Reversed-phase thin-layer chromatography of some angiotensin converting enzyme (ACE) inhibitors and their active metabolites

Abstract

The chromatographic behaviour of some ACE inhibitors and their active metabolites was examined under conditions of reversed-phase thin-layer chromatography on RP-18 silica using water-methanol, water ethanol and water-acetone as binary solvent systems. The relationship between the R-M values and the concentration of organic modifier in the mobile phases was linear. It was found that an increase in the content of the organic modifier in the employed solvent systems led to a decrease of the R-M values, i.e., of the retention. Also, the more hydrophobic compounds had a longer retention. Based on regression analysis of the plots, the lipophilicity parameters R-M(0) and c(0) were calculated. The chromatographically obtained lipophilicity parameters were correlated with the calculated log P values.

Ispitivano je hromatografsko ponašanje nekih ACE inhibitora i njihovih aktivnih metabolita u uslovima reversno-fazne tankoslojne hromatografije na RP-18 silika-gelu primenom sledećih binarnih sistema rastvarača voda-metanol, voda-etanol i voda-aceton. Utvrđena je linearna zavisnost između RM-vrednosti i koncentracije organskog modifikatora u mobilnoj fazi. Nađeno je da povećanje sadržaja organskog modifikatora u upotrebljenom rastvaraču dovodi do opadanja RM-vrednosti, odnosno do slabljenja retencije. Jača retencija uočena je za hidrofobnije supstance. Na osnovu odgovarajućih regresionih podataka, izračunati su parametri lipofilnosti RM 0 i c0. Hromatografski utvrđeni parametri lipofilnosti korelisani su sa izračunatim log P vrednostima.