No abstract

Delonix regia (Bojer ex Hook.) Raf. (Fabaceae) is an umbrella-shaped tree reaching up to 40 feet high and with large red-orange flowers. Its leaves are alternate, bipinnately compounded, having 10 to 20 pairs of major leaflets and fruits are 30-50 cm long. It grows all over Bangladesh and has folkloric reputation as a medicinal agent. D. regia is used as a diuretic, anthelmintic and astringent (1, 2). It is also used in leucorrhoea. In this study, five compounds, lupeol (1), epilupeol (2), b-sitosterol (3), stigmasterol (4) and p-methoxybenzaldehyde (5) were isolated from the petroleum ether and dichloromethane fractions of a methanolic extract of the stem bark of Delonix regia. Antimicrobial screening of the different extracts (15 mg mm -2 ) was conducted by the disc diffusion method. The zones of inhibition demonstrated by the petroleum ether, carbon tetrachloride and dichloromethane fractions ranged from 9-14 mm, 11-13 mm and 9-20 mm, respectively, compared to kanamycin standard with the zone of inhibition of 20-25 mm. In brine shrimp lethality bioassay, the carbon tetrachloride soluble materials demonstrated the highest toxicity with LC 50 of 0.83 mg mL -1 , while petroleum ether and dichloromethane soluble partitionates of the methanolic extract revealed LC 50 of 14.94 and 3.29 mg mL -1 , respectively, in comparison with standard vincristine sulphate with LC 50 of 0.812 mg mL -1 . This is the first report on compounds separation from D. regia, their antimicrobial activity and cytotoxicity.

ABSTRACT:The antimicrobial activity of methanol extracts of 17 plant species of Bangladesh was evaluated by the agar disc diffusion method. Among those, eight plant extracts exhibited potent antimicrobial activity against a wide variety of Gram positive and Gram negative bacteria and fungi at a concentration of 400 µg /disc.

Structure–activity relationship and crystallographic studies on HIF prolyl hydroxylase inhibitors reveal spiro[4.5]decanones as useful templates for generation of potent and selective 2OG oxygenase inhibitors.