RESUMO
The present study, we prepared polysaccharides from Rosa rugosa petals (RRPS) using hot-water extraction and purified the polysaccharides by chromatography to obtain RRPS-1 and RRPS-2. Preliminary structural features of RRPS were characterized by different instrumental methods, such as HPGPC, FT-IR, and GC analysis. The average molecular weights of RRPS-1 and RRPS-2 were 8.8â¯kDa and 443.8â¯kDa, respectively. Then, antioxidant and moisture-preserving activities of RRPS were determined in vitro. The analysis of antioxidant activities suggested that RRPS-2 had good potential for scavenging activity of radicals. We also found that the RRPS-2 has strong moisture-preserving activity in vitro. These results clearly indicated that RRPS-2 might have a good potential to be utilized in pharmaceutical, food and cosmetics industries.
Assuntos
Sequestradores de Radicais Livres/química , Higroscópicos/química , Extração Líquido-Líquido/métodos , Polissacarídeos/química , Rosa/química , Compostos de Bifenilo/antagonistas & inibidores , Flores/química , Sequestradores de Radicais Livres/isolamento & purificação , Radical Hidroxila/antagonistas & inibidores , Higroscópicos/isolamento & purificação , Cinética , Peso Molecular , Picratos/antagonistas & inibidores , Extratos Vegetais/química , Polissacarídeos/isolamento & purificação , Água/químicaRESUMO
Many marine microorganisms can secrete exopolysaccharides (EPSs) which have important applications in biotechnology. We have purified a novel EPS from deep-sea bacterium Zunongwangia profunda SM-A87, identified its glycosyl composition and linkage, and optimized its production to 8.9 g/l in previous studies. To reduce the fermentation cost, an economical fermentation medium containing 60.9 % whey, 10 g/l soybean meal, and 2.9 % NaCl was developed. The EPS yield of batch fermentation in this medium reached 12.1 ± 0.3 g/l. Fed-batch fermentation was conducted and led to an EPS yield of 17.2 ± 0.4 g/l, which represents the highest EPS yield ever reported for a marine bacterium. The EPS was extracted and it displayed good rheological properties, moisture-retention ability, and antioxidant activity. Particularly, its moisture-retention ability is superior to that of other marine bacterial EPSs reported to date. SM-A87 EPS also showed high antioxidant activity. These results suggest that SM-A87 EPS has promising potentials in biotechnology.
Assuntos
Antioxidantes/metabolismo , Flavobacteriaceae/metabolismo , Higroscópicos/metabolismo , Polissacarídeos Bacterianos/metabolismo , Antioxidantes/isolamento & purificação , Organismos Aquáticos/metabolismo , Meios de Cultura/química , Fermentação , Higroscópicos/isolamento & purificação , Polissacarídeos Bacterianos/isolamento & purificaçãoRESUMO
A method for the determination of dimethyl fumarate (DMF) in desiccant and antimould sachets, employed for protecting consumer products from humidity and mould, has been developed. The method is based on a solid-liquid extraction followed by HPLC-UV analysis. The method was validated with respect to recovery, linearity, limits of detection and quantitation and precision. The recovery was 98%. The correlation coefficient value (r) was equal to 0.94. Both intra- and inter-day precisions were studied at several concentration levels, being satisfactory in all cases (RSD < 5). Limits of detection and quantification values were in the low microgram per gram level, thus allowing the determination of DMF at concentrations below the limit established (0.1 mg/kg) by the recent EU Directive (Decision 2009/251/EC). The proposed procedure was applied for the determination of the target compound in 41 desiccant and antimould samples. DMF was detected in 39.0% of samples and its content in many samples exceeded the legal limits. The results of our analysis highlight the high risk of exposure to this powerful allergic sensitizer for consumers.