Because of the evolving resistance of microorganisms against existing antibiotics, there is an increasing need for new ones, not only in human, but also in veterinary medicine. The dichloromethane extract of a fungal strain of the genus Lophiostoma, isolated from driftwood collected from the coast of the Baltic Sea, displayed antibacterial activity against some fish pathogenic bacteria. Ergosterol epoxide (1), cerebroside C (2) and oxasetin (3) were isolated from the extract and structurally elucidated on the basis of spectroscopic data and chemical evidence. Compound 3 exhibited in vitro activity against Vibrio anguillarum, Flexibacter maritimus and Pseudomonas anguilliseptica with minimal inhibitory concentrations of 12.5, 12.5 and 6.25 microg/mL, respectively. Molecular docking studies were performed to understand the interaction of compound 3 with different macromolecular targets. Analysis of in silico results, together with experimental findings, validates the antimicrobial activity associated with compound 3. These results may be exploited in lead optimization and development of potent antibacterial agents. arabic 23 English 137
Muftah A Shushni, Faizul Azam, Ulrike Lindequist, (9-2013)

Mosquitoes can transmit more diseases than any other group of arthropods and affect millions of people throughout the world. They act as a vector for most of the life-threatening diseases like malaria, yellow fever and dengue fever. The major tool in mosquito control operation is the application of synthetic insecticides such as organochlorine and organophosphate compounds. Use of many of the former synthetic insecticides in mosquito control program has been limited due to high cost, environmental sustainability, harmful effect on human health, and other non-target populations, their non-biodegradable nature, higher rate of biological magnification through ecosystem, and increasing insecticide resistance on a global scale. One of the most effective alternative approaches under the biological control program is to explore the floral biodiversity and enter the field of using safer insecticides of botanical origin as a simple and sustainable method of mosquito control. This study aimed to evaluate larvicidal and pupicidal effect of five plant extracts (thyme, peppermint and citronella leaf extracts, clove buds extracts and lemon peels extract). Methanol extracts of thyme, peppermint and citronella leaf, clove buds and lemon peels were tested for their larvicidal and pupicidal activity. The standard WHO guideline for larvicides and pupicides evaluation was used. Three plant extract concentrations were prepared (25, 50 and 100 mg/ml) and tested on 20 larvae and 20 pupas (3rd and 4th instars) for each concentration on white enamel trays. Mortality percentage were calculated after 24 hrs. where larvae who doesn’t show swimming movement considered dead. Adult mosquitoes were identified to genus level. Thyme showed the highest % of yield (56%) followed by clove, peppermint, lemon and citronella with 13, 13, 8 and 5 % of yield respectively. The highest mortality % of larvae were by clove with 100% for the three tested concentrations, followed by thyme, lemon and peppermint. Citronella gave no effect as larvicidal agent. In pupicida activity test, thyme showed the highest activity followed by clove. Lemon didn’t show any pupicidal activity. Mosquito was identified as Culex. This result clearly reveals that buds extract of E. caryophyllus and leaf extracts of T. vulgaris and peels extract of C. limonoids could serve as a potential larvicidal agents against the Culex mosquito. The mode of action and larvicidal efficiency of these plant spp. extract should be scrutinized and determined. Besides, further investigation regarding the effect on non-target organism is extremely important and imperative in the near future. arabic 11 English 79
Sakina Salem Mohammed Saadawi, , , (4-2019)

The antibacterial activity of peppermint oil and different extracts of Mentha piperita against some Gram-positive and Gram-negative bacterial strains was evaluated in the present research work by agar well diffusion method. It was found that the distilled concentrations of essential oil inhibited the growth of microorganisms and the results were comparable with those of antibiotic gentamycin. Essential oils showed a wider spectrum of activity but less strong inhibition as compared to the investigated commercial antibiotic. Minimum inhibitory concentrations (MICs) for the bacterial species ranged from 0.4% to 0.7% v/v. The oil and extracts also exhibited significant antioxidant activity and the oil showed about half potency when compared to the standard BHT. These results indicated the strong antibacterial and antioxidant activities of peppermint oil but additional investigations need to be performed in order to confirm the safety of these concentrations (MIC) for human consumption. Peppermint oil could be used as a good conservation agent by inhibiting some food borne pathogens. arabic 8 English 54
Rajinder Singh, Muftah A. Shushni, Asma Belkheir(5-2015)