Microbial Dimerization and Chlorination of Isoflavones by a Takla Makan Desert-Derived Streptomyces sp. HDN154127

Abstract

Sixteen new biisoflavones, bisoflavolins A−N (1−16), were discovered from cultures of the Takla Makan desert-derived strain Streptomyces sp. HDN154127. The chemical structures, including axial chirality, were elucidated by NMR, MS, and ECD analyses. Antibacterial activity of dimerized compounds was tested against seven different bacteria. The dimerized compounds showed better activity (MIC from 0.8 to 50.0 μM) than the corresponding monomers (daidzein and genistein, MIC > 50.0 μM). The rare dimeric and chlorinated structures in 1−16 were proved to be biotransformation products obtained from soy isoflavones and sodium chloride, which constituted the culture medium. This is the first report of an actinomycete that promotes both dimerization and chlorination utilizing natural isoflavones as skeletons sources.

Substrate Conformational Switch Enables the Stereoselective Dimerization in P450 NascB: Insights from Molecular Dynamics Simulations and Quantum Mechanical/Molecular Mechanical Calculations

“…Therefore, our study highlights that the conformational movement of the substrate, which is controlled by the protein environment, can be vital to P450-catalyzed dimerization reactions. We anticipate that these findings can aid our understanding of other P450-catalyzed dimerization reactions, such as intermolecular C–C coupling, − C–N coupling, ,, and C–S coupling. − …”

A Survey of Recently Discovered Naturally Occurring Organohalogen Compounds

“…The axial chirality of 405 is deduced as an M -isomer by ECD calculations. Several of these compounds show antibacterial activity (MIC 0.4–3.1 μM) . Cultures of Nocardia uniformis IFM0856 from Solonetz soil yield the novel peptides, uniformides A ( 406 ) and B ( 407 ), which are cytotoxic toward J774.1 immune cells (IC 50 0.85 and 0.69 μM, respectively).…”

Perplexing Polyphenolics: The Isolations, Syntheses, Reappraisals, and Bioactivities of Flavonoids, Isoflavonoids, and Neoflavonoids from 2016 to 2022

“…Their dimeric and chlorinated forms are rare, and an actinomycete producing both features in an isoflavone has not been reported earlier. Compounds 60–65 are the first biisoflavone atropisomers isolated from a bacterial culture [ 40 ]. Compounds 76–81 are isoflavones isolated from the leaves of Vatairea guianenis .…”

“…The latter’s potent activity indicated that the C5′ and C5″ hydroxyl groups (absent in compound 64 ) are major determinants of bioactivity. Furthermore, the complete inactivity of compounds 68 and 71 further demonstrated the importance of the C5″ hydroxyl substituent [ 40 ].…”