Phytochemical Characterization of Humulus lupulus L. Varieties Cultivated in Brazil: Agricultural Zoning for the Crop in Tropical Areas

This work was carried out in order to valorize a medicinal and aromatic plant of Tunisia: Mentha aquatica. Mentha aquatica dried leaves were submitted to hydrodistillation in a Clevenger apparatus. Their essential oil (EO) composition was analysed by gas chromatography coupled to mass spectrometry (GC-MS). The antioxidant activity of Mentha aquatica Essential oil was evaluated by DPPH free radical -scavenging method. We tested also its biological activity against some microorgnisms : Escherichia Coli ATCC 25922, Staphylococcus aureus ATCC 29213 and Bacillus and also a fungi : candida. Results showed that the most abundant volatile compound of M. aquatica Essential oil was pulegone with a percentage of 39.36 %. It was followed by menthone accounting for 27.69 % of total volatile compounds. Furthermore, oxygenated monoterpenes accounting for 91.4 % of total volatiles constituted the prominent chemical class of this volatile oil. Respective amounts of hydrocarbon monoterpenes and sesquiterpenes were of 3.51 and 5.06 %. The half maximal inhibitory concentration (IC50) of the M. aquatica Essential oil was similar to that of trolox (8 μg /ml ) which is a synthetic molecule with a high antioxidant activity used as a blanck, The antibacterial assay showed that M. aquatia Essential oil was active against Staphylococcus ATCC, E. coli and Bacillus but it doesn’t show an inhibitory effect against Candida.


 ABSTRACT. The chemical composition of hydro-distilled essential oil of dried roots of Anaphalis contorta Hook F. was analyzed for the first time by using gas chromatography equipped with flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). The compounds of essential oil were identified according to their mass spectra and their relative retention indices determined on a capillary GC column (non-polar stationary phase). Twenty-seven compounds were identified representing 94.8% of the total oil. The major constituents were 2,2-dimethyl-2[2,4,6-trimethylphenyl] acetic acid (12.1%), labda-8,14-dien-13-ol (8.4%), δ-cadinene (8.1%), labda-7,14-dien-13-ol (6.9%), α-gurjunene (6.7%), viridiflorene (5.1%), and caryophyllene oxide (4.9%). The root essential oil of A. contorta produced different chemotypes.
 
 KEY WORDS: Anaphalis contorta Hook F., Essential oil composition, 2,2-Dimethyl-2[2,4,6-trimethylphenyl] acetic acid. labda-8,14-dien-13-ol, GC/MS
 Bull. Chem. Soc. Ethiop. 2022, 36(1), 235-240. 
 DOI: https://dx.doi.org/10.4314/bcse.v36i1.19 

In this study, we determined the antimicrobial activity of ten essential oils (EOs)—oregano, thyme, clove, arborvitae, cassia, lemongrass, melaleuca, eucalyptus, lavender, and clary sage—against drug-resistant microorganisms previously isolated from patients with skin infections. The essential oil compositions were determined using gas chromatography coupled to mass spectrometry (GC/MS). The assayed bacteria included Pseudomonas aeruginosa, Proteus vulgaris, Citrobacter koseri, and Klebsiella pneumoniae. Two drug-resistant yeasts (Candidaalbicans and Candida parapsilosis) were also involved in our survey. Oregano, thyme, cassia, lemongrass and arborvitae showed very strong antibacterial and antifungal activity against all tested strains. These results show that these essential oils may be effective in preventing the growth of the drug-resistant microorganisms responsible for wound infections. In this study, the genotoxic effects of tested essential oils on healthy human keratinocytes HaCaT were evaluated using the comet assay for the first time. These results revealed that none of the essential oils induced significant DNA damage in vitro after 24 h. Moreover, the treatment of HaCaT cells with essential oils increased the total antioxidant status (TAS) level. The obtained results indicate that EOs could be used as a potential source of safe and potent natural antimicrobial and antioxidant agents in the pharmaceutical and food industries.

The purpose of this study was to compare the yield, chemical composition, antimicrobial and antioxidant properties of essential oils isolated from leaves of Laurus nobilis L. by two different distillation methods. The essential oils isolated by hydrodistillation (HD) and steam distillation (SD) were analyzed by gas chromatography coupled to mass spectrometry (GC-MS) and gas chromatography with flame ionization detector (GC-FID). Hydrodistillation produced a yield of 0.95 ± 0.06% which is slightly higher than yield obtained by steam distillation 0.79 ± 0.07%. Seventy three compounds in the bay leaves oil obtained by steam distillation were identified while in essential oil obtained by hydrodistillation were identified only 54 compounds. The antioxidant activity was evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical method. Antimicrobial activity of obtained essential oils was evaluated by disc diffusion method in comparison with several chosen antimicrobials. The antimicrobial activity was tested on five microorganisms - Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa and Candida albicans. In general, oils produced by steam distillation had higher antimicrobial and antioxidant activities than hydrodistillation extracts. It seems that hydrodistillation is better for higher yield while steam distillation is better to use for more quality oils with stronger biological properties.

In infectiology, some essential oils (EOs) are able to competewith antibiotic therapy and even surpass it; it is in this context that a study of the chemical composition and the antibacterial power of the EOs of three aromatic and widely used medicinal plants in traditional medicine was conducted which are Satureja calamintha subsp. nepeta (L.) Briq, Lavandula multifida L., and Mentha pulegium L. The extracted EO yields were of the order of 2.6%, 0.12%, and 5.29% for Satureja calamintha, Lavandula multifida, and Mentha pulegium, respectively. The obtained EOs were analyzed by gas chromatography coupled with mass spectrometry (GC/MS). The results of these analyses showed that Lavandula multifida contains carvacrol as a majority compound (70.65%); by contrast, the pulegone is the majority compound of Satureja calamintha and Mentha pulegium that contain about 87.04% and 71.97%, respectively. The EOs with the pulegone as predominant compound (Mentha pulegium and Satureja calamintha) showed higher antibacterial activity when tested against some multiresistant strains, compared to those with the carvacrol as major compound. In conclusion, this study may open up prospects for the formulation of phytomedicines against resistant and nonresistant bacteria incriminated in nosocomial infections.

Essential oils (EOs) are mixtures of aromatic and volatile compounds. Owing to their biological properties, they are of increasing interest in the food industry as a viable alternative to natural additives. The objective of this study was to evaluate the in vitro biological activity of EOs extracted from eight plant species growing in northeastern Peru in relation to their chemical composition. EOs were extracted by hydrodistillation and evaluated for antibacterial activity, antioxidant capacity, and total phenolic content. Chemical characterization was performed by gas chromatography coupled with mass spectrometry (GC-MS), and the extraction yield was evaluated in two seasons of the year. The extraction yields varied from 0.04 to 1.50%, according to the species, with greater seasonal variation observed during the rainy season. The chemical compounds identified included monoterpene and sesquiterpene hydrocarbons, oxygenated monoterpenes and sesquiterpenes, benzene derivatives, fatty acids and derivatives, diterpenes, and phenylpropanoids. The EOs of Magnolia jaenensis, Piper amalago, Piper glabribaccum, and Tesaria integrifolia demonstrated high antibacterial activity against the Gram-positive pathogen Staphylococcus aureus, while the other EOs, such as Magnolia manguillo and Zanthoxylum fagara, showed intermediate activity. However, all EOs had low performance against the Gram-negative bacteria Escherichia coli and Salmonella enteritidis. The EOs from T. integrifolia, Piper aduncum, M. manguillo, M. jaenensis, and P. glabribaccum had high antioxidant activity. The EOs with the best biological performance were T. integrifolia, M. jaenensis, and P. glabribaccum.

The objective of this work is to study the chemical composition of Thymus leptobotrys Murb essential oil and its antimicrobial properties on ten bacteria and three yeasts. The essential oil is extracted by hydrodistillation and analyzed by gas chromatography coupled with mass spectrometry (GC/MS). The active substances are monoterpenic alcohols, mainly carvacrol (73.68%), and monoterpenic hydrocarbons: p-cymene (8.68%) and γ-terpinene (4.14%). The antibacterial and antifungal activity determined by disc diffusion method reveals an inhibitory effect of the essential oil on all studied strains, the potential for inhibition being greater than the reference antibiotics (Ciprofloxacin and Amoxicillin).

SUMMARY The present study aimed to identify and quantify the components of the essential oil of Zanthoxylum caribaeum and to evaluate the antimicrobial potential of different plant extracts and the essential oil of this plant against different serotypes of Salmonella enterica, which is of greater occurrence and isolated in the western region of Paraná, Brazil. The extraction of the essential oil was performed using Clevenger apparatus and the chemical composition was determined by Gas Chromatography coupled to Mass Spectrometry (GC-MS). The extracts were obtained through different solvents (ethanol, methanol, hexane, acetone, dichloromethane, ethyl acetate and distilled water). The antibacterial activity was carried out according to the broth microdilution technique. The GC-MS analysis resulted in the identification of 15 main components, all terpenes, representing 63.88% of the total essential oil. The major compounds identified were Germacrene-D (20.77%), a-Panasinsene (14.40 %) and b-Selinene (11.68 %). The essential oil presented antibacterial activity against 5 serotypes of Salmonella enterica, with MIC and MBC ranging from 7000 to 437 μg.mL-1. While MIC and MBC from the range from 200 to 25 mg.mL-1, being effective to most serotypes of S. enterica, with the exception of the aqueous extract. The results suggest that the essential oil and leaf extracts of Z. caribaeum represent an alternative for the control of S. enterica in the poultry sector, in this way reflecting a new perspective for studies with natural products.

Turmeric or curcuma (Curcuma longa L.) is a Zingiberaceae whose essential oil and coloring pigments obtained from the rhizome have been widely used in the food industry and medicine. This study aimed to extract and identify the chemical compounds found in C. longa essential oil from rhizomes collected in six different locations of Brazil. The oil extraction was carried out by hydrodistillation technique, using a Clevenger- type apparatus. The chemical constituents were identified by Gas Chromatography coupled to Mass Spectrometry (GC-MS). The principal component analysis (PCA) and the hierarchical cluster analysis (cluster)were done for the obtained data; and the composition of the studied accesses was verified. Three groups of chemotypes were obtained: group I was formed by the accesses of Campo Grande / Indígena-MS, Mara Rosa-GO, Campo Grande-MS and Perobal-PR, and had Ar-turmerone as its main compound; group II, formed by the access of Santa Tereza do Oeste-PR, presented α-costol and α-Phellandrene as the predominant compounds; and group III, the access of Holambra-SP, differed from the others regarding its essential oil chemical composition whose main agents were Curlone, Zingiberene, β-sesquiphellandrene, Humulene epoxide II, cis-α-trans-Bergamotol. The predominant chemical class in all accesses was hydrocarbon sesquiterpenes (Santa Tereza do Oeste-PR and Holambra-SP) and oxygenated sesquiterpenes (the others). This study evidenced the formation of three chemotypes

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.

Dataset for Hop varieties classification

Lippia origanoides Kunth. is a medicinal shrub native to some countries in South America, Central America and the Caribbean. This study aims to investigate the chemical composition of the essential oil and the genetic diversity of a natural population of Lippia origanoides in two seasons. Leaf samples were collected from 30 individuals in the dry and rainy seasons. The essential oil was extracted into a Clevenger apparatus and analyzed by gas chromatography coupled to mass spectrometry (GC-MS). The relative quantification of thymol and carvacrol was performed by gas chromatography coupled to a flame ionization detector (GC-FID). Multivariate analysis was used to evaluate the genetic divergence between plants. Carvacrol was the major compound found in most plants for both seasons. In the rainy season, plant 15 presented thymol as the major compound, and plants 16, 27, 28 and 29 presented camphor as the major compound. In the dry season, thymol remained the main compound of plant 15 and camphor remained the main compound of plants 16, 28 and 29; however, plant 27 presented carvacrol as the main compound in this season. After carvacrol, the compounds with the highest content were γ-terpinene, p-cymene and methyl-ether-thymol. Of the 30 plants studied, only five differed in their chemical composition, showing some degree of stability in relation to the dry and rainy seasons. There was no variation in the main compounds between the two seasons, but there was chemical diversity among the main compounds. Tocher grouping revealed five distinct groups, with group 1 including most of the plants in both dry and rainy seasons, indicating that the time of year evaluated did not significantly interfere with the essential oil composition of most plants.

The chemical composition of Gallesia integrifolia fruits essential oil was obtained by hydrodistillation using a modified Clevenger apparatus was investigated by gas chromatography coupled to mass spectrometry (GC/MS). In addition, the cytotoxicity activity against human tumor cell lines MCF-7 (breast adenocarcinoma), NCI-H460 (large cell lung carcinoma), HeLa (cervical carcinoma), and HepG2 (hepatocellular carcinoma), and non-tumor PLP2 (porcine liver primary cells) as well as the anti-inflammatory action was proposal. The compounds were predominantly organosulfates (2,8-dithianonane, dimethyl trisulfide, and lenthionine). Anti-inflammatory activity that provides 50% inhibition of nitric oxide production (55 µg/mL) of essential oil of the fruits. It also presents cytotoxic activity against MCF-7 (GI50 = 66 µg/mL), NCI-H-460 (GI50 = 147 µg/mL), HeLa (GI50 = 182 µg/mL) and HepG2 (GI50 = 240 µg/mL). The essential oil is more active in tumor cells than in non-tumor cells and the GI50 values for essential oil reported in our work support future studies.

Eugenia florida DC. belongs to the Myrtaceae family, which is present in almost all of Brazil. This species is popularly known as pitanga-preta or guamirim and is used in folk medicine to treat gastrointestinal problems. In this study, two specimens of Eugenia florida (Efl) were collected in different areas of the same region. Specimen A (EflA) was collected in an area of secondary forest (capoeira), while specimen B (EflB) was collected in a floodplain area. The essential oils (EOs) were extracted from both specimens of Eugenia florida by means of hydrodistillation. Gas chromatography coupled to mass spectrometry (GC/MS) was used to identify the volatile compounds present, and the antioxidant capacity of the EOs was determined by antioxidant capacity (AC-DPPH) and the Trolox equivalent antioxidant (TEAC) assay. For E. florida, limonene (11.98%), spathulenol (10.94%) and α-pinene (5.21%) were identified as the main compounds of the EO extracted from sample A, while sample B comprised selina-3,11-dien-6α-ol (12.03%), eremoligenol (11.0%) and γ-elemene (10.70%). This difference in chemical composition impacted the antioxidant activity of the EOs between the studied samples, especially in sample B of E. florida. This study is the first to report on the antioxidant activity of Eugenia florida DC. essential oils.

In this study, the essential oil composition of Thymus algeriensis genuinus from Algeria was characterised by gas chromatography with flame ionization detector (GC/FID) and confirmed by gas chromatography coupled to mass spectrometry (GC/MS). The combination of GC/FID and GC/MS has resulted in the identification of 48 compounds then classified into four classes: monoterpene hydrocarbons, oxygenated monoterpenes, sesquiterpene hydrocarbons and oxygenated sesquiterpenes. The essential oil obtained by hydrodistillation is characterized by a rich content of phenolic compounds such as thymol (71%) and carvacrol (4%) versus a minor presence of monoterperne hydrocarbons like p-cymene (3%) and γ-terpinene (0.5%). Furthermore, extraction kinetic study has revealed the effect of conservation period on oil yield and extraction rate especially during the first thirty minutes. As a consequence, we would argue that high moisture content in fresh plant material would produce a high oil yield in a reduced processing time and that reduced conservation period would prevent loss of volatiles before processing. Finally, the antimicrobial and antifungal activities were evaluated using the disc diffusion method. The extracted essential oil has presented a high inhibiting activity against eight bacterial strains up to 75 mm and two species of fungus up to 45 mm.