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Z J Kamiński

Publications and source records attributed to Z J Kamiński.

10 recordsLinked to original sources
PubMed2004

Synthesis and cytostatic properties of monoterpene derivatives of cyanuric and isocyanuric acids.

Symmetric, trisubstituted derivatives of cyanuric and isocyanuric acid 3a-e and 4a-e, respectively have been prepared by treatment of cyanuric chloride 1 with appropriate terpenic alcohols 2a-e. Under less basic conditions involving treatment of appropriate alcohols 2a-e with metallic sodium, less polar cyanuric acid derivatives 3a-e were obtained in 74-85 yield. Under more basic conditions, in the presence of sodium hydride, isocyanuric acid derivatives 4a-e were prepared in 71-88 yield. Cytostatic activity of (IR,2S,5R)-menthol derivative (3a) has been evaluated on 9 cancer subtypes including 62 tumor cell lines. The studies have shown that contrary to expectations, 2,4,6-trimentoloxy-1,3,5-triazine revealed a weak or moderate activity against most of the cell lines.

Antineoplastic Agents↗
PubMed2001

A novel generation of coupling reagents. Enantiodifferentiating coupling reagents prepared in situ from 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT) and chiral tertiary amines.

Coupling of racemic N-protected amino acids with amino components by means of 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT) in the presence of chiral tertiary amines such as strychnine, brucine, and sparteine proceeds enantioselectively, affording appropriate amides or dipeptides in 69-85% yield. The configuration of the preferred enantiomer and enantiomeric enrichment depend on the structures of the amine and carboxylic acid. Calculated Kagan enantioselectivity parameters (s) are in the range 1.6-195. Chiral triazinylammonium chlorides formed in situ from CDMT and chiral tertiary amines are postulated as reactive intermediates involved in the process of enantioselective activation of N-protected amino acids.

Journal Article↗
PubMed2000

Triazine-based condensing reagents.

The synthesis, properties, and application of condensing reagents derived from 1,3,5-triazines are described. The mechanism of activation of carboxylic function, structure of reactive intermediates, and mechanism of acylation of nucleophiles are presented. The synthetic versatility of mono- and bifunctional reagents for syntheses in solution, triazine-based immobilized reagents, chiral triazines for enantiodifferentiating syntheses, are discussed. The scope and limitation of the synthetic utility of triazine reagents in the preparation of heterocyclic compounds, amides, esters, oligopeptides-including large-scale syntheses and use in the combinatorial chemistry-is demonstrated.

Combinatorial Chemistry Techniques↗
PubMed2000

The library of p-nitrophenyl esters of oligopeptides as a model to study the anticancer drug-peptide conjugates activated during tumor angiogenesis.

An indexed library of oligopeptide p-nitrophenyl esters immobilized via methoxy-1,3,5-triazine scaffold on the cellulose support, was synthesized by the step by step procedure and by segment coupling, involving 2-chloro-4,6-dimethoxy-1,3,5-triazine as a condensing reagent. The substrate specificity towards homogenate supernatant of mouse lung cancer LL2 cells has been studied.

Animals↗
PubMed2000

The library of p-nitrophenyl esters of oligopeptides as a model to study the anticancer drug-peptide conjugates activated during tumor angiogenesis.

An indexed library of oligopeptide p-nitrophenyl esters immobilized via methoxy-1,3,5-triazine scaffold on the cellulose support, was synthesized by the step by step procedure and by segment coupling, involving 2-chloro-4,6-dimethoxy-1,3,5-triazine as a condensing reagent. The substrate specificity towards homogenate supernatant of mouse lung cancer LL2 cells has been studied.

Animals↗
PubMed1994

The concept of superactive esters. Could peptide synthesis be improved by inventing superactive esters?

According to the concept presented, esters forming an amide (peptide) bond by the mechanism SN#DN or SN#*DN involving fast decay of the tetrahedral intermediate may behave as 'superactive acylating reagents'. These should render coupling involving less reactive substrates, i.e. sterically hindered or 'difficult coupling sequences', much faster and more uniform than classic active esters. In extremely cases this advantage could be significant, and the calculated increase in time required for 99.9% coupling substrates 6 pKa units less reactive than the standard ones reaches 2,512,000 tau 1/2 units for classic active esters, but only 631 tau 1/2 units for reaction involving 'superactive esters'. The postulated change of mechanism is expected for esters bearing a leaving group which is able to undergo an additional, synchronous, energetically favored process accompanying its departure, as has been observed in the case of triazine esters. Some advantages of triazine superactive esters in the condensation of sterically hindered substrates are demonstrated.

Amino Acid Sequence↗