A reverse-phase High Performance Liquid Chromatographic (HPLC) method was developed for the analysis of metoprolol in the large number of human plasma samples obtained in in vitro-in vivo correlations (IVIVC) and bioavailability studies of extended release formulations of metoprolol tartrate. The metabolite, alpha-hydroxy metoprolol (OH-met), could also be quantified. The analytes were extracted from the plasma using solid phase columns, separated on a C-4 analytical column followed by fluorimetric detection. The linearity, precision, accuracy, stability, selectivity and ruggedness were validated for the concentration ranges of 1-400 ng ml-1 for metoprolol and 0.5-200 ng ml-1 for OH-met. The same chromatographic conditions were slightly modified to quantify dextromethorphan and its metabolite dextrorphan in urine in the concentration range 0.052-0.05 microgram ml-1 as a method for screening for fast metabolizers.
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http://dx.doi.org/10.1016/s0731-7085(97)00115-5 | DOI Listing |
Int J Gen Med
December 2024
Department of Neurosurgery, The Second Hospital of Hebei Medical University, Shijiazhuang, 050000, People's Republic of China.
BMC Cancer
September 2024
Department of Forensic Medicine, First College for Clinical Medicine, Xuzhou Medical University, 84 West Huaihai Rd, Xuzhou, Jiangsu, 221000, China.
Background: Glioblastoma multiforme (GBM) is a highly aggressive primary malignant brain tumor characterized by rapid progression, poor prognosis, and high mortality rates. Understanding the relationship between cerebrospinal fluid (CSF) metabolites and GBM is crucial for identifying potential biomarkers and pathways involved in the pathogenesis of this devastating disease.
Methods: In this study, Mendelian randomization (MR) analysis was employed to investigate the causal relationship between 338 CSF metabolites and GBM.
Indian J Pharmacol
July 2024
Department of Pharmacology, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India.
Background: Paclitaxel is a promising anticancer drug for patients with ovarian, breast, lung, gastrointestinal, genitourinary, prostate, and head-and-neck cancers. Paclitaxel follows nonlinear pharmacokinetics. The major metabolite of paclitaxel is 6-alpha-hydroxy paclitaxel, mediated by CYP2C8, while metabolism to two of its minor metabolites, 3'-p-hydroxypaclitaxel and 6a, 3'- p-dihydroxypaclitaxel, is catalyzed by CYP3A4.
View Article and Find Full Text PDFJ Agric Food Chem
August 2024
Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstraße 20, 38106 Braunschweig, Germany.
In the brewing process, methionine is a decisive amino acid for (off-)flavor formation. A significant part of methionine is oxidized to methionine sulfoxide (MetSO) in malt. We hypothesized that MetSO and MetSO are metabolized to volatile compounds during yeast fermentation and examined whether the yeast is able to catabolize l-MetSO and l-MetSO in free and dipeptide-bound forms.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
October 2024
Institut für Pharmazeutische Wissenschaften, Albert-Ludwigs-Universität Freiburg, Albertstrasse 25, 79104, Freiburg, Germany.
Many bacterial natural products contain C-branched sugars, including components from the outer cell wall or antibiotically active metabolites. The enzymatic C-branching of keto sugars leading to longer side chains (≥C) is catalyzed by thiamine diphosphate (ThDP)-dependent enzymes. Chiral tertiary α-hydroxy ketones are formed in this process.
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