[Fundamentals of stationary phase optimized selectivity LC (SOS-LC)].

A new procedure (SOS-LC) is described for the optimization of the HPLC stationary phase, using serially connected columns and the principle of the "PRISMA" model. In the course of the base measurements the retention factors (k) of the analytes were determined on three different base stationary phases; other parameters were fixed. By use of these data the k values were predicted in the cases of all theoretically combined stationary phases.

Structure elucidation and antioxidant activity of (-)-isosilandrin isolated from Silybum marianum L.

A regioisomer of the known flavanolignan (-)-silandrin (3a), named (-)-isosilandrin (8a), was isolated from the fruits of a white-flowered variant of Silybum marianum L. populated in Hungary. Its structure was established both by spectroscopic methods and total synthesis, and its absolute configuration was determined by means of circular dichroism.

Separation strategies of plant constituents--current status.

The paper summarizes the state of art of different separation methods which are used for the analysis and isolation of plant constituents. An overview about the extraction methods which are frequently used for the non-volatile constituents of plants is given. Special attention is paid to the identification possibilities of non-volatile and volatile compounds, since generally the role of identification of plant's constituents is undervalued.

[Comparative botanical and phytochemical investigations on the Gentiana species native to Hungary].

The aim of this work was to compare the three Gentiana species native to Hungary (Gentiana asclepiadea L., Gentiana pneumonanthe L. and Gentiana cruciata L.