Characterization and identification of the constituents of the essential oil of the leaves Agelaea pentagyna (Lam.) Baill. Connaraceae, endemic plant of Madagascar

The chemical composition of the volatile fractions obtained from distilled woody terminal branches and roots of Tetraclinis articulata (Vahl.) Masters was identified by Gas Chromatography- Flame ionization detectors (GC-FID) and Gas Chromatography-Coupled with Mass Spectrometry (GC-MS). Twenty compounds represented 83.7% of the essential oil from woody terminal branches and 29.2% from the roots. Nonan-1-ol was the main constituent present in the second fraction of the essential oil from woody terminal branches with the highest percentage of 75.22. Monoterpene hydrocarbons viz: α-terpinene (3.04), δ-carene (1.17) and β-ocimene (1.09) were the main compounds. In the fourth fraction of the essential oil from roots, the major compounds detected were Bornyl acetate (16.63), Camphene (1.59) and γ-cadinene (2.86). This fraction was mainly rich in oxygenate compounds (20.25) and sesquiterpene hydrocarbons (6.84). Furthermore, the oils were tested for their antifungal activity against five phytopathogenic fungi. These oils from woody terminal branches and roots of T. articulata (Vahl.) Masters were found to possess antifungal activity. Key words: Antifungal activity, Cupressaceae, essential oil, Nonan-1-ol, Tetraclinis articulata (Vahl.) Masters.

Objective: In this study, the chemical composition and biological activities of the essential oils extracted from the leaves and fruits of Zanthoxylum mantaro were analyzed. Methods: The essential oils were obtained through hydrodistillation using a Clevenger-type apparatus. Chemical composition was determined by gas chromatography coupled with mass spectrometry (GC-MS) and gas chromatography with a flame ionization detector (GC-FID). The antimicrobial activity was evaluated against four Gram-positive bacteria, three Gram-negative bacteria, and two fungi using the broth microdilution method. Antioxidant activity was assessed using the ABTS (2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assays. Additionally, the acetylcholinesterase inhibitory effect of the essential oils was measured by a spectrophotometric method. Results and Conclusions: A total of 23 compounds were identified in the essential oil from the fruits, while 47 compounds were found in the essential oil from the leaves. The major constituents of the fruit essential oil were α-thujone (39.85%), β-thujone (25.04%), sabinene (10.71%), and terpinen-4-ol (4.38%), whereas the main compounds in the leaf essential oil were germacrene D (21.75%), nerolidol (E) (12.39%), and pentadecanal (7.14%). The essential oil from the fruits exhibited antifungal activity against Aspergillus niger (ATCC 6275), with a minimum inhibitory concentration (MIC) of 1000 μg/mL. Both the fruit and leaf essential oils showed moderate antioxidant activity in the ABTS assay, with SC50 values of 274.14 ± 1.06 μg/mL and 2798.85 ± 15.69 μg/mL, respectively. Furthermore, the fruit essential oil demonstrated considerable acetylcholinesterase inhibitory activity with an IC50 value of 65.46 ± 1.01 μg/mL, while the leaf essential oil exhibited an IC50 value of 158.2 ± 1.02 μg/mL.

Chemical composition and larvicidal activity of edible plant-derived essential oils against the pyrethroid-susceptible and -resistant strains of Aedes aegypti (Diptera: Culicidae)

Identification of perfumery residues contained in glass objects from Parthian to early Islamic period with gas-chromatography coupled with mass spectroscopy

Essential oil from the leaves of Eucalyptus globulus collected in north centre region ofMorocco obtained by hydro-distillation were analyzed by gas chromatography equipped with flame ionisation detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). To evaluate the antifungal activities of these aromatic extracts, their in vitroantifungal activities were determined by disk diffusion testing to find out minimum inhibitory concentration (MIC). Penicillium citrinum was used as test fungal strains. The results of the study revealed that essential oil yields and the total oil of E. globulus were 1.21 and 63.96%,respectively. 54 compounds were identified in the essential oils and the main constituents of the essential oils were: 1.8-cineole (22.35%), limonene, (7.01%), solanol (6.05%), β-pinene (5.20%), trans-verbenol (4.02%), terpinen-4-ol (3.10%), aristolene (2.35%), terpinyl acetate (2.10%), isosativene (1.85%), sabinene (1.49%), α-myrcene (1.15%) and α-terpineol (1.10%).The essential oil of E. globulus exhibited the activity against, P. citrinum exerting the minimum inhibitory concentration values (MIC) ranging from 3.07 to 96.14 μl/ml, respectively.  These results showed that extracts could be considered as a natural antifungal source that can be used for production of natural antifungal agents.   Key words: Eucalyptus globulus, essential oil, gas chromatography coupled with mass spectrometry (GC-MS), antifungal activity, 1.8-cineole.

Oil mill wastewater is the main by-product of the olive oil industry resulting mainly from the treatment and pressing of olives in mills. It is a rich source of nutrients and phytochemicals with a wide spectrum of biological properties. The present study focuses on the chemical analysis and evaluation of the antimicrobial and antioxidant activity of the essential oil (EO) and the volatile fraction (VF) obtained, respectively, by hydrodistillation. Chemical analysis by gas chromatography coupled to mass spectrometry (GC/MS) and a flame ionisation detector (GC/FID) revealed the predominance of phenolic compounds (25.71%, 60.36%) and fatty acids (62.37%, 38.25%) for the VF and EO, respectively. It was also shown that the main compounds were oleic acid (24.9%) for the VF and 4-ethylphenol (28.5%) for the EO. The results of the antimicrobial activity in terms of MIC values against twelve microorganisms showed that, overall, the VF was more active than the EO. The antioxidant activity of the VF and EO was evaluated using the DPPH assay and expressed as half-maximal inhibitory concentration (IC50), where the EO (218 μg/mL) showed better antioxidant activity than the VF (244 μg/mL). The results also revealed that the antimicrobial activity and antioxidant activity values for both oils were significantly lower than the standards used.

Tuta absoluta is one of the most destructive pests of tomatoes. Chemical insecticides used to control this leafminer harm all organisms, increasing the risk to public health and the environment. Developing natural alternatives, such as bioinsecticides formulated from essential plant oils, is a key strategy to address this problem. These volatile compounds, derived from the secondary metabolic pathways of plants, exhibit targeted activity against specific pest species. Their use is consistent with an environmentally responsible framework that reduces adverse impacts on ecosystems, protects non-target organisms, safeguards human health, and enhances the efficacy of integrated crop management systems. This study aims to determine the chemical composition of the essential oils (EOs) of from round leaf mint (Mentha rotundifolia) and crown chrysanthemum (Chrysanthemum coronarium) and to evaluate their toxicity to T. absoluta larvae in-vitro. The chemical composition of EOs obtained by steam distillation from the leaves of the plants was analyzed by gas chromatography coupled with mass spectrometry (GC-MS). Indeed, 77 volatile compounds representing 98.19% of the total oil of M. rotundifolia, including cyclobutane acetonitrile, 1-methyl-2-(1-methyl ethenyl)-, terpinene-4-ol, p-menthane, germacrene D, caryophyllene and myrcene, were the main compounds. However, farnesene, myrcene, eugenol, germacrene D, phytol, and pinene were significant components among 69 compounds representing 95.39% of the total oil of C. coronarium. Results showed that the EOs were toxic to the different larval stages. According to the Finney method, concentrations 2.88 and 1.07% are the LC50 of M. rotundifolia and C. coronarium oils, which induce 50% mortality of T. absoluta within 7 days of exposure. Statistical analysis of in-vitro tests showed that both EOs had a similar level of insecticidal efficacy by contact. The overall results showed that the oils used have been shown to have an important insecticidal effect and can be used as a source of biological and natural treatment against tomato leafminer (TLM).

Aromatic and medicinal plants form a reservoir of active molecules; among them, Juglans regia is a plant of the Juglandaceae family, and it is used thanks to its medicinal properties. The present study was conducted to investigate the secondary metabolite content and biological activities of the infusion, methanolic extracts, and essential oil of the bark essential oil (EO) of Juglans regia harvested from North Tunisia, as well as its chemical composition. Essential oil, infusion, and methanolic extracts were prepared. Identification of essential oil composition was determined using GC-MS. Phenolic content, antioxidant, and antimicrobial activities were evaluated with the colorimetric method. The obtained data indicate that J. regia is very abundant in bioactive compounds. The infusion extract of J. regia bark has been found to contain elevated amounts of phenolic compounds. The infusion extract showed stronger antioxidants and radical scavenging action than methanol. The studied methanolic extract displayed antimicrobial activity against all ten tested microbial strains but with variable degrees according to the microbial strain. The infusion extract, instead, was inactive. The use of gas chromatography coupled with mass spectrometry (GC-MS) revealed the existence of 34 components in the bark (EO). The main compounds were: carvacrol (13.82%), isoeugenol (13.71%), β-caryophyllene (7.81%), 1,8-cineole (8.60%), and bornyl acetate (7.13%). Our results suggest that Juglans regia is a natural source of potent antioxidants and antimicrobials and may be useful as preventive agents in some diseases.

The present study aims to evaluate the effect of essential oil (EO) from Cymbopogon citratus leaves against the spoilage flora of fresh orange juice. Thus, the EO was extracted by hydrodistillation from fresh leaves of Cymbopogon citratus collected in southern Benin and its chemical composition was determined by gas chromatography, coupled to mass spectrometry (GC/MS). Orange samples were collected from large production areas of South and Central Benin and juices were extracted by mechanical pressing. After identification of spoilage flora of fresh orange juice, antimicrobial tests were carried out with the EO of Cymbopogon citratus to evaluate its antimicrobial activity on spoilage flora of fresh orange juice. Results indicate that the spoilage flora of fresh orange juice is mainly composed of fungi belonging to the genera of Cladosporium, Penicillium and Fusarium. Bacteria such as Enterobacter cloacae and Enterobacter aerogenes were also identified in some samples. The major compounds identified in the EO by GC/MS are Neral (33.0%) and geranial (41.3%) with a predominance of oxygenated monoterpenes (85.5%). Antimicrobial tests have revealed a high antibacterial activity of the EO, with minimum bactericidal concentrations (MBC) between 0.1 and 0.15 μL.mL-1. Antifungal tests revealed that fungi are also susceptible to this EO with minimum fungicidal concentration (MFC) between 0.15 and 0.25 μL.mL-1. Results obtained during the evaluation of the physicochemical characteristics of the orange juice stored by adding EO, indicated a significant decrease in the pH and vitamin C content. However, with EO concentration of 0.250 μL.mL-1, the pH of stored juice was 6.4 ± 0.1 after 15 days of preservation, with a best vitamin C content of 28.06 ± 0.03 mg / 100mL. The EO of Cymbopogon citratus, with high antimicrobial activity, could be used as an alternative in the preservation of fruit juices, replacing antimicrobials from chemical synthesis.

Background: Essential oils are widely recognized for their antioxidant properties, including their ability to neutralize free radicals and protect cells from oxidative stress, a key factor in cell death associated with neurodegenerative diseases. Objective: The aim of this study was to analyze the chemical composition of essential oil extracted from the leaves and flowers of Xanthium italicum and to evaluate its antioxidant activity using the DPPH test and the Ferric Antioxidant Power Reduction Test (FRAP), as well as its hemolytic properties. Methods: Leaf and fruit chemical composition was determined by gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS). Antioxidant properties were evaluated using DPPH and FRAP methods. A suspension of human blood erythrocytes was used to determine the hemolytic effect of essential oils. Results: Thirty-five compounds were identified in the essential oil extracted from the leaves of Xanthium italicum. The main compounds were limonene (41.5%) and germacrene D (14.2%). For fruit essential oil, twenty-five compounds were identified, with α-bisabolol (62.2%), α-humulene (8.1%), and limonene (5.2%) as the main constituents. In-vitro antioxidant activity tests showed that the essential oil of Xanthium italicum fruits is a powerful antioxidant (0.038 mg/mL), surpassing even ascorbic acid (0.048 mg/mL). Human erythrocyte toxicity tests showed that the essential oil of Xanthium italicum leaves and fruits have a relatively low hemolytic effect, with hemolysis rates of 15.3% and 8.1%, respectively, even at high concentrations of 1000 μg/mL. Conclusion: The essential oils of Xanthium italicum show a strong antioxidant activity, especially in fruits, and a low hemolytic effect on human erythrocytes. This could be a safe and effective natural antioxidant.

In the present work, essential oils (EOs) extracted from different parts of sour orange Citrus aurantium (green leaves/twigs, small branches, wooden branches, and branch bark) were studied through gas chromatography coupled with mass spectrometry (GC/MS). Furthermore, the EOs in the amounts of 5, 10, 15, 20, and 25 µL were studied for their antibacterial activity against three pathogenic bacteria, Agrobacterium tumefaciens, Dickeya solani, and Erwinia amylovora. The main EO compounds in the leaves/twigs were 4-terpineol (22.59%), D-limonene (16.67%), 4-carvomenthenol (12.84%), and linalool (7.82%). In small green branches, they were D-limonene (71.57%), dodecane (4.80%), oleic acid (2.72%), and trans-palmitoleic acid (2.62%), while in branch bark were D-limonene (54.61%), γ-terpinene (6.68%), dodecane (5.73%), and dimethyl anthranilate (3.13%), and in branch wood were D-limonene (38.13%), dimethyl anthranilate (8.13%), (-)-β-fenchol (6.83%), and dodecane (5.31%). At 25 µL, the EO from branches showed the highest activity against A. tumefaciens (IZ value of 17.66 mm), and leaves/twigs EO against D. solani and E. amylovora had an IZ value of 17.33 mm. It could be concluded for the first time that the wood and branch bark of C. aurantium are a source of phytochemicals, with D-limonene being the predominant compound in the EO, with potential antibacterial activities. The compounds identified in all the studied parts might be appropriate for many applications, such as antimicrobial agents, cosmetics, and pharmaceuticals.

The chemical constituents of essential oils obtained from the hydrodistillation of the leaf and stem of Michelia foveolata Merr. et Dandy (Magnoliaceae) were being reported. The main compounds of the leaf essential oil are β-caryophyllene (37.1%) and bicyclogermacrene (23.3%). However, βcaryophyllene (26.4%), germacrene D (5.9%), trans-α-bergamotene (5.6%), δ-cadinene (5.5%), bicyclogermacrene (5.4%), bicycloelemene (5.3%), spathulenol (5.3%) and 3,7-guaiadiene (5.1%) were present in the stem. Aims: The aim of this study was to isolate essential oils from the leaf and stem bark of Michelia Original Research Article Dai et al.; JSRR, 10(6): 1-6, 2016; Article no.JSRR.25304 2 foveolata Merr. et Dandy (Magnoliaceae) and investigate the volatile constituents present therein. Study Design: The study involves the hydrodisitillation of essential oils from the air-dried plant materials and analysis of their chemical composition. Place and Duration of Study: The leaf and stem bark of M. foveolata were collected from Vũ Quang National Park, Ha Tĩnh Province Vietnam, in July 2014. Methodology: About 500 g of air-dried plant samples was shredded and their oils were obtained by separate hydrodistillation for 4 h at normal pressure, according to the Vietnamese Pharmacopoeia. The chemical constituents of the distilled oils were analyzed by means of gas chromatography-flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). Results: The main compounds of the leaf essential oil are β-caryophyllene (37.1%) and bicyclogermacrene (23.3%) while the stem bark contained large amounts of β-caryophyllene (26.4%), germacrene D (5.9%), trans-α-bergamotene (5.6%), δ-cadinene (5.5%), bicyclogermacrene (5.4%), bicycloelemene (5.3%), spathulenol (5.3%) and 3,7-guaiadiene (5.1%). Conclusion: The present oil compositions were found to be different from the results obtained previously from the essential oils of Michelia species grown in Vietnam and other parts of the world.

Chemical composition, antimicrobial activity, and antioxidant capacity of Micromeria flagellaris Baker and M. madagascariensis Baker: Two endemic species from Madagascar as sources of essential oils

Medicinal and aromatic plants from the Comoros Islands are a potential source of unexploited bioactive compounds. This study investigates the chemical composition and biological properties of essential oils (EOs) from three emblematic Comorian plants: Syzygium aromaticum (L.) Merr. & L.M.Perry (clove), Cananga odorata (Lam.) Hook. f. & Thomson (ylang-ylang), and Zingiber officinale Roscoe (ginger). EOs were characterized using gas chromatography coupled with mass spectrometry (GC-MS). Antioxidant activities were evaluated using the DPPH and molybdenum-reducing power methods, while antimicrobial properties were determined by the microdilution method against various pathogenic strains. A mixture design was applied to optimize EO combinations, identifying significant synergies in their biological activities. GC-MS analysis revealed that the major compounds in S. aromaticum EO were cinnamal (53.23%), eucalyptol (16.37%), and camphene (9.74%), Z. officinale EO was characterized by α-zingiberene (19.33%), eucalyptol (16.37%), β-citral (12.93%), and β-cymene (7.16%), while C. odorata EO contained primarily o-cresol (14.09%), germacrene D (11.16%), and β-linalool (10.47%). Mixture design optimization revealed that the combination of S. aromaticum and Z. officinale EOs significantly enhanced antioxidant activity (DPPH assay). Additionally, Escherichia coli, Candida albicans, and Pseudomonas aeruginosa exhibited the highest susceptibility to a binary mixture of S. aromaticum and C. odorata EOs. Moreover, S. aromaticum EO alone demonstrated the highest total antioxidant activity in the phosphomolybdenum assay. Furthermore, molecular docking analysis of the three main compounds in the EOs revealed strong interactions with the binding sites of various selected proteins, confirming their potential antioxidant and antibacterial properties. This research contributes to the valorization of Comorian natural resources and opens new perspectives for their exploitation in pharmaceutical and environmental sectors.

To investigate, for the first time, the chemical composition of essential oil of the buds species of Sophora japonica L., a native to eastern Asia and a popular species in almost all Europe, growing in Ukraine. A hydrodistillation apparatus was used for the extraction of volatile components of buds species and then it was analysed by gas chromatography equipped with a split-splitless injector (split ratio, 1:50) and flame ionization detector (FID). The oil was analyzed under linear temperature programming applied at 4°C/min from 50°C - 340°C. Temperatures of the injector and FID detector were maintained at 280°C and 300°C, respectively. The chemical analysis of the oil was carried out using gas chromatography coupled to mass spectrometry (GC-MS), to determine the chemical composition of the volatile fraction. The essential oil content in green bud, formed bud, and beginning of bud opening ranged from 0.00002 – 0.00193 g/100 g, 0.00002 – 0.00684 g/100 g and from 0.00003 – 0.00638 g/100 g, respectively. The qualitative and quantitative analysis led to the identification of 80 components that were identified in Sophora japonica L. flower buds. Out of these 71 components are from the green flower bud and the beginning of flower bud opening stages, and 67 components are from the formed flower bud stage. The major component found in green bud was 3-methoxypyridine (0.00193 g/100 g). In both formed bud and beginning of bud opening was dodecanoic acid with concentrations of 0.00684 g/100 g and 0.00638 g/100 g, respectively. Contents of Sophora japonica L. were significantly affected by the harvesting stage of bud flower. Harvesting at the formed bud stage yielded the highest essential oil content compared to buds harvested at other stages. Flowers harvested at the green bud and beginning of bud opening stages yielded a lower quality essential oil compared with flowers harvested at the formed bud stage.