Foeniculum vulgare Miller, a New Chemotype from Montenegro

Previous studies relating to prolonged and fractionated distillation procedures highlighted essential oils’ (EOs) chemical composition to be significantly dependent on the extraction duration and harvesting time. As a continuation, a hydrodistillation procedure was applied to ripe fruit material of fennel, Foeniculum vulgare Miller (Apiaceae), collected from three localities in Montenegro (Podgorica, Nikšić, and Kotor) to furnish a total of 12 EOs. Liquid and vapor phases of the samples were analyzed by Gas Chromatography/Mass Spectrometry and Headspace-Gas Chromatography/Mass Spectrometry techniques, and 18 compounds have been identified. Although both quantitative and qualitative differences between the samples were notable, the phenylpropanoids anethole (ANE) and estragole and the monoterpenoids α-terpineol (TER) and fenchone (FEN) could be singled out as the most abundant constituents. The EOs from Podgorica belong to the most common ANE-rich chemotype, while the predominance of the monoterpenoid fraction is characteristic of the samples from Nikšić and Kotor. The latter is particularly rich in TER (up to 56.5%), with significant amounts of FEN and ANE. This chemical profile could represent a new chemotype of fennel EO. Vapor phases contained mainly monoterpenoids, with increased amounts of FEN and TER, while the number of phenylpropanoids was significantly decreased.

Validation of Qualitative Broth Volatilization Checkerboard Method for Testing of Essential Oils: Dual-Column GC–FID/MS Analysis and In Vitro Combinatory Antimicrobial Effect of Origanum vulgare and Thymus vulgaris against Staphylococcus aureus in Liquid and Vapor Phases

Combinatory action of antimicrobial agents such as essential oils (EOs) show to be an effective strategy to overcome the problem with increasing antibiotic resistance of microorganisms, including Staphylococcus aureus. The objective of this study was to evaluate in vitro antimicrobial interactions between Origanum vulgare and Thymus vulgaris EOs against various S.aureus strains in both liquid and vapor phases using the broth volatilization checkerboard method. Fractional inhibitory concentrations (FICs) were determined for both liquid and vapor phases, and the composition of EOs was analyzed by gas chromatography-mass spectrometry using dual-column/dual-detector gas chromatograph. Results of oregano and thyme EOs combination showed additive effects against all S. aureus strains in both phases. In several cases, sums of FICs were lower than 0.6, which can be considered a strong additive interaction. The lowest FICs obtained were 0.53 in the liquid phase and 0.59 in the gaseous phase. Chemical analysis showed that both EOs were composed of many compounds, including carvacrol, thymol, γ-terpinene, and p-cymene. This is the first report on oregano and thyme EOs interactions against S. aureus in the vapor phase. It also confirms the accuracy of the broth volatilization checkerboard method for the evaluation of combinatory antimicrobial effects of EOs in the vapor phase.

Antimicorbial Potency of Major Functional Foods’ Essential Oils in Liquid and Vapor Phases: A Short Review

Due to the increasing risk of chemical contaminations in the application of synthetic fungicides, the use of plant essential oils and extracts has recently been increased. In the present review, the antimicrobial potential of the most active plant-food essential oils in liquid and vapor phases has been reviewed. The volatile isothiocyanates, aldehydes, and phenols, including allyl isothiocyanate, carvacrol, thymol, and eugenol, are considered to be the predominant components of essential oils, possessing significant antimicrobial activities. These components alone or in mixture can be effective. Overall, the antimicrobial activity of aroma compounds depends on the plant species, concentration, and method of application. This review provides useful information about the inhibitory application of the most common plant-foods’ essential oils in liquid and vapor phases against the growth of pathogenic microorganisms. Essential oils (EOs) are promising natural antimicrobial alternatives in food processing facilities. Although the food industry primarily uses spices and herbs to impart flavor, aroma, and pungency to foods, potent EOs represent interesting sources of natural products for food preservation.

EXPERIMENTAL STUDY OF THE PRESSURE DROP OF THE ECOFLUID R1234YF COMPARED TO THE FLUID R134A IN SMOOTH TUBES WITH 4.8MM INTERNAL DIAMMETER

The refrigerant fluid R1234yf is a hydrofluorefine with zero potential for degradation of the ozone layer and low potential for global warming. It is one of the potential substitutes for the currently used R134a in automotive systems. In this work, the pressure drop suffered by the fluids R134a and R1234yf when flowing in a test section through a pipe with a 4.8 mm internal diameter was measured. The pressure drop was plotted as a function of the void fraction at the exit of the test section and the values were compared concerning the change in mass flux, change in saturation temperature, and comparatively between R1234yf and R134a. A significant increase in pressure drop was observed by the increases of the mass flux, showing an increment of 155.46% of the pressure loss from 200 to 300 kg·m-2·s-1 for R1234yf at 35ºC and 161.07% for R134a in the same conditions. Despite being high, those values are expected since increasing mass flux also increases the friction between both phases. On the other hand, by increasing the saturation temperature, the pressure drop is slightly lower once the differences between the densities of the liquid and vapor phases are reduced. Compared with R134a, the R1234yf ecofluid presents less pressure drop, showing a reduction of 24% for 300 kg·m-2·s-1.

Chemical constituents involved in e-cigarette, or vaping product use-associated lung injury (EVALI)

BackgroundThe Centers for Disease Control (CDC) declared e-cigarette (e-cig), or vaping product use-associated lung injury (EVALI) a national outbreak due to the high incidence of emergency department admissions and deaths. Investigators have identified vitamin E acetate (VEA) as the plausible cause for EVALI, based on compounds found in bronchoalveolar lavage fluid.ObjectivesWe defined the chemical constituents present in e-cig cartridges associated with EVALI and compared constituents to medical-grade and cannabidiol (CBD) containing cartridges.MethodsWe measured chemicals and elemental metals in e-liquid and vapor phases of e-cig counterfeit cartridges by Gas Chromatography (GC) and Mass Spectrometry (MS), EPA method TO-15 by GCMS, and ICP-MS analysis.ResultsWe have identified chemical constituents in e-cig vaping tetrahydrocannabinol (THC)-containing counterfeit cartridges compared to medical-grade and cannabidiol (CBD) containing cartridges. Apart from VEA and THC, other potential toxicants correlated with EVALI included solvent-derived hydrocarbons, silicon conjugated compounds, various terpenes, pesticides/plasticizers/polycaprolactones, and metals. These chemicals are known to cause symptoms, such as cough, shortness of breath or chest pain, nausea, vomiting or diarrhea, fatigue, fever, or weight loss, all symptoms presenting in patients with EVALI.ConclusionThis study provides insights into understanding the chemical-induced disease mechanism of acute lung injury.

A new challenge for nanocrystalline α-zirconium phosphate: reaction with a diepoxyalkane

The reaction of nanocrystalline layered α-zirconium phosphate with a diepoxyalkane led to covalently pillared layered materials able to reversibly take up organic molecules both from liquid and vapor phases at room temperature.

Exceptionally effective benzene/cyclohexane separation using a nitro-decorated metal–organic framework

A nitro-decorated MOF is used for the selective separation of benzene and cyclohexane in both liquid and vapor phases.

An electron-rich small AIEgen as a solid platform for the selective and ultrasensitive on-site visual detection of TNT in the solid, solution and vapor states

A simple trimethoxybenzene-linked anthracenyl π-conjugate is developed for the ultra-sensitive and selective detection of TNT in solid, liquid and vapor phases. The TNT could also be detected in the field soil.