The stability of the drug actarit was studied under different stress conditions like hydrolysis（acid,alkaline and neutral）,oxidation,photolysis and thermal degradation as recommended hy International Conference on H...The stability of the drug actarit was studied under different stress conditions like hydrolysis（acid,alkaline and neutral）,oxidation,photolysis and thermal degradation as recommended hy International Conference on Harmonization（ICH） guidelines.Drug was found to be unstable in acidic,basic and photolytic conditions and produced a common degradation product while oxidative stress condition produced three additional degradation products.Drug was impassive to neutral hydrolysis,dry thermal and accelerated stability conditions.Degradation products were identified,isolated and characterized by different spectroscopic analyses.Drug and the degradation products were synthesized by a new route using green chemistry.The chromatographic separation of the drug and its impurities was achieved in a phenomenex luna C18 column employing a step gradient elution by high performance liquid chromatography coupled to photodiode array and mass spectrometry detectors（HPLC-PDAMS）.A specilic and sensitive stability-indicating assay method for the simultaneous determination of the drug actarit.its process related impurities and degradation products was developed and validated.展开更多
Objective To explore a highly sensitive and highly specific method to detect the serum MG7 antigen(Ag)level for early gastric cancer diagnosis.Methods The serum MG7-Ag level was detected by enzyme-linked immunosorbent...Objective To explore a highly sensitive and highly specific method to detect the serum MG7 antigen(Ag)level for early gastric cancer diagnosis.Methods The serum MG7-Ag level was detected by enzyme-linked immunosorbent assay(ELISA)method in 116 preoperative gastric cancer patients,63 postoperative gastric cancer patients,41 patients with precancerous lesion,37 pa-展开更多
SDS-PAGE was applied to determine trypsin activity and inhibition. After the hydrolysis by trypsin to substrate bovine serum albulnin (BSA) under different temperatures and pH, the hydrolysis degree of BSA was conduct...SDS-PAGE was applied to determine trypsin activity and inhibition. After the hydrolysis by trypsin to substrate bovine serum albulnin (BSA) under different temperatures and pH, the hydrolysis degree of BSA was conducted using SDS-PAGE. From the quantitative analysis to the electrophoresis bands of BSA and its hydrolysis products in SDS-PAGE pattern, the change of trypsin activity was determined, and then the optimum temperature at 40°C and the optimum pH at pH 8.5 - 8.7 for trypsin activity were obtained. All the target bonds in BSA molecule could be hydrolyzed at the same time by trypsin. The inhibition was due to the binding of inhibitor to trypsin, which made it impossible for trypsin to touch the substrate protein. SDS-PAGE was demonstrated to be also an effect method for assaying the characteristics of trypsin activity and its inhibition.展开更多
Ten actinomycete strains isolated from the Yellow Sea off China＇s coasts were identified as belonging to two genera by 16S rDNA phylogenetic analysis： Streptomyces and Nocardiopsis. Six Streptomyces strains （MA10, ...Ten actinomycete strains isolated from the Yellow Sea off China＇s coasts were identified as belonging to two genera by 16S rDNA phylogenetic analysis： Streptomyces and Nocardiopsis. Six Streptomyces strains （MA10, 2SHXF01-3, MA35, MA05-2, MA05-2-1 and MA08-1） and one Nocardiopsis strain （MA03） were predicted to have the potential to produce aromatic polyketides based on the analysis of the KSa （ketoacyl-synthase） gene in the type II PKS （polyketides synthase） gene cluster. Four strains （MA03, MA01, MA10 and MA05-2） exhibited significant inhibitory effects on mycelia growth （inhibition rate 〉50%） and subsequent aria- toxin production （inhibition rate 〉75%） of the mutant aflatoxigenic Aspergillus parasiticus NFRI-95. The ethyl acetate extracts of the broth of these four strains displayed significant inhibitory effects on mycelia growth, and the IC50 values were calculated （MA03： 0.275 mg mL-1, MA01：0.106 mg mL-1, MA10：1.345 mg mL-1 and MA05-2：1.362 mg mL-1）. Five strains （2SHXF01-3, MA03, MA05-2, MA01 and MA08-1） were selected based on their high cytotoxic activities. The ethyl acetate extract of the Nocardiopsis strain MA03 was particularly noted for its high antitumor activity against human carcinomas of the cervix （HeLa）, lung （A549）, kidney （Caki-1） and liver （HepG2） （IC50： 2.890, 1.981, 3.032 and 2.603 μgmL-1, respectively）. The extract also remarkably inhibited colony formation of HeLa cells at an extremely low concentration （0.5μgmL 1）. This study highlights that marine-derived actinomycetes are a huge resource of compounds for the biological control of aflatoxin contamination and the development of novel drugs for human carcinomas.展开更多
文摘The stability of the drug actarit was studied under different stress conditions like hydrolysis（acid,alkaline and neutral）,oxidation,photolysis and thermal degradation as recommended hy International Conference on Harmonization（ICH） guidelines.Drug was found to be unstable in acidic,basic and photolytic conditions and produced a common degradation product while oxidative stress condition produced three additional degradation products.Drug was impassive to neutral hydrolysis,dry thermal and accelerated stability conditions.Degradation products were identified,isolated and characterized by different spectroscopic analyses.Drug and the degradation products were synthesized by a new route using green chemistry.The chromatographic separation of the drug and its impurities was achieved in a phenomenex luna C18 column employing a step gradient elution by high performance liquid chromatography coupled to photodiode array and mass spectrometry detectors（HPLC-PDAMS）.A specilic and sensitive stability-indicating assay method for the simultaneous determination of the drug actarit.its process related impurities and degradation products was developed and validated.
文摘Objective To explore a highly sensitive and highly specific method to detect the serum MG7 antigen(Ag)level for early gastric cancer diagnosis.Methods The serum MG7-Ag level was detected by enzyme-linked immunosorbent assay(ELISA)method in 116 preoperative gastric cancer patients,63 postoperative gastric cancer patients,41 patients with precancerous lesion,37 pa-
文摘SDS-PAGE was applied to determine trypsin activity and inhibition. After the hydrolysis by trypsin to substrate bovine serum albulnin (BSA) under different temperatures and pH, the hydrolysis degree of BSA was conducted using SDS-PAGE. From the quantitative analysis to the electrophoresis bands of BSA and its hydrolysis products in SDS-PAGE pattern, the change of trypsin activity was determined, and then the optimum temperature at 40°C and the optimum pH at pH 8.5 - 8.7 for trypsin activity were obtained. All the target bonds in BSA molecule could be hydrolyzed at the same time by trypsin. The inhibition was due to the binding of inhibitor to trypsin, which made it impossible for trypsin to touch the substrate protein. SDS-PAGE was demonstrated to be also an effect method for assaying the characteristics of trypsin activity and its inhibition.
基金supported by the COMRA project (No. DY125-15-R-01)
文摘Ten actinomycete strains isolated from the Yellow Sea off China＇s coasts were identified as belonging to two genera by 16S rDNA phylogenetic analysis： Streptomyces and Nocardiopsis. Six Streptomyces strains （MA10, 2SHXF01-3, MA35, MA05-2, MA05-2-1 and MA08-1） and one Nocardiopsis strain （MA03） were predicted to have the potential to produce aromatic polyketides based on the analysis of the KSa （ketoacyl-synthase） gene in the type II PKS （polyketides synthase） gene cluster. Four strains （MA03, MA01, MA10 and MA05-2） exhibited significant inhibitory effects on mycelia growth （inhibition rate 〉50%） and subsequent aria- toxin production （inhibition rate 〉75%） of the mutant aflatoxigenic Aspergillus parasiticus NFRI-95. The ethyl acetate extracts of the broth of these four strains displayed significant inhibitory effects on mycelia growth, and the IC50 values were calculated （MA03： 0.275 mg mL-1, MA01：0.106 mg mL-1, MA10：1.345 mg mL-1 and MA05-2：1.362 mg mL-1）. Five strains （2SHXF01-3, MA03, MA05-2, MA01 and MA08-1） were selected based on their high cytotoxic activities. The ethyl acetate extract of the Nocardiopsis strain MA03 was particularly noted for its high antitumor activity against human carcinomas of the cervix （HeLa）, lung （A549）, kidney （Caki-1） and liver （HepG2） （IC50： 2.890, 1.981, 3.032 and 2.603 μgmL-1, respectively）. The extract also remarkably inhibited colony formation of HeLa cells at an extremely low concentration （0.5μgmL 1）. This study highlights that marine-derived actinomycetes are a huge resource of compounds for the biological control of aflatoxin contamination and the development of novel drugs for human carcinomas.
