title: Physicochemical and antimicrobial properties of copaiba oil: implications on product quality control.
abstract: BACKGROUND
  The copaiba oil is a common natural product used in cosmetic industry and as a nutraceutical product. However, lack of quality control and scarce knowledge about its antimicrobial activity is a point of concern. The proposal of this study was to investigate the physicochemical properties and the antimicrobial activity of five commercial brands of copaiba oil.
  
  
  METHODS
  Acidity and ester index, refractory index, solubility in alcohol, and thin layer chromatography were performed to verify the physicochemical properties of five commercial copaiba oils sold in local pharmacies. Ultra performance liquid chromatography coupled with diode-array detection and electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-DAD/ESI-Q-TOF-MS) was used to investigate diterpene acids while the volatile compounds were analysed by gas chromatography-mass spectrometry (GC-MS). Antibacterial and antifungal activities were also evaluated by agar diffusion technique; and minimal inhibitory concentration and maximal bactericidal concentration were defined for each sample and bacteria.
  
  
  RESULTS
  The physical-chemical analysis revealed heterogeneity between all samples analysed. The A1 sample showed characteristics of copaiba oil and was mainly composed by hydrocarbon sesquiterpenes (29.95% β-bisabolene, 25.65% Z-α-bergamotene and 10.27% β-cariophyllene). Among diterpene acids, the UPLCDAD/ESI-Q-TOF-MS data are compatible with presence of copalic and/or kolavenic acid (m/z 305 [M + H]+). Candida albicans was sensitive to almost all samples at high concentration and Saccaromyces. Cerevisiae showed sensitivity to A1 sample at 100 mg/mL. Although variable, all samples showed antibacterial activity. Significant activity was seen for A3 (19.0 ±0 and 15.6 ±0.5 mm), A4 (16.6 ±0.5 and 15.6 ±0 mm), and A5 (17.1 ±0 and 17.1 ±0 mm) on Staphylococcus saprophyticus and S. aureus, respectively. All samples were active against Klebsiella pneumoniae showing ≥15 mm diameter halo inhibition; and only A2 was active against Eschirichia coli. Phytopatogens tested revealed resistance of Ralstonia solanacearum CGH12 to all samples and susceptibility of Xcv 112 strain of Xanthomonas campestris pv campestris to almost all samples. MIC and MMC showed bacteriostatic effect against clinical interest bacteria and bactericidal effect against phytopatogens.
  
  
  CONCLUSIONS
  The results from physicochemical analysis reinforce the fact that it is imperative to include simple conventional methods in the analysis of oil products. The analysis of copaiba oil gives safe products and purity which ensure products with quality. Also, since copaiba oil is an over-the-counter product the results indicate that pharmacosurveillance must be improved by the governmental regulation agency to avoid microorganism resistance selection and to achieve better international quality products.
authors.affiliation: Biological Science Department, State University of Santa Cruz, Ilheus, Bahia, Brazil.
authors.forename: Renata G
authors.initials: RG
authors.lastname: Fonseca
authors.affiliation: Pharmaceutical Science Graduate Program, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Francisco M
authors.initials: FM
authors.lastname: Barros
authors.affiliation: Pharmaceutical Science Graduate Program, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Miriam A
authors.initials: MA
authors.lastname: Apel
authors.affiliation: Pharmaceutical Science Graduate Program, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Gilsane L von
authors.initials: GL
authors.lastname: Poser
authors.affiliation: Biological Science Department, State University of Santa Cruz, Ilheus, Bahia, Brazil.
authors.forename: Jo O L
authors.initials: JO
authors.lastname: Andriolli
authors.affiliation: Basic and Instrumental Studies Department, State University of Southeast Bahia, Itapetinga, Bahia, Brazil.
authors.forename: Pedro C Campos
authors.initials: PC
authors.lastname: Filho
authors.affiliation: Basic and Instrumental Studies Department, State University of Southeast Bahia, Itapetinga, Bahia, Brazil.
authors.forename: Dhierlate F
authors.initials: DF
authors.lastname: Sousa
authors.affiliation: Exact and Technological Sciences Department, State University.
authors.forename: Ivon P
authors.initials: IP
authors.lastname: Lobo
authors.affiliation: Biological Science Department, State University of Santa Cruz, Ilheus, Bahia, Brazil.
authors.forename: Aline O
authors.initials: AO
authors.lastname: Conceiç O
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry* / Q000494:pharmacology; D001938:Brazil; D055598:Chemical Phenomena; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D019587:Dietary Supplements / Q000032:analysis* / Q000191:economics; D052978:Disk Diffusion Antimicrobial Tests; D007887:Fabaceae / Q000737:chemistry*; D063427:Food Quality; D008401:Gas Chromatography-Mass Spectrometry; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000254:growth & development; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000254:growth & development; D006863:Hydrogen-Ion Concentration; D010938:Plant Oils / Q000737:chemistry* / Q000191:economics; D012995:Solubility; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D013729:Terpenes / Q000032:analysis* / Q000737:chemistry / Q000494:pharmacology; D055549:Volatile Organic Compounds / Q000032:analysis* / Q000737:chemistry / Q000494:pharmacology; D015003:Yeasts / Q000187:drug effects / Q000254:growth & development
chemical_list: D000890:Anti-Infective Agents; D010938:Plant Oils; D013729:Terpenes; D055549:Volatile Organic Compounds
keywords: antimicrobial action; microorganisms; nutraceutical product