RESUMO
(-)-Agelasidine A was identified from the methanol extract of the marine sponge Agelas clathrodes for the first time together with zooanemonin, 1-carboxymethylnicotinic acid, hymenidin, mukanadins A and C, monobromodispacamide, agelasidine D, 2-amide-4-bromopyrrole, O-methyltryptophan and an agelasines mixture. The structures were characterized by spectroscopic methods. (-)-Agelasidine A was tested for antibacterial and antifungal activities and shown to act as a bacteriostatic agent as it inhibited the growth of Staphylococcus aureus and partially the growth of other bacteria.
Assuntos
Agelas/química , Antibacterianos/farmacologia , Guanidinas/isolamento & purificação , Guanidinas/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Sulfonas/isolamento & purificação , Sulfonas/farmacologia , Animais , Antibacterianos/química , Antibacterianos/isolamento & purificação , Guanidinas/química , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Conformação Molecular , Estrutura Molecular , Staphylococcus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Sulfonas/químicaRESUMO
A strain of Bacillus subtilis was examined for antifungal activity against phytopathogenic and wood-surface contaminant fungi. The bacterium was grown in five culture media with different incubation times in order to study cell development, sporulation, and the production of metabolites with antifungal activity. The anti-sapstain and anti-mould activity of the bacterium grown in yeast extract glucose broth (YGB) medium in wood was also evaluated. In YGB, the bacterium inhibited the growth of several fungi and displayed a broader spectrum of activity than in the other media tested. A relationship between bacterial spore production and the formation of metabolites with antifungal activity was detected. YGB medium displayed effective control in wood block tests. YGB medium was extracted with solvents of increasing polarity and the dry residues were applied to silicagel plates, resolved with the appropriate solvent and sprayed with different solutions, detecting the presence, of amines, and higher alcohols. The bioautographic method revealed the presence of at least two active compounds against the blue-stain fungus Cladosporium cucumerinum.
Assuntos
Antifúngicos/farmacologia , Bacillus subtilis/química , Madeira , Antibiose , Bacillus subtilis/crescimento & desenvolvimento , Bacillus subtilis/metabolismo , Bioensaio , Meios de Cultivo Condicionados/farmacologia , Fungos/efeitos dos fármacosRESUMO
A new naturally occurring isoflavone, derrone, was isolated from Ulex jussiaei (Leguminosae) together with the isoflavones ulexins A-C, lupalbigenin, isolupalbigenin, 7-O-methylso-lupalbigenin, isoderrone, ulexone A and isochandalone, the pterocarpans (6aR,11aR)-(-)-maackiain, (6aR,11aR)-(-)-2-methoxymaackiain and (6aR,11aR)-(-)-4-methoxymaackiain, the chalcone 4-hydroxylonchocarpine and the dihydrochalcone crotaramosmine. The antifungal activity of the new compound was tested by a bioautographic method against Cladosporium cucumerinum, and as expected from structural features it proved to have no activity.
Assuntos
Fabaceae/química , Isoflavonas/química , Isoflavonas/isolamento & purificação , Espectroscopia de Ressonância Magnética , Conformação Molecular , Portugal , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
From the dichloromethane extract of Ulex airensis three new isoflavonoids, ulexin C (1), ulexin D (2), and 7-O-methylisolupalbigenin (3), were isolated and characterized by spectroscopic methods. Ulexin D (2) was also identified from the dichloromethane extract of Ulex europaeus ssp. europaeus. Together with these new metabolites, 18 compounds of previously known structures were isolated and identified from both species. The antifungal activity of these compounds was tested against Cladosporium cucumerinum by a bioautographic TLC assay.
