Egyptian chemist, Amir Wahba of the universities of Damietta, Egypt, and Mississippi, USA, and colleagues have isolated a new compound, acantholactone (pictured), from the Indonesian sponge Acanthostrongylophora. The compound is the first manzamine-related alkaloid with a unique epsilon-lactam as well as a delta-lactone ring. Manzamines show wide-ranging biological activity and have been the focus of interest in drug development against tuberculosis and malaria and as neuroprotective agents.

The team used NOESY (Nuclear Overhauser Effect Spectroscopy) correlations in the compound’s nuclear magnetic resonance spectra in their characterization and determined its absolute configuration by comparing the experimental data with computed electronic circular dichroism (ECD) spectra. They point out that the compound can only be isolated in low yield from the sponge and so offer up this new structure to the synthetic community to develop an efficient synthesis so that enough can be made for medicinal studies to be carried out.

• Acantholactone, a new manzamine related alkaloid with an unprecedented δ-lactone and ε-lactam ring system,
  Amir E. Wahba, Yann Fromentin, Yike Zou, Mark T. Hamann,
  Tetrahedron Lett. 2012, 53, 6329–6331.
  DOI: 10.1016/j.tetlet.2012.08.140