Chemical variation from the neoantimycin depsipeptide assembly line.

Here we report the biosynthetic pathway for the neoantimycin and present three novel neoantimycin analogues, neoantimycin D (1), E (2) and F (3), from this assembly system from Streptoverticillium orinoci. Identification of these novel neoantimycin variants was achieved by selective MS/MS interrogation of natural product extracts using diagnostic fragments of the known neoantimycins. Their structures, including the absolute configurations, were elucidated using a combination of NMR experiments, detailed MS/MS experiments and the advanced Marfey's method. The biosynthetic pathway of neoantimycin was dissected by genome sequencing data analysis for the first time, which includes a hybrid nonribosomal peptide synthetase (NRPS) and polyketide synthetase (PKS) assembly lines.

Chemical and biosynthetic evolution of the antimycin-type depsipeptides.

Evolution of natural products, and particularly those resulting from microbial assembly line-like enzymes, such as polyketide (PK) and nonribosomal peptides (NRP), has resulted in a variety of pharmaceutically important and chemically diverse families of molecules. The antimycin-type depsipeptides are one such grouping, with a significant level of diversity and members that have noted activities against key targets governing human cellular apoptosis (e.g. Bcl-xL and GRP78). Chemical variance originates from ring size, with 9-, 12-, 15-, and 18-membered classes, and we show that such distinctions influence their molecular targeting. Further, we present here a systematic interrogation of the chemistry and assembly line evolution of antimycin-type analogues by conducting metabolomic profiling and biosynthetic gene cluster comparative analysis of the depsipeptide assembly lines for each member of the antimycin-group. Natural molecular evolution principles of such studies should assist in artificial re-combinatorializing of PK and NRP assembly lines.