PubMed Health⌕ Search

Biomedical subjects

A J Pfizenmayer

Publications and source records attributed to A J Pfizenmayer.

4 recordsLinked to original sources

Total syntheses of conformationally constrained didemnin B analogues. replacements of N,O-dimethyltyrosine with L-1,2,3,4-tetrahydroisoquinoline and L-1,2,3,4-tetrahydro-7-methoxyisoquinoline.

The design and synthesis of two conformationally constrained analogues of didemnin B are described. The [N,O-Me(2)Tyr(5)]residue of didemnin B was replaced with L-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (Tic) and L-1,2,3,4-tetrahydro-7-methoxyisoquinoline-3-carboxylic acid (MeO-Tic), which mimic the N,O-dimethylated tyrosine while constraining the conformation of the molecule. Preliminary results indicate that the conformation of the [N,O-Me(2)Tyr(5)]residue closely matches the conformation imposed by the Tic replacement.

Depsipeptides↗

Synthesis and biological evaluation of didemnin photoaffinity analogues.

The synthesis of four benzophenone-containing analogues of the antiproliferative natural product didemnin B is presented. In vitro protein biosynthesis inhibition potency and antitumor activity were evaluated. The results indicate that all four analogues are biologically active and could serve as photoaffinity reagents for the study of receptor-binding interactions of didemnins. These analogues could also be useful in studying antitumor effects of didemnins.

Antineoplastic Agents↗

[Lys3]Didemnins as potential affinity ligands.

The synthesis and biological activity of N(epsilon)-Z-[Lys3]didemnin B are reported. This novel analogue retains antiproliferative, cytotoxic, and protein biosynthesis inhibition activities, but at reduced levels. This result suggests the use of [Lys3]didemnin derivatives as potential affinity probes for studying the molecular target(s) of the didemnin class of natural products.

Affinity Labels↗

Synthesis and biological activity of [Tic5] didemnin B.

A didemnin B analog containing a Tic (1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid) as a conformationally restrained replacement for tyrosine has been synthesized and shown to have comparable potency as a protein biosynthesis inhibitor. Synthetic highlights include an oxidation of an alcohol to an acid in the presence of the sensitive Tic heterocycle and a modified Schmidt-type one-pot macrocyclization.

Animals↗