Determination by GC/MS and ¹³C NMR of the Major Chemical Groups and Compounds in the Essential Oil from the Roots of Cyperus rotundus L. from Daloa, Côte d’Ivoire

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

The essential oil of the leaves of Verbesina macrophylla (Cass.) S.F.Blake has antimicrobial, anti-inflammatory and antipyretic activities and is toxicologically safe

Reinvestigation of essential oil constituents of Blumea malcolmii Hook. F. (Asteraceae) was carried out after 100 years using gas chromatography equipped with flame ionisation detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC/MS). Eighteen constituents, representing 99.2% of the total oil, were identified. The major compound was identified by GC/MS and NMR (1H and 13C) as carvotanacetone (92.1%). The minor compounds of essential oil have also been identified for the first time in B. malcolmii. The oil was found to be rich in oxygenated monoterpene-type constituents (95.0%).

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

Background: The increasing use of synthetic antimicrobials and antioxidants is a concern for human health. Aims: The main objective of this study was to examine the chemical composition of the essential oil extracted from Salvia argentea and its hydrosol extract while evaluating their antioxidant and antimicrobial effects in vitro. Materials and Methods: The essential oil was obtained by hydrodistillation, while the hydrosol extract was obtained by the liquid-liquid extraction method. The volatile compounds of the essential oil and hydrosol extract were analysed by gas chromatography (GC/FID) and gas chromatography coupled with mass spectrometry (GC/MS). Antioxidant activities were evaluated using two methods: free radical scavenging activity (DPPH) and iron reduction antioxidant power (FRAP), with BHT used as a positive control. The antimicrobial activity of the essential oil and hydrosol extract was evaluated using the agar disc diffusion method. Results: According to the GC/FID and GC/MS analysis, the essential oil of S. argentea consisted mainly of germacrene D-4-ol (26.3%), epi-α-muurolol (19.2%), and epi-α-cadinol (10.2%). In contrast, the hydrosol extract consisted of oxygenated compounds, including (E)- phytol (23.5%), 14-hydroxy-δ-cadine (17.5%), caryophyllene oxide (11.5%), piperitone (13.5%), and piperitone oxide (11.5%). The essential oil and hydrosol extract showed positive antioxidant activity with both tests. It should be noted that the hydrosol extract showed the best performance, with an IC50 of 8.3 g/L with the DPPH and an IC50 of 12.3 g/L with the FRAP test compared to the BHT. The essential oil revealed antimicrobial activity with strong inhibition against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus subtilis compared to Gentamicin. Conclusion: The results showed that essential oil and hydrosol extract have promising antimicrobial and antioxidant properties. These findings provide encouraging prospects for their potential use in the pharmaceutical or cosmetic sectors.

This study was initiated to evaluate the chemical composition and in vitro antimicrobial activity of essential oils from four Cameroonian spices and to determine the therapeutic effect of a cream based on essential oil from Aframomum citratum. Essential oils were extracted from seeds by hydrodistillation and analyzed by gas chromatography coupled with mass spectrometry (GC/MS). The broth microdilution method was used for the minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) determinations. The therapeutic effect of a cosmetic cream based on essential oil from A. citratum seed (1.25, 2.5 and 5% w/w) was evaluated against dermatosis induced with a Methicillin-Resistant Staphylococcus aureus (MRSA) in rats. The main identified compounds in the essential oils are geraniol for A. citratum; eucalyptol, α-terpineol and geraniol for Aframomum daniellii; β-pinene, germacrene D, trans-β-caryophyllene, α-pinene, naphthalene and sabinene for Piper capense; α-phellandrene, germacradienol and δ-cadinene for Monodora myristica. Essential oil of A. citratum (MIC = 8-4096 µg/ml) was the most active against bacteria and fungi, following in decreasing order by those of A. daniellii, P. capense and M. myristica. The antibacterial activity of the essential oil of A. citratum against MRSA and Escherichia coli S2(1) (MIC = 8 µg/ml) was higher than that of amoxicillin used as reference drug (MIC = 128- 256 µg/ml). The combination of essential oils of A. citratum and A. daniellii (1:1) displayed a synergistic effect. The cream based on essential oil of A. citratum (5%) and Baneocin (reference drug) eradicated the dermatosis induced with MRSA in rat after two weeks of treatment. These results indicate that the tested essential oils possess antimicrobial activities which could be a function of either the individual or the additive effects of the identified phytoconstituents. Key words: Spices, hydrodistillation, essential oils, gas chromatography/mass spectrometry (GC/MS), antibacterial, antifungal, synergistic effect.

Essential oils (EOs) are chemical products produced by odoriferous glands from a variety of plants. These essential oils have many health benefits: antiseptic, anti-inflammatory and antimicrobial activities. So due to these medicinal properties, the present study was designed to analyze essential oils of Thymus zygis L. and Thymus willdenowii Boiss. for their chemical composition and biological activities. These two thyme species were collected from the region of Ifrane, Middle Atlas of Morocco. The EO was obtained by hydrodistillation, and the yields were 5.25% for T. zygis and 3.00% for T. willdenowii. The chemical composition of the EOs was analyzed by gas chromatography coupled with mass spectrometry (GC-MS), and the results showed that T. zygis EO is dominated by carvacrol (52.5%), o-cymene (23.14%), and thymol (9.68%), while the EO of T. willdenowii contains germacrene D (16.51%), carvacrol (16.19%), and geranyl acetate (8.35%) as major compounds. The antioxidant activity assessed by Diphenylpicrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays revealed that both EOs have excellent antioxidant activities; by DPPH it resulted in IC50 = 6.13 ± 0.11 for T. zygis and 6.78 ± 0.3 µg/mL for T. willdenowii, while the one by FRAP yielded EC50 = 2.46 ± 0.01 (T. zygis) and 5.17 ± 0.2 (T. willdenowii) µg/mL. The antimicrobial activity of the two essential oils was evaluated against six bacterial strains and five fungal strains by the disk diffusion method to determine the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and Minimum Fungicidal Concentration (MFC). The EOs revealed variable antimicrobial activities against the different tested microbial strains and showed strong antimicrobial activities, even against strains known as multi-resistant to antibiotics (Acinetobacter baumannii) at low concentrations (2 µL/mL). T. zygis EO showed the most powerful activity against all the studied bacteria, while that of T. willdenowii recorded moderate activity when tested against Shigella dysenteriae and Salmonella Typhi. With inhibition diameters that vary between 75 mm and 84 mm for concentrations of 2 µL/mL up to 12 µL/mL, S. aureus was shown to be the most sensitive to T. zygis EO. For the antifungal activity test, T. zygis EO showed the best inhibition diameters compared to T. willdenowii EO. These results showed that T. zygis EO has more powerful antioxidant and antimicrobial activities than T. willdenowii EO, therefore, we deduce that thyme EOs are excellent antioxidants, they have strong antimicrobial properties, and may in the future represent new sources of natural antiseptics that can be used in pharmaceutical and food industry.

Baccharis vulneraria Baker is used popularly for the treatment of skin infections. So, this study aimed investigate the antimicrobial activity and chemical characterization of the essential oil (EO) against microorganisms that cause cutaneous infections. The EO was analyzed by GC-MS. The antimicrobial test was performed using the serial microdilution method, and the antimicrobial activity was determined by the minimum inhibitory concentration against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Trichophyton interdigitale, Trichophyton rubrum, Fusarium solani and Fusarium oxysporum within the 32-0.0625 mg/mL concentration range. Were identified 31 EO compounds. Its major compounds are bicyclogermacrene, trans-cadin-1,4-diene, β-caryophyllene, and germacrene A. EO showed antifungal action against T. rubrum and T. interdigitale (2 and 4 mg/mL MIC, respectively). The growth of C. albicans, at 4 mg/mL, decreased by 50% compared to control. The oil had no significant potential for other microorganisms at the selected concentrations.

The essential oil (EO) of plants of the Poaceae family has diverse chemical constituents with several biological properties. But, data on the chemical constituents and toxicity are still unavailable for some species belonging to this family, such as Euclasta condylotricha Steud (Eu. condylotricha). In this study, the chemical composition of the EOs of Eu. condylotricha flowers was evaluated by gas chromatography coupled with mass spectrometry (GC-MS). The EOs larvicidal property was assessed against third instar larvae of three Anopheles gambiae laboratory strains (Kisumu, Acerkis and Kiskdr) according to the WHO standard protocol. The percentage yields of the EOs obtained from hydro distillation of Eu. condylotricha flowers varied 0.070 to 0.097%. Gas Chromatography-Mass Spectrometry (GC-MS) applied to the EOs revealed fifty-five (55) chemical constituents, representing 94.95% to 97.78% of the total essential oils. Although different chemical profiles of the dominant terpenes were observed for each sample, EOs were generally dominated by sesquiterpenoids with juvenile hormones as the major compounds. The primary compounds were juvenile hormone C16 (JH III) (35.97-48.72%), Methyl farnesoate 10,11-diol (18.56-28.73%), tau-Cadinol (18.54%), and β-Eudesmene (12.75-13.46%). Eu. condylotricha EOs showed a strong larvicidal activity with LC50 values ranging from 35.21 to 52.34 ppm after 24 hours of exposition. This study showed that Eu. Condylotricha flowers essential oils are potent sources of juvenile hormones that could be a promising tool for developing an eco-friendly malaria vector control strategy.

This study was carried out to determine the antimicrobial activity of essential oil derived from leaves of eucalyptus (Eucalyptus globulus) against Phytophthora colocasiae, the causal agent of taro leaf blight (TLB). Essential oil was obtained by Clevenger-type water distillation. The major compounds in this essential oil were identified using gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC/MS). Antimicrobial activity of the essential oil was tested in vitro against mycelial growth, sporangia and zoospores germination of P. colocasiae. Additionally, in situ tests were conducted on detached healthy taro leaves discs and evaluating necrosis symptoms of TLB were assessed. Results of the chemical composition of the essential oil analysis showed that, 1.8-cineole (26.4 %), α-pinene (14.1 %) and p-cymene (10.2 %) are the most abundant compounds. In addition, four components could be identified in noticeable amounts (18.1 % in the total): regulator G1/G2 and its derivatives as well as flavesone, a regulator G3 derivative. G is a generic term for a family of 2,3-dioxabicyclo[4,4,0] decane system growth regulators. Here, G-regulators and derivatives are described for the first time in E. globulus. Antimicrobial activity of the essential oil was recorded with total inhibition of mycelia growth and sporangia germination at 0.625 mg/ml, while the complete inhibition of zoospores germination was recorded at 0.156 mg/ml. In situ results showed that essential oil completely inhibited the appearance of disease symptoms, necrosis development and sporulation at 3.5 mg/ml. These results demonstrated that, the essential oil of Eucalyptus globulus has high ability to inhibit the development of P. colocasiae, and might be used for controlling TLB.

In order to search for new chemotypes and to carry out a comparative study with the literature, the current study investigated the chemical composition of the essential oil of the flowers of Daucus carota (L.) ssp. carota using gas chromatography coupled with mass spectrometry (GC-MS). Moreover, the antimicrobial and insecticidal potentials of essential oil were studied. Hydrodistillation was used to extract the essential oil. Due to the immiscibility of essential oils in water and, therefore, in the culture medium, emulsification was carried out using a 0.2 % agar solution to promote germ/composite contact. Fumigation with the oil phase of the essential oil was carried out in airtight and transparent plastic boxes, with a capacity of 1 L as an exposure chamber to test the lightness of essential oils against adults of Sitophilus oryzae (L.). In each box, five Petri dishes were placed. Each replicate consisted of five adults of S.oryzae (L.). The essential oils were spread on Wathman filter paper and placed inside the exposure chamber. Mortality control was carried out by counting insect deaths from the first day of treatment until the death of all individuals. α-Pinene (22.2 %) was the major compound in the essential oil of the oil phase of D.carota (L.) ssp. carota followed by β-asarone (15.1 %), sabinene (12.4 %), and α-himachalene (10.1 %), as well as the crystallized phase containing β-asarone. In terms of antimicrobial activity, the essential oils showed significant inhibition of the six bacteria and seven molds studied at a concentration of 0.45 mg/mL. The essential oils were found to be highly effective against S.oryzae (L.). This approach can help reduce the amount of synthetic antibiotics applied and, therefore, decrease the negative impact of artificial agents, such as residues, resistance, and environmental pollution.

The essential oils (EOs) of Rosmarinus officinalis (Ro) are from two cities located in the eastern region of Morocco (Taourirt and Jerrada) were extracted using the steam distillation method in two cooperatives, namely "Belahssan" and "Beni Yaala Zkara", respectively. The chemical composition was determined by gas chromatography coupled with mass spectrometry (GC/MS), in which 1,8-cineole (53.6%), α-pinene (12.3%), and camphor (9.6%) represented the major compounds for essential oil of Rosmarinus officinalis from Taourirt (RoEOT). While, 1,8-cineole (42.3%), α-pinene (11.6%), and camphor (10.5%) were predominant in that of Jerada Rosmarinus officinalis (RoEOJ). The antioxidant activity of the two essential oils was assessed using, the free radical scavenging activity against the DPPH•, the ferric reducing power assay (FRAP), and the β-carotene bleaching technique.

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.

Los aceites esenciales (AE) de las hojas de Mangifera indica L. recolectadas en los estados Mérida (M), Barinas (B) y Portuguesa (P), Venezuela, fueron obtenidos por el método de hidrodestilación, utilizando la trampa de Clevenger, obteniéndose 0,1 mL (0,0025%), 1,4 mL (0,035%) y 1,0 mL (0,025%), respectivamente. Los AE se caracterizaron por el método de cromatografía de gases acoplado a espectrometría de masas (CG/EM), se identificaron 30 compuestos en la muestra recolectada en M, 24 en B y 14 en P, siendo los mayoritarios en M: β-selineno (22,56%), α-gurjuneno (14,66%), β-cariofileno (10,40%), en B: β-cariofileno (36,32%), α-humuleno (22,71%), α-gurjuneno (21,43%) y en P: β-cariofileno (36,07%), α-gurjuneno (22,55%) y α-humuleno (21,24%). Debido al rendimiento, solo se determinó la actividad antibacteriana en los AE de B y P, por el método de difusión en agar con discos, frente a bacterias de referencia internacional (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 23357 y Pseudomonas aureginosa ATCC 27853). Ambos AE inhibieron el desarrollo de S. aureus y E. faecalis con una concentración inhibitoria mínima de 200 µL/mL y 300 µL/mL, respectivamente. Este es el primer estudio comparativo y actividad antibacteriana del aceite esencial obtenido de las hojas de M. indica L. de tres regiones de Venezuela.

Gas chromatography coupled with mass spectrometry (GC/MS), using both electron impact (EI) and chemical ionization (CI) detection modes on apolar and polar stationary phases, led to the determination of the volatile composition of the essential oil obtained from tubers of Cyperus rotundus (Cyperaceae). In this study, more than 33 compounds were identified and then compared with the results obtained in our previous work. Cyperene, alpha-cyperone, isolongifolen-5-one, rotundene, and cyperorotundene were the principal compounds comprising 62% of the oil. An in vitro cytotoxicity assay with MTT indicated that this oil was very effective against L1210 leukaemia cells line. This result correlates with significantly increased apoptotic DNA fragmentation. The oxidative effects of the essential oil were evaluated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH), xanthine/xanthine oxidase assays, and the scavenging of superoxide radical assay generated by photo-reduction of riboflavin. The antimutagenic activity of essential oil has been examined by following the inhibition of H(2)O(2) UV photolysis which induced strand-break formation in pBS plasmid DNA scission assay. Based on all these results, it is concluded that C. rotundus essential-oil composition established by GC/MS analysis, in EI- and CI-MS modes, presents a variety of a chemical composition we were not able to detect with only GC/MS analysis in our previous work. This essential oil exhibited antioxidant, cytotoxic, and apoptotic properties.