RESUMO
Food spoilage is a widely neglected problem and the constant use of synthetic fungicides could develop resistant fungi. The objective of this study was to evaluate the chemical composition and antimicrobial activity of Tetradenia riparialeaf essential oil against foodborne disease microorganisms. Leaf essential oil was obtained by hydrodistillation and identified by gas chromatography coupled to mass spectrometry. The antimicrobial activity was studied by broth microdilution. The major compounds identified were oxygenated sesquiterpenes (43.6%): 14-hydroxy-9-epi-(E)-cariophylene (20.8%) and τ-cadinol (18.4%); followed by oxygenated diterpenes (24.6%): 6,7-dehydroroyleanone (12.6%) and 9ß, 13ß-epoxy-7-abiethene (10.6%); sesquiterpenic hydrocarbons (17.1%) and oxygenated monoterpenes (7.4%): fenchone (5.6%). The essential oil had broad antibacterial and antifungal activity, mainly against A. versicolor and P. ochrochloron with fungistatic and fungicidal activities and B. cereus, L. monocytogenes, and S. aureuswith bacteriostatic and bactericidal activities. T. riparialeaf essential oil is a potential alternative to control microorganisms-
El deterioro de los alimentos es un problema ampliamente desatendido y el uso constante de fungicidas sintéticos podría desarrollar hongos resistentes. El objetivo de este estudio fue evaluar la composición química y la actividad antimicrobiana del aceite esencial de hoja de Tetradenia riparia contra microorganismos patógenos transmitidos por los alimentos. El aceite esencial de hoja se obtuvo por hidrodestilación y se identificó mediante cromatografía de gases acoplada a espectrometría de masas. La actividad antimicrobiana estudiada fue por microdilución en caldo. Los compuestos principales del aceite esencial se identificaron como sesquiterpenos oxigenados (43,6%): 14-hidroxi-9-epi-(E)-cariofileno (20,8%) y τ-cadinol (18,4%); seguido de diterpenos oxigenados (24,6%): 6-7-deshidroroileanona (12,6%) y 9ß, 13ß-epoxi-7-abieteno (10,6%); hidrocarburos sesquiterpénicos (17,1%) y monoterpenos oxigenados (7,4%): fenchona (5,6%). Tenía amplia actividad antibacteriana y antifúngica, principalmente contra A. versicolor y P. ochrochloron con actividades fungistáticas y fungicidas, y principalmente contra B. cereus, L. monocytogenes y S. aureus con actividades bacteriostáticas y bactericidas. El aceite esencial de hoja de T. riparia es una alternativa potencial para controlar microorganismos.
Assuntos
Óleos Voláteis/farmacologia , Extratos Vegetais/farmacologia , Lamiaceae/química , Anti-Infecciosos/uso terapêuticoRESUMO
Bioactive compounds extracted from plants such as antimicrobials have attracted the attention of consumers and the food industry. This study aimed to determine the antimicrobial activity and chemical composition of Annona muricata leaf oleoresin obtained by supercritical CO2 extraction. The oleoresin was obtained by supercritical CO2 extraction and the chemical identification by gas chromatography coupled to mass spectrometry. Antimicrobial activity was evaluated by broth microdilution method against 14 foodborne fungi and bacteria. The oleoresin major chemical class was phytosterols (22.7%) and the major compounds were γ-sitosterol (15.7%), α-tocopherol (13.7%), phytol (13.1%), and hexadecanoic acid (11.5%). Minimum inhibitory concentration against bacteria ranged from 0.0025 to 0.010 mg mL-1. The oleoresin had high bactericidal activity against all bacteria, mainly Enterobacter cloacae and Pseudomonas aeruginosa with 0.005 mg mL-1 minimum bactericidal concentration. However, it had low fungicidal activity. The leaf oleoresin of A. muricata has promising applications in food, cosmetic, and pharmaceutical industries.
Assuntos
Annona , Anti-Infecciosos , Annona/química , Anti-Infecciosos/química , Bactérias , Dióxido de Carbono/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Extratos Vegetais/química , Folhas de Planta/químicaRESUMO
Tetradenia riparia (Hochstetter) Codd belongs to the Lamiaceae family and it was introduced in Brazil as an exotic ornamental plant. A previous study showed its antimicrobial, acaricidal and analgesic activities. Two compounds were isolated from essential oil of T. riparia leaves and identified as 9ß,13ß-epoxy-7-abietene (1), a new one, and 6,7-dehydroroyleanone (2), already reported for another plant. The structure of these compounds was determined by spectroscopic analysis and by comparison with literature data. The cytotoxic activities of the essential oil and compounds 1 and 2 were determined by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, and by tumor cells MDA-MB-435 (human breast carcinoma), HCT-8 (human colon), SF-295 (human nervous system) and HL-60 (human promyelocytic leukemia). The essential oil and compound 1 showed high cytotoxic potential of the cell lines SF-295 (78.06% and 94.80%, respectively), HCT-8 (85.00% and 86.54%, respectively) and MDA-MB-435 (59.48% and 45.43%, respectively). Compound 2 had no cytotoxic activity. The antioxidant activity was determined by 2,2-diphenyl-1-picryl-hydrazyl (DPPH), ß-carotene-linoleic acid system and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. The inhibitory concentration (IC50 in µg mL-1) for essential oil and compound 2 was, respectively 15.63 and 0.01 for DPPH; 130.1 and 109.6 for ß-carotene-linoleic acid and 1524 and 1024 for ABTS. Compound 1 had no antioxidant activity. By fractioning the oil, it was possible to identify two unpublished compounds: 1 with high cytotoxic potential and 2 with high antioxidant potential.
Assuntos
Abietanos/química , Abietanos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Lamiaceae/química , Óleos Voláteis/química , Abietanos/toxicidade , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Extratos Vegetais/químicaRESUMO
The essential oil of Lippia alba is reported as an antifungal against human pathogenic microorganisms but few articles report its use as an alternative to synthetic fungicides on green mould control. The objective of this study was to determine chemical characteristics of L. alba essential oil and its antifungal activity against green molds as an alternative to synthetic fungicides. Essential oil was extracted by Clevenger hydrodistillation, characterized by GC-MS analysis, and the structure of the main compounds confirmed by (1)H and (13)C-NMR spectroscopy. Microdilution assays evaluated the essential oil minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC). Commercial fungicides Ketoconazole and Bifonazole were used as control. Essential oil yield is of 0.15% and the major components are neral (33.32%) and geranial (50.94%). The L. alba essential oil has MIC of 0.300-1.250 mg/mL and MFC of 0.600-1.250 mg/mL. Ketoconazole and Bifonazole show MIC ranging from 0.025-0.500 to 0.100-0.200 mg/mL, and MFC ranging from 0.250-0.100 to 0.200-0.250 mg/mL, respectively. L. alba essential oil is classified as citral type and the results indicate that it is a potential alternative to synthetic fungicides.