Genome mining, isolation, chemical synthesis and biological evaluation of a novel lanthipeptide, tikitericin, from the extremophilic microorganism: Thermogemmatispora strain T81

© The Royal Society of Chemistry 2018. Genome mining of the New Zealand extremophilic microorganism Thermogemmatispora strain T81 indicated the presence of biosynthetic machinery to produce several different peptidic natural products. Solid-phase culture of T81 led to the isolation of tikitericin 1, a new lanthipeptide characterised by four (methyl)lanthionine bridges. The mass-guided isolation and structural elucidation of tikitericin 1 is described together with its total synthesis via Fmoc-solid-phase peptide synthesis (SPPS). The key non-canonical (methyl)lanthionine residues were synthesised in solution phase via an improved synthetic route and subsequently assembled to construct the peptide backbone using Fmoc-SPPS. N-Terminal truncated analogues of tikitericin (2-5) were also prepared in order to evaluate the contribution of each sequential ring of the polycyclic lanthipeptide to the antibacterial activity

The absolute structure of (+)-aplysulfurin

The spongian diterpene aplysulfurin (CHO ) is a marine natural product whose relative stereochemistry has been previously elucidated by X-ray crystallography and NMR, but its absolute structure has only been proposed on biogenetic grounds. Herein we have determined the absolute structure of (+)-aplysulfurin by anomalous dispersion effects of a highly redundant data set collected with Cu-Kα radiation. We have found that the four chirotopic centres have the absolute configuration C7(R), C10(S), C15(S) and C16(S)