Novel Extracellular Diterpenoids with Biological Activity from the Cyanobacterium Nostoc c ommune

• Published in: Journal of natural products (Washington, D.C.) Vol. 63; no. 3; pp. 339 - 343
• Main Authors: Jaki, B, Orjala, J, Heilmann, J, Linden, A, Vogler, B, Sticher, O
• Format: Journal Article
• Language: English
• Published: American Chemical Society 24.03.2000
• ISSN: 0163-3864; 1520-6025
• DOI: 10.1021/np9903090

Five novel extracellular metabolites with an unprecedented diterpenoid skeleton, 5-[(5-carboxy-2-hydroxy)benzyl]-11-hydroxymethyl-2,5,6,8a,11-pentamethyldodecahydrocyclopenta〈a〉naphthalene (1), 5-[(5-carboxy-2-hydroxy)benzyl]-11-formyl-2,5,6,8a,11-pentamethyl-dodecahydrocyclopenta〈a〉naphthalene (2), 5-[(5-carboxy-2-hydroxy)benzyl]-11-carboxy-2,5,6,8a,11-pentamethyl-dodecahydrocyclopenta〈a〉naphthalene (3), 5-[(5-carboxy-2-hydroxy)benzyl]-11-dihydroxymethyl-2,5,6,8a,11-pentamethyldodecahydrocyclopenta〈a〉naphthalene (4), and 5-[(5-carboxy-2-hydroxy)benzyl]-11-acetyl-2,5,6,8a-tetramethyldodecahydrocyclopenta〈a〉naphthalene (5), have been isolated from the culture medium of the terrestrial cyanobacterium Nostoc commune by means of bioguided isolation. The molecules were designated as comnostins A−E. The structures were determined by spectroscopic methods, mainly NMR and mass spectrometry. The relative stereochemistry of comnostin A was confirmed by single-crystal X-ray structure analysis. All comnostins showed antibacterial activities. Additionally, cytotoxic and molluscicidal activities were found for comnostin B.