Chromatomass-spectrometric determination of new antiulcer drug in rats blood plasma
T15N4
K.A. Leonov, D.A. Vishenkova, V.V. Bykov, A.A. Bakibaev
Synthesis of an innovative drug 9-(2,5-dihydroxyphenyl)-2-(4-ethoxyphenyl)-2,3,7,8-tetrahydro-1H-pyrido [1,2-a] pyrazine-1,4(6H)-dione (PPI) for the treatment of peptic ulcer with a new mechanism of action has necessitated the pharmacokinetics study of the substance in the blood plasma and investigation of its absorption and elimination processes. This paper describes the development and validation of a technique for quantitative determination of the new compound PPI in rat blood plasma by HPLC/MS. The method of solid-phase extraction is applied to extract PPI from blood plasma in the process of biological samples preparation. The lower limit of quantification is 0.1 ng ml–1, the linearity range from 0.1 to 1000 ng ml–1. By the developed technique the sample analysis of rats blood plasma was carried out after pharmaceutical PPI substance introduction in a dose of 20 mg kg–1, a pharmacokinetic profile of the substance was established, and pharmacokinetic parameters were calculated that allows one to judge the degree and rate of absorption and excretion of new antiulcer drug in the blood of laboratory rats.
Products of intermediate oxidation of flavonoids in aqueous solutions and determination of their composition by high-performance liquid chromatography in combination with mass spectrometry
T14N3
V.V. Khasanov, K.A. Dychko, A. V. Labutin, S.S. Kravtsova, T.T. Kuryaeva
Using high-performance liquid chromatography in combination with electrospray ionization mass spectrometry [HPLC-MS-ESI(NEG)], quercetin [Q] and luteolin [L] oxidation intermediate products were investigated. It was established that in aqueous solutions at pH=8.0 under aerobic conditions, quercetin forms double and triple donor- acceptor type complexes of the {[Q][Q–H2]} and {[Q][Q–H2]2} composition, which can be separated by HPLC, but rapidly converted to deeper oxidation products. In the presence of another flavonoid, luteolin (L), the oxidized form of quercetin also forms mixed complexes of {[L][Q–H2]} and {[L][Q–H2]2} types. Luteolin during oxidation does not generate donor-acceptor {[L][L–H2]} complexes. Quercetin in complexes with luteolin is always present in an oxidized form. It can be assumed that these complexes are formed as a result of recombination of two radicals of flavonoids, which formed initially as a result of manifestation of the antioxidants properties (one-electron transfer). These transformations of flavonoids are possible if strict anaerobic conditions in their quantitative determination are not implemented.
Использование высокоэффективной жидкостной хроматографии
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Использование масс-спектрометрии для структурной идентификации продуктов метаболизма синтетического каннабиноида JWH-018
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(Русский) Систематический токсиколого-аналитический скрининг биологических образцов
Sorry, this entry is only available in Русский.
