RESUMO
In this study, we report the first isolation of three antibiotic indole alkaloid compounds from a Pseudomonad bacterium, Pseudomonas aeruginosa UWI-1. The bacterium was batch fermented in a modified Luria Broth medium and compounds were solvent extracted and isolated by bioassay-guided fractionation. The three compounds were identified as (1) tris(1H-indol-3-yl) methylium, (2) bis(indol-3-yl) phenylmethane, and (3) indolo (2, 1b) quinazoline-6, 12 dione. A combination of 1D and 2D NMR, high-resolution mass spectrometry data and comparison from related data from the literature was used to determine the chemical structures of the compounds. Compounds 1-3 were evaluated in vitro for their antimicrobial activities against a wide range of microorganisms using the broth microdilution technique. Compounds 1 and 2 displayed antibacterial activity against only Gram-positive pathogens, although 1 had significantly lower minimum inhibitory concentration (MIC) values than 2. Compound 3 displayed potent broad-spectrum antimicrobial activity against a range of Gram positive and negative bacteria. Several genes identified from the genome of P. aeruginosa UWI-1 were postulated to contribute to the biosynthesis of these compounds and we attempted to outline a possible route for bacterial synthesis. This study demonstrated the extended metabolic capability of Pseudomonas aeruginosa in synthesizing new chemotypes of bioactive compounds.
Assuntos
Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Alcaloides Indólicos/isolamento & purificação , Alcaloides Indólicos/farmacologia , Indóis/isolamento & purificação , Indóis/farmacologia , Pseudomonas aeruginosa/química , Quinazolinas/isolamento & purificação , Quinazolinas/farmacologia , Antibacterianos/química , Bactérias/crescimento & desenvolvimento , Humanos , Alcaloides Indólicos/química , Indóis/química , Testes de Sensibilidade Microbiana , Quinazolinas/químicaRESUMO
Morinda citrifolia L. (noni) is one of the most important traditional Polynesian medicinal plants. The primary indigenous use of this plant appears to be of the leaves, as a topical treatment for wound healing. The ethanol extract of noni leaves (150 mg kg(-1) day(-1)) was used to evaluate the wound-healing activity on rats, using excision and dead space wound models. Animals were randomly divided into two groups of six for each model. Test group animals in each model were treated with the ethanol extract of noni orally by mixing in drinking water and the control group animals were maintained with plain drinking water. Healing was assessed by the rate of wound contraction, time until complete epithelialization, granulation tissue weight and hydoxyproline content. On day 11, the extract-treated animals exhibited 71 per cent reduction in the wound area when compared with controls which exhibited 57 per cent. The granulation tissue weight and hydroxyproline content in the dead space wounds were also increased significantly in noni-treated animals compared with controls (P < 0.002). Enhanced wound contraction, decreased epithelialization time, increased hydroxyproline content and histological characteristics suggest that noni leaf extract may have therapeutic benefits in wound healing.
Assuntos
Morinda , Cicatrização , Trinidad e TobagoRESUMO
A new cyclic nonapeptide, crotogossamide (1), was isolated from the latex of Croton gossypifolius. Its structure was elucidated by use of 1D and 2D NMR and MS and by hydrolysis followed by GC-MS analysis as cyclo(-Gly(1)-Ala(2)-Ser(3)-Gly(4)-Leu(5)-Asn(6)-Gly(7)-Ile(8)-Phe(9)-). This is the first report of a cyclic peptide from a Croton species. The known flavonoids kaempferol 3-O-rhamnopyranoside, quercitrin, and myricitrin were also isolated from the plant latex.