Antibacterial compounds from Salvia adenophora Fernald (Lamiaceae)

• Published in: Phytochemistry (Oxford) Vol. 110; pp. 120 - 132
• Main Authors: Bisio, Angela, Schito, Anna Maria, Ebrahimi, Samad Nejad, Hamburger, Matthias, Mele, Giacomo, Piatti, Gabriella, Romussi, Giovanni, Dal Piaz, Fabrizio, De Tommasi, Nunziatina
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-02-2015
• Subjects: Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - isolation & purification; Anti-Bacterial Agents - pharmacology; Antimicrobial activity; Campanulaceae; Candida albicans; Candida albicans - drug effects; Clerodane diterpenes; Derivatives of 12-oxo-phytodienoic acid; Diterpenes - chemistry; Diterpenes - isolation & purification; Diterpenes - pharmacology; Diterpenes, Clerodane - chemistry; Diterpenes, Clerodane - isolation & purification; Diterpenes, Clerodane - pharmacology; Drug Resistance, Bacterial - drug effects; ECD; Enterococcus faecalis - drug effects; Fatty Acids, Unsaturated - chemistry; Fatty Acids, Unsaturated - isolation & purification; Fatty Acids, Unsaturated - pharmacology; Humans; Italy; Lamiaceae; Microbial Sensitivity Tests; Molecular Structure; Plant Components, Aerial - chemistry; Plant Roots - chemistry; Salvia; Salvia - chemistry; Salvia adenophora Fernald; Staphylococcus aureus; Staphylococcus aureus - drug effects; Staphylococcus epidermidis; Staphylococcus epidermidis - drug effects; Stereoisomerism; Streptococcus agalactiae; Italy; Salvia adenophora Fernald; Antimicrobial activity; Lamiaceae; Clerodane diterpenes; Derivatives of 12-oxo-phytodienoic acid; ECD
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2014.10.033

From the aerial parts of Salvia adenophora Fernald four derivatives of 12-oxo-phytodienoic acid (1–4) together with five clerodane diterpenoids (5, 6, 8–10), and one known diterpene (7) have been isolated. Compounds 1–6 and 8–10 are described for the first time. Three oxylipins (2–4) displayed a promising inhibition on Gram-positive multidrug-resistant clinical strains including Staphylococcus aureus, Streptococcus agalactiae and, particularly, Staphylococcus epidermidis, while two clerodane diterpenoids (9, 10) revealed a specific and strain-dependent activity against S. epidermidis. [Display omitted]
•Isolation of four prostaglandine-like compounds and six clerodane diterpenoids.•Elucidation of structures and determination of absolute configurations.•Evaluation of the antimicrobial activity of the isolated compounds.
From the aerial parts of Salvia adenophora Fernald four derivatives of 12-oxo-phytodienoic acid (1–4) together with five clerodane diterpenoids (5, 6, 8–10), and one known diterpene (7) have been isolated. Compounds 1–6 and 8–10 are described for the first time. The structures were established by extensive 1D, 2D NMR and HRESI-TOFMS spectroscopic methods. Finally, the absolute configuration has been established by comparing of experimental and quantum chemical calculation of ECD spectra. Despite a total lack of antimicrobial activity of the plant extract, hinting to the existence of antagonistic interactions in the crude material, three oxylipins (2–4) displayed a promising inhibition on Gram-positive multidrug-resistant clinical strains including Staphylococcus aureus, Streptococcus agalactiae and, particularly, Staphylococcus epidermidis, while the compounds 9 and 10 revealed a specific and strain-dependent activity against S. epidermidis. Interestingly, the inhibition provided by these compounds was independent of the resistance patterns of these pathogens to classic antibiotics. No action was reported on Gram-negative strains nor on Candida albicans. These results confirm that clerodanes and, particularly, prostaglandin-like compounds can be considered as interesting antimicrobial agents deserving further study.