Conversion of nitroarenes to aminoarenes has attracted great attention in pharmaceutical industry, agricultural production, environmental protection and chemical catalysis area. In this work, ficin capped gold nanoclu...Conversion of nitroarenes to aminoarenes has attracted great attention in pharmaceutical industry, agricultural production, environmental protection and chemical catalysis area. In this work, ficin capped gold nanoclusters(ficin@AuNCs) were prepared for the reduction of 4-nitrophenol to 4-aminophenol.The proposed catalyst was characterized by transmission electron microscopy,dynamic light scattering, fluorescence spectra and UV-Vis spectra. With NaBH4 as the reducing agent, the reduction reaction could carry out completely within 10 min at 25 ℃. Interestingly, the resultant catalyst exliibited size-related properties in the reduction, smaller ficin@AuNCs exhibited liigher catalytic activity. Its present pseudo-first-order rate constant was found to be 2.95×10^-3 s^-1 and the catalytic activation energy was 27.7 kJ/mol. Moreover, ficin@AuNCs-based catalyst displayed good stability, heading to 4-nitrophenol conversion of 98.5%-100.0% after six consecutive cycles. It has shown a great potential in construction of unique catalysts based on AuNCs for reduction reaction.展开更多
Enzymatic whey proteins concentrates (WPC) hydrolysis under optimal conditions of ficin crude extract (FCE) in two ratios E/S (0.5 and 1%) was studied,assessing the impact of hydrolysis on WPC by determination degree ...Enzymatic whey proteins concentrates (WPC) hydrolysis under optimal conditions of ficin crude extract (FCE) in two ratios E/S (0.5 and 1%) was studied,assessing the impact of hydrolysis on WPC by determination degree of hydrolysis (DH),Fast proteins liquid chromatography (FPLC),Tricine SDS-PAGE,antioxidant activity at sampling time beside,and technological properties (solubility,emulsifying activity index (EAI) and foaming activity (FA)) at the best condition (maximum DH and antioxidant activity) other side.Results showed,in the first 30 min,DH reached 22.76% at E/S (1%) with a total degradation of α-lactalbumin (α-La) and almost of β-lactoglobulin (β-Lg).A significant increase in antioxidant activity and solubility was observed,while not for EAI,and FA.These results indicate for the first time that β-Lg is susceptible to hydrolyse by FCE that rarely found for other enzymes.Ficin hydrolysates showed very relevant performance,and suggest that could be appropriate production of functional ingredients.展开更多
对无花果蛋白酶凝乳特性进行了研究.结果表明,最适凝乳温度为85℃,55℃以下该酶具有较好的稳定性,75℃处理30 m in 活性完全丧失.随着乳的pH 降低,凝乳活性增高,酶在pH 3～8 之间处理5 h 凝乳活性稳定.Ca2+ 具有明显的促凝乳作用.随着...对无花果蛋白酶凝乳特性进行了研究.结果表明,最适凝乳温度为85℃,55℃以下该酶具有较好的稳定性,75℃处理30 m in 活性完全丧失.随着乳的pH 降低,凝乳活性增高,酶在pH 3～8 之间处理5 h 凝乳活性稳定.Ca2+ 具有明显的促凝乳作用.随着底物浓度的增加,凝乳活性逐渐增高.展开更多
Ficin is an important component of plants in Ficus family such as fig latex. It is of special significance in medicine and industry because it exhibits activity throughout a wide range of temperature and pH values. In...Ficin is an important component of plants in Ficus family such as fig latex. It is of special significance in medicine and industry because it exhibits activity throughout a wide range of temperature and pH values. In this work, we purified a component of ficin from the latex homogeneity of Shandong fig trees, and the properties of the purified ficin were studied. The current findings revealed that heavy metal ions were able to inhibit ficin, while DTT, L-cysteine, and β-ME were found to promote ficin activity. It was also observed that the half life of ficin at 65 °C was longer than 1 h and the Michaelis constant（Km） for casein hydrolyzation was determined to be 1.56 mg/mL. Our study shows that this purified ficin is a cysteine protease.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.21635008,21621062).
文摘Conversion of nitroarenes to aminoarenes has attracted great attention in pharmaceutical industry, agricultural production, environmental protection and chemical catalysis area. In this work, ficin capped gold nanoclusters(ficin@AuNCs) were prepared for the reduction of 4-nitrophenol to 4-aminophenol.The proposed catalyst was characterized by transmission electron microscopy,dynamic light scattering, fluorescence spectra and UV-Vis spectra. With NaBH4 as the reducing agent, the reduction reaction could carry out completely within 10 min at 25 ℃. Interestingly, the resultant catalyst exliibited size-related properties in the reduction, smaller ficin@AuNCs exhibited liigher catalytic activity. Its present pseudo-first-order rate constant was found to be 2.95×10^-3 s^-1 and the catalytic activation energy was 27.7 kJ/mol. Moreover, ficin@AuNCs-based catalyst displayed good stability, heading to 4-nitrophenol conversion of 98.5%-100.0% after six consecutive cycles. It has shown a great potential in construction of unique catalysts based on AuNCs for reduction reaction.
基金supported by National Funds from FCT-Fundaç˜ao para a Ciˆencia e a Tecnologia through project UID/Multi/50016/2019Algerian Ministry of higher education and scientific research for their fellowship。
文摘Enzymatic whey proteins concentrates (WPC) hydrolysis under optimal conditions of ficin crude extract (FCE) in two ratios E/S (0.5 and 1%) was studied,assessing the impact of hydrolysis on WPC by determination degree of hydrolysis (DH),Fast proteins liquid chromatography (FPLC),Tricine SDS-PAGE,antioxidant activity at sampling time beside,and technological properties (solubility,emulsifying activity index (EAI) and foaming activity (FA)) at the best condition (maximum DH and antioxidant activity) other side.Results showed,in the first 30 min,DH reached 22.76% at E/S (1%) with a total degradation of α-lactalbumin (α-La) and almost of β-lactoglobulin (β-Lg).A significant increase in antioxidant activity and solubility was observed,while not for EAI,and FA.These results indicate for the first time that β-Lg is susceptible to hydrolyse by FCE that rarely found for other enzymes.Ficin hydrolysates showed very relevant performance,and suggest that could be appropriate production of functional ingredients.
基金the National Natural Science Foundation of China(Nos.20771030 and 20671025)
文摘Ficin is an important component of plants in Ficus family such as fig latex. It is of special significance in medicine and industry because it exhibits activity throughout a wide range of temperature and pH values. In this work, we purified a component of ficin from the latex homogeneity of Shandong fig trees, and the properties of the purified ficin were studied. The current findings revealed that heavy metal ions were able to inhibit ficin, while DTT, L-cysteine, and β-ME were found to promote ficin activity. It was also observed that the half life of ficin at 65 °C was longer than 1 h and the Michaelis constant（Km） for casein hydrolyzation was determined to be 1.56 mg/mL. Our study shows that this purified ficin is a cysteine protease.
