A survey of bacterial, fungal and plant metabolites against Aedes aegypti (Diptera: Culicidae), the vector of yellow and dengue fevers and Zika virus

Aedes aegypti L. is the major vector of the arboviruses responsible for dengue fever, one of the most devastating human diseases. Some bacterial, fungal and plant metabolites belonging to different chemical subgroups, including Amaryllidaceae alkaloids, anthracenes, azoxymethoxytetrahydropyrans, cytochalasans, 2,5-diketopiperazines, isochromanones, naphthoquinones, organic small acids and their methyl esters, sterols and terpenes including sesquiterpenes and diterpenes, were tested for their larvicidal and adulticidal activity against Ae. aegypti. Out of 23 compounds tested, gliotoxin exhibited mosquitocidal activity in both bioassays with an LC50 value of 0.0257 +/- 0.001 mu g/mu L against 1st instar Ae. aegypti and LD50 value of 2.79 +/- 0.1197 mu g/mosquito against adult female Ae. aegypti. 2-Methoxy-1,4-naphthoquinone and cytochalasin A showed LC 50 values of 0.0851 +/- 0.0012 mu g/mu L and 0.0854 +/- 0.0019 mu g/mu L, respectively, against Ae. aegypti larvae. In adult bioassays, fusaric acid (LD 50 = 0.8349 +/- 0.0118 mu g/mosquito), 3-nitropropionic acid (LD 50 = 1.6641 +/- 0.0494 mu g/mosquito) and a-costic acid (LD50 = 2.547 +/- 0.0835 mu g/mosquito) exhibited adulticidal activity. Results from the current study confirm that compounds belonging to cytochalsin, diketopiperazine, naphthoquinone and low molecular weight organic acid groups are active and may stimulate further SAR investigations.