187753-75-9Relevant academic research and scientific papers
Probing host-selective phytotoxicity: Synthesis of destruxin B and several natural analogues
Ward,Gai,Lazny,Pedras
, p. 7832 - 7840 (2007/10/03)
The syntheses of the host-selective phytotoxin destruxin B [cyclo(βAla-Hmp-Pro-Ile-MeVal-MeAla), Hmp = (2R)-2-hydroxy-4-methylpentanoic acid], and the closely related natural analogues homodestruxin B (MeVal→MeIle), desmethyldestruxin B (MeVal→Val), hydroxydestruxin B (Hmp→Dhmp, Dhmp = (2R)-2,4-dihydroxy-4-methylpentanoic acid), and hydroxyhomodestruxin B (MeVal→MeIle, Hmp→Dhmp) are described. In each case, the MeAla-βAla linkage was formed by cyclization and the precursor linear hexadepsipeptides were formed by condensing two three-residue fragments. Radiolabeled samples of destruxin B, homodestruxin B, and hydroxydestruxin B were prepared by coupling [3-14C]-β-alanine to the appropriate pentadepsipeptide followed by cyclization. A noteworthy feature of the synthesis involves the novel use of a Boc-hydrazide protecting group on dipeptides with a C-terminal N-methylalanine residue to inhibit the otherwise facile dioxopiperazine formation during peptide coupling.
Synthesis of the host-selective phytotoxin destruxin B. Avoiding diketopiperazine formation from an N-methyl amino acid dipeptide by use of the Boc-hydrazide derivative
Ward, Dale E.,Lazny, Ryszard,Soledade,Pedras
, p. 339 - 342 (2007/10/03)
An efficient synthesis of the cyclic hexdepsipeptide destruxin B from its component residues is described that involves a [3+3] fragment coupling followed by cyclization via the azide method. A novel feature of the synthesis is the use of the Boc-hydrozide protecting group for the C-terminal N-methylalanine residue. This group serves bath to inhibit facile diketopiperazine formation from the N-methylvalyl-N-methylalanine dipeptide and as a latent activating group for hexadepsipeptide cyclization.
