Larvicidal Activity of Mellein from Cultures of an Ascomycete Pezicula Livida against Aedes Aegypti

Mosquito-borne diseases remain one of the major health problems in many developing countries in Sub-Saharan Africa as well as other tropical and sub-tropical countries. The resistance of mosquitoes to synthetic chemicals and environmental toxicity created by the chemicals raised the demand for finding of alternate natural molecules that control mosquito. In the present study, a crystalline compound mullein was isolated from the crude extracts prepared from cultures of an ascomyete Pezicula livida. The crude extracts showed larvicidal activity which was tracked by bio-activity guided chromatographic purification to obtain mellein. The larvicidal activity of mellein was evaluated against late 3rd and early 4th instars larvae of Aedes aegypti. The crude extract exhibited 100% larval mortality of Ae. aegypti at 20 ppm. Mellein had LC50 and LC50 values of 1.4 and 4.3 ppm against Ae. aegypti, respectively at 24 h. Mellein is reported here as larvicidal compound for the first time to our best of knowledge

Larvicidal Activity of Mellein from Cultures of an Ascomycete Pezicula Livida against Aedes Aegypti

Mosquito-borne diseases remain one of the major health problems in many developing countries in Sub-Saharan Africa as well as other tropical and sub-tropical countries. The resistance of mosquitoes to synthetic chemicals and environmental toxicity created by the chemicals raised the demand for finding of alternate natural molecules that control mosquito. In the present study, a crystalline compound mullein was isolated from the crude extracts prepared from cultures of an ascomyete Pezicula livida. The crude extracts showed larvicidal activity which was tracked by bio-activity guided chromatographic purification to obtain mellein. The larvicidal activity of mellein was evaluated against late 3rd and early 4th instars larvae of Aedes aegypti. The crude extract exhibited 100% larval mortality of Ae. aegypti at 20 ppm. Mellein had LC50 and LC50 values of 1.4 and 4.3 ppm against Ae. aegypti, respectively at 24 h. Mellein is reported here as larvicidal compound for the first time to our best of knowledge

Antimicrobial prenylated acetophenones from berries of Harrisonia abyssinica

The ripe berries of Harrisonia abyssinica yielded two new prenylated acetophenones, namely 5-(ethan-1‴-one)-4,6-dihydroxy-7-(3″, 3″-dimethylallyl)-2S-(1′S-hydroxy-1′,5′-dimethylhex- 4′-enyl)-2,3-dihydrobenzofuran (1) and 5-(2″′-hydroxyethan- 1″′-one)-4,6-dihydroxy-7-(3″,3″-dimethylallyl) -2S-(1′S-hydroxy-1′,5′-dimethylhex-4′-enyl)-2, 3-dihydrobenzofuran (2), herein named harronin I and harronin II, respectively. The compounds were isolated following activity guided fractionation and the structures were determined using 1D, 2D NMR spectroscopic, CD and MS spectrometric techniques. The methanol-dichloromethane mixture (1: 1 v/v) crude extract exhibited strong antimicrobial activity against Candida albicans, Bacillus cereus, Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, and Lactobacillus casei. Harronin I (1) showed a MIC of 5 μg/mL against C. albicans, 6 μg/mL against B. cereus, and more than 20 μg/mL against other tested microorganisms. Harronin II (2) showed much weaker MIC values (> 100 μg/mL) against all the tested microorganisms. © Georg Thieme Verlag KG Stuttgart

Low antiplasmodial activity of alkaloids and amides from the stem bark of Zanthoxylum rubescens

The stem bark of Zanthoxylum rubescens (syn. Fagara rubescens) is used for treating fevers associated with malaria in the Ivory Coast. Three alkaloids: N-nornitidine, 7,9-dimethoxy-2,3- methylenedioxybenzophenanthridine, and bis[6-(5,6- dihydrochelerythrinyl)] ether; and two amides: zanthomamide and lemairamide, were isolated from the stem bark of this plant. These compounds were screened in vitro against the chloroquine-sensitive 3D7 strain and the chloroquine-resistant FCM29 strain of P. falciparum. N-nornitidine was found to be inactive. 7,9- dimethoxy-2,3-methylenedioxybenzophenanthridine, lemairamide and zanthomamide showed weak activity with average IC50 values ranging from 45.6 μM to 149.9 μM. Bis[6-(5,6- dihydrochelerythrinyl)] ether was the most active of the tested compounds with mean IC50s of 14.9 ± 1.4 μM in FCM29 strain and 15.3 ± 3.4 μM in 3D7 strain (~ 58 to ~ 1130 times less active than chloroquine respectively). The anti-Plasmodium activities of the tested alkaloids of Z. rubescens were low; and do not encourage the use of this plant as antimalarial