Crystallographic and NMR studies of antiinfective tricyclic guanidine alkaloids from the sponge Monanchora unguifera.

Abstract

Three tricyclic guanidine alkaloids, including 1,8a;8b,3a-didehydro-8beta-hydroxyptilocaulin (1), 1,8a;8b,3a-didehydro-8alpha-hydroxyptilocaulin (2) and mirabilin B (3), were identified from the marine sponge Monanchora unguifera. 1,8a;8b,3a-Didehydro-8alpha-hydroxyptilocaulin (2) is a new stereoisomer of 1, the structure of which was elucidated by spectroscopic analysis, comparison of its spectral data with those of 1, and confirmed by X-ray analysis. Compounds 1 and 2 co-crystallized in an unusual perfect order and packed around an approximate inversion center. A mixture of 1 and 2 is active against the malaria parasite Plasmodium falciparum with an IC50 value of 3.8 microg/mL while mirabilin B (3) exhibited antifungal activity against Cryptococcus neoformans with an IC50 value of 7.0 microg/mL and antiprotozoal activity against Leishmania donovani with an IC50 value of 17 microg/mL.

• Authors: Hui-ming Hua, Jiangnan Peng, Frank R Fronczek, Michelle Kelly, Mark T Hamann
• Journal: Bioorganic & medicinal chemistry (Bioorg Med Chem) Vol. 12 Issue 24 Pg. 6461-4 (Dec 15 2004) ISSN: 0968-0896 [Print] England
• PMID: 15556763 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Alkaloids
• Anti-Infective Agents
• Antifungal Agents
• Antiprotozoal Agents
• Guanidine

Topics

• Alkaloids (chemistry, pharmacology)
• Animals
• Anti-Infective Agents (chemistry, pharmacology)
• Antifungal Agents (chemistry, pharmacology)
• Antiprotozoal Agents (chemistry, pharmacology)
• Cryptococcus neoformans (drug effects)
• Crystallization
• Crystallography, X-Ray
• Guanidine
• Inhibitory Concentration 50
• Leishmania donovani (drug effects)
• Magnetic Resonance Spectroscopy
• Plasmodium falciparum (drug effects)
• Porifera (chemistry)