Essential oil from the leaves of Annona vepretorum: chemical composition and bioactivity

The essential oil from the leaves of Annona vepretorun was obtained by hydrodistillation using a Clevenger-type apparatus and analyzed by GC-MS and GC-FID. Eighteen compounds representing 98.1% of the crude essential oil were identified. The major compounds identified were bicyclogermacrene (43.7%), spathulenol (11.4%), alpha-felandrene (10.0%), alpha-pinene (7.1%), (E)-beta-ocimene (6.8%), germacrene D (5.8%), and p-cymene (4.2%). The trypanocidal activity against Trypanosoma cruzi epimastigote forms, as well as, the antimicrobial and antioxidant proprieties was investigated. The essential oil showed a potent trypanocidal activity with IC50 value of 31.9 +/-1.3 microg x mL(-1). For antimicrobial activity, the best result was observed against Candida tropicalis with a MIC value of 100 microg x mL(-1). For antioxidant capacity the essential oil showed weak activity.     

Chemical composition and antimicrobial activity of the essential oil of Tanacetum walteri (Anthemideae-Asteraceae) from Iran

The composition and antimicrobial activity of the essential oil of Tanacetum walteri were studied. Aerial flowering parts of plant were collected from North Khorasan Province of Iran and the essential oil was isolated by hydrodistillation and analysed by GC-FID and GC-MS. Antimicrobial activity of the essential oil was determined by disc diffusion and MIC and MBC determination. Thirty-five compounds were identified in the oil of T. walteri accounting for 94.4% of the total oil. Thymol (22.5%), 1,8-cineole (8.2%), umbellulone (6.9%), α-bisabolol (6.3%) and camphor (5.3%) were as the principal constituents. The highest antimicrobial activity of the essential oil was observed against Staphylococcus aureus, Enterococcus faecalis and Klebsiella pneumoniae with MIC value of 0.63 mg/mL. The inhibitory effect of the essential oil of T. walteri could be attributed mainly to the high levels of phenolic compound thymol and oxygenated terpenes in essential oil.     

Antimicrobial and antioxidant activities of essential oils of Satureja thymbra growing wild in Libya

The composition of essential oil isolated from Satureja thymbra, growing wild in Libya, was analyzed by GC and GC-MS. The essential oil was characterized by γ-terpinene (39.23%), thymol (25.16%), p-cymene (7.17%) and carvacrol (4.18%) as the major constituents. Antioxidant activity was analyzed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method. It possessed strong antioxidant activity (IC50 = 0.0967 mg/mL). The essential oil was also screened for its antimicrobial activity against eight bacterial and eight fungal species, showing excellent antimicrobial activity against the microorganisms used, in particular against the fungi. The oil of S. thymbra showed bacteriostatic activity at 0.001-0.1 mg/mL and was bactericidal at 0.002-0.2 mg/mL; fungistatic effects at 0.001-0.025 mg/mL and fungicidal effects at 0.001-0.1 mg/mL. The main constituents thymol, carvacrol and γ-terpinene also showed strong antimicrobial activity. The commercial fungicide bifonazole showed much lower antifungal activity than the tested oil.     

Composition, antioxidant, antimicrobial and anti-wood-decay fungal activities of the twig essential oil of Taiwania cryptomerioides from Taiwan

This study investigated the chemical composition, antioxidant, antimicrobial and anti-wood-decay fungal activities of the essential oil isolated from the twigs of Taiwania cryptomerioides from Taiwan. The essential oil was isolated using hydrodistillation in a Clevenger-type apparatus, and characterized by GC-FID and GC-MS. A total of 35 compounds were identified, representing 100% of the oil. The main components identified were alpha-cadinol (45.9%), ferruginol (18.9%) and beta-eudesmol (10.8%). The antioxidant activity of the oil was tested by the DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging capability test. The results showed an IC50 of 90.8 +/- 0.2 microg/mL. The active source compound was ferruginol. The antimicrobial activity of the oil was tested by the disc diffusion and micro-broth dilution methods against ten microbial species. The oil exhibited strong growth suppression against Gram-positive bacteria and yeast with inhibition zones of 45-52 mm and MIC values of 31.25-62.5 microg/mL, respectively. The anti-wood-decay fungal activity of the oil was also evaluated. The oil demonstrated excellent activity against four wood-decay-fungal species. For the antimicrobial and anti-wood-decay fungal activities of the oil, the active source compounds were determined to be alpha-cadinol, beta-eudesmol and ferruginol.     

Composition, antioxidant and antimicrobial activities of the leaf essential oil of Machilus japonica from Taiwan

The chemical composition, and antioxidant and antimicrobial activities of the essential oil isolated from the leaf of Machilus japonica from Taiwan have been investigated. The essential oil from the fresh leaves was isolated using hydrodistillation in a Clevenger-type apparatus, and characterized by GC-FID and GC-MS. A total of 97 compounds were identified, representing 100% of the oil. The main components identified were alpha-phellandrene (14.5%), alpha-pinene (12.8%), thymol (12.6%), beta-pinene (8.3%), alpha-terpineol (6.5%) and carvacrol (6.0%). The antioxidant activity of the oil was tested by the DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging capability test. The results showed that the IC50 was 51.8 microg/mL. The antimicrobial activity of the oil was tested by the disc diffusion and micro-broth dilution methods against ten microbial species. The oil exhibited strong growth suppression against Gram-positive bacteria and yeast, with inhibition zones of 48-54 mm and MIC values of 16.12-32.25 microg/mL, respectively. For the antioxidant and antimicrobial activities of the oil, the active source compounds were determined to be thymol and carvacrol.     

Composition and antimicrobial activity of Seseli montanum subsp. tommasinii essential oil

The essential oil isolated from Seseli montanum L. subsp. tommasinii Reich. f. was analyzed by GC/MS and the most abundant components were beta-pinene (30.2%), germacrene D (10.1%), sabinene (8.0%), alpha-pinene (7.2%) and limonene (6.6%). The antimicrobial effect of the essential oil was evaluated against four bacterial and four fungal species among which were food contaminants, spoilage fungi, and plant, fungal and animal pathogens. The oil possessed moderate to strong antimicrobial activity.     

Chemical composition and antimicrobial activity of essential oils from Centaurea pannonica and C. jacea

The chemical composition and antimicrobial activity of the essential oils obtained by hydrodistillation from Centaurea pannonica (Heufel) Simonkai and C. jacea L. (Asteraceae), were investigated. The essential oils were analyzed by GC and GC-MS. Forty five and twenty nine compounds were identified in the two oils, respectively. C. pannonica oil was rich in fatty acids (43.7%), with 9-octadecanoic acid (34.0%) and (Z,Z)-9,12-octadecadienoic acid (8.6%) as the major compounds. In contrast, the essential oil of C. jacea was dominated by oxygenated sesquiterpenes (43.2%), among which caryophyllene oxide (23.5%) and spathulenol (8.9%) were the major constituents. However, the oil was also characterized by an important fatty acid fraction (15.5%), with 9-octadecanoic acid (8.9%) and hexadecanoic acid (6.6%) being the main components. The antimicrobial activities of the essential oils were evaluated by the microdilution method against three Gram-positive and three Gram-negative bacteria, and one yeast. Both oils exhibited significant antimicrobial activity, especially against Gram-positive bacteria.     

Chemical compositions and antimicrobial activities of the essential oil from Pterocarya stenoptera C. DC

Abstract

The present study investigated the chemical compositions and antimicrobial activities of essential oil from Pterocarya stenoptera. The essential oil obtained by hydrodistillation from the dried leaves of P. stenoptera was analysed by GC–MS and 39 constituents accounting for the total 90.44% of the oil were identified. The main constituents were δ-cadinene (24.83%), caryophyllene oxide (9.10%), α-cadinol (7.48%) and β-elemene (6.24%). The antimicrobial activity of the oil was evaluated by disc diffusion and broth microdilution methods. The essential oil was found to show broad-spectrum antimicrobial activities against all the tested microorganisms. Bacillus subtilis was the most sensitive strain with the minimum inhibitory concentration of 0.23?mg/mL. The results suggested that the essential oil was a potential source of natural antimicrobials in food preservation and pharmaceutical industry.     

Chemical composition and antimicrobial activity of essential oil of Heracleum rigens

The essential oil was extracted from the seeds of Heracleum rigens by hydrodistillation and a total of twenty compounds accounting for 98.5% of the total oil composition were identified. Physicochemical properties and chemical composition of the oil was determined by a combination GC/FID and GC/MS analysis. The major compounds identified were bornyl acetate (51.2%), alpha-pinene (22.6%), limonene (9.62%), octyl acetate (3.94%), rho-cymene (2.85%) and gamma-terpinene (1.93%). The antimicrobial activity of the oil was screened by the disc diffusion method against nine pathogenic bacterial strains. Maximum antimicrobial activity was noted against Klebsiella pneumonia and Bacillus subtillis. This investigation corroborates the traditional claim of H. rigens as an effective antimicrobial agent.     

Major constituents and antimicrobial activity of Korean herb Acorus calamus

The constituents and antimicrobial activity of the essential oil from Acorus calamus were analysed. Methyl isoeugenol and cyclohexanone were identified as the major constituents of the essential oil. The essential oil was tested for antimicrobial activity against bacteria and yeast, and has shown strong antibiotic activities against most of the tested microbes, except Escherichia coli. The hexane extract has shown a similar pattern of antimicrobial activity as the essential oil. Methyl isoeugenol, the most abundant constituent in the essential oil, has also shown similar antimicrobial activity, except against Bacillus subtilis. The essential oil as well as the hexane extract and methyl isoeugenol have shown antimicrobial activity against Propionibacterium acne, which is known to be involved in acne vulgaris.     

Major volatile constituents of Annona squamosa L. bark

The volatile constituents of Annona squamosa L. bark were identified from the essential oil obtained by steam distillation and studied by GC/MS. Six major components were identified as 1H-Cycloprop(e)azulene (3.46%), germacrene D (11.44%), bisabolene (4.48%), caryophyllene oxide (29.38%), bisabolene epoxide (3.64%) and kaur-16-ene (19.13%). The oil was also screened for its antimicrobial activity, which exhibited a significant antimicrobial activity against Bacillus subtilis and Staphylococcus aureus.     

Chemical and biological evaluation of essential oils from two species of Myrtaceae - Eugenia uniflora L. and Plinia trunciflora (O. Berg) Kausel

The chemical composition and antimicrobial activity of essential oils obtained from leaves of two Myrtaceae species-Eugenia uniflora L. and Plinia trunciflora (O. Berg) Kausel-were determined. Analysis by GC/MS as well as determination of Kovatz indexes indicated atractylone (26.78%) and curzerene (17.96%) as major constituents of E. uniflora oil and α-cadinol (19.15%), apiole (11.15%) and cubenol (5.43%) as main components in P. trunciflora oil. Both essential oils were tested for antimicrobial activity against yeasts and bacteria. E. uniflora and P. trunciflora essential oils were active towards two Gram-positive bacteria, Streptococcus equi and Staphylococcus epidermis. In addition, biological activity of both essential oils was detected for pathogenic yeasts of the genus Candida and Cryptococcus. E. uniflora was active towards all yeast tested and exhibited interesting minimal inhibitory concentrations (0.11 to 3.75 mg/mL) across a broad spectrum of activity.     

Chemical constituents, antioxidant and antimocrobial activity of essential oil of Pogostemon paniculatus (Willd.)

The essential oil extracted from the leaves of Pogostemon paniculatus (Willd.) Benth. (Lamiaceae), was analysed by gas chromatography-mass spectrometry (GC-MS). Nineteen compounds constituting 85.36% of the total oil were identified in the oil. Patchouli alcohol (30.65%), α-guaiene (10.67%), β-guaiene (9.09%), caryophyllene (8.64%), eicosene (5.27%) were the major constituents present. The essential oil was analysed for antimicrobial activity by disc diffusion assay and minimum inhibition concentration against six bacteria and three fungi. Results showed inhibitory activity against some of the tested microorganisms. The essential oil was also tested for the DPPH free-radical scavenging activity and had an inhibitory concentration (IC(50)) value of 18.5?μg?mL(-1).     

Chemical composition and antimicrobial activity of essential oil of Cupressus atlantica

Cupressus atlantica Gaussen, an endemic species from Morocco, is used in traditional medicine. The chemical composition of the essential oil isolated by hydrodistillation from the leaves was investigated by capillary gas chromatography and gas chromatography/mass spectrometry, and also evaluated for in vitro antimicrobial activity. Sixty-one components, representing 98.1% of the total, were detected of which fifty-seven were identified. Germacrene D (34.8%), alpha-pinene (13.6%), delta-cadinene (6.1%), alpha-phellandrene (5.5%), gamma-cadinene (5.0%), beta-caryophyllene (4.8%) and alpha-humulene (4.4%) were the predominant compounds. The oil was characterized by a relatively high amount of oxygenated monoterpenes (66.5%). The oil, screened for antimicrobial activity against both Gram-positive and Gram-negative, showed pronounced activity against all the microbes tested, except Pseudomonas, which showed resistance.     

Composition of Satureja kitaibelii essential oil and its antimicrobial activity

The composition of the essential oil obtained by hydrodistillation from the aerial parts of Satureja kitaibelii from Rtanj mountain (Serbia), collected during three years, was studied. Thirty-nine components were identified in each sample of S. kitaibelii essential oil, representing about 87% of the oils. p-Cymene was the most dominant compound in all three oils (27.9%, 14.7% and 24.4%, respectively). The simple formulation of a lozenge with 0.2% of S. kitaibelii essential oil was prepared and the antimicrobial activity of the essential oil and the lozenge with essential oil was tested using a broth microdilution assay. Both essential oil and lozenge possessed strong antimicrobial activity with MIC values of 0.10-25 microg/mL, and 0.97-15.6 mg/mL, respectively.     

Potential interaction between the volatile and non-volatile fractions on the in vitro antimicrobial activity of three South African Pelargonium (Geraniaceae) species

Previous studies have reported promising antimicrobial efficacy for the essential oils and solvent extracts of several indigenous Pelargonium species. This study aimed to determine if any pharmacological interaction (e.g. synergism or antagonism) exists between the volatile and non-volatile components when the different fractions were investigated. The antimicrobial activity of the following fractions were tested; the essential oil prepared by hydrodistillation (EO), non-volatile fraction (NV), prepared by extraction of plant material remaining in the distilling apparatus (having no or negligible volatile constituents) and solvent extracts prepared from fresh (FC) and dried (DC) plant material containing both volatile and non-volatile constituents. Pelargonium quercifolium oil was dominated by p-cymene (42.1%) and viridiflorol (16.9%), while P. graveolens and P. tomentosum oil had high levels of isomenthone (84.0 and 58.8%, respectively). Menthone was noted as a major constituent in the P. tomentosum EO sample. It was evident from the results that the presence of volatile constituents in the three species; P. graveolens, P. quercifolium and P. tomentosum is generally not a pre-requisite for antimicrobial activity. The most significant variations of antimicrobial activity were noted for P. tomentosum where poorer activity was noted for the FC and EO fractions against Bacillus cereus and Candida albicans. Studies on Staphylococcus aureus, however, showed the converse, where best activity was noted for the FC fraction (3.0 mg/mL). For P. quercifolium, the DC fraction indicated a notable increase in anti-staphylococcal activity (2.0 mg/mL) when compared with the FC (8.0 mg/mL) and EO (16.0 mg/mL) fractions. For P. tomentosum, the FC fraction indicated much lower antimicrobial activity (against both B. cereus and C. albicans) when compared with all other fractions, suggesting that the essential oils may impact negatively on the antimicrobial activity when tested against these two pathogens.     

Antibacterial activities of essential oils extracted from leaves of Murraya koenigii by solvent-free microwave extraction and hydro-distillation

Solvent-free microwave extraction (SFME) for the isolation of essential oil from leaves of Murraya koenigii L. (Rutaceae) has been compared with the conventional hydro-distilled oil (HD) in terms of yield, composition, antioxidant activity, and antibacterial activity against Listeria innocua. The yield of essential oil obtained from 30 min of SFME was similar to that of HD for 180 min. By GC-MS analysis, the major compounds of the essential oil extracted by SFME, which were obtained in somewhat lower amounts than in the essential oil obtained by HD, were alpha-copaene (44.3%), beta-gurjunene (25.5%), isocaryophyllene (12.1%), beta-caryophyllene (8.7%) and germacrene D (2.9%). The content of oxygenated terpenes, slightly higher for the SFME-essential oil (2.3%) than the HD-essential oil (1.4%), were much lower than that of nonoxygenated terpenes in both oils. DPPH radical scavenging activities of both essential oils were relatively low (10%-24%). Complete inhibition of growth of L. innocua was observed with both SFME and HD essential oils, at 400 and 600 microg/mL (minimum inhibitory concentration), respectively. The SFME-essential oil at 300 microg/mL provided 92% inhibition, indicating its potential as a natural antimicrobial agent.     

Antimicrobial and antioxidant activities of the flower essential oil of Halimodendron halodendron

The essential oil obtained by hydro-distillation from the flowers of Halimondendron halodendron (Leguminosae) was analyzed for its chemical composition by gas chromatography-mass spectrometry (GC-MS). Undecane (16.4%), dodecane (15.3%), tridecane (12.5%), decane (8.2%), 6,10,14-trimethyl-pentadecan-2-one (6.3%), methyl palmitate (6.0%), methyl linolenate (4.1%) and ethylcyclohexane (4.1%) were the major compounds of the thirty-five identified components of the oil. The essential oil was shown to have a broad spectrum of antimicrobial activity with MIC values ranging from 100 to 250 microg/mL, and IC50 values from 40.4 to 193.8 microg/mL. The oil also showed strong antioxidant activity, with an especially high metal chelating capacity of ferrous ions with an IC50 value of 7.4 microg/mL on ferrozine-Fe2+ complex formation.     

Chemical composition, antimicrobial and antioxidant activities of the essential oil of Tibetan herbal medicine Dracocephalum heterophyllum Benth

The essential oil of Tibetan medicine Dracocephalum heterophyllum Benth was obtained by hydrodistillation with a 0.7% (v/w) yield. The chemical composition of the essential oil was analyzed by gas chromatography-mass spectral (GC-MS). Eighty-three compounds, constituting about 89.83% of the total oil, were identified. The main compound in the oil were Cineole (14.89%), trans-nerolido (7.10%), 1-m-ethyl-2-(1-methylethyl)-benzene (4.42%), Germacrene-D (4.84%), Decahydro-1,1,4,7-tetramethyl-4aH-cycloprop[e]azulen-4a-ol (4.94%), p-menth-1-en-4-ol,acetate (4.34%), 4-methyl-1-(1-methylethyl)-3-cyclohexen-1-ol (4.10%). The antimicrobial activity of the oil was evaluated against nine bacterial, one yeast, and three fungi. The antimicrobial test result showed that the essential oil strongly inhibited the growth of test microorganisms studied. The maximal inhibition zones and MIC values for bacterial, yeast and fungi strain were in the range of 18-25 mm and 0.039-0.156 mg mL(-1); *20 mm, and 0.156 mg mL(-1); 8-24 mm and 0.313-2.5 mg mL(-1); respectively. The antioxidant activity of the oil was determined by the malonyldialdehyde (MDA) test, measuring the MDA concentration in mouse liver cell microsomal after induced lipid peroxidation using FeSO(4) and ascorbic acid, The inhibition of lipid peroxidation was 59.3% with a concentration of 0.5 mg mL(-1). Result presented here may suggest that the essential oil of D. heterophyllum posses antimicrobial and antioxidant properties, and therefore, they can be one of new medicinal resources for antimicrobial agent and/or used as a natural preservative ingredient in food and cosmetics and pharmaceuticals industry.     

Chemical composition and antimicrobial activity of the essential oil of Sagittaria trifolia

The essential oil of Sagittaria trifolia, a well-known famous medicinal foodstuff in China, was analyzed for the first time using GC-MS. Twenty-eight constituents were identified. The major components of the oil were hexahydrofarnesyl acetone (62.3%), tetramethylhexadecenone (5.8%), myristaldehyde (4.7%), n-pentadecane (2.9%), and 2-hexyldecanol (2.9%).The antimicrobial activity of the essential oil was evaluated against seven microorganisms, including two clinically isolated strains and five reference strains, using microbiological cylinder plate assay and broth microdilution methods. The results showed that the oil had a significant antimicrobial effect on four of them. This antimicrobial activity can partly explain why the oil is used medicinally during childbirth and for skin diseases in Chinese traditional medicine. Published in Khimiya Prirodnykh Soedinenii, No. 5, pp. 419–420, September–October, 2006.