Totopotensamide Congeners from a Halogenase-Inactivated Mutant

J Nat Prod. 2023 Jan 27;86(1):76-84. doi: 10.1021/acs.jnatprod.2c00772. Epub 2023 Jan 6.

Abstract

The installation of halogen atoms into aromatic and less activated polyketide substrates by halogenases is a powerful strategy to tune the bioactivity, bioavailability, and reactivity of compounds. In the biosynthetic pathway of totopotensamide A (1), the halogenase TotH was confirmed in vivo to catalyze the C-4 chlorination to form the nonproteinogenic amino acid ClMeDPG. Herein, we report the isolation, structure elucidation, and bioactivity evaluation of six new deschloro totopotensamide (TPM) congeners TPMs H2-H7 (5-10) from the totH-inactivated strain and the proposed absolute configuration of the polyketide chain in TPMs using 4 as a model compound by a combination of the JBCA and bioinformatic analysis. Compounds 5, 6, 8, and 9 displayed cytotoxicity against the A549, PANC-1, Calu3, and BXPC3 cell lines with IC50 values ranging from 2.3 to 9.7 μM.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Halogenation*