Astrapterocarpan(AP) is a bioactive constituent of Astragali Radix and was selected as a model compound for investigating the in vitro metabolism of pterocarpans in this study. Its in vitro metabolism was conducted by...Astrapterocarpan(AP) is a bioactive constituent of Astragali Radix and was selected as a model compound for investigating the in vitro metabolism of pterocarpans in this study. Its in vitro metabolism was conducted by incubation with rat hepatic 9000 g supernatant(S9) in the presence of an NADPH-generating system. At first, four compounds were isolated and their structures were elucidated as 6 a-hydroxy-AP(M1), astrametabolin I [M2, 1 a-hydroxy-9, 10-dimethoxy-pterocarp-1(2), 4-diene-3-one], 9-demethyl-AP(M3, nissolin) and 4-methoxy-astraisoflavan(M4, 7, 2’-dihydroxy-4, 3’, 4’-trimethoxy-isoflavan) on the basis of NMR data, respectively. Among them, M1, M2 and M4 were new compounds. Next, the metabolite profile of AP in rat hepatic S9 was obtained via HPLC-DAD-ESI-IT-TOF-MSn, and 40 new metabolites were tentatively identified. These newly identified metabolites included 9 monohydroxylated metabolites, 1 demethylated metabolite, 7 demethylated and monohydroxylated metabolites, 4 dihydroxylated metabolites, 1 hydration metabolite, 1 didemethylated metabolite, 2 glucosylated metabolites, 1 monohydroxylated and dehydrogenated metabolite, 2 monohydroxylated and demethylated and dehydrogenated metabolites, 2 dimerized metabolites, 3 dimerized and monohydroxylated metabolites, 2 dimerized and didemethylated metabolites, and 5 dimerized and demethylated metabolites. Finally, the major metabolic reactions of AP in rat hepatic S9 were summarized and found to be hydroxylation, demethylation, dimerization, hydration, and dehydrogenation. More importantly, the biotransformation from AP to M2 and the dimerization of AP by incubation with hepatic S9 were reported for the first time. In conclusion, this is the first report on the metabolism of a pure pterocarpan in animal tissues, and these findings will provide a solid basis for further studies on the metabolism of other pterocarpans.展开更多
Chlormequat is a quaternary ammonium and choline chlorinated derivated is used as plant growth regulating agent. There are very few documented cases of poisoning in humans. We reported a case of non-fatal suicide atte...Chlormequat is a quaternary ammonium and choline chlorinated derivated is used as plant growth regulating agent. There are very few documented cases of poisoning in humans. We reported a case of non-fatal suicide attempt by chlormequat in France. A 34-year-old woman was admitted to hospital after deliberate consumption of plant growth regulator, C5 SUN, containing chlormequat chloride (460 g/L) and choline chloride (320 g/L). Immediately, she developed symptoms of respiratory distress and a cardiac massage was begun by her father. In this case report, we described the method for an accurate and reliable screening of chlormequat which was based on the combination of Target Analysis powerful software and a high performance TOF-MS (Impact HD from Bruker). After forced diuresis, the kinetic of elimination of chlormequat is biphasic: vascular phase diffusion (half-life of 5.6 hr) followed by a phase of free elimination (half-life of 16.2 h). Although chlormequat poisoning is clinically similar to that observed with anticholinesterase compounds, chlormequat chloride is not an acetylcholinesterase inhibitor. Chlormequat seems to be a weak substrat competitor for cholinesterase leading to acetylcholine accumulation and prolonged depolarization in muscular junction. Cardiac massage, artificial respiration and forced diuresis have significantly improved the prognosis of our patient.展开更多
Background: Determination of cyclosporine A (CsA) and tacrolimus (Tac) in dried blood spots (DBS) could enable drug monitoring in transplanted patients without the necessity of having to take venous blood samples. The...Background: Determination of cyclosporine A (CsA) and tacrolimus (Tac) in dried blood spots (DBS) could enable drug monitoring in transplanted patients without the necessity of having to take venous blood samples. Therefore, we have developed a method for quantitative determination of calcineurin inhibitors (CNI) by liquid-chromatography-tandem mass spectrometry (LCMS). Methods: In a study with 68 kidney transplant recipients (KTR, 34 CsA, 34 Tac), we tested the clinical application of LCMS monitoring in DBS in comparison to LCMS in whole blood. Results: The measuring range is proven for 27.33 to 1345 ng/ml for CsA and for 1.63 to 39.7 ng/ml for Tac. The requirements for clinical chemical analyses for precision and accuracy are complied with. Stability is documented for a period of 14 days. The study showed the following deviations from LCMS in whole blood for determination of CsA and Tac in DBS after introducing a correction factor by the haematocrit (Hct) value (CsA trough level: mean = 4.7%, ±1.96 standard deviation (SD) -52.1% to 61.4%, N = 96;CsA peak level: mean = 7.3%, ±1.96 SD -39.7% to 54.4%, N = 95;Tac trough level: mean = -0.5%, ±1.96 SD -76.4% to 75.3%, N = 88;Tac peak level: mean = 3.9%, ±1.96 SD -80.1% to 88.7%, N = 92). Conclusions: Our data show comparable results with the reference method by means of LCMS in whole blood. Therefore, DBS of KTR for determination of CNI levels could be transported on filter cards by mail to the respective laboratory resistant to breakage and the hazard of infection.展开更多
一、概论林肯霉素(Lincomycin)是从美国的尼布拉斯加(Neb raska)林肯市(Lin-coln)州附近土壤中分离到的一种由链霉菌——林肯链霉素林肯变种(Streptomyctslincolnensis var lincolnensis)所产生的抗生素。1962年首先由美国发表,是一个...一、概论林肯霉素(Lincomycin)是从美国的尼布拉斯加(Neb raska)林肯市(Lin-coln)州附近土壤中分离到的一种由链霉菌——林肯链霉素林肯变种(Streptomyctslincolnensis var lincolnensis)所产生的抗生素。1962年首先由美国发表,是一个抗革兰氏阳性菌的抗生素。在国外文献上林肯霉素(以下简称展开更多
GCMS-QP2010 The GCMS-QP2010 Ultra is our most advanced gas chromatograph mass spectrometer.Descended from the GCMS-QP2010 Plus,it features best-in-class scan speed and sensitivity.A newly designed and patented technol...GCMS-QP2010 The GCMS-QP2010 Ultra is our most advanced gas chromatograph mass spectrometer.Descended from the GCMS-QP2010 Plus,it features best-in-class scan speed and sensitivity.A newly designed and patented technology called ASSP(Advanced Scan Speed Protocol) allows展开更多
LCMS-8040LCMS-8040 incorporates newly improved ion optics and collision cell technology to provide higher multiple reaction monitoring （MRM） sensitivity.
LCMS-8050Continuing the evolution of Shimadzu’s UF technology,Shimadzu introduces the LCMS-8050 triple quadrupole mass spectrometer,offering unparalleled measurement speeds and high-sensitivity performance.The high p...LCMS-8050Continuing the evolution of Shimadzu’s UF technology,Shimadzu introduces the LCMS-8050 triple quadrupole mass spectrometer,offering unparalleled measurement speeds and high-sensitivity performance.The high performance of the LCMS-8050 defies expectations,redefining high-sensitivity,high-speed analysis.展开更多
LCMS-8040LCMS-8040 incorporates newly improved ion optics and collision cell technology to provide higher multiple reaction monitoring （MRM） sensitivity.
LCMS-8050 Continuing the evolution of Shimadzu＇s UF technology, Shimadzu introduces the LCMS-8050 triple quadrupole mass spectrometer, offering unparalleled measurement speeds and high-sensitivity performance. The hi...LCMS-8050 Continuing the evolution of Shimadzu＇s UF technology, Shimadzu introduces the LCMS-8050 triple quadrupole mass spectrometer, offering unparalleled measurement speeds and high-sensitivity performance. The high pertbrmance of the LCMS-8050 defies expectations, redefining high-sensitivity, high-speed analysis.展开更多
LCMS-8050 Continuing the evolution of Shimadzu＇s UF technology, Shimadzu introduces the LCMS-8050 triple quadrupole mass spectrometer, offering unparalleled measurement speeds and high-sensitivity performance.
基金supported by the National Natural Science Foundation of China(No.81673595)China Postdoctoral Science Foundation(Nos.20080430293 and 200902040)Guizhou Natural Science Foundation(No.QIANKEHE [2018]1071)
文摘Astrapterocarpan(AP) is a bioactive constituent of Astragali Radix and was selected as a model compound for investigating the in vitro metabolism of pterocarpans in this study. Its in vitro metabolism was conducted by incubation with rat hepatic 9000 g supernatant(S9) in the presence of an NADPH-generating system. At first, four compounds were isolated and their structures were elucidated as 6 a-hydroxy-AP(M1), astrametabolin I [M2, 1 a-hydroxy-9, 10-dimethoxy-pterocarp-1(2), 4-diene-3-one], 9-demethyl-AP(M3, nissolin) and 4-methoxy-astraisoflavan(M4, 7, 2’-dihydroxy-4, 3’, 4’-trimethoxy-isoflavan) on the basis of NMR data, respectively. Among them, M1, M2 and M4 were new compounds. Next, the metabolite profile of AP in rat hepatic S9 was obtained via HPLC-DAD-ESI-IT-TOF-MSn, and 40 new metabolites were tentatively identified. These newly identified metabolites included 9 monohydroxylated metabolites, 1 demethylated metabolite, 7 demethylated and monohydroxylated metabolites, 4 dihydroxylated metabolites, 1 hydration metabolite, 1 didemethylated metabolite, 2 glucosylated metabolites, 1 monohydroxylated and dehydrogenated metabolite, 2 monohydroxylated and demethylated and dehydrogenated metabolites, 2 dimerized metabolites, 3 dimerized and monohydroxylated metabolites, 2 dimerized and didemethylated metabolites, and 5 dimerized and demethylated metabolites. Finally, the major metabolic reactions of AP in rat hepatic S9 were summarized and found to be hydroxylation, demethylation, dimerization, hydration, and dehydrogenation. More importantly, the biotransformation from AP to M2 and the dimerization of AP by incubation with hepatic S9 were reported for the first time. In conclusion, this is the first report on the metabolism of a pure pterocarpan in animal tissues, and these findings will provide a solid basis for further studies on the metabolism of other pterocarpans.
文摘Chlormequat is a quaternary ammonium and choline chlorinated derivated is used as plant growth regulating agent. There are very few documented cases of poisoning in humans. We reported a case of non-fatal suicide attempt by chlormequat in France. A 34-year-old woman was admitted to hospital after deliberate consumption of plant growth regulator, C5 SUN, containing chlormequat chloride (460 g/L) and choline chloride (320 g/L). Immediately, she developed symptoms of respiratory distress and a cardiac massage was begun by her father. In this case report, we described the method for an accurate and reliable screening of chlormequat which was based on the combination of Target Analysis powerful software and a high performance TOF-MS (Impact HD from Bruker). After forced diuresis, the kinetic of elimination of chlormequat is biphasic: vascular phase diffusion (half-life of 5.6 hr) followed by a phase of free elimination (half-life of 16.2 h). Although chlormequat poisoning is clinically similar to that observed with anticholinesterase compounds, chlormequat chloride is not an acetylcholinesterase inhibitor. Chlormequat seems to be a weak substrat competitor for cholinesterase leading to acetylcholine accumulation and prolonged depolarization in muscular junction. Cardiac massage, artificial respiration and forced diuresis have significantly improved the prognosis of our patient.
文摘Background: Determination of cyclosporine A (CsA) and tacrolimus (Tac) in dried blood spots (DBS) could enable drug monitoring in transplanted patients without the necessity of having to take venous blood samples. Therefore, we have developed a method for quantitative determination of calcineurin inhibitors (CNI) by liquid-chromatography-tandem mass spectrometry (LCMS). Methods: In a study with 68 kidney transplant recipients (KTR, 34 CsA, 34 Tac), we tested the clinical application of LCMS monitoring in DBS in comparison to LCMS in whole blood. Results: The measuring range is proven for 27.33 to 1345 ng/ml for CsA and for 1.63 to 39.7 ng/ml for Tac. The requirements for clinical chemical analyses for precision and accuracy are complied with. Stability is documented for a period of 14 days. The study showed the following deviations from LCMS in whole blood for determination of CsA and Tac in DBS after introducing a correction factor by the haematocrit (Hct) value (CsA trough level: mean = 4.7%, ±1.96 standard deviation (SD) -52.1% to 61.4%, N = 96;CsA peak level: mean = 7.3%, ±1.96 SD -39.7% to 54.4%, N = 95;Tac trough level: mean = -0.5%, ±1.96 SD -76.4% to 75.3%, N = 88;Tac peak level: mean = 3.9%, ±1.96 SD -80.1% to 88.7%, N = 92). Conclusions: Our data show comparable results with the reference method by means of LCMS in whole blood. Therefore, DBS of KTR for determination of CNI levels could be transported on filter cards by mail to the respective laboratory resistant to breakage and the hazard of infection.
文摘一、概论林肯霉素(Lincomycin)是从美国的尼布拉斯加(Neb raska)林肯市(Lin-coln)州附近土壤中分离到的一种由链霉菌——林肯链霉素林肯变种(Streptomyctslincolnensis var lincolnensis)所产生的抗生素。1962年首先由美国发表,是一个抗革兰氏阳性菌的抗生素。在国外文献上林肯霉素(以下简称
文摘GCMS-QP2010 The GCMS-QP2010 Ultra is our most advanced gas chromatograph mass spectrometer.Descended from the GCMS-QP2010 Plus,it features best-in-class scan speed and sensitivity.A newly designed and patented technology called ASSP(Advanced Scan Speed Protocol) allows
文摘LCMS-8040LCMS-8040 incorporates newly improved ion optics and collision cell technology to provide higher multiple reaction monitoring （MRM） sensitivity.
文摘LCMS-8050Continuing the evolution of Shimadzu’s UF technology,Shimadzu introduces the LCMS-8050 triple quadrupole mass spectrometer,offering unparalleled measurement speeds and high-sensitivity performance.The high performance of the LCMS-8050 defies expectations,redefining high-sensitivity,high-speed analysis.
文摘LCMS-8040LCMS-8040 incorporates newly improved ion optics and collision cell technology to provide higher multiple reaction monitoring （MRM） sensitivity.
文摘LCMS-8050 Continuing the evolution of Shimadzu＇s UF technology, Shimadzu introduces the LCMS-8050 triple quadrupole mass spectrometer, offering unparalleled measurement speeds and high-sensitivity performance. The high pertbrmance of the LCMS-8050 defies expectations, redefining high-sensitivity, high-speed analysis.
文摘LCMS-8050 Continuing the evolution of Shimadzu＇s UF technology, Shimadzu introduces the LCMS-8050 triple quadrupole mass spectrometer, offering unparalleled measurement speeds and high-sensitivity performance.
