title: GC-MS characterisation and biological activity of essential oils from different vegetative organs of Plectranthus barbatus and Plectranthus caninus cultivated in north Italy.
abstract: Essential oils (EOs) from the roots, stems and leaves of Plectranthus barbatus (A) and Plectranthus caninus (B), cultivated in north Italy, were obtained by steam distillation and chemically characterised by gas chromatography-mass spectrometry. The highest yields were obtained from roots (268.15 and 673.60 mg/kg from A and B), followed by leaves (64.34 and 26.65 mg/kg) and stems (19.76 and 18.63 mg/kg). A total of 128 structures were identified in A and 121 in B. Fe(++) chelating and antiradical activities (DPPH and ABTS) were evaluated: root and stem EOs showed the strongest activities, while EOs from leaves did not show relevant activities. All EOs were tested for their in vitro antimicrobial activity, showing optimal growth-inhibition in antibiogram (∅>35 mm) and MIC tests (32-64 μg/mL) against Candida albicans, while EOs from leaves of both species showed a good activity (25 < ∅ < 34 mm, MIC 64-128 μg/mL) against Escherichia coli.
authors.affiliation: a Department of Pharmaceutical Sciences , University of Milan , via Mangiagalli, 25, 20133 Milan , Italy.
authors.forename: F
authors.initials: F
authors.lastname: Gelmini
authors.forename: P
authors.initials: P
authors.lastname: Squillace
authors.forename: C
authors.initials: C
authors.lastname: Testa
authors.forename: A C
authors.initials: AC
authors.lastname: Sparacino
authors.forename: S
authors.initials: S
authors.lastname: Angioletti
authors.forename: G
authors.initials: G
authors.lastname: Beretta
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology; D002176:Candida albicans / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects; D016166:Free Radical Scavengers / Q000494:pharmacology; D008401:Gas Chromatography-Mass Spectrometry; D007558:Italy; D008826:Microbial Sensitivity Tests; D009822:Oils, Volatile / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D031346:Plectranthus / Q000737:chemistry*
chemical_list: D000890:Anti-Infective Agents; D016166:Free Radical Scavengers; D009822:Oils, Volatile
keywords: GC–MS; Plectranthus barbatus; Plectranthus caninus; antimicrobial activity; essential oil