Larvicidal efficacies of plants from Midwestern Brazil: melianodiol from Guarea kunthiana as a potential biopesticide against Aedes aegypti

A total of 36 ethanol extracts from different anatomical parts of 27 plant species (18 families), native to the Pantanal and Cerrado biomes in Midwest Brazil, was assessed for their effect against Aedes aegypti larvae, the vector of dengue, hemorrhagic dengue, Zika and chikungunya fevers. Only the extract obtained from seeds of Guarea kunthiana (Meliaceae) proved active (LC50 = 169.93 μg/mL). A bioassay-guided investigation of this extract led to the isolation and identification of melianodiol, a protolimonoid, as the active constituent (LC50 = 14.44 mg/mL). Meliantriol, which was also obtained from the bioactive fraction, was nevertheless devoid of any larval toxicity, even at the highest concentration tested (LC50 > 100.0 mg/mL). These results indicate that the larvicidal activity of melianodiol stems from the presence of the carbonyl moiety at C-3 in the 21,23-epoxy-21,24,25-trihydroxy-tirucall-7-ene-type skeleton. The structures of both protolimonoids were established on the basis of spectral methods (1H and 13C NMR and MS). This is the first report on the toxicity of melianodiol against Ae. aegypti larvae. Based on the results, melianodiol can be regarded as a potential candidate for use as an ecologically sound biocontrol agent for reducing the larval population of this vector

Ecological phytochemistry of Cerrado (Brazilian savanna) plants

The Cerrado (the Brazilian savanna) is one of the vegetation formations of great biodiversity in Brazil and it has experienced strong deforestation and fragmentation. The Cerrado must contain at least 12,000 higher plant species.We discuss the ecological relevance of phytochemical studies carried out on plants from the Cerrado, including examples of phytotoxicity, antifungal, insecticidal and antibacterial activities. The results have been classified according to activity and plant family. The most active compounds have been highlighted and other activities are discussed. A large number of complex biochemical interactions occur in this system. However, only a small fraction of the species has been studied from the phytochemical viewpoint to identify the metabolites responsible for these interactions

Further constituents of Galianthe thalictroides (Rubiaceae) and inhibition of DNA topoisomerases I and II alpha by its cytotoxic beta-carboline alkaloids

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)A new cytotoxic beta-carboline alkaloid, 1-methyl-3-(2-hydroxypropan-2-yl)-2-(5-methoxy-9H-beta-carbolin-1-yl)-cyclopentanol (1), was isolated from roots of Galianthe thalictroides, together with the alkaloid 1-(hydroxymethyl)-3-(2-hydroxypropan-2-yl)-2-(5-methoxy-9H-beta-carbolin-1-yl)-cyclopentanol (2), the anthraquinones 1-methyl-alizarin and morindaparvin-A, the coumarin scopoletin, homovanillic alcohol, (-)-epicatechin, and the steroids stigmast-4-en-3-one, 4,22-stigmastadien-3-one, campest-4-en-3-one, stigmast-4-en-3,6-dione, 6-beta-hydroxy-stigmast-4-en-3-one, stigmasterol, campesterol, beta-sitosterol, and beta-sitosterol-3-O-beta-D-glucopyranoside. Among the previously known compounds, homovanillic alcohol is a novel finding in Rubiaceae, while 1-methyl-alizarin, morindaparvin-A, scopoletin, stigmast-4-en-3-one, 4,22-stigmastadien-3-one, campest-4-en-3-one, stigmast-4-en-3,6-dione, and 6-beta-hydroxy-stigmast-4-en-3-one is reported for the first time in the genus Galianthe. The cytotoxic beta-carboline alkaloids 1 and 2 exhibited potent antitopoisomerase I and IIa activities and strong evidence is provided for their action as topoisomerase IIa poisons and redox-independent inhibitors. (C) 2014 Elsevier Ltd. All rights reserved.24513581361Fundect-MSCPq-PROPP-UFMSCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Industrial trial to evaluate the effect of oxygen concentration on overall quality of refined, bleached, and deodorized soybean oil in PET bottles

Soybean oil, owing to its FA composition, is highly susceptible to deterioration by oxidation. The use of nitrogen gas permits the removal of dissolved oxygen and oxygen in the headspace of tanks and bottles. The objective of this work (an industrial trial) was to evaluate the shelf life of soybean oil packaged in polyethylene terephthalate (PET) bottles with different levels of oxygen in the headspace (< 0.3, 5-6.5, 7-9, and > 15%). The quality of the oil was evaluated during 6 mon. FFA and moisture increased and the smoke point decreased in all experimental conditions, even though the difference between the experiments was not significant. An increase was observed for peroxide value (PV), anisidine value (AV), and specific extinction, and higher increases in these parameters were observed in higher oxygen concentrations. After 180 d, the difference between the PV and AV was significant. According to sensory analysis, the shelf life of the oil increased from 60 to 90, 120, and 180 d as the initial concentration of oxygen was reduced from > 15%, 7-9%, 5-6.5%, and 0-3%, respectively. The results demonstrated that shelf life of soybean oil packaged in PET bottles can be significantly increased by using nitrogen to reduce available oxygen in the headspace.83979780