Identification Of Volatile Organic Compounds Research Articles

Identification of Volatile Organic Compounds Produced by Xenorhabdus indica Strain AB and Investigation of Their Antifungal Activities.

Xenorhabdus spp. are symbiotic bacteria associated with entomopathogenic nematodes to form a model complex that is used for the biological control of insect pests. These bacteria also produce secondary metabolites that have commercial potential in the pharmaceutical and agroforestry industries. Volatile organic compounds (VOCs) produced by the Xenorhabdus indica "strain AB" have been shown to have significant antifungal activity against Fusarium oxysporum f. sp. cucumerinum. Using gas chromatography-mass spectrometry, we identified 61 volatiles in the mixture of VOCs emitted by strain AB compared to a control strain, 6 of which were investigated for their antifungal activities. Of these, methyl anthranilate exhibited the highest mycelial growth suppression toward F. oxysporum, with a minimum inhibitory volume (MIV) of 50 μL/plate. Fluorescence assays, scanning electron microscopy, and measurements of the leakage of intracellular components revealed that the use of methyl anthranilate changed cell wall and cell membrane integrity as well as the permeability of the plasma membrane. Furthermore, methyl anthranilate treatment upregulated the transcription level of target genes related to redox reactions and the cell wall integrity pathway. The results suggest a novel mechanism used by Xenorhabdus spp. to overcome competitors during its life cycle and open up a new approach to using these bacteria in biological control. IMPORTANCE Fungal phytopathogens, particularly Fusarium oxysporum, are a major problem worldwide, especially in the postharvest of vital economic crops. Concerns about negative effects on the environment and human health have led to increasing restrictions on the use of chemical fungicides, and therefore, biological control agents are now being considered alternatives. It is in this context that we investigated the antifungal activity of VOCs produced by X. indica strain AB against F. oxysporum. We found that AB VOCs have a strong effect on the growth of the fungal phytopathogen. In addition, 85% of the identified volatile compounds were determined to be new compounds, opening up new lines of research to discover their properties, effects, and potential for pharmaceutical and agricultural applications. Antifungal assays proved that four of the six compounds with a high concentration in the GC-MS profile had a significant inhibitory effect on pathogen growth. Accordingly, this study opens up a new approach for the use of these bacteria in biocontrol.

Identification of Volatiles of the Dinoflagellate Prorocentrum cordatum.

The dinoflagellate Prorocentrum cordatum, often called P. minimum, is a potentially toxic alga found in algal blooms. Volatile compounds released by the alga might carry important information, e.g., on its physiological state, and may act as chemical messengers. We report here the identification of volatile organic compounds emitted by two strains, xenic P. cordatum CCMP 1529 and axenic P. cordatum CCMP 1329. The volatiles released during culture were identified despite their low production rates, using sensitive methods such as open-system-stripping analysis (OSSA) on Tenax TA desorption tubes, thermodesorption, cryofocusing and GC/MS-analysis. The analyses revealed 16 compounds released from the xenic strain and 52 compounds from the axenic strain. The majority of compounds were apocarotenoids, aromatic compounds and small oxylipins, but new natural products such as 3,7-dimethyl-4-octanolide were also identified and synthesized. The large difference of compound composition between xenic and axenic algae will be discussed.

Profiling exhaled breath of smokers using mass spectrometry to identify a signature related to tobacco use for diagnostic perspectives

Breath analysis for the identification of volatile organic compounds by mass spectrometry is a very innovative and non-invasive technology, which represents a great opportunity for an early and personalised diagnosis. In this pilot study we recruited a series of volunteers, smokers and non-smokers, characterized from the respiratory point of view, and profiled their exhaled breath through SESI- HRMS technology. The aim of the study is to identify a volatile molecular signature associated with tobacco use. The supervised analysis highlighted 32 features that discriminate the breath of smokers and non-smoker subjects, at the baseline. We therefore identified a volatile molecular signature closely related to tobacco smoke, which will be characterized in subsequent studies.

Virtual Sensor Array Based on Piezoelectric Cantilever Resonator for Identification of Volatile Organic Compounds.

Piezoelectric cantilever resonator is one of the most promising platforms for real-time sensing of volatile organic compounds (VOCs). However, it has been a great challenge to eliminate the cross-sensitivity of various VOCs for these cantilever-based VOC sensors. Herein, a virtual sensor array (VSA) is proposed on the basis of a sensing layer of GO film deposited onto an AlN piezoelectric cantilever with five groups of top electrodes for identification of various VOCs. Different groups of top electrodes are applied to obtain high amplitudes of multiple resonance peaks for the cantilever, thus achieving low limits of detection (LODs) to VOCs. Frequency shifts of multiple resonant modes and changes of impedance values are taken as the responses of the proposed VSA to VOCs, and these multidimensional responses generate a unique fingerprint for each VOC. On the basis of machine learning algorithms, the proposed VSA can accurately identify different types of VOCs and mixtures with accuracies of 95.8 and 87.5%, respectively. Furthermore, the VSA has successfully been applied to identify the emissions from healthy plants and "plants with late blight" with an accuracy of 89%. The high levels of identifications show great potentials of the VSA for diagnosis of infectious plant diseases by detecting VOC biomarkers.

Monarda didyma Hydrolate Affects the Survival and the Behaviour of Drosophila suzukii.

Simple SummaryDuring the steam distillation of aromatic plants, two main fractions are usually obtained: the hydrophobic essential oils and the hydrophilic fraction commonly known as hydrolate (HY). The essential oils are largely used in several industry fields, including the agricultural industry as biopesticides. Residual HYs, instead, are often discarded as by-products of little or no value. Our research pointed out that also HYs have biological activity, suggesting their potential use in plant-based strategy for the pest control. In more detail, we investigated the insecticidal properties of the hydrolate from Monarda didyma, scarlet beebalm, towards Drosophila suzukii. Using specific molecular and behavioural assays, we showed that M. didyma hydrolate affected the fitness and behaviour of D. suzukii, providing new insights in the D. suzukii control strategies through M. didyma hydrolate.Drosophila suzukii (Matsumara) is an herbivorous pest whose control in the field with conventional chemical is particularly difficult and has important drawbacks. Here, we investigated the insecticidal properties of hydrolate from Monarda didyma, scarlet beebalm, an aromatic herb in the Lamiaceae family. The identification of volatile organic compounds (VOCs) by CG–MS systems revealed that thymol (38%) and carvacrol (59%) were the most abundant VOCs in the hydrolate. M. didyma hydrolate did not show fumigant toxicity. Conversely, in contact assays, M. didyma hydrolate showed a LC50 of 5.03 µL mL−1, 48 h after the application on D. suzukii adults. Expression of detoxification genes increased in flies that survived the LC50 application. Furthermore, toxicity persisted for 7 days after the treatment in the survival evaluation. Artificial diet assays with 100 and 1000 µL mL−1 of M. didyma hydrolate resulted in a significant decrease in total food intake in both male and female D. suzukii adults. In addition, electropenetrography (EPG) showed that the D. suzukii females’ feeding behaviour was altered in hydrolate-treated diets. The hydrolate also caused a significant reduction in the number of eggs laid in two different oviposition assays. Overall, our findings provide a new perspective for the improvement of D. suzukii control strategies through M. didyma hydrolate.

Biocontrol Activity, Mode of Action, and Colonization of Aureobasidium pullulans Dmg 30 DEP on Controlling Early Blight Disease on Tomato Plant

We investigated the biocontrol activity of A. pullulans Dmg 30 DEP against Alternaria solani causal agent of early blight. Biocontrol activity was tested by the in vivo and ad planta. Biocontrol activity were tested by investigating the antibiosis capabilities with dual culture method, paper dish assay, two-compartment petri dish assay, and trapping and identification of volatile organic compounds (VOCs) with GC-MS. Lysis activity was examined by observing the clear zone formed by growing yeast on chitin agar and skim milk agar. The ability of hyperparasitism was assessed by the agar block method, and observed by light microscopy and scanning electron microscopy (SEM). The results showed that A. pullulans Dmg 30 DEP plays a role in the suppression of early blight disease at 106 cells/ml and 107 cells/ml yeast cell density. The mechanism involved in biocontrol activity is the production of VOCs, the production of chitinase and protease enzymes, the production of siderophore and hyperparasitism. The result shows that A. pullulans Dmg 30 DEP was colonizing the tomato leaves following the areole.

The entomopathogenic fungus Metarhizium anisopliae enhances Arabidopsis, tomato, and maize plant growth

Species of the entomopathogenic fungi Metarhizium are used worldwide as biocontrol agents. Recently, other lifestyles have been associated with some Metarhizium species, which include their role as saprophytes, endophytes, and plant growth promoters. Herein, the effect of three Metarhizium anisopliae strains on the growth of Arabidopsis thaliana plantlets was evaluated using an in vitro split system. Arabidopsis fresh weight and total chlorophyll content significantly increased 7 days post-inoculation with the three Metarhizium anisopliae strains evaluated. The primary root length was promoted by all fungal strains without physical contact, whereas in direct contact primary root growth was inhibited. Volatile organic compounds identification revealed that during the interaction of Arabidopsis with Ma-20 and Ma-25 strains only β-caryophyllene was produced, whereas in the Arabidopsis-Ma-28 interaction o-cymene was mainly emitted. The plant growth promoting effect induced by Metarhizium anisopliae strains was also achieved in Arabidopsis, tomato and maize plants grown in soil pots. Our results showed that three Metarhizium anisopliae strains were able to increase plant fresh weight, opening promising perspectives for field production, with the advantages of insect biocontrol and plant growth promotion induced by this species of fungus.

Emission Ratios and Source Identification of VOCs in Moscow in 2019–2020

Measurements of CO and 15 volatile organic compounds (VOCs) at the IAP-RAS (A.M. Obukhov Institute of Atmospheric Physics) site located in the center of Moscow were analyzed. Acetaldehyde, ethanol, 1.3-butadiene, isoprene, toluene and C-8 aromatics were established to be the main ozone precursors in the observed area, providing up to 82% of the total ozone formation potential of the VOCs measured. Diurnal and seasonal variations of the compounds are discussed. The concentrations of anthropogenic VOCs (acetaldehyde, benzene, 1.3-butadiene, toluene, and C-8 aromatics) did not exceed their maximum permissible levels, reaching their maxima in summer and autumn in the morning and evening hours. Biogenic ethanol and isoprene were the highest in summer midday but their concentrations were low enough (up to 4 and 0.4 ppbv, respectively) due to small vegetation area around the site. Emission ratios (ERs) for the main ozone precursors—acetaldehyde, ethanol, 1.3-butadiene, isoprene, toluene, and C-8 aromatics—were estimated from two-sided linear regression fits using benzene and CO as tracers for anthropogenic emissions, with spatial and temporal filters being applied to account for the influence of chemistry and local emission sources. The best estimates of ERs were obtained using benzene as a reference species. Anthropogenic fractions of VOCs (AFs) were then estimated. As expected, acetaldehyde, toluene, 1.3-butadiene, and C8aromatics were entirely anthropogenic and emitted mainly from urban vehicle exhausts throughout the day, both in summer and in winter. AFs of isoprene and ethanol did not exceed 30% and 50% in summer, respectively, during both daytime and nighttime hours. In winter, the anthropogenic fractions of isoprene and ethanol were slightly higher (up to 35% and 60%, respectively).

Identification of Volatile Organic Compounds Emitted by Two Beneficial Endophytic Pseudomonas Strains from Olive Roots.

The production of volatile organic compounds (VOCs) represents a promising strategy of plant-beneficial bacteria to control soil-borne phytopathogens. Pseudomonas sp. PICF6 and Pseudomonas simiae PICF7 are two indigenous inhabitants of olive roots displaying effective biological control against Verticillium dahliae. Additionally, strain PICF7 is able to promote the growth of barley and Arabidopsis thaliana, VOCs being involved in the growth of the latter species. In this study, the antagonistic capacity of these endophytic bacteria against relevant phytopathogens (Verticillium spp., Rhizoctonia solani, Sclerotinia sclerotiorum and Fusarium oxysporum f.sp. lycopersici) was assessed. Under in vitro conditions, PICF6 and PICF7 were only able to antagonize representative isolates of V. dahliae and V. longisporum. Remarkably, both strains produced an impressive portfolio of up to twenty VOCs, that included compounds with reported antifungal (e.g., 1-undecene, (methyldisulfanyl) methane and 1-decene) or plant growth promoting (e.g., tridecane, 1-decene) activities. Moreover, their volatilomes differed strongly in the absence and presence of V. dahliae. For example, when co incubated with the defoliating pathotype of V. dahliae, the antifungal compound 4-methyl-2,6-bis(2-methyl-2-propanyl)phenol was produced. Results suggest that volatiles emitted by these endophytes may differ in their modes of action, and that potential benefits for the host needs further investigation in planta.

Performance of wet scrubbers to remove VOCs from rubber emissions

Poor performance of wet scrubbers in rubber processing plants due to breakthrough of specific volatile organic compounds (VOCs) causes odour impact events. The performance of wet scrubbers in the rubber drying process to remove VOCs was investigated in order to determine the responsible odorants. VOC emissions originating at the inlet and outlet of wet scrubbers were quantified using gas chromatography-mass spectrometry/olfactometry (GC-MS/O). Critical VOCs were identified alongside seasonal and daily variations of those VOCs. Altogether, 80 VOCs were detected in rubber emissions with 16 classified as critical VOCs based on their chemical concentration, high odour activity value (OAV) and unpleasant odour. Volatile fatty acids (VFAs) were the dominant VOCs with seasonal variations affecting emission composition. Results demonstrated the ineffectiveness of the wet scrubbers to mitigate odorous VOCs whereas the removal of some VOCs could be improved based on their polarity and solubility. It was found that there is a correlation between the wet scrubber performance and VFAs concentration in the emissions. The findings demonstrated that combining quantitative and sensory analyses improved accuracy in identifying odorous VOCs, which can cause odour annoyance from rubber processing. A VOC identification framework was proposed using both analyses approaches.

Detection and Identification of VOCs Using Differential Ion Mobility Spectrometry (DMS).

The article presents a technique of differential ion mobility spectrometry (DMS) applicable to the detection and identification of volatile organic compounds (VOCs) from such categories as n-alkanes, alcohols, acetate esters, ketones, botulinum toxin, BTX, and fluoro- and chloro-organic compounds. A possibility of mixture identification using only the DMS spectrometer is analyzed, and several examples are published for the first time. An analysis of different compounds and their mechanisms of fragmentation, influence on effective ion temperature, and high electric field intensity is discussed.

Profile of the volatile organic compounds of pink pepper and black pepper

Black pepper (Piper nigrum L.) and pink pepper (Schinus terebinthifolius Raddi) are two plant-based spices, which despite having a common popular name, have a botanical family and distinct centers of origin. Its fruits are known worldwide in cuisine as condiments; in addition, the extraction of essential oil from these species is interesting from a pharmacological and industrial perspective. In this sense, the present study aimed to analyze the chemical profile of volatile organic compounds (VOC's) present in black pepper and pink pepper. The solid phase microextraction method in headspace mode (HS-SPME) was used, using the fiber, polydimethylsiloxane-divinylbenzene (PDMS/DVB) for the extraction of VOCs. In the extraction of volatile compounds, 2g of the seeds of each sample were used, previously ground in an analytical mill, and placed in a 20 ml headspace flask. The adsorption of the compounds was carried out at a temperature of 60ºC, for 20 minutes, with the exposed PDMS/DVB fiber, after extraction, the desorption was carried out in the gas chromatograph injector coupled to mass spectrometry (CG-MS), where the fiber was exposed for 5 minutes. The identification of VOCs was performed by comparing the mass spectra obtained with data from the NIST library. Thirty-six volatile organic compounds (VOCs) were identified and quantified among pink pepper and black pepper seed samples. Of which 16 were found in black pepper, and 20 in pink pepper. These compounds are divided into monoterpenes, sesquitepenes, and other classes such as alkaloids and sesquiterpenoids. The volatile organic compounds found in higher concentrations in black pepper were Carnegine with 36.32 %, beyerene (30.84%), alpha-gurjunene (6.10%) and 1R,4S,7S,11R-2, 2,4,8-Tetramethyltricyclo [5.3.1.0 (4.11)] undec-8-ene also with 6.10%. In pink pepper, the compounds with the highest concentrations were, phyllocladene (36.16%), 3-carene (12.49%), and 1R,4S,7S,11R-2,2,4,8-tetramethyltricyclo [ 5.3.1.0 (4.11)] undec-8-ene (12.43%).

Identification of Volatile Organic Compounds in Extremophilic Bacteria and Their Effective Use in Biocontrol of Postharvest Fungal Phytopathogens.

Phytopathogenic fungal growth in postharvest fruits and vegetables is responsible for 20–25% of production losses. Volatile organic compounds (VOCs) have been gaining importance in the food industry as a safe and ecofriendly alternative to pesticides for combating these phytopathogenic fungi. In this study, we analysed the ability of some VOCs produced by strains of the genera Bacillus, Peribacillus, Pseudomonas, Psychrobacillus and Staphylococcus to inhibit the growth of Alternaria alternata, Botrytis cinerea, Fusarium oxysporum, Fusarium solani, Monilinia fructicola, Monilinia laxa and Sclerotinia sclerotiorum, in vitro and in vivo. We analysed bacterial VOCs by using GC/MS and 87 volatile compounds were identified, in particular acetoin, acetic acid, 2,3-butanediol, isopentanol, dimethyl disulphide and isopentyl isobutanoate. In vitro growth inhibition assays and in vivo experiments using cherry fruits showed that the best producers of VOCs, Bacillus atrophaeus L193, Bacillus velezensis XT1 and Psychrobacillus vulpis Z8, exhibited the highest antifungal activity against B. cinerea, M. fructicola and M. laxa, which highlights the potential of these strains to control postharvest diseases. Transmission electron microscopy micrographs of bacterial VOC-treated fungi clearly showed antifungal activity which led to an intense degeneration of cellular components of mycelium and cell death.

Abiotic and Biotic Damage of Microalgae Generate Different Volatile Organic Compounds (VOCs) for Early Diagnosis of Algal Cultures for Biofuel Production.

Open microalgal ponds used in industrial biomass production are susceptible to a number of biotic and abiotic environmental stressors (e.g., grazers, pathogens, pH, temperature, etc.) resulting in pond crashes with high economic costs. Identification of signature chemicals to aid in rapid, non-invasive, and accurate identification of the stressors would facilitate targeted and effective treatment to save the algal crop from a catastrophic crash. Specifically, we were interested in identifying volatile organic compounds (VOCs) that can be used to as an early diagnostic for algal crop damage. Cultures of Microchloropsis gaditana were subjected to two forms of algal crop damage: (1) active grazing by the marine rotifer, Brachionus plicatilis, or (2) repeated freeze–thaw cycles. VOCs emitted above the headspace of these algal cultures were collected using fieldable solid phase microextraction (SPME) fibers. An untargeted analysis and identification of VOCs was conducted using gas chromatography-mass spectrometry (GC-MS). Diagnostic VOCs unique to each algal crop damage mechanism were identified. Active rotifer grazing of M. gaditana was characterized by the appearance of carotenoid degradation products, including β-cyclocitral and various alkenes. Freeze–thaw algae produced a different set of VOCs, including palmitoleic acid. Both rotifer grazing and freeze–thawed algae produced β-ionone as a VOC, possibly suggesting a common stress-induced cellular mechanism. Importantly, these identified VOCs were all absent from healthy algal cultures of M. gaditana. Early detection of biotic or abiotic environmental stressors will facilitate early diagnosis and application of targeted treatments to prevent algal pond crashes. Thus, our work further supports the use of VOCs for monitoring the health of algal ponds to ultimately enhance algal crop yields for production of biofuel.

Characteristic-Aroma-Component-Based Evaluation and Classification of Strawberry Varieties by Aroma Type.

The unique fruity aroma of strawberries, a popular fruit of high economic value, is closely related to all the volatile organic compounds (VOCs) contained within them. Despite extensive studies on the identification of VOCs in strawberries, systematic studies on fruit-aroma-related VOCs are few, resulting in a lack of effective standards for accurately distinguishing aroma types. In the present study, solid-phase micro extraction and gas chromatography–mass spectrometry were used to analyze and identify VOCs in the ripe fruit of each of the 16 strawberry varieties at home and abroad and to explore their characteristic aroma components and the classification of such varieties by aroma type. The results suggested remarkable variations in the types and contents of VOCs in different strawberry varieties, of which esters were dominant. The principal volatile components, consisting of four esters, three alcohols, one aldehyde, and one ketone, in 16 strawberry varieties were detected based on the absolute and relative contents of VOCs in the fruit. The characteristic aroma components in strawberries, containing nine esters, six aldehydes, and one alcohol, were determined based on the aroma values of different VOCs, and the characteristic aroma components were divided into five types further based on aroma descriptions. Sixteen strawberry varieties were finally divided into four aroma types, namely, peachy, pineapple, fruity, and floral, based on the contributions of different types. The results provided a basis and standard for classifying strawberries by aroma type, studying the hereditary regularity of the fruity aroma of strawberries, and improving aroma quality.

Gold Nanoparticle-Based Chemiresistors: Recognition of Volatile Organic Compounds Using Tunable Response Kinetics

The development of sensors enabling the identification of volatile organic compounds (VOCs) and their mixtures is an ongoing challenge driven by many potential applications, such as breath analysis...

Research Advances in Allelopathy of Volatile Organic Compounds (VOCs) of Plants

Allelopathy is an ecological phenomenon in which organisms interfere with each other. As a management strategy in agricultural systems, allelopathy can be mainly used to control weeds, resist pests, and disease and improve the interaction of soil nutrition and microorganisms. Volatile organic compounds (VOCs) are allelochemicals volatilized from plants and have been widely demonstrated to have different ecological functions. This review provides the recent advance in the allelopathic effects of VOCs on plants, such as growth, competition, dormancy, resistance of diseases and insect pests, content of reactive oxygen species (ROS), enzyme activity, respiration, and photosynthesis. VOCs also participate in plant-to-plant communication as a signaling substance. The main methods of collection and identification of VOCs are briefly summarized in this article. It also points out the disadvantages of VOCs and suggests potential directions to enhance research and solve mysteries in this emerging area. It is necessary to study the allelopathic mechanisms of plant VOCs so as to provide a theoretical basis for VOC applications. In conclusion, allelopathy of VOCs released by plants is a more economical, environmentally friendly, and effective measure to develop substantial agricultural industry by using the allelopathic effects of plant natural products.

Extraction and Identification of Volatile Organic Compounds Emitted by Fragrant Flowers of Three Tillandsia Species by HS-SPME/GC-MS.

Numerous volatile organic compounds (VOCs) with a large chemical diversity are emitted by plant flowers. They play an important role in the ecology of plants, such as pollination, defense, adaptation to their environment, and communication with other organisms. The Tillandsia genus belongs to the Bromeliaceae family, and most of them are epiphytes. The aromatic profile of the Tillandsia genus is scarcely described. In this study, we use the headspace solid phase microextraction (HS-SPME) coupled with gas chromatography combined with mass spectrometry (GC-MS) method developed in our laboratory to explore the chemical diversity of the VOCs of fragrant flowers of three species of the genus Tillandsia. We were able to identify, for the first time, 66 volatile compounds (monoterpenes, sesquiterpenes, phenylpropanoids, and other compounds). We identified 30 compounds in T. xiphioides, 47 compounds in T. crocata, and 43 compounds in T. caliginosa. Only seven compounds are present in all the species studied. Comparison of the volatile compounds profiles by principal component analysis (PCA) between T. xiphoides, T. crocata, and T. caliginosa species showed a clear difference in the floral emissions of the studied species. Moreover, floral VOCs profiles allowed to differentiate two forms of T. xiphioides and of T. crocata.

Untargeted Metabolomics of Rind Essential Oils Allowed to Differentiate Two Closely Related Clementine Varieties.

Chemical characterization of clementine varieties (Citrus clementina Hort. ex Tan.) essential oils (EO) can lead to variety identification and valorization of their potential use in food and aroma industries. The goal of this study was the chemometric discrimination between two very closely related and morphologically identical clementine varieties, Clemenules (NL) and Clemenpons (PO), based on their rind EO, to identify the differential volatile organic compounds (VOCs) and to determine their antioxidant capacity. EO rind volatile profile was determined by gas chromatography coupled to mass spectrometry in Citrus fruit at different ripening stages grown two independent years in two different locations. Untargeted metabolomics and multivariate data analysis showed an evolution of EO volatile profiles markedly parallel in both varieties. Although EO qualitative composition was identical in both varieties, PLS-DA allowed the identification of characteristic VOCs, quantitatively discriminating them along all the ripening process. PO showed higher accumulation of several mono- and sesquiterpene compounds such as trans-carveol, while NL showed higher levels of aldehyde and alcohol non-terpenoids like dodecanal. Both varieties evinced identical EO antioxidant activities, indicating a similar value for food preservation. Hence, untargeted metabolomics approach based on rind EO volatiles was revealed as a powerful technique able to differentiate between morphologically undistinguishable Citrus varieties.

Identification of volatile organic compounds in the urine of patients with cervical cancer. Test concept for timely screening

The objective of this research was to identify a global chemical pattern of volatile organic compounds (VOCs) in urine capable of discriminating between women with cervical cancer (CC) and control women using an electronic nose and to elucidate potential biomarkers by gas chromatography-mass spectrometry (GC–MS). A cross-sectional study was performed, with 12 control women, 5 women with CIN (Cervical Intraepithelial Neoplasia) and 12 women with CC. Global VOCs in urine were assessed using an electronic nose and specific by GC–MS. Multivariate analysis was performed: Principal Component Analysis (PCA), Canonical Principal Coordinate Analysis (CAP) and Partial Least Squares Discriminant Analysis (PLS-DA) and the test's diagnostic power was evaluated through ROC (Receiver Operating Characteristic) curves. Results from the PCA between the control group compared to the CC present variability of 98.4% (PC1 = 93.9%, PC2 = 2.3% and PC3 = 2.1%). CAP model shows a separation between the overall VOCs profile of the control and CC group with a correct classification of 94.7%. PLS-DA indicated that 8 sensors have a higher contribution in the CC group. The sensitivity, specificity, value reached 91.6% (61.5%-99.7%) and 100% (73.5%-100%) respectively, according to the ROC curve. GC–MS analysis indicated that 33 compounds occur only in the CC group and some of them have been found in other types of cancer. In all, this study provides the basis for the development of an accessible, non-invasive, sensitive and specific screening platform for cervical cancer through the application of electronic nose and chemometric analysis.