2. Academic Validation
  3. Colletotrichalactones A-Ca, unusual 5/6/10-fused tricyclic polyketides produced by an endophytic fungus, Colletotrichum sp. JS-0361

Colletotrichalactones A-Ca, unusual 5/6/10-fused tricyclic polyketides produced by an endophytic fungus, Colletotrichum sp. JS-0361

  • Bioorg Chem. 2020 Dec;105:104449. doi: 10.1016/j.bioorg.2020.104449.
Sunghee Bang 1,  Ha Eun Kwon 2,  Ji Yun Baek 3,  Dae Sik Jang 4,  Soonok Kim 5,  Sang-Jip Nam 6,  Dongho Lee 2,  Ki Sung Kang 3,  Sang Hee Shim 7
Affiliations

Affiliations

  • 1 College of Pharmacy, Duksung Women's University, Seoul 01369, Republic of Korea.
  • 2 Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Republic of Korea.
  • 3 College of Korean Medicine, Gachon University, Seongnam 13120, Republic of Korea.
  • 4 Department of Life & Nanopharmaceutical Sciences, Graduate School, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea.
  • 5 Biological Resources Assessment Division, National Institute of Biological Resources, Incheon 22689, Republic of Korea.
  • 6 Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Republic of Korea.
  • 7 College of Pharmacy, Duksung Women's University, Seoul 01369, Republic of Korea. Electronic address: sangheeshim@duksung.ac.kr.
PMID: 33189995 DOI: 10.1016/j.bioorg.2020.104449
Abstract

Three unusual polyketides with a 5/6/10-fused ring system, named colletotrichalactones A-Ca (1-3a), were isolated from cultures of the endophytic fungus, Colletotrichum sp. JS-0361, which was isolated from a leaf of Morus alba. Their structures, including their absolute stereochemistries, were completely established using extensive spectroscopic methods together with a chemical reaction utilizing competing enantioselective acylation coupled with LC/MS. Compounds possessing this ring skeleton were previously reported in three studies. Our rigorous chemical investigation revealed the complete configuration of this skeleton, which agreed with the results for glabramycin B with this ring skeleton established by computational chemistry and enantioselective synthesis in previous reports. 1 and 2 had unstable aldehyde groups that were easily converted to acetal groups in the presence of solvents. Meanwhile, compound 3a, with terminal acetal functionality, was deduced to be an artefact originating from compound 3 with a terminal aldehyde group. Compounds 1 and 3a displayed moderate-to-potent cytotoxic activities against MCF7 cells with IC50s of 35.06 and 25.20 µM, respectively.

Keywords

5/6/10-Fused ring system; Colletotrichum sp.; Cytotoxicity; Polyketides.

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