Diverse polyketides from the marine endophytic Alternaria sp. LV52: Structure determination and cytotoxic activities

Manar M. Mahmoud, Ahmed S. Abdel-Razek, Hesham S.M. Soliman, Larissa V. Ponomareva, Jon S. Thorson, Khaled A. Shaaban, Mohamed Shaaban

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


We report the isolation and characterization of five polyketides [alternariol (1), alternariol-9-methyl ether (2), altertoxin I (3), altertoxin II (4) and tenuazonic acid (5)] from the marine endophytic Alternaria sp. LV52 derived from Cystoseira tamariscifolia, collected from the Red Sea at Nabq-Bay, Egypt. The chemical structures of compounds 1–5 were identified by extensive 1D, 2D NMR, and HR mass measurements. Isolation and phenotypic and genotypic characterization of the producing fungus is reported. The antimicrobial activity of the produced extract and derived compounds was examined against a panel of test organisms. In addition, an in vitro cytotoxic activity of 1–5 was performed against diverse cancer cell lines: HEPG2, HELA, A549 and PC3, revealing that compounds 2 and 4 are potentially cytotoxic against A549 and PC3 with EC50 of 0.73 µg/ml (2.69 µM) and 0.17 µg/ml (0.64 µM) for 2, and 0.40 µg/ml (1.15 µM) and 0.12 µg/ml (0.33 µM) for 4, respectively.

Original languageEnglish
Article numbere00628
JournalBiotechnology Reports
StatePublished - Mar 2022

Bibliographical note

Funding Information:
The authors are thankful to the NMR and MS Departments in Bielefeld University for the spectral measurements. This research work has been financed by the German Academic Exchange Service (DAAD) in the frame of the Research Training Network “Novel Cytotoxic Drugs from Extremophilic Actinomycetes” (Project ID 57166072 ). This work was also supported by National Institutes of Health grant R01 GM115261 (JST), the Center of Biomedical Research Excellence (COBRE) in Pharmaceutical Research and Innovation ( CPRI , NIH P20 GM130456 ), the University of Kentucky College of Pharmacy and the National Center for Advancing Translational Sciences ( UL1TR000117 and UL1TR001998 ).

Publisher Copyright:
© 2021 The Authors


  • Alternaria sp.
  • Cytotoxicity
  • Marine endophyte
  • Polyketides
  • Taxonomy

ASJC Scopus subject areas

  • Biotechnology
  • Applied Microbiology and Biotechnology


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