Circadian Rhythm and Larvicidal Activity Against Aedes aegypti of Essential Oils from Croton piauhiensis

Croton piauhiensis, popularly known as velame, is a restricted species of Caatinga biome. In this context, this work aims to study for the first time the circadian cycle and larvicidal activity against Aedes aegypti of the essential oils from C. piauhiensis. The chemical composition of the essential oils from leaves obtained by hydrodistillation was analyzed and identified by GC-MS and GC-FID. According to the results, the circadian study showed differences in the chemical composition of oils extracted from C. piauhiensis leaves collected at different hours of the day. The major components of essential oils from C. piauhiensis collected at 8, 12 and 17 h, were beta-caryophyllene 21.58, 34.69 and 21.01 %, D-limonene 13.47, 13.75 and 16.35, gamma-terpinene 10.08, 8.00 and 9.60 %, germacrene D 9.56, 10.42 and 8.71 %, respectively. Sesquiterpenes contents were 52.59 % and 67.29 % at 8 and 12 h, respectively. On the other hand, at in the oil collected 17 h there was a greater predominance of the monoterpenes (50.77 %). Regarding the larvicidal activity, the essential oils of C. piauhiensis showed larvicidal activity with LC50 = 336.8 mu g / mL (oil extracted at 8:00 h), LC50 = 283.9 mu g/mL (oil extracted at 12:00 h) and LC50 = 252.5 mu g/ml (oil extracted at 17:00 h).