1. Academic Validation
  2. Rhizovarins A-F, Indole-Diterpenes from the Mangrove-Derived Endophytic Fungus Mucor irregularis QEN-189

Rhizovarins A-F, Indole-Diterpenes from the Mangrove-Derived Endophytic Fungus Mucor irregularis QEN-189

  • J Nat Prod. 2016 Aug 26;79(8):2066-74. doi: 10.1021/acs.jnatprod.6b00403.
Shu-Shan Gao 1 2 Xiao-Ming Li 1 Katherine Williams 2 Peter Proksch 3 Nai-Yun Ji 4 Bin-Gui Wang 1
Affiliations

Affiliations

  • 1 Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences , Nanhai Road 7, Qingdao 266071, People's Republic of China.
  • 2 School of Chemistry, University of Bristol , Bristol BS8 1TS, United Kingdom.
  • 3 Institut für Pharmazeutische Biologie und Biotechnologie, Heinrich-Heine-Universität Düsseldorf , Universitätsstraße 1, Geb. 26.23, 40225 Düsseldorf, Germany.
  • 4 Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences , Chunhui Road 17, Yantai 264003, People's Republic of China.
Abstract

Genome mining of the fungus Mucor irregularis (formerly known as Rhizomucor variabilis) revealed the presence of various gene clusters for secondary metabolite biosynthesis, including several terpene-based clusters. Investigation into the chemical diversity of M. irregularis QEN-189, an endophytic fungus isolated from the fresh inner tissue of the marine mangrove plant Rhizophora stylosa, resulted in the discovery of 20 structurally diverse indole-diterpenes including six new compounds, namely, rhizovarins A-F (1-6). Among them, compounds 1-3 represent the most complex members of the reported indole-diterpenes. The presence of an unusual acetal linked to a hemiketal (1) or a ketal (2 and 3) in an unprecedented 4,6,6,8,5,6,6,6,6-fused indole-diterpene ring system makes them chemically unique. Their structures and absolute configurations were elucidated by spectroscopic analysis, modified Mosher's method, and chemical calculations. Each of the isolated compounds was evaluated for antitumor activity against HL-60 and A-549 cell lines.

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