M. Ekramul Haque

Antimicrobial activity and cytotoxicity of Trapa bispinosa

The extracts of Trapa bispinosa showed interesting antimicrobial activity against Gram-positive and Gram-negative test organisms and significant cytotoxic activity.

Antibacterial activity and cytotoxicity of Nyctanthes arbor-tristis flowers.

The flowers of Nyctanthes arbor-tristis showed interesting antibacterial activity against some gram-positive and gram-negative microorganisms (chloroform and ethyl acetate extracts) and significant cytotoxic activity (petroleum ether, chloroform and ethyl acetate extracts).

Mosquitocidal triterpenes from the stem of Duranta repens

Two triterpenes, β-amyrin and 12-oleanene 3β, 21β-diol, were isolated as a mixture from the chloroform soluble fraction of an ethanol extract of Duranta repens Linn (Verbenaceae) stem. The structures of the two compounds were confirmed by analysis of their IR, 1H-NMR, 13C-NMR and LC-MS spectral data. The mixture of β-amyrin and 12-oleanene 3β, 21β-diol (compound 1) was highly effective against the larvae of the mosquito, Culex quinquefasciatus Say (Diptera: Culicidae), as a mosquitocide.

Antibacterial compounds from the flowers of Alangium salviifolium

1-Methyl-1H-pyrimidine-2,4-dione and 3-O-beta-D-glucopyranosyl-(24beta)-ethylcholesta-5,22,25-triene, isolated from the flowers of Alangium salviifolium, showed remarkable antibacterial activities against a number of Gram-positive and Gram-negative bacterial species.

Toxicological Evaluation of Goniothalamin Isolated from Bryonopsis laciniosa Linn, in Rats

The potential toxicity of goniothalamin isolated from Bryonopsis laciniosa Linn., used in folk medicine in Bangladesh, was evaluated in rats. Goniothalamin (300 μg) was administered daily for 14 days, and the effect on body weight, haematology and biochemical parameters of the blood was studied. There was no significant difference between weight gain in rats receiving goniothalamin and control rats (130.6 ± 5.5 vs 128.6 ± 3.6 g, respectively). There were no significant changes detected in haematology (red blood cells, 5.42 ± 0.08 vs 5.62 ± 0.31 (cells mL−1) × 106; white blood cells, 12525 ± 163 vs 12250 ± 178 (cells mL−1) × 106; platelets, 360000 ± 12247 vs 340000 ± 1224 (cells mL−1) × 106; haemoglobin, 14.15 ± 0.49 vs 13.77 ± 0.28%, for experimental and controls rat, respectively) or blood biochemistry (serum glutamic-oxaloacetic transaminase, 11.75 ± 1.08 vs 10.75 ± 1.92 int. units L−1; serum glutamate puruvate transaminase 7.25 ± 1.29 vs 8.75 ± 1.29 int. units L−1; serum alkaline phosphatase, 44.25 ± 2.86 vs 38.75 ± 3.36 int. units L−1; uric acid, 7.30 ± 0.40 vs 7.05 ± 6.12 mg dL−1; urea, 43.75 ± 3.03 vs 38.75 ± 4.75 mg dL−1; creatinine, 1.08 ± 0.15 vs 1.06 ± 0.18 mg dL−1 for experimental and control rats, respectively). Goniothalamin (300 μg/day) over 14 days, had no toxic effects in rats.

Antishigellosis and Cytotoxic Potency of Crude Extracts and Isolated Constituents from Duranta repens

The crude ethanol extracts (stem and fruits), their fractions and two triterpenes, β-Amyrin and 12-Oleanene 3β, 21β-diol, isolated as a mixture from the chloroform soluble fraction of an ethanolic extract of Duranta repens stem, were evaluated for antibacterial, antifungal activities by the disc diffusion method and cytotoxicity by brine shrimp lethality bioassay. The structures of the two compounds were confirmed by IR, 1 H-NMR, 13 C-NMR and LC-MS spectral data. The chloroform soluble fraction of stem and ethanol extract of fruits possess potent antishigellosis activity and also exhibited moderate activity against some pathogenic bacteria and fungi but the isolated compound 1 (mixture of β-Amyrin and 12-Oleanene 3β, 21β-diol) showed mild to moderate inhibitory activity to microbial growth. The minimum inhibitory concentrations (MICs) of the extracts (stem and fruits), their fractions and compound 1 were found to be in the range of 32~128 μg/ml. The chloroform soluble fractions of stem and ethanol extract of fruit showed significant cytotoxicity with LC50 value of 0.94 μg/ml and 0.49 μg/ml, respectively against brine shrimp larvae.

Antimicrobial and cytotoxic activities of Laportea crenulata

Crude extracts and 2alpha,3beta,21beta,24beta,28-pentahydroxy-olean-12-ene (1) obtained from the root of Laportea crenulata exhibited remarkable antibacterial activities against both Gram (+) and Gram (-) bacteria. The antifungal activities of crude extracts and compound (1) were also determined. The cytotoxic activities of crude extracts and compound (1) were observed by brine shrimp bioassay and LC(50) value of the compound (1) was found to be 27.54 microg/ml.