Quality Control Assays of Essential Oils Using Benchtop NMR Spectroscopy: Quantification of Key Terpenes, Terpenoids, and Aldehydes Using an Internal Calibrant Approach.

The stems of Allium monanthum were extracted, and the major essential oil composition and larvicidal effects were studied. The analyses were conducted by gas chromatography and mass spectroscopy revealed that the essential oils of A. monanthum stems. The A. monanthum essential oil yield was 4.25%, and gas chromatography and mass spectroscopy analysis revealed that its major constituents were dimethyl trisulfide (23.21%), dimethyl tetrasulfide (11.24%) and methlyl propyl trisulfide (8.21%). The essential oil had a significant toxic effect against early fourth-stage larvae of Aedes aegypti L with an LC50 value of 23.14 ppm and an LC90 value of 36.31 ppm. Also, dimethyl trisulfide (≥95.0%), dimethyl tetrasulfide (≥95.0%) and methlyl propyl trisulfide (≥95.0%) were tested against the F21 laboratory strain of A. aegypti. Methlyl propyl trisulfide (≥95.0%) has good activity with an LC50 value of 19.38 ppm. Also, the above indicates that other major compounds may play a more important role in the toxicity of essential oil.

The Atlas cedar belongs to the Pinaceae family of trees and can be found in a crucial resinous mountain forest in Morocco that spans 133,000 hectares. This endemic species is valued for its wood quality and essential oil (EO), which has various biological activities. However, pathogenic fungi, particularly Trametes pini and Ungulina officinalis, frequently attack Atlas cedarwood, causing significant damage and loss of value. This study aims to extract EO from both healthy and infected Atlas cedarwood to promote its valorization and to assess the antibacterial properties of the resulting EOs. The EOs from healthy and sick cedarwood, as well as a combination of these woods, were extracted using hydrodistillation and simultaneous hydrodistillation. Gas chromatography and mass spectrometry were used to examine the chemical compositions of the EOs. In addition, the disk diffusion method and a measurement of the minimum inhibitory concentration were used to assess the EOs' antibacterial activity against two bacterial strains, namely, Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The results show that the extraction yields of healthy cedarwood, cedarwood infected by Trametes pini, and cedarwood infected by U. officinalis were 1.43 ± 0.03, 0.56 ± 0.03, and 0.26 ± 0.06%, respectively, Moreover, the antibacterial results showed that neither the healthy nor the diseased cedar oil had any impact on either strain. However, the EOs from some binary mixtures (75:25, 50:50, and 25:75%) of cedarwood infected by Trametes pini and cedarwood infected by U.ngulina officinalis and the mixture of healthy cedarwood and cedarwood infected by the two fungi inhibited the growth of S. aureus with different MIC values. The findings of this research could lead to the development of new products with antibacterial properties, such as natural disinfectants, and reduce the amount of waste generated by the cedar industry.

Sesquiterpene constituents from the essential oils of the liverworts Mylia taylorii and Mylia nuda

The essential oil composition of Vitex pooara , V. rehmannii , V. obovata ssp. obovata , V. obovata ssp. wilmsii and V. zeyheri was determined using gas chromatography and mass spectrometry. The in vitro antimicrobial activity of the essential oils was assessed on Staphylococcus aureus , Bacillus cereus and Escherichia coli and the minimum inhibitory concentration values recorded. All essential oils were moderately active with V. zeyheri being the most active (8, 4 and 16mg ml − 1 for S . aureus , B. cereus and E. coli respectively). The in vitro anti-inflammatory activity of the essential oils was evaluated using a 5-lipoxygenase assay and all essential oils effectively inhibited 5-lipoxygenase, a key enzyme in the inflammatory cascade with V . pooara producing the most promising activity (IC 50 value of 25ppm). Using the essential oil data matrix, chemotaxonomic evidence is presented which supports the infrageneric placement of V. pooara in subgenus Vitex while the other four above mentioned taxa are placed in subgenus Holmskiodiopsis .

Rapid classification and quality assessment of citrus essential oils via machine-learning-assisted Raman spectroscopy.

The chemical composition of lemon essential oils, obtained by hydrodistillation, was studied by Gas Chromatography (GC) and Gas Chromatography and Mass Spectroscopy (GC–MS). The oil consisted mainly of propylphosphonic acid, fluoroanhydride, octyl ester (15.72%), decanoic anhydride (12.631%), benzene, 2,4-difluoro-1-isocyanato (11.72%), cyclopentane, 1,1'-hexadecylidenebis- (9.98%), 4-cyanocinnoline (8.58%), 4-cyanocinnoline (8.55%), cyclodocosane, ethyl- (7.58%), butanamide, N-(4-chlorophenyl)-3-oxo- (5.77%), 2-naphthuric acid (4.47%), Limonene (4.25%), (Z)-14-tricosenyl formate (3.51%), diethyl phthalate (2.94%), decanoic acid, 1,2,3-propanetriyl ester (2.91%), 13-tetradecen-1-ol acetate (2.40%). The antioxidant activity using O2-, OH-, DPPH- radicals and the antiproliferative activity on a series of human cervical adenocarcinoma cell lines (LeLA) were investigated for the lemon essential oil. The result showed that the essential oil exhibited strong antioxidant activities as well as antiproliferative activity against HeLA cell line. Key words: Lemon, essential oil, antioxidant activity, cytotoxic activity.

Th e chemical composition of the essential oil obtained from the fruits of Pimpinella affi nis Ledeb. (Apiaceae) was analyzed by gas chromatography (GC) and gas chromatography - mass spectrometry (GC-MS) techniques. Twenty - four components were identifi ed in the essential oil of P. affi nis Ledeb., whose major constituents were geijerene (17.68%), limonene (12.86%), pregeijerene (9.92%), germacrene D (8.54%) and trans- β-ocimene (4.94%). Th e essential oil was evaluated for antibacterial and antifungal activities. Th e oil showed antimicrobial activity against all the tested microorganisms, excepted Pseudomonas aeruginosa. Maximum activity was observed against fungal microorganisms. Key words: Antimicrobial; apiaceae, essential oil, Pimpinella affi nis Ledeb

This study was laid out in Lorestan agricultural farm, Korramabad, Iran during 2016 and 2017. The experiment was designed based on a complete randomized design (CRD) with four replications. In this study, in the spring, fresh leaf samples were randomly collected seven species of Eucalyptus. The composition of essential oils determined using analytical gas chromatography coupled to mass spectrometry (GC–MS).The results showed that the effect of specie treatment was significant on essential oil yield, α-Pinene, β-Pinene, 1, 8-Cineole, γ-Terpinene, Pinocarvone, Epiglobulol and β-Eudesmol. Based on our results, essential oil of Eucalyptus camaldulensis Dehnh. was obtained at rate of 3.43%. The measured oil yield was in range of 2.57% for Eucalyptus nitens (H. Deane & Maiden) Maiden, 1.34% for Eucalyptus globulosusbicosata, 5% for E. globulus madidenii17746, 5.38% for E. globulusmadidenii 2130, 3.74% for Eucalyptus viminalisLabill.and 1.12% for Eucalyptus suggrandis L.A.S. Johnson & K.D. Hill. The main compounds of Eucalyptus camaldulensis Dehnh. oils were 1, 8-cineole (66.72%) followed by α-pinned (17.88) in the samples. The major constituents of Eucalyptus nitens (H. Deane & Maiden) Maidenoils were 1, 8-cineole (46.67%), α-pinene (14.56%) and β-Pinene (4.51%). The main components of E. globulus oils were 1, 8-cineole (70.15%) and α-pinene (3.65%). The main compounds ofE.globulusmadidenii17746 oils were 1,8-cineole (55.82%), α-pinene (3.91%) and Veridiflorol (5.07%). The major constituents of E. globulusmadidenii 12130 were 1,8-cineole (60.29%), α-pinene (15.5%),α–Terpineol (6.11%) and Eudesmol (3.88%). The major constituents of Eucalyptus viminalis Labill. oils were 1, 8-cineole (56.43%), α-pinene (3.91%). The major constituents of Eucalyptus suggrandis L.A.S. Johnson & K.D. Hill oils were 1, 8-cineole (30.94%), α-pinene (18.52%), β-Eudesmol (6.87%) and Pinocarvone (4.96%). The E. globules maidenii 12130 specie had highest rate of essential oil yield. Between all species E. suggrandis had maximum rate of α-Pinene, γ-terpinene, Pinocarvone and β-Eudesmol. Between essential oil compositions 1, 8-Cineole was in higher rate especially in E. globules bicostata specie.

The comparison of the volatile flavor composition from Aster tataricus (gaemichi) and A. koraiensis (byulgaemichi) essential oils, isolated by hydro distillation method, was performed by gas chromatography and mass spectrometry. Ninety-seven volatile flavor components, constituting 95.17 % of the total volatile composition of the essential oil were identified from A. tataricus. Methyl-5-methylene-8-(1-methylethyl)-1,6-cyclodecadiene (14.13 %) was the most abundant compound, followed by spathulenol (13.52 %) and methyl tetrahydroionol (6.06 %). The volatile composition of A. tataricus was characterized by a higher content of sesquiterpene alcohols, especially spathulenol. Ninety-nine volatile flavor components were identified from the essential oil of A. koraiensis. Caryophyllene oxide was the most abundant component (8.38 %), followed by aristolene (7.08 %) and epiglobulol (5.57 %). The volatile flavor composition from A. tataricus and A. koraiensis can easily be distinguished by the percentage of methyl-5-methylene-8-(1methylethyl)-1,6-cyclodecadiene, spathulenol, caryophyllene oxide, aristolene, and phthlides. Methyl-5methylene-8-(1-methylethyl)-1,6-cyclodecadiene, spathulenol, and phthalides were regarded as the character impact odorants of A. tataricus, while caryophyllene oxide and aristolene were of A. koraiensis.

The use of chemical pesticides to protect agricultural products is a global concern because of their adverse effects on the environment and public health. To avoid the dangers of synthetic herbicides, research has turned to natural alternatives. This study was conducted to evaluate the allelopathic effect of essential oil (EO) extracted from Origanum syriacum, Origanum onites, and Origanum majorana. In addition, the chemical composition of the essential oil was elucidated by gas chromatography and mass spectrometry (GC–MS) analysis. A total of 11 different components of O.syriacum were identified, and the main components were carvacrol (88.49), p-Cymene (5.71), γ-Terpinene (1.63), β-Caryoplhyllene (1.48), and Terpinen-4-ol (0.65), respectively. For O. onites, 10 different compounds were identified, and the main components were carvacrol (58.65), Thymol (30.97), Linalool (4.17), p-Cymene (1.94), and β-Caryoplhyllene (0.98), respectively. Finally, for O. majorana, 14 different compounds were identified, and the main components were carvacrol (40.57), α-Terpineol (29.28), p-Cymene (9.02), γ-Terpinene (5.80), and carvacrol methyl ether (3.46). Finally, 14 compounds from the Origanum majorana species were identified, with carvacrol (40.57), -Terpineol (29.28), p-Cymene (9.02), and -Terpinene (5.80) as the parent compound (3.46). Oxygenated monoterpenes were the highest in all species’ EO content. EOs and plant extracts were tested at 5, 10, and 20 L/Petri concentrations against seed germination and seedling growth in four weed species (Thlaspi arvense, Amaranthus retroflexus, Rumex cripus, and Lactuca serriola). The concentrations of essential oil were set as 5, 10, and 20 µL/Petri dishes for seed germination. In the greenhouse experiment, the final concentration of solutions was set as 20 µL and the solutions were directly sprayed on the surface of the weeds, and the mortality rates were noted after 24 and 48 h of application. It was observed that increasing the application decreased seed germination. The phytotoxic effects on the seedling germination in the greenhouse were observed, resulting in 48.76–94% mortality rates. Consequently, the essential oil from Origanum species could be considered as an alternative bio-herbicide to tested weeds.

Eleutherococcus senticosus (Rupr. & Maxim.) Maxim. fruits (ESF), as a natural edible fruit, has long been popularized. However, few studies have conducted comprehensive chemical analyses of it. This study aimed to assess nonvolatile, volatile, and fatty oil components of ESF and to preliminarily explore the antioxidant activities. The qualitative and quantitative analyses of volatile and fatty oil components of ESF from 15 different regions were performed by the gas chromatography-mass spectrometry (GC-MS). Totally, 37 and 28 compounds were identified from volatile oil and fatty oil, respectively. The ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS/MS) was used to accurately detect 43 compounds of nonvolatile components. The volatile and fatty oil components and nonvolatile components of ESF were used as samples to determine the antioxidant activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) invitro. The components of ESF had antioxidant activity, and the nonvolatile components had stronger antioxidant activity. The results revealed that the proposed method, which is of great significance for the screening of new active ingredients, is valuable for the identification of pharmaceutical component and further development of food industry.

Chemical composition analysis and antioxidant activity evaluation of essential oil from Orthosiphon thymiflorus (Roth) Sleesen

Yen Bai province has 50,000 hectares under cinnamon cultivation, which is the largest of cultivation area in Vietnam. Cinnamon essential oil is mainly extracted from the stem bark and leaves of Cinnamomum cassia (L.) J. Presl. The essential oil yield varies depending on species and extraction methods. The aim of this study was to investigate the effect of critical parameters including extraction time, average particle size and material mass to water volume ratio on the yield of essential oil and to evaluate its chemical constituents. The stem bark of Cinnamomum cassia was sourced from Yen Bai province, Vietnam. The powdered stem bark (500 g) was extracted with 2.5 L of distilled water by hydro-distillation for 180 minutes. The chemical composition of the essential oil obtained was determined by Gas Chromatography – Mass Spectrometry (GC-MS) analysis. Morphological changes to the cinnamon bark powder before and after hydro-distillation was assessed by Scanning Electron Microscopy (SEM) and Fourier Transform Infra-Red (FTIR) Spectroscopy. Essential oil (14.95 mL) was obtained corresponding to a percentage yield of 3.38%. The GC-MS analysis identified 11 bioactive compounds in thecinnamon essential oil. Cinnamaldehyde was the major compound in cinnamon essential oil constituting about 93.3% of the total oil composition. Generally, cinnamon from Yen Bai province in Vietnam provides a high value essential oil with a high percentage of cinnamaldehyde, and a potential for many applications.

The term “Analytical Microbiology” describes the application of analytical chemistry to identification, structure elucidation, systematics, diagnosis, and detection in microbiology. The most widely applied instrumental chemical techniques have been the various forms of gas chromatography (GC) and mass spectrometry (MS). These and other analytical techniques (e.g., high performance liquid chromatography, HPLC) and the “hyphenated” methods (including GG-MS, HPLC-MS and MS-MS) can be used to detect trace levels and to identify monomers, oligomers, or polymers derived from microorganisms. Chemical information from these analyses can be of great benefit in medicine, ecology, biotechnology, as well as in the food and pharmaceutical industries. Classical microbiological or biochemical procedures may not be sufficiently sensitive, selective, quantitative, or rapid in some instances. Instrumental approaches, hitherto considered the realm of the chemist, have found application in microbiological analysis. We perceive four major areas in analytical microbiology where chromatography and mass spectrometry are having impact.

In the present study, the essential oil from the fresh leaves of Schinus terebinthifolius was extracted using the hydrodistillation method. The oil yield obtained was 0.65%. Gas chromatography and mass spectroscopy (GC-MS) analysis of the essential oil showed that the major constituents of the essential oil were sabinene,
-pinene,
-phellandrene, -pinene, terpinene-4-ol, trans--ocimene and myrcene. Using the hole-plate diffusion testing method, the essential oil exhibited potent antibacterial activity against Yersinia enterocolitica, Pseudomonas aeruginosa, Escherichia coli, Acinetobacter calcoaceticus, Bacillus subtilis, Klebsielia pneumoniae and Bacillus subtilis with at least 58% inhibition compared to the positive control. The mycelium growth inhibition method was used for anti-fungal testing. The essential oil exhibited activity against Aspergillus flavus with 58% inhibition, Candida albicans with 49.8% inhibition and Aspergillus niger with 48.7% inhibition. The -carotene, acetone and linoleic acid method was used to assess the antioxidant activity of the essential oil. The essential oil showed anti-oxidant activity of 13.1 mm mean zone of colour retention representing 72.7% activity compared to the positive control (ascorbic acid). This is the first study on S. terebinthifolius collected from sub-saharan Africa indicating the presence of trans--ocimene in the essential oil and its strong antibacterial activity against Y. enterocolitica and P. aeruginosa as well as moderate antifungal activities of the plant.