Susceptibly of Alphitobius diaperinus to Beauveria bassiana extracts.

Alphitobius diaperinus is an important pathogen with worldwide distribution that causes severe economic loss of efficiency in broilers. This study evaluates the potential of organic extracts of two strains entomopathogenic fungus Beauveria bassiana (CG71 and UNI40) as a biocontrol agent on A. diaperinus and promotes the phytochemical investigation. The effective percentages of mortalities were 95.97% (UNI40 methanolic extract), 69.23, 64.64, and 50.39% (CG 71 methanolic, ethyl acetate and butanol extracts). However, there was a decrease in the lesser mealworms susceptibility in relation to the use of insecticides and extracts. The metabolites 5-hydroxymethyl-2-furanoic acid, dipicolinic acid and monomethyl dipicolinate were isolated from ethyl acetate extract, and ß-adenosine of butanolic extract of B. bassiana CG 71. In addition, the cyclodepsipeptides were identified in methanolic extracts of the two strains. The insecticide activity results indicated that the B. bassiana extracts are an alternative to A. diaperinus control.

Phytochemical and antifungal activity of anthraquinones and root and leaf extracts of Coccoloba mollis on phytopathogens

The aim of this work was to study the phytochemical and antifungal activity of anthraquinones and root and leaf extracts of Coccoloba mollis on phytopathogens. The chemical analysis of ethanolic extracts showed a mixture of long-chain hydrocarbons, carboxyl esters and 3-taraxerone in the leaf extract. Two anthraquinones (emodin and physcion) were isolated and identified from the root extract. Phytochemical screening using the pharmacognostic methods revealed the presence of flavonoids and tannins in the leaves and roots. Anthraquinones were only found in the root extract, no alkaloids, coumarins, saponins and simple phenolics were present. The antifungal activity of C. mollis extracts and anthraquinones isolated from the root of this plant against Botryospheria ribis, B. rhodina, Lasiodiplodia theobromae and Fusarium sp showed promising results for their use as fungicides, where emodin was the most active compound, which inhibited the microorganisms tested up to 44 percent.

Antimicrobial activity of essential oils from Pimenta pseudocaryophyllus and Tynanthus micranthus

The present study describes the chemical composition and antimicrobial activity of essential oils obtained by hydrodistillation from the leaves of Pimenta pseudocaryophyllus (1.0 percent w/w) and Tynanthus micranthus (1.1 percent w/w). GC and GC/MS analysis demonstrated that eugenol was the only component in the T. micranthus essential oil (99.9 percent) and the major component in the P. pseudocaryophyllus essential oil (92.59 percent), which also presented methyleugenol, terpinen-4-ol, o-cymene and (E)-caryophyllene, among others. Both the oils presented antimicrobial activity against bacteria, yeast and filamentous fungi tested.The Bioautography test revealed that eugenol was the bioactive component in both the oils against Cladosporium herbarum. This is the first report about the T. micranthus essential oil, and the antifungal activity of P. pseudocaryophyllus. The results confirmed the potential of eugenol-rich essential oils not only as a source of flavor compounds, but also of use as antimicrobial agent in agriculture and in pharmaceutical and food products.

O presente trabalho descreve a análise da composição química e a avaliação da atividade antimicrobiana dos óleos essenciais obtidos por hidrodestilação das folhas de Pimenta pseudocaryophyllus (1.0 por cento m/m) e de Tynanthus micranthus (1.1 por cento m/m). As análises por CG e CG-EM demonstraram que o óleo essencial de P. pseudocaryophyllus apresenta o eugenol como componente principal (92.6 por cento ), além de outros constituintes como methyleugenol, tepinen-4-ol, O-cimeno e (E)-cariofileno. O óleo de T. micranthus contém o eugenol como único constituinte (99.9 por cento). Ambos os óleos apresentaram atividade contra bactérias, leveduras e fungos filamentosos. O teste de bioautografia revelou o eugenol como a substância responsável pela atividade contra o Cladosporium herbarum dos óleos das duas espécies. Este é o primeiro estudo sobre o óleo essencial de T. micranthus e o primeiro relato sobre a atividade antifúngica do óleo essencial de P. pseudocaryophyllus. Os resultados obtidos confirmaram o potencial de óleos essenciais ricos em eugenol para uso como agentes antimicrobianos na agricultura e na preparação de produtos alimentícios e farmacêuticos.