2β-Acetoxyferruginol—A new antibacterial abietane diterpene from the bark of Prumnopitys andina

• Published in: Phytochemistry letters 2008-04, Vol.1 (1), p.49-53
• Main Authors: Smith, Eileen C.J., Wareham, Neale, Zloh, Mire, Gibbons, Simon
• Format: Article
• Language: English
• Subjects: Antibacterial; Diterpene; Propionibacterium acnes; Prumnopitys andina; Staphylococcus aureus
• ISSN: 1874-3900; 1876-7486
• DOI: 10.1016/j.phytol.2007.12.006

A new antibacterial abietane diterpene, 2β-acetoxyferruginol ( 1) was isolated from the stem bark of Prumnopitys andina and its structure was determined by spectral means. Activity was assessed against multidrug and methicillin-resistant Staphylococcus aureus (MRSA) strains and with Propionibacterium acnes, the major bacterial cause of acne, and the minimum inhibitory concentration value against P. acnes was 4 μg/ml. ▪ As part of an on-going project to isolate antibacterial compounds from rare conifer species, a new abietane diterpene, 2β-acetoxyferruginol was isolated from the stem bark of Prumnopitys andina. Molecular modelling studies were conducted to explain some of the NOEs observed in the A-ring of this compound and to support assignment of relative stereochemistry. This new compound had antibacterial activity at 8 μg/ml against two effluxing strains of Staphylococcus aureus, but interestingly was inactive at 128 μg/ml against a wild-type strain and against a methicillin-resistant (MRSA) clinical isolate. We have previously demonstrated that ferruginol is active against these four S. aureus stains and therefore the results indicate that the presence of the acetoxy group has a detrimental effect on antibacterial activity against certain strains. 2β-Acetoxyferruginol was also assayed against Propionibacterium acnes and was active at 4 μg/ml.