Larvicidal activity of Ramalina usnea lichen against Aedes aegypti

The larvicidal activity of the methanol extract, fractions and compounds 2-hydroxy-4-methoxy-6-propyl-methyl benzoate and (+)-usnic acid identified from the lichen Ramalina usnea (L.) R. Howe, Ramalinaceae, was tested against the third instar larvae of the Aedes aegypti mosquito. The methanol extract and three fractions showed activity, killing 100% and 96.6% of the larvae at a concentration of 150 mu g/ml at 24 h. The isolated compounds, 2-hydroxy-4-methoxy-6-propyl-methyl benzoate and the (+)-usnic acid showed larvicidal activity, presenting LC50 values of 4.85 and 4.48 mu g/ml, respectively. This is the first study of its kind reporting the larvicidal activity against the A. aegypti mosquito with compound (1). (C) 2016 Sociedade Brasileira de Farmacognosia. Published by Elsevier Editora Ltda.