RESUMO
Propolis of Australian stingless bees (Tetragonula carbonaria, Meliponini) originating from Corymbia torelliana (Myrtaceae) fruit resins was tested for its antimicrobial activities as well as its flavonoid contents. This study aimed at the isolation, structural elucidation and antibacterial testing of flavanones of C. torelliana fruit resins that are incorporated into stingless bee propolis. Flavanones of this study were elucidated by spectroscopic and spectrometric methods including UV, 1D and 2D NMR, EI-MS, ESI-MS and HR-MS. The results indicated known C-methylated flavanones namely, 1 (2S)-cryptostrobin, its regioisomer 2 (2S)- stroboponin, 3 (2S)- cryptostrobin 7-methyl ether, and 6 (2S)- desmethoxymatteucinol, and known flavanones 4 (2S)- pinostrobin and 5 (2S)- pinocembrin as markers for C. torelliana fruit resins and one propolis type. Ethanolic preparations of propolis were shown to be active against Staphylococcus aureus (ATCC 25923) and to a lesser extent against Pseudomonas aeruginosa (ATCC 27853). C. torelliana flavanones inhibited the growth of S. aureus therefore contributing to the antibacterial effects observed for Australian stingless bee propolis extracts.
Assuntos
Antibacterianos/farmacologia , Abelhas/química , Flavonoides/farmacologia , Myrtaceae/química , Própole/química , Resinas Vegetais/farmacologia , Animais , Antibacterianos/química , Antibacterianos/isolamento & purificação , Produtos Biológicos , Flavonoides/química , Flavonoides/isolamento & purificação , Frutas/química , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacos , Resinas Vegetais/química , Resinas Vegetais/isolamento & purificação , Staphylococcus aureus/efeitos dos fármacosRESUMO
AIMS: The aim of this study was to determine the spectrum of antimicrobial activity of 11 samples of stingless bee honey compared to medicinal, table and artificial honeys. METHODS AND RESULTS: Activity was assessed by agar diffusion, agar dilution, broth microdilution and time-kill viability assays. By agar dilution, minimum inhibitory concentration (MIC) ranges were 4% to >10% (w/v) for Gram-positive bacteria, 6% to >16% (w/v) for Gram-negative bacteria and 6% to >10% (w/v) for Candida spp. By broth microdilution, all organisms with the exception of Candida albicans and Candida glabrata were inhibited at
Assuntos
Anti-Infecciosos/farmacologia , Abelhas/química , Mel , Animais , Candida albicans/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Testes de Sensibilidade MicrobianaRESUMO
Stingless bees (Apidae: Meliponini) are common visitors to flowering plants in the tropics, but evidence for their importance and effectiveness as crop pollinators is lacking for most plant species. They are known to visit the flowers of approximately 90 crop species. They were confirmed to be effective and important pollinators of 9 species. They may make a contribution to the pollination of approximately 60 other species, but there is insufficient information to determine their overall effectiveness or importance. They have been recorded from another 20 crops, but other evidence suggests that they do not have an important role because these plants are pollinated by other means. The strengths and limitations of stingless bees as crop pollinators are discussed. Aspects of their biology that impact on their potential for crop pollination are reviewed, including generalized flower visiting behavior of colonies, floral constancy of individual bees, flight range, and the importance of natural vegetation for maintaining local populations.
RESUMO
Zucchini, Cucurbita pepo L., infested with 22-h-old eggs of Bactrocera cucumis (French) were completely disinfested using a vapor heat treatment of 45 degrees C with > 94% RH for 30 min. An estimated total of 178,219 eggs (22 h old) was treated without survivors, thus achieving probit 9 mortality. Twenty-two-h-old eggs were significantly more tolerant of heat than first, second, or third instars. All treatments were done in a Sanshu model EHK-1000B vapor heat treatment system.