy-3',5'-di-(3″-hydroxy-3″-methyl-trans-but-1-enyl)flavanone (erycaffra F) (3) were isolated from the stem bark of Erythrina caffra along with four known compounds, namely 5,4'-dihydroxy-6-(3″-methylbut-2″-enyl)-5‴-hydroxyisopropyldihydrofurano[2‴,3‴:7,8]isoflavone (isosenegalensein) (4), 5,7-dihydroxy-4'-methoxy-3'-(3″-methylbut-2-enyl)-5'-(3‴-hydroxy-3‴-methylbut-1-enyl)flavanone (burttinone) (5), 5,4'-dihydroxy-5″-hydroxyisopropyldihydrofurano[2‴,3‴:7,6]isoflavone (erythrinin C) (6) and 5,4'-dihydroxy-6″-hydroxymethyl-6″-methylpyrano[2″,3″:6,7]isoflavone (erysubin B) (7). The structures were determined on the basis of spectroscopic data (1D, 2D NMR and MS) and by comparison with literature values.

Reactions of salicylaldehyde and enolates or their equivalents: versatile synthetic routes to chromane derivatives.

The reported methodologies for the synthesis of chromane derivatives through the reaction of salicylaldehyde and enolates are discussed. The enolates and their equivalents involved in the reactions discussed in this article were derived from ketones, nitroalkanes, malononitrile and α,β-unsaturated compounds.