Methotrexate(MTX)is a folate antagonist drug used for several diseases,such as cancers,various malignancies,rheumatoid arthritis(RA)and inflammatory bowel disease.Due to its structural features,including the presence ...Methotrexate(MTX)is a folate antagonist drug used for several diseases,such as cancers,various malignancies,rheumatoid arthritis(RA)and inflammatory bowel disease.Due to its structural features,including the presence of two carboxylic acid groups and its low native fluorescence,there are some challenges to develop analytical methods for its determination.MTX is metabolized to 7-hydroxymethotrexate(7-OH-MTX),2,4-diamino-N10-methylpteroic acid(DAMPA),and the active MTX polyglutamates(MTXPGs)in the liver,intestine,and red blood cells(RBCs),respectively.Additionally,the drug has a narrow therapeutic range;hence,its therapeutic drug monitoring(TDM)is necessary to regulate the pharmacokinetics of the drug and to decrease the risk of toxicity.Due to environmental toxicity of MTX;its sensitive,fast and low cost determination in workplace environments is of great interest.A large number of methodologies including high performance liquid chromatography equipped with UVevisible,fluorescence,or electrochemical detection,liquid chromatography-mass spectroscopy,capillary electrophoresis,UVevisible spectrophotometry,and electrochemical methods have been developed for the quantitation of MTX and its metabolites in pharmaceutical,biological,and environmental samples.This paper will attempt to review several published methodologies and the instrumental conditions,which have been applied to measure MTX and its metabolites within the last decade.展开更多
Objective:To compare the applicability of the SYBK Grcen-Ⅰ assay with the standard schizont maturalion assay,for determination of sensitivity of Plasmodium vivax(P.vivax) to chloroquine and a new antifolale WR 99210....Objective:To compare the applicability of the SYBK Grcen-Ⅰ assay with the standard schizont maturalion assay,for determination of sensitivity of Plasmodium vivax(P.vivax) to chloroquine and a new antifolale WR 99210.Methods:The study was conducted at Mae Tao Clinic for migrant workers,Tak Province during April 2009 to July 2010.A total of 64 blood samples(1 mL blood collected into sodium heparinized plastic tube) were collected from patients with monoinfection with P.vivax malaria prior to treatment with standard regimen of a 3-day chloroquine. In vitro sensitivity of P.vivax isolates was evaluated by schizont maturation inhibition and SYBR Green-Ⅰ assays.Results:A total of 30 out of 64 blood samples collected from patients with P.vivax malaria were successfully analyzed using both the microscopic schizont maturation inhibition and SYBR Green-I assays.The failure rates of the schizont maturation inhibition assay(50%) and the SYBR Green-I assay(54%) were similar(P=0.51).The median IC_(10)s,IC_(50)s and IC_(90)s of both chloroquine and WR99210 were not significantly different from the clinical isolates of P.vivax tested.Based on the cut-off of 100 nM,the prevalences of chloroquine resistance determined by schizont maturation inhibition and SYBR Green-I assays were 19 and 11 isolates,respectively.The strength of agreement between the two methods was very poor for both chloroquine and WR992I0.Conclusions:On the basis of this condition and its superior sensitivity,the microscopic method appears better than the SYUK Green-I Green assay for assessing in vitro sensitivity of fresh P.vivax isolates to antimalarial drugs.展开更多
A series of 6-thienylethenyl, 6-polyphenyl arylethenyl, 6-thienylethyl and 6-polyphenyl arylethyl deriva- tives of 2,4-diaminopyrido[3,2-d]pyrimidine for targeting dihydrofolate reductase（DHFR） was designed and synt...A series of 6-thienylethenyl, 6-polyphenyl arylethenyl, 6-thienylethyl and 6-polyphenyl arylethyl deriva- tives of 2,4-diaminopyrido[3,2-d]pyrimidine for targeting dihydrofolate reductase（DHFR） was designed and synthe- sized as non-classical antifolates in order to overcome drug resistance. The compounds were evaluated for in vitro antitumor activities, rhDHFR and antimicrobial activities. All the compounds exhibited antitumor activities, with ICs0 values in the range of 0.13--17.8 gmol/L against HL-60, HeLa and A549. Both the types of aryl groups and the orientation of polyphenyl aryl made an impact on the biological activities. 6-Naphthylethyl derivatives 5c and 5d were proved to be the most active Dt-IFR inhibitors, which were more potent than 6-phenylethyl, 6-thienylethyl and 6-biphenylethyl derivatives. Docking studies reveal that flexible saturated carbon-carbon bond of C9--C10 is essential for biological activities in molecular backbone. Antimicrobial test shows that most of the compounds exhibit antibacterial activities.展开更多
Six indigenous folk medicinal plants growing wild in the area of Tabuk, Saudi Arabia which were selected for the study of their phytochemistry as well as their biological activities as antitumor and antifolate agents....Six indigenous folk medicinal plants growing wild in the area of Tabuk, Saudi Arabia which were selected for the study of their phytochemistry as well as their biological activities as antitumor and antifolate agents. Antitumor activities of methanol extracts of the six plants were measured in vitro using three human tumor cell lines （breast, lung and CNS cancers） while antifolate activities were assessed using commercial dihyrofolate reductase obtained from Sigma Co. Among the six plant extracts tested, the most remarkable were those of Caralluma sinaica and Fagonia tenuifolia. Caralluma extract showed strong antitumor activity （low GIso） against the three human tumor cell lines. Fagonia extract, on the other hand, was quite inhibitory to the growth of CNS cancer and breast cancer cell lines but much less so against lung cancer cells. Extracts of both Sonchus oleraceus and Caralluma sinaica were strongly inhibitory to DHFR. These results suggest that the mechanism of anticancer activity of Caralluma plant is through DHFR inhibition but that of Fagonia may follow a different path.展开更多
钴胺素依赖的蛋氨酸合酶催化N5-甲基四氢叶酸转移甲基至同型半胱氨酸生成蛋氨酸和四氢叶酸,直接参与蛋氨酸循环、叶酸循环及含硫氨基酸代谢,与DNA、蛋白质合成及生物甲基化有密切关系。本研究采用蛋白层析技术,将大鼠肝匀浆经超声破碎...钴胺素依赖的蛋氨酸合酶催化N5-甲基四氢叶酸转移甲基至同型半胱氨酸生成蛋氨酸和四氢叶酸,直接参与蛋氨酸循环、叶酸循环及含硫氨基酸代谢,与DNA、蛋白质合成及生物甲基化有密切关系。本研究采用蛋白层析技术,将大鼠肝匀浆经超声破碎和高速离心处理后,依次经过DE-52批处理、Q Sepharose Fast Flow离子交换层析和CHT陶瓷羟基磷灰石吸附柱层析进行纯化,并对纯化产物进行了SDS-PAGE和Western blotting鉴定。采用分光光度法测定蛋氨酸合酶的活性,对纯化酶的酶促反应动力学进行了研究,确定了最佳反应条件,动力学结果显示蛋氨酸合酶的双底物酶促反应的机制为乒乓机制。研究表明,采用层析技术纯化得到的蛋氨酸合酶适用于以其为靶点的化合物高通量筛选。展开更多
Thymidylate synthase (TS) is a critical enzyme for DNA biosynthesis and many nonclassical lipophilic antifolates targeting this enzyme are quite efficient and encouraging as antitumor drugs. In this paper, the binding...Thymidylate synthase (TS) is a critical enzyme for DNA biosynthesis and many nonclassical lipophilic antifolates targeting this enzyme are quite efficient and encouraging as antitumor drugs. In this paper, the binding model of 14 antifolates of substituted benzylamino- and heterocyclylmethylamino- carbodithioate derivatives of 4-(3H)-quinazolinone with TS is examined using molecular simulation methods―― FlexiDock and SCORE2.0. The resulting conformation and orientation of these antifolates are directly applied to CoMFA study. The robust QSAR model, its three-dimensional contour map, and binding score of these antifolates derived from SCORE2.0 provide guidelines for structural optimiza- tion of current antifolates. The experiment indicates that deletion of cancer chemopreventive structure of dithiocarbamate is unfavorable for interaction between TS and antifolates.展开更多
目的:改进经典抗叶酸类药物关键中间体4-氨基-5-甲酰基-8,10-二去氮杂四氢叶酸二乙酯侧链的水解条件。方法:以经典叶酸拮抗剂侧链N-(4-氨基苯甲酰)-L-谷氨酸二乙酯(1)为反应原料,尝试了氢氧化钠(Na OH)和氢氧化钾(KOH)2种碱催化、20~180...目的:改进经典抗叶酸类药物关键中间体4-氨基-5-甲酰基-8,10-二去氮杂四氢叶酸二乙酯侧链的水解条件。方法:以经典叶酸拮抗剂侧链N-(4-氨基苯甲酰)-L-谷氨酸二乙酯(1)为反应原料,尝试了氢氧化钠(Na OH)和氢氧化钾(KOH)2种碱催化、20~180 min 5种反应时间和0.175~1 mol/L 3种碱浓度的反应条件,用高效液相色谱法检测目标产物和副产物,最终确定副产物为单酯水解产物以及酰胺键水解产物,并以此为依据完成了4-氨基-5-甲酰基-8,10-二去氮杂四氢叶酸二乙酯(5)水解条件的优化。结果:改进后的4-氨基-5-甲酰基-8,10-二去氮杂四氢叶酸二乙酯侧链的水解条件为0.3 mol/L KOH溶液中室温条件反应60 min,在该反应条件下,水解反应收率为95.6%。反应产物通过磁共振氢谱(1H nuclear magnetic resonance,1H NMR)、磁共振碳谱(13C nuclear magnetic resonance,13C NMR)和电喷雾飞行时间质谱(electrospray ionization time of flight mass spectrometry,ESI-MS)分析鉴定后结构正确,并通过高效液相色谱法确定其纯度为96%。新的水解反应条件避免了副产物的生成,提高了反应收率。结论:利用新的水解条件可以简便、高效地完成4-氨基-5-甲酰基-8,10-二去氮杂四氢叶酸二乙酯的水解反应,该条件对经典叶酸拮抗剂的合成和生产工艺的改进也有重要的意义。展开更多
基金support of the Vice-Chancellor for Research,Shiraz University of Medical Sciences,Iran(project No.97-01-36-18308)
文摘Methotrexate(MTX)is a folate antagonist drug used for several diseases,such as cancers,various malignancies,rheumatoid arthritis(RA)and inflammatory bowel disease.Due to its structural features,including the presence of two carboxylic acid groups and its low native fluorescence,there are some challenges to develop analytical methods for its determination.MTX is metabolized to 7-hydroxymethotrexate(7-OH-MTX),2,4-diamino-N10-methylpteroic acid(DAMPA),and the active MTX polyglutamates(MTXPGs)in the liver,intestine,and red blood cells(RBCs),respectively.Additionally,the drug has a narrow therapeutic range;hence,its therapeutic drug monitoring(TDM)is necessary to regulate the pharmacokinetics of the drug and to decrease the risk of toxicity.Due to environmental toxicity of MTX;its sensitive,fast and low cost determination in workplace environments is of great interest.A large number of methodologies including high performance liquid chromatography equipped with UVevisible,fluorescence,or electrochemical detection,liquid chromatography-mass spectroscopy,capillary electrophoresis,UVevisible spectrophotometry,and electrochemical methods have been developed for the quantitation of MTX and its metabolites in pharmaceutical,biological,and environmental samples.This paper will attempt to review several published methodologies and the instrumental conditions,which have been applied to measure MTX and its metabolites within the last decade.
基金Supported by the Commission on Higher EducationMinistry of Education of Thailand and Thailand National Research University(NRU)
文摘Objective:To compare the applicability of the SYBK Grcen-Ⅰ assay with the standard schizont maturalion assay,for determination of sensitivity of Plasmodium vivax(P.vivax) to chloroquine and a new antifolale WR 99210.Methods:The study was conducted at Mae Tao Clinic for migrant workers,Tak Province during April 2009 to July 2010.A total of 64 blood samples(1 mL blood collected into sodium heparinized plastic tube) were collected from patients with monoinfection with P.vivax malaria prior to treatment with standard regimen of a 3-day chloroquine. In vitro sensitivity of P.vivax isolates was evaluated by schizont maturation inhibition and SYBR Green-Ⅰ assays.Results:A total of 30 out of 64 blood samples collected from patients with P.vivax malaria were successfully analyzed using both the microscopic schizont maturation inhibition and SYBR Green-I assays.The failure rates of the schizont maturation inhibition assay(50%) and the SYBR Green-I assay(54%) were similar(P=0.51).The median IC_(10)s,IC_(50)s and IC_(90)s of both chloroquine and WR99210 were not significantly different from the clinical isolates of P.vivax tested.Based on the cut-off of 100 nM,the prevalences of chloroquine resistance determined by schizont maturation inhibition and SYBR Green-I assays were 19 and 11 isolates,respectively.The strength of agreement between the two methods was very poor for both chloroquine and WR992I0.Conclusions:On the basis of this condition and its superior sensitivity,the microscopic method appears better than the SYUK Green-I Green assay for assessing in vitro sensitivity of fresh P.vivax isolates to antimalarial drugs.
基金Supported by the National Natural Science Foundation of China（Nos.21172014, 21302007）.
文摘A series of 6-thienylethenyl, 6-polyphenyl arylethenyl, 6-thienylethyl and 6-polyphenyl arylethyl deriva- tives of 2,4-diaminopyrido[3,2-d]pyrimidine for targeting dihydrofolate reductase（DHFR） was designed and synthe- sized as non-classical antifolates in order to overcome drug resistance. The compounds were evaluated for in vitro antitumor activities, rhDHFR and antimicrobial activities. All the compounds exhibited antitumor activities, with ICs0 values in the range of 0.13--17.8 gmol/L against HL-60, HeLa and A549. Both the types of aryl groups and the orientation of polyphenyl aryl made an impact on the biological activities. 6-Naphthylethyl derivatives 5c and 5d were proved to be the most active Dt-IFR inhibitors, which were more potent than 6-phenylethyl, 6-thienylethyl and 6-biphenylethyl derivatives. Docking studies reveal that flexible saturated carbon-carbon bond of C9--C10 is essential for biological activities in molecular backbone. Antimicrobial test shows that most of the compounds exhibit antibacterial activities.
文摘Six indigenous folk medicinal plants growing wild in the area of Tabuk, Saudi Arabia which were selected for the study of their phytochemistry as well as their biological activities as antitumor and antifolate agents. Antitumor activities of methanol extracts of the six plants were measured in vitro using three human tumor cell lines （breast, lung and CNS cancers） while antifolate activities were assessed using commercial dihyrofolate reductase obtained from Sigma Co. Among the six plant extracts tested, the most remarkable were those of Caralluma sinaica and Fagonia tenuifolia. Caralluma extract showed strong antitumor activity （low GIso） against the three human tumor cell lines. Fagonia extract, on the other hand, was quite inhibitory to the growth of CNS cancer and breast cancer cell lines but much less so against lung cancer cells. Extracts of both Sonchus oleraceus and Caralluma sinaica were strongly inhibitory to DHFR. These results suggest that the mechanism of anticancer activity of Caralluma plant is through DHFR inhibition but that of Fagonia may follow a different path.
文摘钴胺素依赖的蛋氨酸合酶催化N5-甲基四氢叶酸转移甲基至同型半胱氨酸生成蛋氨酸和四氢叶酸,直接参与蛋氨酸循环、叶酸循环及含硫氨基酸代谢,与DNA、蛋白质合成及生物甲基化有密切关系。本研究采用蛋白层析技术,将大鼠肝匀浆经超声破碎和高速离心处理后,依次经过DE-52批处理、Q Sepharose Fast Flow离子交换层析和CHT陶瓷羟基磷灰石吸附柱层析进行纯化,并对纯化产物进行了SDS-PAGE和Western blotting鉴定。采用分光光度法测定蛋氨酸合酶的活性,对纯化酶的酶促反应动力学进行了研究,确定了最佳反应条件,动力学结果显示蛋氨酸合酶的双底物酶促反应的机制为乒乓机制。研究表明,采用层析技术纯化得到的蛋氨酸合酶适用于以其为靶点的化合物高通量筛选。
基金Supported by the National Natural Science Foundation of China (Grant No. 20572060)Guangdong Fundamental Research Foundation of China (Grant No. 2005CCAO3400)
文摘Thymidylate synthase (TS) is a critical enzyme for DNA biosynthesis and many nonclassical lipophilic antifolates targeting this enzyme are quite efficient and encouraging as antitumor drugs. In this paper, the binding model of 14 antifolates of substituted benzylamino- and heterocyclylmethylamino- carbodithioate derivatives of 4-(3H)-quinazolinone with TS is examined using molecular simulation methods―― FlexiDock and SCORE2.0. The resulting conformation and orientation of these antifolates are directly applied to CoMFA study. The robust QSAR model, its three-dimensional contour map, and binding score of these antifolates derived from SCORE2.0 provide guidelines for structural optimiza- tion of current antifolates. The experiment indicates that deletion of cancer chemopreventive structure of dithiocarbamate is unfavorable for interaction between TS and antifolates.
文摘目的:改进经典抗叶酸类药物关键中间体4-氨基-5-甲酰基-8,10-二去氮杂四氢叶酸二乙酯侧链的水解条件。方法:以经典叶酸拮抗剂侧链N-(4-氨基苯甲酰)-L-谷氨酸二乙酯(1)为反应原料,尝试了氢氧化钠(Na OH)和氢氧化钾(KOH)2种碱催化、20~180 min 5种反应时间和0.175~1 mol/L 3种碱浓度的反应条件,用高效液相色谱法检测目标产物和副产物,最终确定副产物为单酯水解产物以及酰胺键水解产物,并以此为依据完成了4-氨基-5-甲酰基-8,10-二去氮杂四氢叶酸二乙酯(5)水解条件的优化。结果:改进后的4-氨基-5-甲酰基-8,10-二去氮杂四氢叶酸二乙酯侧链的水解条件为0.3 mol/L KOH溶液中室温条件反应60 min,在该反应条件下,水解反应收率为95.6%。反应产物通过磁共振氢谱(1H nuclear magnetic resonance,1H NMR)、磁共振碳谱(13C nuclear magnetic resonance,13C NMR)和电喷雾飞行时间质谱(electrospray ionization time of flight mass spectrometry,ESI-MS)分析鉴定后结构正确,并通过高效液相色谱法确定其纯度为96%。新的水解反应条件避免了副产物的生成,提高了反应收率。结论:利用新的水解条件可以简便、高效地完成4-氨基-5-甲酰基-8,10-二去氮杂四氢叶酸二乙酯的水解反应,该条件对经典叶酸拮抗剂的合成和生产工艺的改进也有重要的意义。
