Chemistry and Bioactivity of the Deep-Water Antarctic Octocoral Alcyonium sp.

Chemical investigation of an Antarctic deep-water octocoral has led to the isolation of four new compounds, including three illudalane sesquiterpenoids ( 1 – 3 ) related to the alcyopterosins, a highly oxidized steroid, alcyosterone ( 5 ), and five known alcyopterosins ( 4 , 6 – 9 ). The structures...

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Bibliographic Details
Published in:Marine Drugs
Main Authors: Anne-Claire D. Limon, Hiran M. L. W. Patabendige, Ala Azhari, Xingmin Sun, Dennis E. Kyle, Nerida G. Wilson, Bill J. Baker
Format: Article in Journal/Newspaper
Language:English
Published: MDPI AG 2022
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Online Access:https://doi.org/10.3390/md20090576
https://doaj.org/article/3b9bd49b9aa34a44a9b52a7872906be1
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Summary:Chemical investigation of an Antarctic deep-water octocoral has led to the isolation of four new compounds, including three illudalane sesquiterpenoids ( 1 – 3 ) related to the alcyopterosins, a highly oxidized steroid, alcyosterone ( 5 ), and five known alcyopterosins ( 4 , 6 – 9 ). The structures were established by extensive 1D and 2D NMR analyses, while 9 was verified by XRD. Alcyopterosins are unusual for their nitrate ester functionalization and have been characterized with cytotoxicity related to their DNA binding properties. Alcyopterosins V ( 3 ) and E ( 4 ) demonstrated single-digit micromolar activity against Clostridium difficile , an intestinal bacterium capable of causing severe diarrhea that is increasingly associated with drug resistance. Alcyosterone ( 5 ) and several alcyopterosins were similarly potent against the protist Leishmania donovani , the causative agent of leishmaniasis, a disfiguring disease that can be fatal if not treated. While the alcyopterosin family of sesquiterpenes is known for mild cytotoxicity, the observed activity against C. difficile and L. donovani is selective for the infectious agents.