Phytochemical study of Waltheria viscosissima and evaluation of its larvicidal activity against Aedes aegypti

Abstract The species Waltheria viscosissima A.St. – Hil, Malvaceae, which is known as ‘ malva-branca', is traditionally used in the Brazilian northeast for the treatment of coughs. This research looks towards reporting the isolation of phytoconstituents of W. viscosissima, as well as the quantification of its phenolics, total flavonoid content, and free radical scavenging potential, along with an evaluation of its larvicidal activity against Aedes aegypti larvae. Chromatographic techniques were used to isolate the compounds and a structural elucidation was performed by 1D and 2D NMR. The quantification of total phenolics and flavonoids and the DPPH ˙ radical scavenging activity was determined through spectrophotometric methods. Consequently, the phytochemical investigation led to the identification of fourteen compounds from the aerial parts of the W. viscosissima: steroids, triterpenes, alkaloids, and eight flavonoids previously reported in the literature. The quantification of compounds showed that the aerial parts extract possessed high concentration of flavonoids, while the roots extract were rich in other phenolic compounds. At the DPPH ˙ free radical scavenging assay, the roots extract presented EC50 = 77.32 ± 4.37 µg/ml and the aerial parts extracts showed EC50 = 118.10 ± 1.21 µg/ml. W. viscosissima roots extract showed the most potent larvicidal activity against Ae. aegypti (LC50 = 4.78 mg/ml), with the potential of being used i...
Source: Revista Brasileira de Farmacognosia - Category: Drugs & Pharmacology Source Type: research

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(American Association for the Advancement of Science) A team of nine researchers based in the United States and Burkina Faso will receive the 2019 Newcomb Cleveland Prize, presented by the American Association for the Advancement of Science, for the development of a promising tool in the global fight against malaria and other diseases transmitted by mosquitoes, including dengue and Zika.
Source: EurekAlert! - Medicine and Health - Category: International Medicine & Public Health Source Type: news
(University of Maryland) The American Association for the Advancement of Science (AAAS) awarded its 2019 Newcomb Cleveland Prize to University of Maryland entomologists Raymond St. Leger, Brian Lovett and their seven West African collaborators for their study describing the development and testing of a genetically engineered fungus to fight mosquito-borne diseases such as malaria, dengue&Zika.
Source: EurekAlert! - Medicine and Health - Category: International Medicine & Public Health Source Type: news
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Source: Viruses - Category: Virology Authors: Tags: Article Source Type: research
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Source: EurekAlert! - Infectious and Emerging Diseases - Category: Infectious Diseases Source Type: news
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Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research
Source: International Journal of Infectious Diseases - Category: Infectious Diseases Authors: Source Type: research
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Source: EurekAlert! - Infectious and Emerging Diseases - Category: Infectious Diseases Source Type: news
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Source: Acta Neurologica Belgica - Category: Neurology Source Type: research
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Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research
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Source: Environmental Health Insights - Category: Environmental Health Authors: Tags: Environ Health Insights Source Type: research
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