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1903-2003 - the century of chromatography. The impact of the method on development on natural sciences

100%

Soczewiński E.

Chemia Analityczna

2003

tom Vol. 48, No. 4

647-666

Lipofilowość, metody wyznaczania i rola w działaniu biologicznym substancji chemicznych

51%

Jóźwiak K. , Szumiło H. , Soczewiński E.

tom [Z] 55, 11-12

1047--1074

In this review the current concepts of lipophilicity phenomenon are described. It especially deserves special attention in medicinal chemistry. Lipophilicity is the factor of crucial importance in biological action of chemical substances. It is the main physico-chemical determinant influencing the bioavailability, permeability and frequently the toxicity of drugs. Lipophilicity is thus one of the most important factors in research aimed at rational designing of new drugs, what is of great and still growing importance nowadays. In the present review the current definitions of lipophilicity and hydrophobicity are discussed. Next, the role of lipophilicity of drugs in living organisms is widely reviewed. The experimental methods of estimation of biological lipophilicity are described in their historical development. The most widely used method of measuring the lipophilicity of compounds is nowadays the liquid chromatography technique, especially in reversed phase mode (according to the definition of lipophilicity). RP-HPLC is a fast and very precise tool for determination of lipophilicity in a wide range of chemical compounds. In presented paper the influence of the chromatographic systems are described with special attention on novel stationary phases which closely mimic the biological environment (e.g., Immobilized Artificial Membrane phase). Next, the procedures for the determination of chromatographic lipophilicity parameters for a set of derivatives in polycratic and gradient modes are described. The importance of different retention parameters and their usefulness in assessing lipophilicity are widely examined. Finally, a brief description of calculating methods of lipophilicity estimations is presented.

Two-dimensional liquid chromatography in a coupled micro-HPLC-thin-layer chromatography apparatus

51%

Hawrył M. A. , Soczewiński E. , Dzido T. H.

Chemia Analityczna

1999

tom Vol. 44, No. 1

15-21

An apparatus was constructed in which the eluate from micro-HPLC chromatograph (reversed-.phase (RP) system) is transferred directly in the form of an aerosol upon a moving silica TLC plate (normal-phase (NP), nonaqueous system) so that a two-dimen-sional chromatogram was obtained. The combination of RP and NP systems resulted in marked increase of separation efficiency owing to quite different selectivities of the two systems.

Skonstruowano przyrząd (w którym eluat z kolumny mikro-HPLC (w układzie odwró-conym faz, RP-8-woda + metanol) jest nanoszony, w postaci aerozolu, bezpośrednio na linię startu przesuwającej się równolegle płytki z cienką warstwą żelu krzemionkowego. W rezultacie otrzymuje się chromatogram dwuwymiarowy. Połączenie układów RP i NP zapewnia znaczny wzrost ęfektywności rozdzielenia ze względu na odmienne charakterystyki selektywności obu tych układów.