RESUMO
Thioesters of coenzyme A (CoA) carrying different acyl chains (acyl-CoAs) are central intermediates of many metabolic pathways and donor molecules for protein lysine acylation. Acyl-CoA species largely differ in terms of cellular concentrations and physico-chemical properties, rendering their analysis challenging. Here, we compare several approaches to quantify cellular acyl-CoA concentrations in normal and ischemic rat liver, using HPLC and LC-MS/MS for multi-acyl-CoA analysis, as well as NMR, fluorimetric and spectrophotometric techniques for the quantification of acetyl-CoAs. In particular, we describe a simple LC-MS/MS protocol that is suitable for the relative quantification of short and medium-chain acyl-CoA species. We show that ischemia induces specific changes in the short-chain acyl-CoA relative concentrations, while mild ischemia (1-2 min), although reducing succinyl-CoA, has little effects on acetyl-CoA, and even increases some acyl-CoA species upstream of the tricarboxylic acid cycle. In contrast, advanced ischemia (5-6 min) also reduces acetyl-CoA levels. Our approach provides the keys to accessing the acyl-CoA metabolome for a more in-depth analysis of metabolism, protein acylation and epigenetics.
Assuntos
Acil Coenzima A , Espectrometria de Massas em Tandem , Ratos , Animais , Acetilcoenzima A/análise , Cromatografia Líquida/métodos , Acil Coenzima A/metabolismo , Coenzima A/análise , Isquemia , Fígado/metabolismoRESUMO
Chemical investigation of the leaves of Bupleurum lancifolium led to the isolation and identification of two triterpenoid saponins previously undescribed named 3-O-[α-L-rhamnopyranosyl (1 â 4)-ß-D-glucopyranosyl] echinocystic acid 28-O-ß-D-glucopyranosyl ester (1) and 3-O-[α-L-rhamnopyranosyl (1 â 4)-ß-D-glucopyranosyl] oleanolic acid 28-O-ß-D-glucopyranosyl ester (2) along with the two known compounds isorhamnetin 3-rutinoside (3) and rutin (4). Their structures were elucidated by different spectroscopic methods, including HRESIMS analysis as well as 1D and 2D NMR experiments.
Assuntos
Apiaceae/química , Bupleurum/química , Folhas de Planta/química , Saponinas/isolamento & purificação , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Ácido Oleanólico/análogos & derivados , Saponinas/química , Análise Espectral , Triterpenos/química , Triterpenos/isolamento & purificaçãoRESUMO
Six flavonoids, namely 6-methoxykaempferol (1), 6-methoxykaempferol 7-O-glucoside (2), kaempferol 7-O-glucoside (3), 6-methoxyluteolin (4), patuletin 7-O-glucoside (5), and hispidulin 7-O-glucoside (6), were isolated from a n-butanolic fraction of Centaurea microcarpa Coss et Dur. flowers. This work describes for the first time the phytochemical composition of this endemic Algerian plant.
