Chromatography-mass spectrometric study of the chemical composition of Myrtus communis L. leaf essential oil

Elettaria cardamomum (L.) Maton (Zingiberaceae), commonly known as green or true cardamom, is a commercially important species, the seeds of which are extensively used in the pharmaceutical, cosmetic and food industries. In spite of the increasing demand for cardamom essential oil in the international market, the chemical profiling of volatile compounds of different plant parts are not well explored. Though there are a few studies on the chemical characteristics of its leaf oil from other phytogeographical regions, the presence and chemical composition of essential oil from stems have not yet been reported. Therefore, the present study was undertaken to characterize the chemical composition and antioxidant activity of leaf and stem essential oil of E. cardamomum. The essential oil extracted by hydro-distillation from the leaf and stem revealed the presence of 43 and 37 compounds, representing 92.71 % and 92.12 % of total oil respectively by GC/MS analysis. The major constituents of the leaf essential oil were 1,8-cineole (20.66 %), camphene (18.09 %), camphor (10.02 %) and tricyclene (7.36 %); whereas α-terpinyl acetate (19.75 %), 1,8-cineole (10.38 %), caryophyllene oxide (7.13 %) and β-eudesmol (4.85 %) were rich in the stem essential oil. Oxygenated monoterpenes were the major terpenic fraction in the leaf and stem essential oil of E. cardamomum. The free radical scavenging ability assessed by DPPH (2, 2-diphenyl-1-picrylhydrazyl) and ABTS (2, 2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) assay showed that leaf oil had better activities as compared to stem oil. The present findings demonstrated that E. cardamomum growing wild in Eastern India could be considered as an important bioresource and natural antioxidant.

Cinnamomum verum is widely used in traditional medicines, and the different parts of the plant, such as bark, leaves, and flowers, are used for essential oil production. The present study compared the chemical composition of the essential oil of C. verum extracted from the leaves and flowers. In addition, efficacy of these essential oils against the two common pests Sitophilus oryzae and Callosobruchus maculatus was also evaluated. The results indicated the presence of cinnamaldehyde, eugenol, caryophyllene, and linalool in these essential oils, however, at different concentrations. The leaf essential oil was found to be 10–20% more effective as a fumigant against both the pests. Likewise, the leaf essential oil found to repel these pests even at lower concentrations than that of flower essential oil of C. verum. Besides, these essential oils were also effective in controlling the growth of various gram positive and gram negative microbial pathogens and possibly a safeguard for human health. On contrary, both the essential oils were found to be safe for the application on grains, as indicated by their germination potentials. It was also observed that these essential oils do not cause any significant toxicity to guppy fishes, thus confirming their ecological safety for use as a biopesticide.

Psidium guajava L. (commonly known as guava) is a small tree belonging to the family Myrtaceae. It grows well in the tropical and subtropical regions of the world. It has been used in traditional medicine since a long time. The different parts of the plant like bark, leaves and fruit, is used to cure skin ailments, stomach ache, indigestion, anti-inflammatory, diabetes, hypertension, wounds, pain relief, cough, rheumatic pain and various other ailments. The chemical composition of the whole guava tree renders it the medicinal properties. The chemical composition of the essential oil extracted from the leaves of P. guajava, from North East India, was identified in this study. The leaves yielded 0.51 % (v/w) essential oil. Although there are many reports on the chemical composition of its leaf essential oil; there is no report available in the public domain of the chemical composition of Psidium guajava from North East India. Therefore, the leaves of the P. guajava collected from North East India were hydro-distilled and chemical compounds were identified using GC/MS. A total of 27 compounds were identified in the leaf essential oil. The major compounds were α-terpinyl acetate (23.57 %), trans-caryophyllene (17.65 %), nerolidol (12.16 %), α-cadinol (6.71 %), α-copaene (6.5 %) and minor compounds identified were α-humulene (3.92 %) and (-)-caryphyllene oxide (3.66 %).

Introduction. In the family Myrtaceae (Myrtaceae L.) there are more than 100 genera and more than 3000 representatives. Insufficiency of data on diagnostics of raw materials of common myrtle and closely related species is an actual problem of modern pharmacognosy. The aim of the present study is a comparative qualitative and quantitative analysis of essential oil components of leaves of common myrtle, closely related to Myrtle species – Eucalyptus twiggy of family Myrtaceae, as well as industrial samples of essential oils of Myrtle and Eucalyptus by gas chromatography-mass spectrometry. Material and methods. Leaves of common myrtle harvested in the Republic of Crimea (Russia) and Relizane province (Algeria) were used as objects of research. Also as objects of comparison were used leaves of eucalyptus twiggy, harvested in Abkhazia, and industrial samples of common myrtle and eucalyptus twiggy essential oils. Samples of essential oil were obtained from leaves of myrtle and eucalyptus. Essential oil samples were obtained from myrtle and eucalyptus leaves and the qualitative and quantitative composition of their components was determined by gas chromatography-mass spectrometry. Results and discussion. Essential oils samples of Myrtaceae representatives leaves are characterised by a high content of mono- and bicyclic monoterpenes, but they differ significantly in dominant components depending on the place of growth. In a sample of essential oil from the leaves of Crimean Myrtle, 1,8-cineol (eucalyptol) dominates, and in a sample from the leaves of Algerian Myrtle, α-pinene dominates. In the study, it was found that some identified components of the common myrtle essential oil, such as myrtenyl acetate, humulene, linalyl acetate, β-myrcene and their derivatives, were absent in the eucalyptus twiggy essential oil, which may serve as a diagnostic sign for Myrtus species. On the contrary, the presence of globulol and its derivatives in the component composition of essential oil was found only in samples of Eucalyptus viminalis L. species and are not determined in the common myrtle essential oil. Industrial samples of essential oils are characterised by the absence of such important components of Myrtle essential oil as α-pinene, globulol, myrtenyl acetate, geraniol, linalool, terpinen-4-ol, humulene and its derivatives. Conclusion. Species specificity of the common myrtle can be confirmed by gas chromatography-mass spectrometry on diagnostically significant components of the common myrtle essential oil, which are absent in the essential oil of the species closely related to myrtle – еucalyptus twig, which can be used in the preparation of the draft pharmacopoeial article on a new type of medicinal plant raw material – ‘Common myrtle leaves’.

Spoilage of agricultural produce due to the action of Aspergillus spp. pose significant challenges to farmers and importer/exporter of agricultural produce. Aflatoxins are toxin produced by fungi and they contaminate food threatening food safety. Studies have shown that essential oils are capable of inhibiting the growth of Aspergillus spp. This study determined the chemical composition of the essential oils of Bay leaf and Cinnamon using Gas Chromatography-Mass Spectroscopy (GC-MS) techniques and evaluated the in vitro effect of the oils against Aflatoxigenic fungi (Aspergillus flavus, Aspergillus niger and Aspergillus parasiticus). Food poisoning technique was used to determine the inhibitory effect of the oils with radial mycelia growth of each observed and measured 24 hourly. The result of GC-MS analyses revealed cinnamaldehyde (5.83%), 3-Methyl- Benzofuran (14.49%), 2,6,6,9-tetramethyl-Tricycloundec-9-ene (10.59%) and other bioactive constituents as abundant in the essential oil of Cinnamon. Additionally, Bay leaf essential oil recorded Eucalyptol (12.30%), Eugenol (4.15%), and 2-octyl-Cyclopropaneoctanal (9.16%) among other bioactive compounds. Antifungal result revealed that both oils were active against the studied microorganisms as they were able to completely inhibit the growth of A. niger. Cinnamon oil had 92.69 and 91.27% inhibition against A. flavus and A. parasiticus respectively at 72 hr of observation, while essential oil from Bay leaf recorded 23.50% and 76.50% inhibition for A. flavus and A. parasiticus after 72 hr. Results from this study have further confirmed the antimicrobial potentials of essential oils against the tested Aspergillus spp. and their potential use in the development of natural antifungal products.

The chemical composition of the essential oils from the leaves and fruit of Eucalyptus camaldulensis grown in Mersin, Turkey was analyzed using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) techniques. The biological activities (antibacterial and antifungal) were examined using the agar well diffusion method. The main leaf oil constituents were p-cymene (42.1%), eucalyptol (1,8-cineole) (14.1%), α-pinene (12.7%) and α-terpinol (10.7%). The main constituents of the fruit oil were eucalyptol (1,8-cineole) (34.5%), p-cymene (30.0%), α-terpinol (15.1%) and α-pinene (9.0%). Our results showed that both types of oils are rich in terms of monoterpene hydrocarbons and oxygenated monoterpenes. The leaf and fruit essential oils of E. camaldulensis significantly inhibited the growth of Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Streptococcus sp.) bacteria (p<0.05). The oils also showed fungicidal activity against Candida tropicalis and C. globrata. Leaf essential oils showed more activity than fruit essential oils, probably due to the higher p-cymene concentration in leaves.

The present study aimed to analyze the chemical composition and fumigant toxicity of essential oils (EOs) isolated by hydrodistillation from Piper hancei Maxim. EOs extracted from the dry stems and leaves of P. hancei were analyzed by gas chromatography-mass spectrometry (GC-MS). The main compositions of the EOs were humulene (13.624 %), caryophyllene (13.319 %), nerolidol (12.507 %), naphthalene (8.525 %), ledol (6.694 %), caryophyllene oxide (6.404 %), and junenol (6.350 %). The fumigant toxicity of the EOs was tested in 7-14 day old adults of Tribolium castaneum. The LC50 of EOs and individual main compositions were calculated according to the mortality of insects at concentrations of 0, 16, 32, 64, 128, and 256 (μL/L air). The results showed that the EOs (LC50=322.52 (48 h) and 145.82 (72 h) (μL/L air)), caryophyllene (LC50=37.95 (48 h) and 26.53 (72 h) (μL/L air)), junenol (LC50=38.32 (48 h) and 20.33 (72 h) (μL/L air)), caryophyllene oxide (LC50=97.72 (48 h) and 65.22 (72 h) (μL/L air)), and humulene (LC50=104.50 (48 h) and 73.66 (72 h) (μL/L air)) have obvious fumigant activities against T. castaneum adults. The chemical composition of EOs from P. hancei was reported for the first time. The results indicated that the EOs of P. hancei had the potential to be developed as a natural insecticide for the control of T. castaneum adults.

This study aimed to investigate the seasonal variation in the chemical composition and antimicrobial activity of Achillea fragrantissima essential oil (EO). EO was collected at 10 days intervals, from May to July 2014, for a total of seven harvests. The EO was extracted from aerial parts by hydro-distillation for 3 hours. The antimicrobial activity was evaluated by well diffusion method against three bacterial species (Escherichia coli, Staphylococcus aureus and Bacillus subtilis and two fungal species (Candida albicans and Aspergillus niger). The chemical composition of EO was performed by gas chromatography-mass spectrometry (GC-MS). The activity of the essential oils against the tested bacteria and fungi varied depending on harvesting time of A. fragrantissima. In general, the highest activity of A. fragrantissima essential oils was against Gram-positive bacteria at T6 (the end of June). The chemical constituents of EO showed quantitative and qualitative variation of several specific chemical compounds, the ratio of identified compounds range between 92.29 and 95.88%, the major fluctuations in the composition of EO also revealed the presence of trans-sabinyl acetate (0.75-10.20%), α-terpineol (3.53-9.39%), trans-Menth-2-en-1-ol (6.5-13.34%), and β-thujone (11.34-22.11). In this study, the antimicrobial activity and the chemical composition of the EO extracted from A. fragrantissima were affected significantly by the time of collection. T6 period would be the best time to harvest A. fragrantissima plants to obtain EO with the highest antimicrobial activity. The chemical difference noted among seasons may explain the different in antimicrobial activity.

The strawberry guava (Psidium cattleianum Sabine) is a fruit species native from South-Southeast Brazil whose leaf essential oil has potential for commercial uses due to its bioactive properties. However, little is known about the influence of the geographical distribution in small scale on P. cattleianum essential oil chemical composition and yield. The present work aimed to evaluate the yield and chemical composition of the leaf essential oil of P. cattleianum populations in the region of Caxias do Sul, South Brazil. Samples of twelve populations were collected and the essential oil was extracted by hydrodistillation. The chemical composition of the essential oils was determined by GC/MS and GC-FID. The results showed a high variability of essential oil yield, which ranged between 0.08 and 0.75% v/w. Regarding the chemical profiles, nine populations presented the 1,8-cineole chemotype, the β-caryophyllene chemotype was observed in two of them, and in one population there were four major compounds. Both hierarchical cluster and principal component analyses showed differences in essential oil composition in populations geographically close, indicating the existence of an important genetic variability in populations of the same geographical area.

:Myrtus communis L.is one of the most important aromatic and medicinal plants that used in the food, pharmaceutical and cosmetic industries. The effect of six drying methods (shade, Oven 40oC Oven 60oC, Microwave 700 W, Vibro-spouted bed (VSB) 40oC) on yield and chemical composition of essential oil of M. communis leaves was investigated. The oils from fresh and dried leaves were isolated using hydrodistillation in a Clevenger apparatus and analyzed by gas chromatography-mass spectrometry (GC-MS).The highest essential oil yields were obtained by shade (1.87 %) followed by VSB 40oC (1.63 %), oven 40oC (1.35 %),VSB 60oC (1.23 %), microwave (1.05 %), oven 60oC (0.81 %) and fresh (0.47 %). Increasing the drying temperature significantly reduced the essential oil content of in VSB and oven methods. Forty-one components were identified in the oils of M. communis. The major constituents of the essential oil, α-pinene (7.04–31.29 %), dl-limonen (14.98–21.58 %), and linalool (1.72–15.47 %), showed considerable variation regarding drying techniques. Tricyclene, as a new component, was only identified in VSB procedure (7.02 % and 8.07 %). β-fenchylalcohol also found in VSB 60oC. Furthermore, in the microwave technique 3-cyclohexene-1-methanol (17.31 %) was found, while this component was not present in the other treatments. Therefore, these results showed yield and chemical composition of the essential oil from M. communis varied according to drying methods. Shade and VSB techniques could be considered as the two best drying techniques in term of essential oil yield and bioactive compounds contents. Moreover, VSB drying is desirable because of time saving.

The composition of essential oils extracted from leaves and flowers of five selected cultivars of myrtle (Myrtus communis L.) growing in the same orchard was determined by GC/MS at the full bloom time. Yields of essential oil by hydrodistillation ranged from 1.2 to 3.2 g·kg−1 of leaf fresh weight, while flower essential oil yield was comprised between 1.2 and 4.4 g·kg−1. Fifty-one compounds were identified with a percentage of corresponding peak ranging from 94.3 to 99.8% of the total. The main components of the essential oils were 1,8-cineole, linalool, and α-terpineol. Dihydroeugenyl-butanoate was the main component of the flower oil of the ‘Daniela' cultivar with a rate of 19.45%, while in the ‘Barbara' flower oil reached the 21.24%. This compound was not previously detected in the essential oils of myrtle, as well as the dihydroeugenyl-pentanoate, which ranged from 1.40 to 6.82% when detected. Other main compounds of the essential oils were α-pinene, limonene, bornyl-acetate, eugenol, geranyl-acetate, and methyl-eugenol.

In this study, (Myrtus communis L.) was explored in vitro and in vivo for controlling blight disease using two chickpea genotypes ILC 3279, INRA 199 and a local cultivar Bouazza. Blight caused by Ascochyta rabiei Pass. Lab. is major disease affecting chickpea production. To control this disease, chemical harmful fungicides are used hence, developing natural plant protection products as an alternative has become important regarding the environmental impact. The effect of essential oil (EO) extracted from myrtle leaves by hydrodistillation was evaluated on the growth of Ascochyta rabiei Pass. Lab. mycelium, by dilution method using chickpea culture medium added with 0, 200, 300, 500 and 1000 ppm. The radial growth of A. rabiei Pass.Lab. was inhibited at 40.9, 68.18 and 96.69% with 200, 300 and 500 ppm respectively. Myrtle essential oil used at 1000 ppm inhibited the fungus growth completely (100%). In vitro EO efficacy was investigated using detached leaflets method inoculated with 5 µl pathogen spore solution of 106 spores / ml concentration. Efficacy was investigated using 750 ppm EO solution. Disease (DS) Severity and disease incidence (DI) on detached leaflets were determined. Highest disease incidence was observed on Bouazza (100%) followed by ILC 3279 (84.28%) and INRA 199 (17.5%). Myrtle essential oil showed an efficacy in all cases and decreased significantly disease incidence for Bouazza, ILC 3279 and INRA 199 to 63.33, 56.66 and 16% respectively. Disease severity showed the same profile, Bouazza noted the highest rate followed by ILC 3279 and INRA 199 with 60, 40 and 21% respectively and EO showed a significant efficacy and reduced these disease severity rates to 52 32 and 18 %. The bioassay conducted in vivo under greenhouse conditions with plants including a negative control with any treatment and two other batches inoculated by hand held sprayer, a spore solution with a concentration of 106 spores/ ml and treated or not with myrtle EO. Disease incidence percentage (DIP) decreased significantly under common myrtle EO compared to control in INRA 199 and ILC 3279 for severity percent index (SPI) no significant difference was observed for all genotypes under Myrtus communis L. essential oil treatment effect. This study showed Myrtus communis L. essential oil efficacy on chickpea blight disease in vitro on fungal radial growth and in vivo either on deatached leaflets or whole plants under greenhouse condition. This natural product reduced significantly blight disease incidence and severity. And to control disease, myrtle essential oil extraction as fungicide is a promising alternative against this disease.

Nosocomial pathogens are associated with increased hospital stay lengths and mortality rates. Increasing resistance to antibiotics makes the treatment of these infections more difficult. Novel antimicrobial compounds derived from natural sources may be useful for addressing antiobiotic resistance. The objective of this study is to determine the chemical composition and antimicrobial activities of essential oils from Myrtus communis L. (Myrtaceae) leaves against pathogens causing nosocomial infections. The chemical composition of essential oil from M. communis leaves was analysed by gas chromatography-mass spectrometry (GC-MS). The antimicrobial activity of the essential oil against bacteria and fungi was evaluated by broth micro-dilution as per the Clinical and Laboratory Standards Institute (CLSI) methods. GC-MS analysis revealed that the major constituents of the essential oil were α-pinene (39.2 %), 1,8-cineole (22.0 %), and linalool (18.4 %). The essential oil exhibited antimicrobial activity against all Gram positive and Gram nega- tive bacteria with MICs in the range of 0.5-32 µL/mL and 8-64 µL/mL, respectively. MICs for the tested clinical and standard fungi were in the range of 0.03-16 µL/mL. The essential oil exhibited strong antibacte- rial and antifungal activities against all the causative agents of nosocomial infections examined, particularly against strains with antibiotic resistance. The essential oil from M. communis leaves is a potential source of novel antimicrobial agents for the treatment of nosocomial infections.

We have previously studied the chemical composition of essential oil (EO) from seeds of Anethum graveolens from Xinjiang Autonomous District in the PRC [1]. The component composition of essential oils is known to depend on the habitat. It seemed interesting to compare the composition and biological activity of EO from dill seeds growing in China and Uzbekistan. We used GC—MS to establish the structures of the isolated compounds. EO from seeds of A. graveolens (2007 harvest) that were collected in Tashkent Oblast was isolated by steam distillation in 4.2% yield. The chemical composition of the EO was studied using a Perkin—Elmer Turbo GC—MS. The component content of the oil was calculated using areas of GC peaks of total ion current without correlation coefficients. EO components were identified by comparing retention times and mass spectra of the component obtained in mass scanning mode and by using mass-spectral library data for standard oil components and pure compounds. A total of 22 chemical compounds was identified in EO of A. graveolens seeds growing in Uzbekistan. Table 1 lists the chemical composition of the EO. The principal EO components from dill seed growing in Uzbekistan were carvone (73.61%), limonene (14.69), cis-dihydrocarvone (5.87), diplaniol (1-allyl-2,5-dimethoxy-3,4-methylenedioxybenzene) (2.16), and 1,2-diethoxyethane (1.43%), which together made up 99.2% of the total EO component composition. The principal components of EO from dill seed growing in China were n-pentacosane (27.96%), dioctylester of 1,2-phenyldicarboxylic acid (25.10), octacosane (13.81), tricosane (9.14), and n-nonacosane (6.85%) [1]. A comparison of our data with that obtained earlier indicated that both the qualitative and quantitative composition of the principal EO components of A. graveolens growing in different geographic zones differed considerably. The high content in the studied EO of carvone, which is widely used as a growth inhibitor of bacteria [2-4] and certain fungi [5] and as a repellent [6] is noteworthy. Both S-(+)-carvone and R-(-)-carvone are used in the food industry to produce flavors [4] and in agriculture. For example, S-(+)-carvone is used in the Netherlands to prevent premature sprouting of potato tubers and tulip bulbs during storage [7, 8]. Carvone is an available and inexpensive reagent for organic synthesis in both enantiomeric forms. This makes it attractive for asymmetric synthesis of natural compounds [9]. Antimicrobial activity of EO fractions toward Candida albican and Staphylococcus aureus was estimated using the Barry method to determine the minimal inhibiting concentration (MIC) [10]. Growth of microorganisms decreased markedly upon addition of EO to nutrient medium. The experimental results are given below:

ABSTRACTAs a medicinal and industrial plant, Myrtle (Myrtus communis L., Myrtaceae) is widely used in pharmacological, food, and cosmetic industries. In the current study, variabilities in the leaf essential oil (EO) compositions of 23 Myrtle populations, collected from the natural habitats of different regions in Fars Province, Iran, were studied. The EO yields of the populations varied from 0.53% to 1.75% based on dry matter. According to GC/MS analysis, α-pinene (12.2–60.4%), 1,8-cineole (6.2–27.3%), limonene (1.4–26.7%), linalool (0.7–21.0%), myrtenyl acetate (0–29.1%), and geraniol (0.3–8.3%) were the major compounds. Using the hierarchical cluster analysis, the myrtle populations in Fars province were classified into four groups based on the main EO components, namely I α-pinene/1,8-cineole, II α-pinene/1,8-cineole/linalool, III α-pinene/limonene/1,8-cineole and IV myrtenyl acetate/limonene/linalool. In conclusion, this study gave new insights into the breeding programs for obtaining potential plant materials through their commercial cultivations.