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Deoxymanoalides from the nudibranch Chromodoris willani
Mohammad Helal Uddin1, Masahito Otsuka, Toshinobu Muroi
1Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Nishihara, Okinawa, Japan.
Chemical & Pharmaceutical Bulletin
|August 5, 2009
Summary
Two new compounds, deoxymanoalide and deoxysecomanoalide, were isolated from a nudibranch. These compounds exhibit antimicrobial properties and inhibit snake venom phospholipase A2.
Area of Science:
- Marine Natural Products Chemistry
- Chemical Ecology
- Pharmacology
Background:
- Nudibranchs are known to sequester compounds from their prey.
- The sponge-nudibranch interaction is a potential source of novel bioactive molecules.
Purpose of the Study:
- To isolate and characterize new sesterterpenes from the nudibranch Chromodoris willani.
- To investigate the biological activities of the isolated compounds.
Main Methods:
- Isolation of compounds using spectroscopic data (NMR, MS).
- Structure elucidation through chemical conversions.
- Assay of antimicrobial activity against bacteria.
- Enzyme inhibition assay for snake venom phospholipase A2.
Main Results:
- Two sesterterpenes, deoxymanoalide (1) and deoxysecomanoalide (2), were identified.
- Compounds 1 and 2 demonstrated moderate antimicrobial activity against Escherichia coli and Bacillus subtilis.
- Both compounds inhibited snake venom phospholipase A2 at concentrations of 0.2 to 0.5 µM.
Conclusions:
- The nudibranch Chromodoris willani likely biotransforms dietary manoalides into deoxymanoalides.
- Deoxymanoalide and deoxysecomanoalide possess significant antimicrobial and phospholipase A2 inhibitory activities.
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