Abstract
Microbial biotransformation of argentatin A (1), isoargentatin A (2) and argentatin C (3), the triterpenoid constituents of guayule (Parthenium argentatum) resin was conducted with Chaetomium sp. PA001, an endophytic fungus of the same plant. The experiments yielded six new products (4–9) formed by: (i) nucleophilic oxygenation of the 3-ketone moiety resulting in Baeyer-Villiger oxidation; (ii) lactone ring opening of these oxidation products; (iii) rearrangement of the 9(10)-cyclopropane ring; and (iv) reduction of the 3-ketone moiety. The structures of all new biotransformation products were established by detailed analysis of their spectroscopic data. None of the products exhibited any antimicrobial activity. However, the hydroxy-carboxylic acid derivative 5 of argentatin A showed weak cytotoxic activity, but improved selectivity against human breast cancer cell line MCF-7 compared to the parent compound. This constitutes the first report of microbial biotransformation of isoargentatin A and argentatin C.
| Original language | English |
|---|---|
| Pages (from-to) | 124-130 |
| Journal | Phytochemistry Letters |
| Volume | 55 |
| DOIs | |
| Publication status | Published - Jun 2023 |
| MoE publication type | A1 Journal article-refereed |
Funding
This project was supported by the USDA-NIFA (grant # 2017- 68005–26867; Dr. Kimberly Ogden, PI) and Hatch Projects 1005072 and 1020652 to A.A.L.G and I.M.
Keywords
- Argentatins
- Biotransformation
- Chaetomium sp.PA001
- Enzymatic Baeyer-Villiger oxidation
- Guayule
- Parthenium argentatum
