Pseudomonas cepacia lipase （PSL） immobilized on the carboxyl-functionalized meso-cellular foams （HOOC-MCF） was used for the transesterification resolution of （R,S）-l-phenylethanol in organic solvent. The results...Pseudomonas cepacia lipase （PSL） immobilized on the carboxyl-functionalized meso-cellular foams （HOOC-MCF） was used for the transesterification resolution of （R,S）-l-phenylethanol in organic solvent. The results showed that the ee value of （S）-1- phenylethanol and （R）-1-phenylethyl acetate reached 99% with 50% conversion of 1-phenylethanol using toluene as solvent. Furthermore, it was found that PSL/HOOC-MCF exhibited high enantioselectivity in organic solvent with log P ≤ 2 such as toluene and hexane.展开更多
1-phenylethanol (1-PEA) is a flavor extensively used in the production of cosmetics, beverages, and food. The release of 1-PEA into coastal environments has aroused great concern. However, its potential effects on mar...1-phenylethanol (1-PEA) is a flavor extensively used in the production of cosmetics, beverages, and food. The release of 1-PEA into coastal environments has aroused great concern. However, its potential effects on marine organisms are still unknown. In order to provide a better understanding of the ecological risks of 1-PEA in marine environments, this study determined the toxic effects of 1-PEA on two marine diatoms (Phaeodactylum tricornutum and Skeletonema costatum). The diatoms were grown in culture medium containing different concentrations of 1-PEA for 96 h. The contents of chlorophyll a, chlorophyll c, glutathione (GSH), malondialdehyde (MDA), and the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), were measured at the end of the exposure period. 1-PEA was shown to significantly inhibit the growth of diatoms, with 96-h EC50 values of 257.14 mg/Land 126.46 mg/L in P. tricornutum and S. costatum, respectively. In P. tricornutum, the levels of SOD, CAT, GPx, GSH, and MDA were stimulated only when 1-PEA concentrations were close to or greater than the 96-h EC50 value. However, in S. costatum, the activities of SOD and CAT, and the syntheses of two chlorophylls were inhibited even at an exposure concentration below the 96-h EC50 value. Taken together, these findings indicate a potential ecological risk by discharging 1-PEA into coastal areas and its species-specific toxic effects on marine organisms.展开更多
采用硅胶、MCI gel CHP-20、ODS、Toyopearl HW-40C等柱色谱技术,并结合TLC和半制备液相等手段对覃怀1号鲜地黄70%丙酮提取物的乙酸乙酯部位进行分离纯化,得到8个单体化合物。运用现代波谱学技术(NMR、MS、UV、IR)鉴定化合物的结构,分...采用硅胶、MCI gel CHP-20、ODS、Toyopearl HW-40C等柱色谱技术,并结合TLC和半制备液相等手段对覃怀1号鲜地黄70%丙酮提取物的乙酸乙酯部位进行分离纯化,得到8个单体化合物。运用现代波谱学技术(NMR、MS、UV、IR)鉴定化合物的结构,分别鉴定为地黄新苷A(1)、osmanthuside B_(6)(2)、地黄苷(3)、异马蒂罗苷(4)、反式对羟基肉桂酸(5)、咖啡酸(6)、阿魏酸(7)、咖啡酸甲酯(8)。其中,化合物1为新苯乙醇苷,鉴定为地黄新苷A,化合物2为首次从地黄中分离得到。药理活性研究表明,化合物2、6和7可以显著增加相对葡萄糖消耗量,表现出潜在的降糖活性。展开更多
目的比较评价鲜品四翅滨藜-肉苁蓉与梭梭-肉苁蓉汁和渣中苯乙醇苷成分含量的差异。方法通过超高效液相色谱-三重四极杆串联质谱联用法(ultra performance liquid chromatography-triple quadrupole tandem mass spectrometry,UPLC-QQQ-M...目的比较评价鲜品四翅滨藜-肉苁蓉与梭梭-肉苁蓉汁和渣中苯乙醇苷成分含量的差异。方法通过超高效液相色谱-三重四极杆串联质谱联用法(ultra performance liquid chromatography-triple quadrupole tandem mass spectrometry,UPLC-QQQ-MS),对2种寄主鲜品肉苁蓉汁和渣中8种苯乙醇苷成分含量进行比较,并结合偏最小二乘判别分析(partial least-squares discriminant-analysis,PLS-DA),鉴定并评价2种寄主鲜品肉苁蓉的苯乙醇苷成分差异。结果四翅滨藜-肉苁蓉汁和渣中苯乙醇苷含量均高于梭梭-肉苁蓉;经过杀酶5 min的四翅滨藜-肉苁蓉和梭梭-肉苁蓉渣,再经80℃干燥的肉苁蓉苯乙醇苷含量较未杀酶直接干燥的肉苁蓉分别高出131.5108%和93.2983%。结论以肉苁蓉的主要成分苯乙醇苷为评判指标,可快速、高效地评估鲜品四翅滨藜-肉苁蓉与梭梭-肉苁蓉汁与渣中活性成分的差异。且鲜品四翅滨藜-肉苁蓉渣的苯乙醇苷含量更高,杀酶5 min可有效保留鲜品肉苁蓉苯乙醇苷的含量。展开更多
Microorganisms are commonly used to transform chemicals to chiral compounds. Pseudomonas cepacia 1813, Pseudomonas stutzeri 1317, Saccharomyces cerevisiae 1912, and 5 Escherichia coli strains were used to transform...Microorganisms are commonly used to transform chemicals to chiral compounds. Pseudomonas cepacia 1813, Pseudomonas stutzeri 1317, Saccharomyces cerevisiae 1912, and 5 Escherichia coli strains were used to transform acetophenone to 2 phenylethanol. The results show that the E. coli strains have the poorest biotransformation ability. P. stutzeri 1317 provides the best transformation ability with a transformation rate of 30% achieved with either whole or broken P. stutzeri 1317 cells for a reaction pH of 8.2 and an initial acetophenone concentration of 2 g/L. An acetophenone concentration of 10 g/L strongly inhibits the biotransformation for a pH of 8.2. Crude alcohol dehydrogenase obtained from S. cerevisiae 1912 transforms acetophenone to 2 phenylethanol when nicotinamide adenine dinucleotide reduced (NADH) is added.展开更多
基金financially supported by the National Natural Science Foundation of China(No.50662004)the State Key Program of Fundamental Research(No.2004CCA05900).
文摘Pseudomonas cepacia lipase （PSL） immobilized on the carboxyl-functionalized meso-cellular foams （HOOC-MCF） was used for the transesterification resolution of （R,S）-l-phenylethanol in organic solvent. The results showed that the ee value of （S）-1- phenylethanol and （R）-1-phenylethyl acetate reached 99% with 50% conversion of 1-phenylethanol using toluene as solvent. Furthermore, it was found that PSL/HOOC-MCF exhibited high enantioselectivity in organic solvent with log P ≤ 2 such as toluene and hexane.
基金Supported by the National Marine Hazard Mitigation Service,China through its Commissioned Research Scheme(No.2017AB030)
文摘1-phenylethanol (1-PEA) is a flavor extensively used in the production of cosmetics, beverages, and food. The release of 1-PEA into coastal environments has aroused great concern. However, its potential effects on marine organisms are still unknown. In order to provide a better understanding of the ecological risks of 1-PEA in marine environments, this study determined the toxic effects of 1-PEA on two marine diatoms (Phaeodactylum tricornutum and Skeletonema costatum). The diatoms were grown in culture medium containing different concentrations of 1-PEA for 96 h. The contents of chlorophyll a, chlorophyll c, glutathione (GSH), malondialdehyde (MDA), and the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), were measured at the end of the exposure period. 1-PEA was shown to significantly inhibit the growth of diatoms, with 96-h EC50 values of 257.14 mg/Land 126.46 mg/L in P. tricornutum and S. costatum, respectively. In P. tricornutum, the levels of SOD, CAT, GPx, GSH, and MDA were stimulated only when 1-PEA concentrations were close to or greater than the 96-h EC50 value. However, in S. costatum, the activities of SOD and CAT, and the syntheses of two chlorophylls were inhibited even at an exposure concentration below the 96-h EC50 value. Taken together, these findings indicate a potential ecological risk by discharging 1-PEA into coastal areas and its species-specific toxic effects on marine organisms.
文摘采用硅胶、MCI gel CHP-20、ODS、Toyopearl HW-40C等柱色谱技术,并结合TLC和半制备液相等手段对覃怀1号鲜地黄70%丙酮提取物的乙酸乙酯部位进行分离纯化,得到8个单体化合物。运用现代波谱学技术(NMR、MS、UV、IR)鉴定化合物的结构,分别鉴定为地黄新苷A(1)、osmanthuside B_(6)(2)、地黄苷(3)、异马蒂罗苷(4)、反式对羟基肉桂酸(5)、咖啡酸(6)、阿魏酸(7)、咖啡酸甲酯(8)。其中,化合物1为新苯乙醇苷,鉴定为地黄新苷A,化合物2为首次从地黄中分离得到。药理活性研究表明,化合物2、6和7可以显著增加相对葡萄糖消耗量,表现出潜在的降糖活性。
基金Supported by the National Natural Science Foundation of China(No.2 0 0 74 0 2 0 )
文摘Microorganisms are commonly used to transform chemicals to chiral compounds. Pseudomonas cepacia 1813, Pseudomonas stutzeri 1317, Saccharomyces cerevisiae 1912, and 5 Escherichia coli strains were used to transform acetophenone to 2 phenylethanol. The results show that the E. coli strains have the poorest biotransformation ability. P. stutzeri 1317 provides the best transformation ability with a transformation rate of 30% achieved with either whole or broken P. stutzeri 1317 cells for a reaction pH of 8.2 and an initial acetophenone concentration of 2 g/L. An acetophenone concentration of 10 g/L strongly inhibits the biotransformation for a pH of 8.2. Crude alcohol dehydrogenase obtained from S. cerevisiae 1912 transforms acetophenone to 2 phenylethanol when nicotinamide adenine dinucleotide reduced (NADH) is added.
