Lophocladines, bioactive alkaloids from the red alga Lophocladia sp

J Nat Prod. 2006 Apr;69(4):640-4. doi: 10.1021/np050519e.

Abstract

Lophocladines A (1) and B (2), two 2,7-naphthyridine alkaloids, were isolated from the marine red alga Lophocladiasp. collected in the Fijian Islands. Their structures were deduced on the basis of high-resolution mass spectra and one- and two-dimensional NMR spectroscopy. Lophocladine A (1) displayed affinity for NMDA receptors and was found to be a delta-opioid receptor antagonist, whereas lophocladine B (2) exhibited cytotoxicity to NCI-H460 human lung tumor and MDA-MB-435 breast cancer cell lines. Immunofluorescence studies indicated that the cytotoxicity of lophocladine B (2) was correlated with microtubule inhibition. This is the first reported occurrence of alkaloids based on a 2,7-naphthyridine skeleton from red algae.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaloids* / chemistry
  • Alkaloids* / isolation & purification
  • Alkaloids* / pharmacology
  • Antineoplastic Agents* / chemistry
  • Antineoplastic Agents* / isolation & purification
  • Antineoplastic Agents* / pharmacology
  • Drug Screening Assays, Antitumor
  • Female
  • Fiji
  • Humans
  • Molecular Structure
  • Naphthyridines* / chemistry
  • Naphthyridines* / isolation & purification
  • Naphthyridines* / pharmacology
  • Nuclear Magnetic Resonance, Biomolecular
  • Receptors, N-Methyl-D-Aspartate / drug effects
  • Receptors, Opioid, delta / antagonists & inhibitors
  • Rhodophyta / chemistry*

Substances

  • Alkaloids
  • Antineoplastic Agents
  • Naphthyridines
  • Receptors, N-Methyl-D-Aspartate
  • Receptors, Opioid, delta
  • lophocladine A
  • lophocladine B