Aleksander M. Kolodziejczyk

Dynamic ligand-exchange chiral stationary phases derived from N-substituted (S)-phenylglycinol selectors

Abstract Six chiral stationary phases based on N-substituted ( S -phenylglycinol were synthesised and dynamically loaded onto octadecyl-silica gel column. The effect of the alkyl (C 7 , C 9 , C 12 ) and aryl (methoxybenzyl, naphtylmethyl, anthrylmethyl) anchor moieties and influence of various chromatographic conditions (concentration of copper(II) ions, pH of the mobile phase, column temperature and organic modifier addition) on retention and enantioselectivity of the chiral columns toward selected α-amino acids were studied. The surface concentrations of chiral selectors, determined using the breakthrough method, were found to be in the range of 0.66–0.88 μmol/m 2 . The order of elution of α-amino acid enantiomers was found to be R S on the N-C 12 -( S )-phenylglycinol and all N-aryl-( S )-phenylglycinol phases but a reversed elution order ( S R ) was observed on the N-C 7 - and N-C 9 -( S )-phenylglycinol phases.

The in vitro effect of new muramyl peptide derivatives on cytotoxic activity of NK (natural killer) cells from hamsters bearing Ab Bomirski melanoma.

The modulation of NK activity by muramyl dipeptides derivatives against Ab (amelanotic) Bomirski melanoma and human erythroleukemia K562 cells was studied in vitro. The stimulatory effect was observed for 3 of 7 muramyl dipeptides: MDP(L-Ala)C921, MDPC857 and L18-MDP(Ala) in relation to cytotoxic activity of NK cells obtained from peripheral blood and spleen of healthy and Ab Bomirski melanoma bearing hamsters. An increased of cytotoxic activity NK cells isolated from animals before and during the transplantable phase of the tumor against K562 was found. A similar stimulation was received for NK cells obtained from animals against their own melanoma cells. The most significant influence of examined MDP derivatives on the cytotoxic activity of NK cells were obtained from animals between 10 to 12 days of tumor growth. The extent of the modulation of cytotoxic activity of NK cells was dependent on its initial value both in healthy control and Ab Bomirski melanoma bearing hamsters. If natural cytotoxic activity was high the stimulatory effect of the examined MDP derivatives was only slightly expressed.

Application of polarimetric detector for the high-performance liquid chromatographic determination of the optical purity of 5(4H)-oxazolones

An HPLC procedure for monitoring one of the reactive intermediates in peptide synthesis, 5(4H)-oxazolone, was developed. The reversed-phase mode made it possible not only to monitor the formation and consumption of oxazolone, but also to determine the concentration of other components of the reaction mixture. Moreover, with polarimewtric and UV detectors coupled in series it was possible to determine the content of both oxazolone enantiomers in the reaction mixture. Hence with the achiral chromatographic system employed, the enantiomeric excess of the crucial component of the mixture could be monitored.

Simple and precise high-performance liquid chromatographic method for the investigation of carbodiimide-mediated peptide synthesis

A simple HPLC method for the determination of intermediates, products and by-products of peptide synthesis is described. The mean errors of the quantitative determination of all components of the reaction mixture at any stage of peptide synthesis were found to be low (1.3–2.1%). The sensitivity was good enough to detect a 0.05% yield of the products. The method was successfully used to determine the effects of the reaction conditions on optical purity and yield of the synthesised peptide and amino acid derivatives.

Benzo[a]pyrene in soils and ground water: Occurrence, sources, distribution, interrelation

To identify benzo[a]pyrene (BaP) sources in soil and ground water and evaluate its occurrence and distribution in these environmental compartments, survey for BaP in four sites of different character and extent of anthropogenic impact was carried out in Poland in 1993–1994. The applicability of fluoranthene (Fl) as an indicator for evaluation of BaP concentrations in soil and ground water was also estimated and verified. For PAH analysis, simple and reliable method of soil sample preparation comprising ultrasonic extraction with dichloromethane was elaborated and applied. In total, 176 samples of soil and 56 samples of ground water were analyzed using HPLC Hewlett Packard 1090 with fluorescence detector. The BaP concentrations in soil ranged from < 1 to 3030 μg/kg, the highest values being attributed to motor vehicles and hand‐stocked residential furnaces. Surface soil layer proved to be an efficient protective barrier against BaP penetration to ground water. Due to different mechanism and dynamics of bin...

NMR studies of the MDP conjugates with amino-acridine/acridone derivatives

1H and13C NMR studies allowed us to determine the structure of anticancer active MDP analogs modified at the C-terminus with amino-acridine/acridone derivatives. The products contain an isoglutamine residue without contamination by their isomers containing a glutamine residue as could be expected based on the literature data.