Chemical composition, antioxidant and antimicrobial activities of essential oil from the aerial parts of Chuquiraga arcuataHarling grown in the highlands of Ecuador / Composición química, actividades antioxidantes y antimicrobianas del aceite esencial de las partes aéreas de Chuquiraga arcuataHarling cultivado en las tierras altas del Ecuador

Thechemical composition, antioxidant and antimicrobial activities of the essential oil from aerial parts (leaves and flowers) of Chuquiraga arcuataHarling grown in the Ecuadorian Andes were studied. One hundred and twenty-six compounds were identified in the essential oil. Monoterpene hydrocarbons (45.8%) and oxygenated monoterpenes (44.1%) had the major percentages. The most abundant compounds were camphor (21.6%), myrcene (19.5%), and 1,8-cineole (13.4%). Antioxidant activity was examined using DPPH, ABTS,and FRAP assays. The essential oil had a moderate scavenging effect and reduction of ferric ion capacity through FRAP assay. Antimicrobial activity of the essential oil was observed against four pathogenic bacteria and a fungus. The essential oil exhibited activity against all microorganism strains under test, particularly against Candida albicansand Staphylococcus aureuswith MICs of 2.43-12.10 µg/mL.

Se estudió la composición química, actividades antioxidantes y antimicrobianas del aceite esencial procedente de las partes aérea (hojas y flores) de Chuquiraga arcuataHarling cultivadas en los Andes ecuatorianos. Se identificaron 126 compuestos en el aceite esencial. Los hidrocarburos monoterpénicos (45,8%) y los monoterpenos oxigenados (44,1%) tuvieron el mayor porcentaje. Los compuestos más abundantes fueron alcanfor (21,6%), mirceno (19,5%) y 1,8-cineol (13,4%). La actividadantioxidante se examinó mediante ensayos DPPH, ABTS y FRAP. El aceite esencial tuvo un efecto eliminador moderado y una reducción de la capacidad de iones férricos mediante el ensayo FRAP. Se observó actividad antimicrobiana del aceite esencial contra cuatro bacterias y un hongo patógenos. El aceite esencial mostró actividad contra todas las cepas de microorganismos bajo prueba, particularmente contra Candida albicansy Staphylococcus aureuscon CMI de 2,43-12,10 µg/mL.

Aceite esencial de hojas de Minthostachys mollis [HBK] Griseb. del Ecuador: extracción, composición química, capacidad antioxidante y actividad antimicrobiana / Essential oil of Minthostachys mollis [HBK] Griseb. leaves from Ecuador: extraction, chemical composition, antioxidant capacity and antimicrobial activity

The aim of this study was to optimize by response surface design, the extraction of the leaf essential oil (EO) from Minthostachys mollis [HBK] Griseb., grown in Ecuador, using steam distillation. The factors used were extraction time (XTIE) of 60, 105 and 150 min and plant material/water ratio (XRMA) of 1:3, 1:4 and 1:5. The optimal combination was reached with XRMA 1:5 and XTIE 150 min, obtaining a process yield of 0.67%. The chemical composition of the EO analyzed by GC - MS was determined, where the main compounds were carvacryl acetate (44.01%), carvacrol (16.51%) and menthone (8.20%). The anti oxidant capacity of EO was evaluated using the FRAP and ABTS methodologies, with an IC 50 243.21 µmol Fe 2+ /g and 0.12 mg/mL, respectively. In addition, the antimicrobial activity of EO was found against Pseudomonas aeruginosa , Salmonella enterica , Escherich ia coli and Staphylococcus aureus .

El objetivo del estudio fue optimizar, mediante un diseño de superficie respuesta, la extracción d el aceite esencial (AE) de hojas de Minthostachys mollis [HBK] Griseb. del Ecuador, mediante destilación por arrastre de vapor. Los factores fueron el tiempo de extracción (XTIE) de 60, 105 y 150 min, y relación de material vegetal/ agua destilada (XRMA) d e 1:3, 1:4 y 1:5. La combinación óptima se logró con XTIE 150 min y XRMA 1:5 para un rendimiento de 0,67%. Se determinó la composición química del AE por GC - MS donde los compuestos mayoritarios fueron acetato de carvacrilo (44,01%), carvacrol (16,51%) y me ntona (8,20%). Se evaluó la capacidad antioxidante del AE por las metodologías FRAP y ABTS, con CI 50 de 243,21 µmol Fe 2+ /g y 0,12 mg/mL, respectivamente. Además, se demostró la actividad antimicrobiana contra Pseudomonas aeruginosa , Salmonella enterica , Es cherichia coli y Staphylococcus aureus .

Characterization of odor-active volatile compounds of jambolan [Syzgium cumini (L.) Skeels] wine.

Volatile constituents in jambolan [Syzgium cumini (L.) Skeels] wine were isolated by headspace-solid phase microextraction (HS-SPME) and analyzed by gas chromatography-flame ionization detector (GC-FID), gas chromatography-mass spectrometry (GC-MS), and gas chromatography-olfactometry (GC-O). The composition of the jambolan wine included 52 esters, 20 terpenes, 13 alcohols, 12 acids, 11 aldehydes, 4 ketones, 4 oxides, and 5 miscellaneous compounds. Aroma extract dilution analysis and odor activity units were used for the determination of odor-active compounds. A total of 19 odor-active compounds were found as odor-active volatiles, from which (E)-ß-ionone, phenylacetaldehyde, ethyl acetate, ethyl hexanoate, and ethyl benzoate were the most important. The similar results of the GC-O and OAV approaches suggests that HS-SPME-GC-O could be used as a fast and simple tool to quality control of the jambolan wine aroma.

Volatile profiles of five jackfruit (Artocarpus heterophyllus Lam.) cultivars grown in the Mexican Pacific area.

The volatile compounds of five kind of cultivars of jackfruit (Artocarpus heterophyllus Lam.) grown in Nayarit, Mexico, was researched by using extraction and chromatographic methods such as headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). Eighty-six volatile compounds were identified. The most prominent compounds in the analyzed cultivars were alkyl esters of 3-methylbutanoic acid. Ethyl 3-methylbutanoate was the most abundant ester in FMC, JMC and RMC cultivars (190.7-961.2 µg/kg), whereas butyl 3-methylbutanoate (152.8-205.2 µg/kg) and pentyl 3-methylbutanoate (105.1-210.9 µg/kg) were predominant in DMC and BMC cultivars. By utilizing clustering statistical techniques such as principal component analysis was possible to identify certain esters compounds (number and concentration) to differentiate each cultivar.

Assessment of volatile compounds and sensory characteristics of Mexican hibiscus (Hibiscus sabdariffa L.) calyces hot beverages.

This study was conducted to assess and correlate the sensory characteristics and volatile compounds of hot beverages from the calyces of four Mexican varieties of hibiscus (4Q4, Puebla Precoz, UAN 16-1, and Sudan). A panel of 10 judges, detected six flavour descriptors in all samples. Sensory studies revealed highly characteristic flavour profiles of these varieties. In order to obtain the extracts and further characterize the odour-active volatiles of the studied beverages, a simultaneous steam distillation and solvent extraction procedure followed by a GC-MS analysis was employed. A total of 104 volatile compounds were identified in all samples. By determining the odour activity values (OAVs) it was possible to identify compounds with high odor-activity in the beverages, such as: 2-furfural, 5-methyl-2-furfural, hexanal, (E)-2-hexenal, (Z)-3-hexen-1-ol, 1-octen-3-one, 1-octen-3-ol, 5-methyl-2(3H)-furanone, phenylacetaldehyde, nonanal, (E)-2-nonenal, geranylacetone, α-ionone and ß-ionone. Moreover, on the basis of their OAVs, the differences in odour profiles of beverages were predominately due to these odorants.

Development and validation of a gas chromatographic method by solid-phase microextraction for the determination of surface flavouring content in encapsulated flavouring.

A solid-phase microextraction procedure followed by analysis by gas chromatography is proposed to determine surface flavouring content in encapsulated flavouring. The method showed a good selectivity, as well as good intraday and interday precision, CVs<4% in both cases. The calibration curves were linear at the tested ranges (R=0.998). The limits of detection and quantification were 0.52 g kg(-1) and 1.57 g kg(-1), respectively. Good recoveries were obtained (90.8-104.5%). In the ruggedness test, sample amount, pre-extraction time, desorption time and desorption temperature were the factors that stood out as the causing of the greater effects on the analytical results. These results present a SPME methodology, which may be applied as a quality control tool for industrial laboratories.

Characterisation of volatile compounds in a smoke flavouring from rice husk.

An aqueous smoke flavouring from rice husk was obtained on a laboratory scale. The volatile compounds were isolated by simultaneous steam distillation-solvent extraction and its identification and quantitative composition was studied by GC-MS and GC-FID. A total of 93 compounds were isolated and 86 of them were positively identified. Major compounds (more than 5% GC area) were 2-furfural, phenol, 2-methoxyphenol, 4-ethyl-2-methoxyphenol, and 2,6-dimethoxyphenol. Application of aroma extract dilution analysis on the volatile fraction revealed that 2-methoxyphenol, 4-methyl-2-methoxyphenol, 2,6-dimethoxyphenol, 2-furfural, 2-acetylfuran, 3-methyl-1,2-cyclopentanedione, acetic acid, 5-methyl-2-furfural, 4-(2-propenyl)-2-methoxyphenol, 4-methyl-2,6-dimethoxyphenol, phenol, 2,6-dimethylphenol, 4-ethyl-2-methoxyphenol, 2-methylphenol were the most odour-active compounds.

Odour-active compounds in papaya fruit cv. Red Maradol.

Application of solid-phase microextraction and simultaneous distillation-extraction combined with GC-FID, GC-MS, aroma extract dilution analysis, and odour activity value were used to analyse volatile compounds from papaya fruit cv. Red Maradol and to estimate the most odour-active compounds. The analyses led to the identification of 137 compounds; 118 of them were positively identified. Twenty-five odorants were considered as odour-active compounds and contribute to the typical papaya aroma, from which ethyl butanoate, benzyl isothiocyanate, 1-hexen-3-one, (E)-ß-ionone, and methyl benzoate were the most odour-active compounds.

Odour-active compounds in banana fruit cv. Giant Cavendish.

Application of solid-phase microextraction, simultaneous distillation-extraction and liquid-liquid extraction, combined with GC-FID, GC-MS, aroma extract dilution analysis, and odour activity value were used to analyse volatile compounds from banana fruit cv. Giant Cavendish and to estimate the most odour-active compounds. The analyses led to the identification of 146 compounds, 124 of them were positively identified. Thirty-one odourants were considered as odour-active compounds and contribute to the typical banana aroma, eleven of them are reported for the first time as odour-active compounds.

Odour-active compounds in guava (Psidium guajava L. cv. Red Suprema).

BACKGROUND: Solid phase microextraction and simultaneous distillation-extraction combined with GC-FID, GC/MS, aroma extract dilution analysis and odour activity values were used to analyse volatile compounds from guava (Psidium guajava L. cv. Red Suprema) and to estimate the most odour-active compounds. RESULTS: The analysis led to the detection of 141 compounds, 121 of which were positively identified. The composition of guava fruit volatiles included 43 esters, 37 terpenes, 18 aldehydes, 16 alcohols, ten acids, six ketones, four furans and seven miscellaneous compounds. CONCLUSION: Seventeen odorants were considered as odour-active compounds, with (E)-ß-ionone, ethyl hexanoate, ethyl butanoate, hexanal, (Z)-3-hexenal, hexyl acetate, (E)-2-hexenal and limonene contributing most to the typical guava aroma of this cultivar.

Volatiles from Syzygium paniculatum fruit.

The volatile compounds of Syzygium paniculatum Banks ex Gaertn. fruit were isolated by simultaneous distillation-solvent extraction and analyzed by gas chromatography-flame ionization detectection and gas chromatography-mass spectrometry. A total of 155 volatile constituents were identified, accounting for 24.5 mg/kg of the fruit composition. Major compounds were alpha-pinene (32.8% of the total composition), (Z)-beta-ocimene (21.8%), limonene (6.9%), and alpha-terpineol (5.1%), indicating that the volatile composition of the fruit is more rich in terpenes.

Volatiles from Michelia champaca flower: comparative analysis by simultaneous distillation-extraction and solid phase microextraction.

The chemical composition of the volatile compounds isolated by simultaneous distillation-extraction (SDE) and headspace-solid phase microextraction (SPME) from flowers of Michelia champaca growing in Cuba was investigated by GC/FID and GC/MS. Sixty-seven and thirty-four components were identified by SDE and SPME, respectively, with 1,8-cineole (22.8%) as the main constituent in the volatile oil isolated by SDE, and methyl benzoate (30.3%), indole (16.6%) and beta-elemene (10.4%) the major components detected by SPME.

Volatiles from Magnolia grandiflora flowers: comparative analysis by simultaneous distillation-extraction and solid phase microextraction.

The composition of the volatile compounds isolated by simultaneous distillation-extraction (SDE) and headspace-solid phase microextraction (SPME) from flowers of Magnolia grandiflora growing in Cuba was investigated by GC/FID and GC/MS. Sixty-seven and thirty-four components were obtained by SDE and SPME, respectively. beta-Pinene (10.5%), geraniol (7.4%) and germacrene D (6.2%) were the main constituents of the volatile oil isolated by SDE, while (E)-beta-ocimene (24.6%), geraniol (18.9%), beta-elemene (11.2%) and germacrene D (9.9%) were the most abundant in the headspace of the flowers, respectively.

Floral scent composition of Plumeria tuberculata analyzed by HS-SPME.

The headspace volatile compounds of the flowers of Plumeria tuberculata Lodd. were analyzed by solid phase microextraction coupled with capillary gas chromatography/mass spectrometry. Twenty-five compounds were identified, representing 100% of the total composition. The volatile fraction was characterized by oxygenated monoterpenes (79.6%), oxygenated sesquiterpenes (8.4%), sesquiterpene hydrocarbons (7.6%), and benzenoid esters (2.6%). The major components were geraniol (34.9%), citronelol (21.5%) and geranial (16.2%), and they were found to make the major contribution to the typical scent of this flower.

Characterisation of odour-active compounds in aged rum.

The volatiles of rum matured in oak casks were carefully isolated by solvent extraction followed by solvent-assisted flavour evaporation. Among the 116 volatile compounds identified by GC-MS, seven of them were found for the first time in rum. Application of the aroma extract dilution analysis (AEDA) on the volatile fraction revealed 18 odour-active areas in the flavour dilution factor range of 32-1024. On the basis of the quantitative data and odour thresholds in 35% ethanol (v/v), the odour activity values (OAV; ratio of concentration to odour threshold) were calculated. Nineteen aroma compounds showed OAVs >1, among which ethanol, (E)-ß-damascenone, ethyl butanoate, ethyl hexanoate, vanillin, (Z)-oak lactone, ethyl 2-methylpropanoate, 1,1-diethoxyethane, ethyl 2-methylbutanoate, 3-methylbutyl acetate, ethyl octanoate, ethyl decanoate, 2-phenylethyl acetate, 2-phenylethanol, 2-methoxyphenol, 4-ethyl-2-methoxyphenol, 4-propyl-2-methoxyphenol, γ-nonalactone, and eugenol showed the highest values and should be considered as the most odour-active compounds.

Chemical composition and antioxidant activities of the essential oil from Tornabenea bischoffii (Apiaceae).

The chemical composition of Tornabenea bischoffii J. A. Schmidt essential oil from Cape Verde was studied by GC and GC/MS. Sixty volatile compounds were identified of which myristicin was the major constituent (33.6%). Using the 2,2-diphenyl-2-picrylhydrazyl free-radical scavenging method and the in vitro assay for prevention of lipid peroxidation by thiobarbituric reactive species, significant antioxidant activities were evidenced.

Isolation and identification of phenolic compounds from rum aged in oak barrels by high-speed countercurrent chromatography/high-performance liquid chromatography-diode array detection-electrospray ionization mass spectrometry and screening for antioxidant activity.

Beverages, especially wines are well-known to contain a variety of health-beneficial bioactive substances, mainly of phenolic nature which frequently exhibit antioxidant activity. Significant information is available about the separation and identification of polyphenols from some beverages by chromatographic and spectroscopic techniques, but considerably poor is chemical data related to the polyphenolic content in rums. In this paper, a method involving the all-liquid chromatographic technique of high-speed countercurrent chromatography (HSCCC) combined with high-performance liquid chromatography coupled with diode-array detection and electrospray ionization mass spectrometry (HPLC-DAD-ESI-MS(n)) has been successfully applied for separation and identification of phenolic compounds in an aged rum. Besides, the phenolic fraction (PF) was assayed for its antioxidant effects using three different free radical in vitro assays (DPPH·, RO(2)· and spontaneous lipid peroxidation (LPO) on brain homogenates) and on ferric reducing antioxidant power (FRAP). Results showed that PF potently scavenged DPPH and strongly scavenged peroxyl radicals compared to ascorbic acid and butylated hydroxytoluene (BHT); and almost equally inhibited LPO on brain homogenates subjected to spontaneous LPO when compared to quercetin. Moreover, PF also exhibited strong reducing power. This chemical analysis illustrates the rich array of phenols in the aged rum and represents a rapid and suitable method for the isolation and identification of phenolic compounds from mixtures of considerable complexity, achieving high purity and reproducibility with the use of two separation steps.

Photoprotecting action and phytochemical analysis of a multiple radical scavenger lipophilic fraction obtained from the leaf of the seagrass Thalassia testudinum.

The apolar fraction F1 of Thalassia testudinum was chemically characterized by gas chromatography-mass spectrometry, which led to the identification of 43 metabolites, all of them reported for the first time in the genus Thalassia. More than 80% of the F1 composition was constituted by aromatic metabolites including the major components 1,1-bis(p-tolyl)ethane (6.0%), 4,4'-diisopropylbiphenyl (4.8%) and a 1,1-bis(p-tolyl)ethane isomer (4.7%). This lipophilic fraction was assayed for its antioxidant effects and skin protective action. In vitro assays showed that F1 strongly scavenged DPPH* (IC(50) 312.0 ± 8.0 µg mL(-1)), hydroxyl (IC(50) 23.8 ± 0.5 µg mL(-1)) and peroxyl radical (IC(50) 6.6 ± 0.3 µg mL(-1) ), as well as superoxide anion (IC(50) 50.0 ± 0.7 µg mL(-1)). Also, F1 markedly inhibited the spontaneous lipid peroxidation (LPO) in brain homogenates (IC(50) 93.0 ± 6.0 µg mL(-1)) and the LPS-stimulated nitrite generation on RAW624.7 macrophages (58.6 ± 3.2%, 400 µg mL(-1)). In agreement with these findings, its topical application at 250 and 500 µg cm(-2) strikingly reduced skin damage on mice exposed to acute UVB radiation by 45% and 70%, respectively and significantly attenuated the LPO developed following the first 48 h after acute exposure to UVB irradiation, as manifested by the decreased malondialdehide level and by the increased of reduced gluthatione content. Our results suggest that F1 may contribute to skin repair by attenuating oxidative stress due to its antioxidant activity.

Characterization of odor-active compounds in guava wine.

The volatile compounds of guava wine were isolated by continuous solvent extraction and analyzed by GC-FID and GC-MS. A total of 124 volatile constituents were detected, and 102 of them were positively identified. The composition of guava wine included 52 esters, 24 alcohols, 11 ketones, 7 acids, 6 aldehydes, 6 terpenes, 4 phenols and derivatives, 4 lactones, 4 sulfur-compounds, and 5 miscellaneous compounds. The aroma-active areas in the gas chromatogram were screened by application of the aroma extract dilution analysis and by odor activity values. Twelve odorants were considered as odor-active volatiles: (E)-ß-damascenone, ethyl octanoate, ethyl 3-phenylpropanoate, ethyl hexanoate, 3-methylbutyl acetate, 2-methyltetrahydrothiophen-3-one, 2,5-dimethyl-4-methoxy-3(2H)-furanone, ethyl (E)-cinnamate, ethyl butanoate, (E)-cinnamyl acetate, 3-phenylpropyl acetate, and ethyl 2-methylpropanoate.

Essential oil from leaves of Lantana canescens and L. lopez-palacii grown in Colombia.

The chemical composition of the volatile compounds from the leaves of Lantana canescens Kunth (Verbenaceae) and L. lopez-palacii Moldenke grown in Colombia were analyzed by GC and GC/MS. One hundred and thirty-nine volatile compounds were identified in L. canescens, of which the major ones were beta-caryophyllene (13.5%), germacrene D (10.3%) and 1-octen-3-ol (8.4%). In the oil obtained from L. lopez-palacii, eighty-three compounds were identified, of which the most prominent were 1-octen-3-ol (24.4%) and beta-caryophyllene (15.2%). The in vitro antibacterial activity of the L. lopez-palacii essential oil was studied against three bacterial strains using the disc diffusion method. No antimicrobial activity was found against Escherichia coli, Enterobacter sakazakii and Listeria monocytogenes.