Metabolism of dopazinol (DZ) by liver microsomes from control and phenobarbital- and 3-methylcholanthrene-treated rats has been investigated. Liver microsomes from control and treated rats metabolized DZ to N-despropyl-DZ (39-53% of total metabolites); 8-hydroxy-DZ, a catechol metabolite (32-39%); and 5- or 6-hydroxy-DZ (12-20%). The last metabolite was identified as its dehydration product 5,6-dehydro-DZ. N-Dealkylation was favored only slightly over catechol formation (ratio = 1.2) by liver microsomes from control and phenobarbital-treated rats, whereas with liver microsomes from 3-methylcholanthrene-treated rats, N-dealkylation predominated (ratio = 1.7). Liver microsomes from control rats metabolized DZ at a rate of 0.86 nmol/nmol cytochrome P-450/min. Pretreatment of rats with phenobarbital or 3-methylcholanthrene stimulated rates of metabolism by 2.4- and 3-fold, respectively. Metabolism of DZ was inhibited by SKF 525-A, methimazole, and thiobenzamide. SKF 525-A completely inhibited metabolism of DZ, while methimazole and thiobenzamide, two alternate substrates of the microsomal flavin-containing monooxygenase (MFMO) inhibited N-dealkylation only. These results indicated that while the cytochrome P-450-dependent monooxygenase is the primary enzyme system in DZ oxidation, the MFMO also catalyzes the N-dealkylation reaction. The catechol metabolite was converted to isomeric O-methylated derivatives in approximately 1:1 ratio by purified catechol-O-methyl transferase or 105,000g liver cytosol. The late eluting isomer was 8-methoxy-DZ.
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Eur J Med Chem
January 2025
Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, 610041, China; Engineering Center of Catalysis and Synthesis for Chiral Molecules, Department of Chemistry, Fudan University, Shanghai, 200433, China; Shanghai Engineering Center of Industrial Asymmetric Catalysis for Chiral Drugs, Shanghai, 200433, China; Institute of Flow Chemistry and Engineering, School of Chemistry and Materials, Jiangxi Normal University, Nanchang, 330022, China. Electronic address:
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Collaborations Pharmaceuticals, Inc., 1730 Varsity Drivef, Suite 360, Raleigh, North Carolina 27606-5228, United States.
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School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, Zhejiang, P.R. China.
Apatinib, a commonly used tyrosine kinase inhibitor in cancer treatment, can cause adverse reactions such as hypertension. Hypertension, in turn, can increase the risk of certain cancers. The coexistence of these diseases makes the use of combination drugs more common in clinical practice, but the potential interactions and regulatory mechanisms in these drug combinations are poorly understood.
View Article and Find Full Text PDFZhongguo Zhong Yao Za Zhi
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School of Pharmaceutical Sciences, Guizhou Medical University Guiyang 550004, China Engineering Research Center for Development and Application of Ethnic Medicine and Traditional Chinese Medicine, Guizhou Medical University Guiyang 550004, China.
This study aims to compare the metabolic differences of baicalin and its analogues between Shuganning Injection and Scutellariae Radix extract. Twelve SD rats were randomly divided into a Shuganning Injection group and a Scutellariae Radix extract group, with 6 rats in each group. Their liver microsomes were incubated with the drugs, and then the samples were collected.
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Shanxi Key Lab. for modernization of TCVM, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China; College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128, China. Electronic address:
Allocryptopine (ALL), a principal active component of the novel veterinary medicine Bopu Powder®, has gained widespread application in the poultry farming sector for the effective management of Escherichia coli (E. coli) diarrhea. In order to explore the metabolites and the pivotal enzymes associated with ALL, this study was conducted employing an in vitro chicken liver microsomal incubation.
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