title: In vitro antimicrobial activity of royleanone derivatives against Gram-positive bacterial pathogens.
abstract: Infections caused by multiresistant bacterial pathogens are a significant problem worldwide, turning the search for natural compounds to act as alternatives to antibiotics of major importance. The aim of the present study was to investigate the in vitro antimicrobial activity of 7α-acetoxy-6β-hydroxyroyleanone (1), isolated from Plectranthus grandidentatus (Lamiaceae), and 11 additional royleanone abietane derivatives of 1 (2-12) against important Gram-positive human bacterial pathogens. Results showed that the aromatic and alkylic esters 2, 3 and 5 are more active than 1 against Enterococcus and Staphylococcus (minimum inhibitory concentration (MIC) values ranging from 0.98 to 62.50 µg/mL). Moreover, 7α-acetoxy-6β-hydroxy-12-O-(4-chloro)benzoylroyleanone (2) gave rise to a new antibacterial-prototype (MIC values of 3.91-15.63 µg/mL against Staphylococcus and of 0.98-3.91 µg/mL against Enterococcus). The results showed that the compounds under analysis also present antimicrobial activity against resistant bacteria. The hydrophobic extra-interactions with bacterial targets seem to play an important role on the activity of royleanones derivatives.
authors.affiliation: Faculdade de Farmácia da Universidade de Lisboa, Research Institute of Medicines and Pharmaceutical Sciences - iMed.UL, Av. Prof. Gama Pinto, 1649-003, Lisboa, Portugal; CBios - Research Center for Health Sciences & Technologies (Lab. Pharmacology and Therapeutics), Universidade Lusófona, Campo Grande 376, 1749-024, Lisboa, Portugal.
authors.forename: Patrícia
authors.initials: P
authors.lastname: Rijo
authors.forename: Aida
authors.initials: A
authors.lastname: Duarte
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Francisco
authors.forename: Teresa
authors.initials: T
authors.lastname: Semedo-Lemsaddek
authors.forename: Maria Fátima
authors.initials: MF
authors.lastname: Simões
mesh_terms: D045784:Abietanes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002522:Chlorocebus aethiops; D016983:Enterococcus / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D010936:Plant Extracts / Q000494:pharmacology*; D031346:Plectranthus / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000187:drug effects*; D014709:Vero Cells
chemical_list: C587950:7alpha-acetoxy-6beta-hydroxy-12-O-(4-chloro)benzoylroyleanone; D045784:Abietanes; D000900:Anti-Bacterial Agents; D010936:Plant Extracts; C103399:royleanone
keywords: abietane diterpene derivatives; antimicrobial activity; resistant bacterial pathogens; royleanone esters