Flavothione (FT) and a series of 18 hydroxy- and methoxy-substituted flavothiones were screened for photobiological activity. The 5-hydroxy-substituted compounds (group 3) and the methoxy-substituted flavothiones were inactive. FT and the remaining hydroxy-substituted compounds, all displayed photobiological activity. Among these, the 3-hydroxy-substituted compounds (group 2) were the most efficient photosensitizers overall in spite of their concurrent fast photodegradation. FT and all other hydroxyflavothiones, not substituted in the 3- or 5-positions (group 1), were inefficient compared with group 2. Detailed photobiological tests were carried out for four flavothiones of groups 1 and 2. The biological tests included fungi, several strains of Escherichia coli, Salmonella typhimurium and mammalian cells. In addition, the ability of these flavothiones to perform lipid peroxidation was evaluated. FT and 6-hydroxyflavothione (group 1) induce DNA damage via H-atom abstraction from the lowest n, pi* triplet state of the thione (oxygen independent). For 3-hydroxy and 3,6-dihydroxyflavothione (group 2), both DNA and the membrane are targets. The mechanism likely involves both energy transfer and electron transfer from the lowest pi, pi* triplet state to oxygen, to form singlet oxygen and the superoxide anion. Some of these compounds could be considered as models for environmentally safe photopesticides.
Flavothione (FT) and a series of 18 hydroxy‐ and methoxy‐substituted flavothiones were screened for photobiological activity. The 5‐hydroxy–substituted compounds (group 3) and the methoxy‐substituted flavothiones were inactive. FT and the remaining hydroxy‐substituted compounds, all displayed photobiological activity. Among these, the 3‐hydroxy–substituted compounds (group 2) were the most efficient photosensitizers overall in spite of their concurrent fast photodegradation. FT and all other hydroxyflavothiones, not substituted in the 3‐ or 5‐positions (group 1), were inefficient compared with group 2. Detailed photobiological tests were carried out for four flavothiones of groups 1 and 2. The biological tests included fungi, several strains of Escherichia coli, Salmonella typhimurium and mammalian cells. In addition, the ability of these flavothiones to perform lipid peroxidation was evaluated. FT and 6‐hydroxyflavothione (group 1) induce DNA damage via H‐atom abstraction from the lowest n, π* triplet state of the thione (oxygen independent). For 3‐hydroxy and 3,6‐dihydroxyflavothione (group 2), both DNA and the membrane are targets. The mechanism likely involves both energy transfer and electron transfer from the lowest π, π* triplet state to oxygen, to form singlet oxygen and the superoxide anion. Some of these compounds could be considered as models for environmentally safe photopesticides.
As Forças Armadas portuguesas confrontam-se com um problema clássico das organizações militares: atrair, formar, reter e preparar a saída dos homens e mulheres que compõem a força. Problema clássico, porém, sempre reatualizado na confluência das mudanças globais repercutidas no setor da Defesa e respetivos contextos sociais e políticos. O presente artigo descreve os movimentos de saída da atividade, por via da passagem à reserva/reforma dos militares de carreira do Exército português. No plano teórico convocam-se modelos da profissão militar à luz dos quais tais processos adquirem sentido. O suporte empírico decorre da análise da legislação enquadrante e de dados quantitativos referentes aos militares que entre 2000 e 2016 passaram à situação de reserva/reforma, um total de 4872 indivíduos. Verifica-se que a reforma é antecedida por um período na reserva, correspondendo maioritariamente a opções individuais de antecipar a saída da carreira, especialmente quando estão iminentes alterações legislativas que afetam a condição militar.
ResumoO artigo reflete sobre o lugar da Sociologia na formação académica de oficiais, tomando como principal referência a Academia M ilitar, instituição onde se formam os oficiais que ingressarão nos quadros do Exército e da Guarda N acional Republicana. Caracteriza-se a presença da Sociologia no ensino universitário militar, faz-se um enquadramento histórico e compara-se tendências internacionais. N este percurso, ressalta a grande diversidade de situações, bem como as resistências que foi necessário ultrapassar. Em Portugal, a incorporação de abordagens sociológicas na Academia M ilitar antecedeu a institucionalização universitária da Sociologia e foi mais precoce e bem aceite do que em países com antigas e fortes tradições sociológicas.
The constituents of the hydroethanolic extract of Azadiracta indica root were investigated using ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UPLC-QTOOF-MS E ). Acute toxicity was evaluated in an experimental animal model. We investigated the antibacterial activities of A. indica roots against Salmonella typhimurium and Staphylococcus aureus and the antifungal activities against strains of Trichophyton rubrum, Candida albicans and Candida tropicalis. We identified nine secondary metabolites in the hydroethanolic extract by UPLC-QTOOF-MS E . The extract was highly effective in inhibiting the growth of T. rubrum strains, so it can be effective in combating the dermatophyte tested, but it had no inhibition potential on any bacterial strains or Candida species evaluated. It was possible to infer that the extract had no acute toxicity in relation to the animal model Danio rerio. Therefore, since neem has a high bioactive potential and adapts well to the climate of semiarid regions, growing this species could become a source of income for farmers by its use to produce naturals fungicide and drug, as alternatives to conventional products, which can cause microbiological resistance and/or are toxic to the environment, besides being expensive.
ResumoEstudos têm reportado o potencial bioativo da Petiveria alliacea, espécime vegetal com compostos bioativos passíveis de serem utilizados no combate e controle de pragas e verminoses, bem como agente bactericida e fungicida. Dentre os agentes com potencial de provocar doenças encontra-se o Aedes aegypti, atualmente o mosquito com maior dispersão em áreas urbanas no mundo. Na agricultura o Lasiodiplodia theobromae, um fungo oportunista, osmopolita e polífago, que sobrevive na atmosfera e nos tecidos, vivos ou mortos, de vegetais encontra-se disseminado em todas as regiões tropicais e subtropicais do mundo. Desta forma, objetivo do presente trabalho é avaliar o limiar tóxico do extrato etanólico das folhas da espécie Petiveria alliacea L. (EEFPA) frente à Artemia salina com a finalidade de determinar a dose máxima a ser utilizada com segurança como planta medicinal, bem como, determinar os metabólitos secundários presentes no extrato através de testes fitoquímicos e avaliar o potencial antioxidante do extrato através do teste DPPH (difenil-picril-hidrazina), verificar o potencial larvicida frente ao mosquito Aedes aegypti e sua atividade fungicida frente ao fungo L. theobromae. A atividade larvicida foi determinada a partir do método Probitos de análise para obtenção da Concentração Letal Média (CL50). A determinação do percentual de crescimento micelial (PIC) do Lasiodiplodia foi realizada conforme metodologia descrita por Menten, 1976. O ensaio para avaliar a atividade antioxidante revelou que o extrato etanólico das folhas da P. alliacea apresentou baixa atividade antioxidante. Na atividade fungicida os resultados também revelaram que o extrato não apresenta atividade frente ao fungo L. thebromae. Contudo, não se 1 Pós-graduação em Ciências Naturais, Universidade Estadual do Ceará,
Research on the application of plant secondary metabolites in integrated pest management is increasing, as the use of these substances can reduce crop production costs, as well as reduce environmental risks and dependence on synthetic insecticides. However, the most widely used methods for insect pest control are still based on the use of synthetic insecticides, which present high risks of toxicity and environmental contamination, as well as high cost. An important phytopathogen for agriculture is the fungus L. theobromae, which is a very aggressive microorganism capable of infecting various plant species and their different organs. The objective of the present work was to develop fungicidal formulations capable of inhibiting the growth of the fungus L. theobromae. Neem extract (Azadiracta indica) formulation was
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