A facile approach to tryptophan derivatives for the total synthesis of argyrin analogues

Abstract

A facile route has been established for the synthesis of indole-substituted (S)-tryptophans from corresponding indoles, which utilizes a chiral auxiliary-facilitated Strecker amino acid synthesis strategy. The chiral auxiliary reagents evaluated were (S)-methylbenzylamine and related derivatives. To illustrate the robustness of the method, eight optically pure (S)-tryptophan analogues were synthesized, which were subsequently used for the convergent synthesis of a potent antibacterial agent, argyrin A and its analogues.

Synthesis of redox-active fluorinated 5-hydroxytryptophans as molecular reporters for biological electron transfer

“…The strategy, which exploits an evolved TrpB synthase, 11 marks a significant improvement over conventional synthetic methods for unnatural L-Trp derivatives that require multiple steps and are associated with low yields. 12,13 While 5HOW is expected to have different electrostatic properties than Trp (see Fig. S1), incorporation of 5HOW into different proteins has been performed using human and E. coli expression systems without significant deleterious effects on protein structure or function.…”

Stereoselective Synthesis of syn-γ-Hydroxynorvaline and Related α-Amino Acids

“…The following removal of the chiral mediator was achieved by a mild reductive debenzylation by using trifluoroacetic acid as the solvent and triethylsilane as the reducing agent. 30 Our synthesis of syn--hydroxynorvaline (3) was completed by a gentle lactone opening, yielding the natural product in 33% yield over five steps. The spectroscopic data ( 1 H and 13 C NMR), melting point, and specific rotation of our material were in excellent agreement with the published data.…”

Chemical synthesis of tripeptide thioesters for the biotechnological incorporation into the myxobacterial secondary metabolite argyrin via mutasynthesis

“…Finally, Chen et al . described a synthesis yielding several derivatives of argyrin A with modification of the 4’-methoxytryptophan residue [17]. Changing the 4’-methoxy group to halogens or other substituents in different positions led to a loss of antibacterial activity, whereas the 5’-methoxytryptophan regioisomer largely retained activity against P. aeruginosa PAO1.…”