title: Seasonal variation in the chemical composition and antimicrobial activity of volatile oils of three species of Leptospermum (Myrtaceae) grown in Brazil.
abstract: This study investigates the seasonal variation of three species of Leptospermum (Myrtaceae) grown in Brazil. The chemical composition of the volatile oils of L. flavescens and L. petersonii did not show any significant seasonal variation in the major components, while for Leptospermum madidum subsp. sativum the levels of major constituents of the volatile oils varied with the harvest season. Major fluctuations in the composition of L. madidum subsp. sativum oil included α-pinene (0-15.2%), β-pinene (0.3-18.5%), α-humulene (0.8-30%), 1,8-cineole (0.4-7.1%) and E-caryophyllene (0.4-11.9%). Levels of β-pinene (0.3-5.6%), terpinen-4-ol (4.7-7.2%) and nerolidol (55.1-67.6%) fluctuated seasonally in the L. flavescens oil. In L. petersonii, changes were noted for geranial (29.8-32.8%), citronellal (26.5-33.9%) and neral (22.7-23.5%). The activity of the volatile oils against the tested bacteria differed, depending on season the oils were obtained. In general, the volatile oils were more active against Gram-positive bacteria.
authors.affiliation: Departamento de Química, Universidade Federal de Vicosa, Av. P. H. Rolfs s/n, 36570-000 Vicosa, MG, Brazil.
authors.forename: Antonio Jacinto
authors.initials: AJ
authors.lastname: Demuner
authors.forename: Luiz Claudio Almeida
authors.initials: LC
authors.lastname: Barbosa
authors.forename: Cassia Gonçalves
authors.initials: CG
authors.lastname: Magalhaes
authors.forename: Cleber Jose
authors.initials: CJ
authors.lastname: da Silva
authors.forename: Celia Regina Alvares
authors.initials: CR
authors.lastname: Maltha
authors.forename: Antonio Lelis
authors.initials: AL
authors.lastname: Pinheiro
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D001938:Brazil; D031649:Leptospermum / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D009822:Oils, Volatile / Q000737:chemistry* / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D012621:Seasons
chemical_list: D000900:Anti-Bacterial Agents; D009822:Oils, Volatile