A comparative study concerning the chromatographic behaviour and lipophilicity of certain natural toxins.

The characterization and classification of some natural toxins (mycotoxins and alkaloids) is established by high-performance thin-layer chromatography (HPTLC) using chemically bonded stationary phases of RP-18, RP-18W, RP-8, RP-2, RP-NH(2) , RP-CN and RP-Diol. The used mobile phases are mixtures of methanol-water in different proportions of volume, chosen to create a suitable migration during the chromatographic process. The lipophilicity is described through different chromatographic descriptors, such as R(M0), mean of R(M) (mR(M)), and scores of R(M) values corresponding to the first principal component (PC1/R(M)). The investigated compounds are characterized also by a series of computed lipophilicity descriptors (logP and logD values). The chromatographic behaviour of toxins is evidenced by graphical profiles of the lipophilicity descriptors. In addition, scores and loadings resulting from covariance matrix of retention data enable new information about similarity and differences observed between the investigated compounds. The experimental lipophilicity indices estimated from retention data are directly correlated with the computed values, via computer software and Internet module, at a high significant statistical level.