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Biomedical subjects

A M Kołodziejczyk

Publications and source records attributed to A M Kołodziejczyk.

10 recordsLinked to original sources

Synthesis of analogues of anthraquinones linked to tuftsin or retro-tuftsin residues as potential topoisomerase inhibitors.

A novel group of [(4-, 5- or 8)-hydroxy-9,10-anthraquinone-1-yl]-(tuftsin or retro-tuftsin) acids and methyl esters has been synthesized as potential anticancer compounds. The corresponding protected tuftsin or retro-tuftsin derivatives were also synthesized. We hope that combining compounds of different mechanisms of action will improve their clinical properties, and that our new analogues will be much more effective against multidrug-resistant tumour cell lines.

Anthraquinones↗

Synthesis and antitumor activity of conjugates of muramyldipeptide, normuramyldipeptide, and desmuramylpeptides with acridine/acridone derivatives.

The synthesis of two groups (Chart 1, types A and B) of conjugates of MDP (muramyldipeptide) and nor-MDP (normuramyldipeptide) with acridine/acridone derivatives and the synthesis of analogues of desmuramylpeptides (Chart 1, types C and D) containing acridine/ acridone derivatives have been described. In type A conjugates, the hydroxyl group at C6 of the sugar moiety was acylated with acridine/acridone N-substituted omega-aminoalkanocarboxylic acids (Scheme 1), whereas the conjugates of type B (Table 2) and three analogues of type C or D (Scheme 2) have an amide bond formed between the carboxylic group of isoglutamine and the amine function of the respective acridine/acridone derivatives. The preliminary screening data indicate that the analogues of groups A, C, and D exhibit small cytotoxic activity, whereas several analogues of type B, 4b, 4c, 4e, 4g, 4h, 4i, and 4l, exhibiting potent in vitro cytotoxic activity against a panel of human cell lines (Table 4), have been selected by the National Cancer Institute (NCI) Evaluation Committee for further testing. Analogues 4b and 4h were active in the in vivo hollow fiber assay (Table 5). Analogue 3a shows an immunostimulating effect on the cytotoxic activity of the NK cells obtained from the spleen of healthy and Ab melanoma bearing animals.

Acetylmuramyl-Alanyl-Isoglutamine↗

[L-MTP-PE--a potential antineoplastic agent].

Muramyl tripeptide phosphatidylethanolamine (MTP-PE), a synthetic lipophilic analogue of muramyl dipeptide, stimulates monocytes/macrophages to kill a variety of tumor cells in vitro and in vivo. Encapsulation of MTP-PE into multilamellar liposomes (L-MTP-PE) was specifically designed for in vivo targeting to macrophages by i.v. infusion and is the only form of the drug currently available for clinical trials (CGP 19835A Lipid). L-MTP-PE is presently undergoing clinical trials in patients with recurrent osteosarcoma and melanoma. L-MTP-PE combined with other anticancer agents may thus improve long-term cure rates of patients with this diseases.

Acetylmuramyl-Alanyl-Isoglutamine↗

[Muroctasin, a muramyl dipeptide derivative].

This paper presents a review of studies on the metabolism, pharmacological and clinical properties of a new synthetic muramyl dipeptide derivative N2-/(N-acetylmuramoyl)-L-alanyl-D-isoglutaminyl/-N6-stearoyl-L-lysine(MD P- Lys(L18), muroctasin). Due to its effect on the number of peripheral blood leukocytes this compound is expected to be a useful drug for the treatment of leukopenia induced by cancer chemotherapy or radiation therapy.

Acetylmuramyl-Alanyl-Isoglutamine↗

Formation of optically pure N-acyl-N,N'-dicyclohexylurea in N,N'-dicyclohexylcarbodiimide-mediated peptide synthesis.

N-acylurea, a side product in peptide synthesis from DCC, preserves its chiral integrity although peptides formed simultaneously in the same reaction are racemized to a large extent. This observation is inconsistent with the generally accepted opinion that racemization-prone O-acylisourea is a common intermediate for both peptides and N-acylurea. Chiral purity of N-acylureas and peptides was determined by HPLC using chiral stationary phases. An efficient method of synthesis of chirally pure N-acylureas is also presented.

Amino Acids↗