New sesquiterpene lactones from the Portuguese liverwort Targionia lorbeeriana

Three new sesquiterpene lactones (acetyltrifloculoside, 8,15-acetylsalonitenolide and 8-acetylsalonitenolide) and two known sesquiterpene lactones were isolated from a dichloromethane extract of the Portuguese liverwort Targionia lorbeeriana. Their structures were established by spectroscopic methods (EI and D/CI mass spectroscopy, 1H and 13C NMR) and that of acetyltrifloculoside was confirmed by X-ray crystallography. The three isolated guaianolide sesquiterpene lactones presented antifungal activity against Cladosporium cucumerinum and larvicidal activity against Aedes aegypti. Only one of the isolated lactones presented activity against Candida albicans

Absolute Configuration of a Tetrahydrophenanthrene from Heliotropium ovalifolium by LC-NMR of Its Mosher Esters

A new tetrahydrophenanthrene (1, (1R,2R)-1-hydroxy-2-methoxy-6,9-dimethyl-2,3-dihydrophenanthren-4(1H)-one (heliophenanthrone)) has been isolated from the aerial parts of Heliotropium ovalifolium. Its structure was elucidated on the basis of spectroscopic data, and the absolute configuration of the asymmetric centers was determined from LC-NMR data of the Mosher ester derivatives

Two new tropane alkaloids from the bark of Erythroxylum vacciniifolium Mart. (Erythroxylaceae)

Two new tropane alkaloid N-oxides substituted by a methylpyrrole moiety were isolated from the bark of Erythroxylum vacciniifolium Mart. (Erythroxylaceae), a Brazilian indigenous plant, locally known as catuaba and used in traditional medicine as an aphrodisiac. The alkaloid structures were determined by a combination of high resolution mass spectrometry and multi-dimensional NMR spectroscopy

Mosquito larvicidal activities of Solanum villosum berry extract against the dengue vector Stegomyia aegypti

<p>Abstract</p> <p>Background</p> <p>Vector control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. Although several plants have been reported for mosquitocidal activity, only a few botanicals have moved from the laboratory to field use, because they are poorly characterized, in most cases active principals are not determined and most of the works are restricted to preliminary screening. <it>Solanum villosum </it>is a common weed distributed in many parts of India with medicinal properties, but the larvicidal activity of this plant has not been reported so far.</p> <p>Methods</p> <p>Aqueous and polar/non-polar solvent extract of fresh, mature, green berries of <it>S. villosum </it>was tested against <it>Stegomyia aegypti</it>, a common vector of dengue fever. A phytochemical analysis of chloroform:methanol extract was performed to search for the active toxic ingredient. The lethal concentration was determined (log probit analysis) and compared with Malathion. The chemical nature of the active substance was also evaluated following ultraviolet-visual (UV-Vis) and infrared (IR) analysis.</p> <p>Results</p> <p>In a 72 hour bioassay experiment with the aqueous extract, the highest mortality was recorded in 0.5% extract. When the mortality of different solvent extracts was compared, the maximum (<it>p </it>< 0.05) mortality was recorded at a concentration of 50 ppm of chloroform:methanol extract (1:1, v/v). The larvicidal activity was lower when compared with the chemical insecticide, Malathion (<it>p </it>< 0.05). Results of regression analysis revealed that the mortality rate (<it>Y</it>) was positively correlated with the period of exposure (<it>X</it>) and the log probit analysis (95% confidence level) recorded lowest value (5.97 ppm) at 72 hours of exposure. Phytochemical analysis of the chlororm:methanol extract reported the presence of many bioactive phytochemicals. Two toxic compounds were detected having <it>R</it>_f= 0.82 (70% and 73.33% mortality in 24 and 48 hours, respectively) and <it>R</it>_f= 0.95 (40% and 50% mortality in 24 and 48 hours, respectively). IR analysis provided preliminary information about the steroidal nature of the active ingredient.</p> <p>Conclusion</p> <p><it>S. villosum </it>offers promise as potential bio control agent against <it>S. aegypti </it>particularly in its markedly larvicidal effect. The extract or isolated bioactive phytochemical could be used in stagnant water bodies for the control of mosquitoes acting as vector for many communicable diseases.</p