Application of chemometric methods for determination the lipophilicity of pentacyclic triterpene derivatives

Abstract

Chemometric analysis is often used in many fields of science. One of the most popular are cluster analysis and principal component analysis. The presented work considers those methods to evaluate the lipophilicity of groups of pentacyclic triterpene derivatives. They are newly synthesized compounds with biological activity, so they can be used in the future as drugs and lipophilicity is an essential parameter. The experimental values of lipophilicity were determined using thin-layer chromatography. The plates were precoated with silica gel, and a mixture of 1,4-dioxane and acetate buffer was applied as the mobile phase. The experimental values of lipophilicity for investigated compounds were correlated with lipophilicity taken from freely available databases (ALOGPs, KowWin, XLOGP2, XLOGP3, miLogP, AClogP, ALOGP, MLOGP, iLOGP, WLOGP and SILICOS-IT). Those experimental values were also correlated with physicochemical properties such as molecular weight, the topological polar surface of the molecule, the number of rotatable bonds, and the number of donor and acceptor sites for hydrogen bonds. Some correlation equations could be formed for the correlation obtained. The cluster and principal component analysis were done based on the data obtained. All the experimental lipophilicity data correlate well with those theoretically calculated based on the structural formula. Almost all dependencies can be described by the correlation equation, with a high correlation coefficient. Thus, it is possible to infer the lipophilicity values of triterpene derivatives without any laboratory work. The physicochemical properties turned out to be less valuable and, apart from the compounds' molar mass, not helpful.