Simultaneous determination of chloroquine, proguanil and their metabolites in human biological fluids by high-performance liquid chromatography.

A reversed-phase ion-pair high-performance liquid chromatographic method with ultraviolet detection is described for the simultaneous measurement of chloroquine, proguanil and their major metabolites in human plasma, erythrocytes and urine. After a liquid-solid extraction on a Bond Elut C8 cartridge, the compounds are separated on a C8 Lichrospher 60 RP select B column by isocratic elution; the mobile phase is water-acetonitrile-methanol (78:28:4, v/v/v) with 0.5 M ammonium formate and 0.075 M perchloric acid. The eluent is monitored with an ultraviolet detector at 254 nm. The lower limits of quantification in plasma are near 6.0 ng ml-1 for chloroquine and near 9.0 ng ml-1 for proguanil. No chromatographic interference can be detected from endogenous compounds or from other antimalarial drugs. The method is accurate and precision is good with inter- and intra-assay relative standard deviations lower than 6.8% for plasma samples. N-(2-6 dichlorobenzylidene amino)guanidine is used as an internal standard. The chromatographic procedure takes 35 min and can be used for therapeutic drug monitoring and clinical studies.

[Simple methods of chloroquine determination in urine and their adaptation in the field]. / Les méthodes simples de dosage de la chloroquine dans les urines et leur adaptation sur le terrain.

Field malaria studies require often the on site detection of chloroquine in urine for monitoring chemoprophylaxis and treatment compliance, investigating drug-use patterns and screening prospective subjects for in vitro and in vivo chemosensitivity tests. The field adapted methods are described, analytical characteristics are compared and different approaches to field adapted assay of chloroquine are discussed.

Transfer of N-acetylglucosamine to nuclear endogenous acceptors of rat hepatocytes.

1. Nuclei were prepared from rat hepatocytes. A biochemical analysis of marker enzymes showed that the nuclei are not contaminated by other subcellular fractions, especially endoplasmic reticulum. 2. The transfer of [14C]N-acetylglucosamine to endogenous acceptors were studied comparatively in the nuclei and in the other subcellular fractions of rat hepatocytes. 3. In this report we describe the presence of the transfer of N-acetylglucosamine within the nucleus of rat hepatocytes. We found 21% of this transfer in the nucleus fraction with an enrichment of 26 in comparison to homogenate.

Evidence for incorporation of N-acetylglucosamine in endogenous nuclear acceptors during the nuclear matrix preparation.

1. The presence of glycoproteins within the nucleus of cell is now well established and the question arises on the nature of the nuclear glycosylation and the site of their glycosylation. 2. In order to study endogenous nuclear proteins acceptors, we have isolated a subnuclear fraction: nuclear matrix characterized by DNA, RNA, phospholipids and proteins content. Nuclear matrix acceptors were obtained from nuclei incubated with UDP-N-acetyl [14C]glucosamine. 3. In this report we describe the presence of three major glycoproteins labeled with N-acetyl [14C]glucosamine in the nuclear matrix fraction. We obtained gP32, gP67 and gP70 with pI values around 6.2, 6.5 and 8.2.