Penitol A and Penicitols E-I: Citrinin Derivatives from Penicillium citrinum and the Structure Revision of Previously Proposed Analogues

  • J Nat Prod. 2021 Apr 23;84(4):1345-1352. doi: 10.1021/acs.jnatprod.1c00082.
Meimei Cheng  1  2 ,  Pinglin Li  1  2 ,  Yun Jiang  1  2 ,  Xuli Tang  3 ,  Wenjie Zhang  1  2 ,  Qi Wang  1  2  4 ,  Guoqiang Li  1  2
Affiliations
  • 1. Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, People's Republic of China.
  • 2. Laboratory of Marine Drugs and Biological Products, Pilot National Laboratory for Marine Science and Technology, Qingdao 266235, People's Republic of China.
  • 3. College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, People's Republic of China.
  • 4. Department of Natural Medicinal Chemistry and Pharmacognosy, School of Pharmacy, Qingdao University, Qingdao 266021, People's Republic of China.
PMID: 33847126 DOI: 10.1021/acs.jnatprod.1c00082
Abstract

Penitol A (1), a new citrinin derivative with a rare tricyclic spiro skeleton, was isolated from a coral-derived strain of the fungus Penicillium citrinum. In addition, penicitols E-I (2-6), five new citrinin analogues, were coisolated. Their structures were determined by an analysis of 1D/2D NMR and HRESIMS data, statistical DP4+ analyses based on DFT-GIAO NMR calculations, quantum chemistry ECD calculations, and a single-crystal X-ray diffraction study. The structures of penicitol A (7) and two related synthetic intermediates were revised. Biological evaluation results revealed that penitol A (1) exhibited cytotoxic activity against K562 tumor cells, with an IC50 value of 8.8 μM. A proposed route of formation of compounds 1-7 was reported.