RESUMO
OBJECTIVES: The present study focused on isolation, characterization and evaluation of purified compounds from Morus alba against Streptococcus mutans biofilm formation. METHODS: The effect of crude extract from M. alba leaves was evaluated against oral pathogens, chiefly S. mutans. MICs were determined by the microdilution method. The compound was purified by employing silica gel chromatography and critically analysed with GC-MS, NMR and IR spectroscopy. The S. mutans traits of adherence and biofilm formation were assessed at sub-MIC concentrations of the crude extract and purified compound. Both water-soluble and alkali-soluble polysaccharide were estimated to determine the effect of the purified compound on the extracellular polysaccharide secretion of S. mutans. Its effect on biofilm architecture was also investigated with the help of confocal microscopy. RESULTS: The purified compound of M. alba showed an 8-fold greater reduction of MIC against S. mutans than the crude extract (MICs, 15.6 and 125 mg/L, respectively). The extract strongly inhibited biofilm formation of S. mutans at its active accumulation and plateau phases. The purified compound led to a 22% greater reduction in alkali-soluble polysaccharide than in water-soluble polysaccharide. The purified compound was found to be 1-deoxynojirimycin (DNJ). Confocal microscopy revealed that DNJ distorts the biofilm architecture of S. mutans. CONCLUSIONS The whole study reflects a prospective role of DNJ as a therapeutic agent by controlling the overgrowth and biofilm formation of S. mutans.
Assuntos
1-Desoxinojirimicina/farmacologia , Antibacterianos/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Morus/química , Folhas de Planta/química , Streptococcus/efeitos dos fármacos , 1-Desoxinojirimicina/isolamento & purificação , Antibacterianos/isolamento & purificação , Biofilmes/efeitos dos fármacos , Cromatografia em Gel , Cromatografia Gasosa-Espectrometria de Massas , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Microscopia Confocal , Espectrofotometria InfravermelhoRESUMO
From leaves of Rhus alata, one new benzofuranic acid named [(2E)-3-(4-hydroxy-5,7-dimethyl- benzo[3,4-b] furan-6-yloxy)-prop-2-enoic acid has been isolated together with eight known compounds: dimethyl ester of terephthalic acid, beta-amyrin, friedelin, lupeol, beta-sitosterol, oleanolic acid, taraxerone and ethyl gallate. Structural elucidations were done on the basis of chemical and physical data (IR, UV, 1H-NMR, 13C-NMR and MS spectra).
Assuntos
Benzofuranos/isolamento & purificação , Rhus/química , Benzofuranos/química , Espectrometria de Massas , Ressonância Magnética Nuclear Biomolecular , Folhas de Planta/química , Propionatos/química , Propionatos/isolamento & purificação , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Syntheses of steroidal heterocycles containing a five-membered N,S- heterocycle attached at the 6,7 positions of the B ring are reported. 5Alpha-cholestane-6-one (1), its 3beta-acetoxy- (2) and 3beta-chloro- (3) analogues reacted with semicarbazide and aqueous sodium acetate in refluxing ethanol to yield 5alpha-cholestan-6-one-semicarbazone 1a and its 3-beta-acetoxy and 3beta-chloro derivatives 2a and 3a, respectively. The reactions of 1a, 2a and 3a with thionyl chloride in dichloromethane at low temperature afforded the cyclized thiadiazole 4 and its 3beta-acetoxy- and 3beta-chloro analogues 5 and 6 in good yields.
Assuntos
Compostos Heterocíclicos/síntese química , Cetonas/síntese química , Preparações Farmacêuticas/síntese química , Esteroides/síntese química , Tiadiazóis/síntese química , Espectrometria de Massas , Modelos Moleculares , Conformação Molecular , Semicarbazidas/síntese químicaRESUMO
The isolation of a new biflavonoid, identified as I-3, II-3, I-5, II-5, I-7, II-7, I-4', II-4'-octahydroxy [I-2', II-2'] biflavone, from the leaves of Garcinia nervosa is reported. The structure was established by chemical and physical means (IR, UV, 1H-NMR, 13C-NMR data).
