A core trisaccharide of laminin, β-D-Gal-（1→4）-β-D-GlcpNAc-（1→6）-α-D-Manp-OMe, with potential anti-rumor metastatic activity was designed and prepared. 2-Iodoglactosyl azide was used as the donor to construct...A core trisaccharide of laminin, β-D-Gal-（1→4）-β-D-GlcpNAc-（1→6）-α-D-Manp-OMe, with potential anti-rumor metastatic activity was designed and prepared. 2-Iodoglactosyl azide was used as the donor to construct 2-N-acetamido-2-deoxylactosyl moiety through an azidoiodo-glycosylation reaction. Simultaneously, 1, 2-trans-β-glycosic bond was formed stereoselectively in one step with a moderate yield. This novel procedure avoided the use of 2-amino-2-deoxyglucose as both donor and acceptor.展开更多
To show the vegetation succession interaction with soil properties, microbial biomass, basal respiration, and enzyme activities in different soil layers （0-60 cm） were determined in six lands, i.e., 2-, 7-, 11-, 20-...To show the vegetation succession interaction with soil properties, microbial biomass, basal respiration, and enzyme activities in different soil layers （0-60 cm） were determined in six lands, i.e., 2-, 7-, 11-, 20-, and 43-year-old abandoned lands and one native grassland, in a semiarid hilly area of the Loess Plateau. The results indicated that the successional time and soil depths affected soil microbiological parameters significantly. In 20-cm soil layer, microbial biomass carbon （MBC）, microbial biomass nitrogen （MBN）, MBC/MBN, MBC to soil organic carbon ratio （MBC/SOC）, and soil basal respiration tended to increase with successional stages but decrease with soil depths. In contrast, metabolic quotient （qCO2） tended to decrease with successional stages but increase with soil depths. In addition, the activities of urease, catalase, neutral phosphatase, β-fructofuranosidase, and earboxymethyl cellulose （CMC） enzyme increased with successional stages and soil depths. They were significantly positively correlated with microbial biomass and SOC （P 〈 0.5）, whereas no obvious trend was observed for the polyphenoloxidase activity. The results indicated that natural vegetation succession could improve soil quality and promote ecosystem restoration, but it needed a long time under local climate conditions.展开更多
AIM: To investigate the effect of Bu-Zhong-Yi-Qi-Tang (Decoction for Reinforcing Middle Jiao and Replenishing Qi) on deficiency of N-glycan/nitric oxide (NO) and islet damage induced by injecting two medium doses of s...AIM: To investigate the effect of Bu-Zhong-Yi-Qi-Tang (Decoction for Reinforcing Middle Jiao and Replenishing Qi) on deficiency of N-glycan/nitric oxide (NO) and islet damage induced by injecting two medium doses of streptozotocin (STZ). METHODS: Diabetes was induced by intraperitoneal injection of STZ at 55 mg/kg on day 1 and day 8. Islet damage was evaluated using a scoring system. Nitrite, nitrate, α-mannosidase and amylase activities were measured by colorimetry. N-glycan patterns of amylase were determined with lectin [ConA, pisum sativum agglutinin (PSA), peanut agglutinin (PNA), and lens culinaris agglutinin (LCA)] affinity precipitation method. RESULTS: Severe islet necrosis and mild islet atrophy were observed in diabetic rats. The number and size ofislets, the activities of α-mannosidase, amylase and nitrite were decreased, while the binding of PNA and LCA to amylase was increased. All of which were improved after treatment with Bu-Zhong-Yi-Qi-Tang. Islet damage was significantly correlated with nitrite, nitrate, α-mannosidase, amylase and the binding of LCA, PNA, and PSA to amylase.CONCLUSION: STZ-induced islet damage is related to N-glycan deficiency in proteins by blocking α-mannosidase activity and no deficiency, accumulation of unfolded proteins, and endoplasmic reticulum stress and activation of cellular signals, all of which are improved after treatment with Bu-Zhong-YiQi-Tang.展开更多
Tumor-associated carbohydrate antigens （TACAs）, important molecular markers on tumor cells, are major targets for the development of anti-cancer vaccines. However, due to the immunotolerance and weak immunogenicity,...Tumor-associated carbohydrate antigens （TACAs）, important molecular markers on tumor cells, are major targets for the development of anti-cancer vaccines. However, due to the immunotolerance and weak immunogenicity, native TACAs cannot induce powerful immune response. The use of modified TACAs such as N-glycosides could be an alternative strategy to overcome this problem. Herein, the synthesis of N（OMe）-linked analogue of tumor-associated disaccharide antigen Thomsen-Friedenreich （TF） by the glycosylation reaction is described.展开更多
OBJECTIVE： To study the effects of extracts from Honghua （Flos Carthaml~ on lipopolysaccharide in- duced nitric oxide （NO） production in RAW 264.7 cells and the influence of the extracts on yeast a-glucosidase act...OBJECTIVE： To study the effects of extracts from Honghua （Flos Carthaml~ on lipopolysaccharide in- duced nitric oxide （NO） production in RAW 264.7 cells and the influence of the extracts on yeast a-glucosidase activity. The total flavonoid content of the extracts was also determined. METHODS： Cytotoxicity of the extracts to RAW 264.7 cells was evaluated by the ATPliteTM method. Inhibitory effects of the extracts on NO production were evaluated by Griess assay. Curcumin was used as a positive control. Screening of extracts for po- tential a-glucosidase inhibitors was done by a fiuo- rometric assay. The assay was based on the hydroly- sis of 4-methylumbelliferyl-a-D-glucopyranoside toform the fluorescent product, 4-methylumbellifer- one. Acarbose was used as a positive control. The total t3avonoid content was tested using kaempfer- ol as the standard. RESULTS： There were significant inhibitory effects on NO production when the extracts were 25-100 μg/ mL （P〈0.05） and curcumin was 2-4 μg/mL （P〈 0.001）. The extracts showed an inhibitory effect on a-glucosidase activity at the concentrations of 15.6-125 μg/mL with a half maximal （50%）inhibito- ry concentration （ICs0） of （32.8± 5.7） μg/mL, com- pared with the ICs0 of acarbose at （1.8±0.4） μg/mL. There was a significant difference between the two IC50 values （P〈0.001）. The total content of flavo- noids per gram of dried herb was 1.14 mg. CONCLUSION： Honghua （Flos Carthami） showed in- hibitory effects on NO production in activated RAW 264.7 macrophage cells and an inhibitory effect on yeast a-glucosidase. There might be a relationship between these pharmacological effects and its fla- vonoid content.展开更多
基金National Science Foundation of China (Grant No.20732001 and 90713004).
文摘A core trisaccharide of laminin, β-D-Gal-（1→4）-β-D-GlcpNAc-（1→6）-α-D-Manp-OMe, with potential anti-rumor metastatic activity was designed and prepared. 2-Iodoglactosyl azide was used as the donor to construct 2-N-acetamido-2-deoxylactosyl moiety through an azidoiodo-glycosylation reaction. Simultaneously, 1, 2-trans-β-glycosic bond was formed stereoselectively in one step with a moderate yield. This novel procedure avoided the use of 2-amino-2-deoxyglucose as both donor and acceptor.
基金Project supported by the National Key Basic Research Program (973 Program) of China (No. 2007CB106804)the PhD candidate Training Program (No. 20060730027)+1 种基金the "111" Project from the State Administration of Foreign Experts Affairs (SAFEA)the Ministry of Education of China
文摘To show the vegetation succession interaction with soil properties, microbial biomass, basal respiration, and enzyme activities in different soil layers （0-60 cm） were determined in six lands, i.e., 2-, 7-, 11-, 20-, and 43-year-old abandoned lands and one native grassland, in a semiarid hilly area of the Loess Plateau. The results indicated that the successional time and soil depths affected soil microbiological parameters significantly. In 20-cm soil layer, microbial biomass carbon （MBC）, microbial biomass nitrogen （MBN）, MBC/MBN, MBC to soil organic carbon ratio （MBC/SOC）, and soil basal respiration tended to increase with successional stages but decrease with soil depths. In contrast, metabolic quotient （qCO2） tended to decrease with successional stages but increase with soil depths. In addition, the activities of urease, catalase, neutral phosphatase, β-fructofuranosidase, and earboxymethyl cellulose （CMC） enzyme increased with successional stages and soil depths. They were significantly positively correlated with microbial biomass and SOC （P 〈 0.5）, whereas no obvious trend was observed for the polyphenoloxidase activity. The results indicated that natural vegetation succession could improve soil quality and promote ecosystem restoration, but it needed a long time under local climate conditions.
基金Supported by The Project of Guangdong Science and Technology
文摘AIM: To investigate the effect of Bu-Zhong-Yi-Qi-Tang (Decoction for Reinforcing Middle Jiao and Replenishing Qi) on deficiency of N-glycan/nitric oxide (NO) and islet damage induced by injecting two medium doses of streptozotocin (STZ). METHODS: Diabetes was induced by intraperitoneal injection of STZ at 55 mg/kg on day 1 and day 8. Islet damage was evaluated using a scoring system. Nitrite, nitrate, α-mannosidase and amylase activities were measured by colorimetry. N-glycan patterns of amylase were determined with lectin [ConA, pisum sativum agglutinin (PSA), peanut agglutinin (PNA), and lens culinaris agglutinin (LCA)] affinity precipitation method. RESULTS: Severe islet necrosis and mild islet atrophy were observed in diabetic rats. The number and size ofislets, the activities of α-mannosidase, amylase and nitrite were decreased, while the binding of PNA and LCA to amylase was increased. All of which were improved after treatment with Bu-Zhong-Yi-Qi-Tang. Islet damage was significantly correlated with nitrite, nitrate, α-mannosidase, amylase and the binding of LCA, PNA, and PSA to amylase.CONCLUSION: STZ-induced islet damage is related to N-glycan deficiency in proteins by blocking α-mannosidase activity and no deficiency, accumulation of unfolded proteins, and endoplasmic reticulum stress and activation of cellular signals, all of which are improved after treatment with Bu-Zhong-YiQi-Tang.
基金Grant from the Ministry of Science and Technology of China(Grant No.2012ZX09502001-001)the National Natural Science Foundation of China(Grant No.81172916)
文摘Tumor-associated carbohydrate antigens （TACAs）, important molecular markers on tumor cells, are major targets for the development of anti-cancer vaccines. However, due to the immunotolerance and weak immunogenicity, native TACAs cannot induce powerful immune response. The use of modified TACAs such as N-glycosides could be an alternative strategy to overcome this problem. Herein, the synthesis of N（OMe）-linked analogue of tumor-associated disaccharide antigen Thomsen-Friedenreich （TF） by the glycosylation reaction is described.
基金Supported by Shanxi Scholarship Council of China(No.2010-102)
文摘OBJECTIVE： To study the effects of extracts from Honghua （Flos Carthaml~ on lipopolysaccharide in- duced nitric oxide （NO） production in RAW 264.7 cells and the influence of the extracts on yeast a-glucosidase activity. The total flavonoid content of the extracts was also determined. METHODS： Cytotoxicity of the extracts to RAW 264.7 cells was evaluated by the ATPliteTM method. Inhibitory effects of the extracts on NO production were evaluated by Griess assay. Curcumin was used as a positive control. Screening of extracts for po- tential a-glucosidase inhibitors was done by a fiuo- rometric assay. The assay was based on the hydroly- sis of 4-methylumbelliferyl-a-D-glucopyranoside toform the fluorescent product, 4-methylumbellifer- one. Acarbose was used as a positive control. The total t3avonoid content was tested using kaempfer- ol as the standard. RESULTS： There were significant inhibitory effects on NO production when the extracts were 25-100 μg/ mL （P〈0.05） and curcumin was 2-4 μg/mL （P〈 0.001）. The extracts showed an inhibitory effect on a-glucosidase activity at the concentrations of 15.6-125 μg/mL with a half maximal （50%）inhibito- ry concentration （ICs0） of （32.8± 5.7） μg/mL, com- pared with the ICs0 of acarbose at （1.8±0.4） μg/mL. There was a significant difference between the two IC50 values （P〈0.001）. The total content of flavo- noids per gram of dried herb was 1.14 mg. CONCLUSION： Honghua （Flos Carthami） showed in- hibitory effects on NO production in activated RAW 264.7 macrophage cells and an inhibitory effect on yeast a-glucosidase. There might be a relationship between these pharmacological effects and its fla- vonoid content.
