Objective： （＋）-Clausenamide （（＋）-CLA）, the active ingredient of wampee, was isolated from the leaves of Clausena lansium （Lour.） Skeels. This study aimed to evaluate the protective potential of ...Objective： （＋）-Clausenamide （（＋）-CLA）, the active ingredient of wampee, was isolated from the leaves of Clausena lansium （Lour.） Skeels. This study aimed to evaluate the protective potential of （＋）-CLA against acetaminophen （APAP）-induced nephrotoxicity in mice. Methods： Mice were divided into control, APAP, high-dose （＋）-CLA, and low-dose （＋）-CLA groups. Then, mice were preadministered （＋）-CLA （50 and 100 mg/kg） for 5 consecutive days. After the last treatment, the animals received a single intraperitoneal injection of APAP （600 mg/kg）. Renal histopathology was evaluated by staining with hematoxylin and eosin. The levels of malondialdehyde （MDA） and glutathione （GSH） and the activities of catalase （CAT） and superoxide dismutase （SOD） were determined using corresponding kits. Western blotting was used to analyze the expression of apoptosis-related proteins in renal tissue. Results： Administration of APAP increased serum creatinine and blood urea nitrogen levels in comparison with the control group. An increase in renal MDA level, depletion of GSH, and reductions in CAT and SOD activities in renal tissue indicated that APAP-induced kidney injury was mediated by oxidative stress. The expressions of Bax and caspase-3, cleavage of caspase-3, and cytoplasm cytochrome c levels were up-regulated in renal tissue, whereas Bcl-2 expression and mitochondrial cytochrome c levels were down-regulated in the APAP group, which revealed that APAP-induced kidney injury significantly increased cell apoptosis in renal tubules. The histopathology of kidney tissue supported these biochemical mechanisms. （＋）-CLA can reverse changes in most of the abovementioned parameters and nearly restore the normal structure of the kidney. Conclusion： Oxidative stress and apoptosis are considered to be the mechanisms underlying APAP-induced nephrotoxicity. （＋）-CLA could be a promising antidote for APAP-induced acute renal damage owing to its antioxidative and antiapoptotic effects.展开更多
Three polymeric adsorbents with hydrogen bonding acceptors, methylamine, N-methyl-acetamide and aminotri(hydroxymethyl)methane modified resins are synthesized from chloromethylated X-5 resin. Adsorption isotherms of p...Three polymeric adsorbents with hydrogen bonding acceptors, methylamine, N-methyl-acetamide and aminotri(hydroxymethyl)methane modified resins are synthesized from chloromethylated X-5 resin. Adsorption isotherms of phenol and theophylline onto the three modified resins and the original X-5 resin from aqueous solution are measured. The results show that adsorption of compounds with hydrogen bonding donor onto methylamine and N-methylacetamide modified resins is enhanced as compared with that onto X-5 resin, and adsorption mechanism between the adsorbents and the adsorbates is mainly based on hydrogen bonding and hydrophobic interaction. While adsorption of compounds with hydrogen bonding donor onto aminotri(hydroxymethyl)methane modified resin is lowered as compared with that onto X-5 resin, and adsorption mechanism between the adsorbent and the adsorbates is mainly based on hydrophobic interaction.展开更多
The covalent attachment of O-linked β-N- acetylglucosamine （O-GIcNAc） to Ser/Thr residues of proteins acts as not only a posttranslational modification but also a nutritional sensor in nucleus and cytoplasm, which ...The covalent attachment of O-linked β-N- acetylglucosamine （O-GIcNAc） to Ser/Thr residues of proteins acts as not only a posttranslational modification but also a nutritional sensor in nucleus and cytoplasm, which directly regulates the expression of genes and multiple crucial signal transduction pathways. Dynamic O- GlcNAcylation at Ser/Thr residues is catalyzed by two key enzymes, O-GIcNAc transferase （OGT） and O-GlcNAcase, which are responsible for addition and removal of the O- GlcNAc modification, respectively. O-GlcNAc modifica- tion plays important roles in cellular signaling in animals, especially in human diseases. Two orthologs of OGT in plants, SECRET AGENT and SPINDLY, have been reported to be involved in diverse plant processes. However, compared with the functional mechanisms revealed in animals, the consequences of protein O-GlcNAc modifi- cation in plants is largely unknown, and the relationship between O-GlcNAcylation and cellular processes needs to be explored. In this review, we summarized the recent advances on O-GlcNAc modification and its biological functions in animals and plants, and prospect of more special functions of O-GlcNAc will be revealed in plants.展开更多
基金This work was partly supported by TCM Modernization Program of Hainan Province （2015ZY01）, Natural Science Foundation of China （81573675 ＆ 81622050 ＆ 81673709）, Science and Technology Program of Guangzhou （201604046016 ＆ 201604020175） and Research Project of Guangdong Provincial Bureau of Traditional Chinese Medicine （20161070）.
文摘Objective： （＋）-Clausenamide （（＋）-CLA）, the active ingredient of wampee, was isolated from the leaves of Clausena lansium （Lour.） Skeels. This study aimed to evaluate the protective potential of （＋）-CLA against acetaminophen （APAP）-induced nephrotoxicity in mice. Methods： Mice were divided into control, APAP, high-dose （＋）-CLA, and low-dose （＋）-CLA groups. Then, mice were preadministered （＋）-CLA （50 and 100 mg/kg） for 5 consecutive days. After the last treatment, the animals received a single intraperitoneal injection of APAP （600 mg/kg）. Renal histopathology was evaluated by staining with hematoxylin and eosin. The levels of malondialdehyde （MDA） and glutathione （GSH） and the activities of catalase （CAT） and superoxide dismutase （SOD） were determined using corresponding kits. Western blotting was used to analyze the expression of apoptosis-related proteins in renal tissue. Results： Administration of APAP increased serum creatinine and blood urea nitrogen levels in comparison with the control group. An increase in renal MDA level, depletion of GSH, and reductions in CAT and SOD activities in renal tissue indicated that APAP-induced kidney injury was mediated by oxidative stress. The expressions of Bax and caspase-3, cleavage of caspase-3, and cytoplasm cytochrome c levels were up-regulated in renal tissue, whereas Bcl-2 expression and mitochondrial cytochrome c levels were down-regulated in the APAP group, which revealed that APAP-induced kidney injury significantly increased cell apoptosis in renal tubules. The histopathology of kidney tissue supported these biochemical mechanisms. （＋）-CLA can reverse changes in most of the abovementioned parameters and nearly restore the normal structure of the kidney. Conclusion： Oxidative stress and apoptosis are considered to be the mechanisms underlying APAP-induced nephrotoxicity. （＋）-CLA could be a promising antidote for APAP-induced acute renal damage owing to its antioxidative and antiapoptotic effects.
基金The National Natural Science Foundation of China (No.: 29974015 and 20174017)
文摘Three polymeric adsorbents with hydrogen bonding acceptors, methylamine, N-methyl-acetamide and aminotri(hydroxymethyl)methane modified resins are synthesized from chloromethylated X-5 resin. Adsorption isotherms of phenol and theophylline onto the three modified resins and the original X-5 resin from aqueous solution are measured. The results show that adsorption of compounds with hydrogen bonding donor onto methylamine and N-methylacetamide modified resins is enhanced as compared with that onto X-5 resin, and adsorption mechanism between the adsorbents and the adsorbates is mainly based on hydrogen bonding and hydrophobic interaction. While adsorption of compounds with hydrogen bonding donor onto aminotri(hydroxymethyl)methane modified resin is lowered as compared with that onto X-5 resin, and adsorption mechanism between the adsorbent and the adsorbates is mainly based on hydrophobic interaction.
文摘目的:建立测定米拉贝隆原料中有关物质的方法。方法:采用HPLC方法分离分析米拉贝隆的有关物质,使用Cosmosil C18(250 mm×4.6 mm,5μm)色谱柱;流动相A为10 mmol·L^(-1)庚烷磺酸钠+20 mmol·L^(-1)磷酸二氢钾溶液(用磷酸调至p H 3.0)-乙腈(90∶10),流动相B为乙腈,梯度洗脱,流速1.0 m L·min^(-1),检测波长220 nm,柱温35℃;采用流动相A为0.1%乙酸(用氨水调至p H 3.0)-乙腈(90∶10),流动相B为乙腈,梯度洗脱,利用LC-MS/MS方法进行鉴别。结果:米拉贝隆与有关物质均能有效分离;LC-MS/MS鉴定了3种主要降解产物:杂质a(2-氨基噻唑-4-乙酸,化合物4)、杂质b((R)-2-[[[2-(4-氨基苯基)乙基]氨基]甲基]苯甲醇,化合物8)和杂质c(2-(2-氨基噻唑-4-基)-N-[4-[2-(苯基乙基氨基)乙基]苯基]乙酰胺,化合物9)的定量限分别为7.02、7.32和9.18 ng,且在各自的线性范围内线性关系良好(r=1.000、0.999 0、1.000,n=5);校正因子分别为1.4、1.6和1.3。结论:建立的方法可对米拉贝隆的有关物质进行定量测定。
基金This work was supported by the National Basic Research Program of China （2011CB915404） the National Natural Science Foundation of China （No.31270310） and the Fundamental Research Funds for the Central Universities （2572014EA04）.
文摘The covalent attachment of O-linked β-N- acetylglucosamine （O-GIcNAc） to Ser/Thr residues of proteins acts as not only a posttranslational modification but also a nutritional sensor in nucleus and cytoplasm, which directly regulates the expression of genes and multiple crucial signal transduction pathways. Dynamic O- GlcNAcylation at Ser/Thr residues is catalyzed by two key enzymes, O-GIcNAc transferase （OGT） and O-GlcNAcase, which are responsible for addition and removal of the O- GlcNAc modification, respectively. O-GlcNAc modifica- tion plays important roles in cellular signaling in animals, especially in human diseases. Two orthologs of OGT in plants, SECRET AGENT and SPINDLY, have been reported to be involved in diverse plant processes. However, compared with the functional mechanisms revealed in animals, the consequences of protein O-GlcNAc modifi- cation in plants is largely unknown, and the relationship between O-GlcNAcylation and cellular processes needs to be explored. In this review, we summarized the recent advances on O-GlcNAc modification and its biological functions in animals and plants, and prospect of more special functions of O-GlcNAc will be revealed in plants.
