Jacek Cybulski

Synthesis and anti-microbial activities of some pyridinium salts with alkoxymethyl hydrophobic group.

A novel class of functionalized cationic surfactant has been obtained. The work-up procedure of synthesis is very simple, the yield is high and the pyridinium salts with alkoxymethyl hydrophobic group are easily purified. All the salts examined showed anti-microbial activities. Some of them exhibited strong activity and wide anti-bacterial spectra similar to the activity of benzalkonium chloride. The relationship between chemical structure and anti-microbial activity was analysed by the QSAR method.

Long-Alkyl-Chain Quaternary Ammonium Lactate Based Ionic Liquids

A new group of quaternary ammonium lactate based ionic liquids have been prepared and characterized. Didecyldimethylammonium (DDA) and benzalkonium (BA) D,L- and L-lactates are air-stable, hydrophilic, surface-active salts. They are very effective antibacterial and antifungal agents, especially the DDA lactates, against Streptococcus mutants and Candida albicans. Their activities are comparable or more effective than the original benzalkonium chloride. In addition, they have been shown to be good insect-feeding deterrents. However, they are poor antifungal agents for wood preservation. The toxicity of the DDA and BA lactates has also been studied and the results are presented in this paper.

Direct separation of ?-hydroxy acid enantiomers by ligand exchange chromatography

Direct separation of several α-hydroxy acid racemic mixtures was performed by the aid of ligand exchange chromatography using L-hydroxyproline chemically bound to silica stationary phase and aqueous solutions of copper (II) sulphate as a mobile phase. The elution order of the D- and L-enantiomers of α-hydroxy acids is interpreted in terms of a modified Davankovs rule. Several aspects of the Davankovs model of selectand-Cu(II)-selector ternary complexes are discussed based on the theoretical calculations within the quantum mechanical semiempirical and density functional theories. Chirality 10:821–830, 1998.

Non-linear structure-enantioselective retention relationships in a homologous series of 1,4-disubstituted piperazine derivatives

A high-performance liquid chromatography method for the direct separation of enantiomers of a homologous series of 1,4-disubstituted piperazine derivatives, using a chiral cellulose tris(4-methylbenzoate) stationary phase and a hexane-propan-2-ol eluent, is described. An atypical relationship was found between enantioselectivity and the carbon number of the alkyl substituent with a maximum corresponding to four-five carbon atoms in the substituent. The optimum enantioselectivity observed suggests the existence of a limited size interaction site on the stationary phase and an input to retention due to the steric exclusion of individual solutes.

NMR studies of buspirone (an anxiolytic drug) analogues

Abstract Conformations of piperazine rings in 8-{4-[4-(2-pyrimidyl)-1-piperazinyl]butyl}-8-azaspiro[4.5]-decane-7,9-dione (buspir-one — 1 ) and its two analogues 8-{4-[4-(2-quinolinyl)-1-piperazinyl]butyl}-8-azaspiro[4.5]-decane-7,9-dione (kaspar — 2 ) and 4,4-dimethyl-1-{4-[4-(2-quinolinyl)-1-piperazinyl]butyl}-2,6-piperidinedione (mesmar — 3 ) (Fig. 1) have been studied with the aid of 1 H NMR and 13 C NMR spectra. For free bases the two bands corresponding to piperazine hydrogen atoms in the spectra broaden considerably with a decrease in temperature to divide into four separate bands, indicating the presence of a dynamic exchange process. A similar dynamic process, but for higher temperatures, was observed for buspirone ( 1 ), kaspar ( 2 ) and mesmar ( 3 ) hydrochlorides. Proton and carbon atom resonance lines have been assigned with the aid of 2D COSY and 2D HETCOR two-dimensional spectra.

Nuphacristine—an alkaloid from Nuphar luteum

Abstract From the rhizomes of Nuphar luteum a new C 15 alkaloid, nuphacristine, has been isolated. The structure and stereochemistry of nuphacristine have been established on the basis of spectral analysis and chemical transformations.

Methiodides of nuphar alkaloids: Part I. Studies on stereochemistry by carbon-13 nuclear magnetic resonance spectra of some thiospirane C30 and C15 methiodides

Abstract The 13 C NMR spectra of deoxynupharidine, 7-epideoxynupharidine and thiobinupharidine methiodides have been studied and the correlations between the stereochemistry of these compounds and corresponding chemical shifts are described. Quaternization of the nitrogen causes no steric changes in the trans -quinolizidine system of 7-epideoxynupharidine, whereas deoxynupharidine methiodide has a transformed quinolizidine system with cis ring fusion. Quaternization of thiobinupharidine with methyl iodide results in two isomeric monomethiodides which have been characterized as A′-B′- trans and AB- trans isomers of quaternary salts.

Methiodides of nuphar alkaloids: Part III. Studies on trans—cis transformation of quinolizidine system in thiospiro C30 alkaloids methiodides by 13C-NMR spectroscopy

Abstract The 13 C-NMR spectra of two new monomethiodides isolated from a reaction mixture obtained as a result of quaternisation of thiobinupharidine are reported. It has been established that the quaternisation causes conformational changes of N -substituted quinolizidine rings resulting in transformation of a trans form into a cis one. The structure and stereochemistry of products obtained have been determined by 13 C-NMR spectra. For two monomethiodides in question, the structures of N + 5 ′ − C H 3 cis quinolizidine (A′B′) or N + 5 − C H 3 cis quinolizidine (AB) were assigned.

Methiodides of nuphar alkaloids: Part VI. Studies on stereochemistry by carbon-13 nuclear magnetic resonance spectra of thiobinupharidine dimethiodides

Abstract Quaternization of thiobinupharidine, besides the four monomethiodides described earlier [1,2], resulted in the formation of another four dimethiodides. Thus only one or both nitrogen atoms of the quinolizidine rings could be subjected to quaternization. The following structures were assigned to the dimethiodides: (a) both quinolizidine rings trans , (b) both quinolizidine rings cis , (c) one ring system cis and the one trans and (d) one ring system trans and the other cis . The structures and stereochemistry of the dimethiodides obtained were determined on the basis of 13 C NMR spectra.

Methiodides of Nuphar alkaloids: Part V. Studies on 13C NMR of Hofmann degradation products of C15 alkaloids methiodides

Abstract 13 C NMR spectra of the products of the multistage Hofmann degradation of C 15 Nuphar alkaloids methiodides, 7-epideoxynupharidine and deoxynupharidine, have been studied and respective structures have been assigned to the products formed at each stage.