Biosynthesis and Total Synthesis of Pyrronazol B: a Secondary Metabolite from Nannocystis pusilla

Abstract

The first stereoselective total synthesis of the natural product pyrronazol B, which contains a chlorinated pyrrole-oxazole-pyrone framework, has been achieved. Genome sequencing of the myxobacterial producer strain Nannocystis pusilla Ari7 led to the identification of the putative biosynthetic gene cluster. The proposed biosynthetic pathway was supported by feeding experiments with stable isotopes of three biosynthetic building blocks, namely l-proline, l-serine, and l-methionine.

Synthesis of the C18-C27 fragment of georatusin

“…In the context of our program to establish synthetic access to various natural products [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] we focused on those featuring the 1,3-(poly)deoxypropionate motif. A structurally challenging example is the polyketide-peptide hybrid georatusin (1) which was isolated from the soil fungus Geomyces auratus in 2018 by Bode and coworkers.…”

Total Synthesis of Pericoannosin A

“…In light of our ongoing work with hybrid peptide–polyketide natural products, we focused our efforts on the total synthesis of pericoannosin A ( 1 ) aiming for the first synthetic approach toward its unique tricyclic core structure. In our retrosynthetic analysis (Scheme ), we envisioned lactol formation via nucleophilic attack of an alcohol to a ketone as one of the last steps of our synthesis.…”

Genome Mining Reveals Endopyrroles from a Nonribosomal Peptide Assembly Line Triggered in Fungal–Bacterial Symbiosis

“…Because an intact A-DH-T gene assembly is obligatory for pyrrole biosynthesis, we colored all nodes gray that represent gene clusters lacking either the A or T domain genes. Thus, the SSN identified 20 known biosynthesis gene clusters for pyrrole-containing natural products (orange nodes, Figure c). − …”