Quantitative structure-retention relationships of antimicrobial hydrazidesevaluated by reverse-phase liquid chromatography

Quantitative structure-retention relationships of antimicrobial hydrazides were investigated by reversed-phase liquid chromatography (RPLC), to disclo se retention mechanisms operating in a C-8 column. Capacity factors (log k) were obtained using methanol-water mobile phase in volume fractions: 25-75 % nu/nu. Extrapolated log k,values were derived from log k versus mobile p hase, volume fraction of organic modifier, phi, using log k = log k(w) - S phi. The chemical validity of a linear relationship between the slopes (S) and intercepts (log k(w)) was established. S-log k(w) correlations are chem ically meaningful for a non-homologous series of compounds. The existence o f a clear separation of hydrazides into two different sets of hydrogen-bond ing capabilities demonstrated the role of such relationships. Standard CoMF A fields were used to delineate those specific intermolecular interactions responsible for changes in retention of study hydrazides. Thus, a 3D QSAR ( CoMFA) model showed that S exhibits electrostatic behaviour towards a C-8 H PLC column.