Senna occidentalis (L.) Link and Senna hirsuta (L.) H. S. Irwin & Barneby: constituents of fruit essential oils and antimicrobial activity

Senna occidentalis and S. hirsuta are mostly gathered from the wild for medicinal use and have a disagreeable odour when crushed. The volatile oils isolated from fresh fruits of S. occidentalis and S. hirsuta were subjected to gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS) and antimicrobial assays. GC and GC-MS analyses permitted the identification of 58 constituents. S. occidentalis oil was dominated by cyperene (10.8%), β-caryophyllene (10.4%), limonene (8.0%) and caryophyllene oxide (6.8%). The main components of S. hirsuta fruit oil were benzyl benzoate (24.7%), τ-cadinol (18.9%), 2,5-dimethoxy-p-cymene (14.6%) and β-caryophyllene (5.1%). S. occidentalis fruit oil exhibited better antimicrobial activity (MIC 78–312 μg/mL) against Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Aspergillus niger compared with S. hirsuta oil. The compositions and the activities of the fruit essential oils of S. occidentalis and S. hirsuta are reported for the first time.     

Curcuma ecalcarata – new natural source of pinocembrin and piperitenone

Phytochemical analysis of the rhizome extract of Curcuma ecalcarata, a hitherto uninvestigated south Western Ghats endemic species, resulted in the isolation and identification of the diaryl heptanoid trans, trans-1,7-diphenyl-5-hydroxy-4,6-heptadiene-3-one (1), steroid β-sitosterol (2), flavanone pinocembrin (4) and monoterpenoids piperitenone (3) and 8-hydroxy piperitone (5). HPTLC estimation of pinocembrin in the rhizome revealed the plant as a rich source of pinocembrin (0.37% dry wt.). The rhizome essential oil was isolated by hydrodistillation and analysed by GC–FID, GC–MS and ¹³C NMR. Among the 30 constituents identified in the oil, monoterpenoids predominated (94.2%) followed by sesquiterpenoids (5.8%). The major compound consisting of 65.2% of the oil was isolated and identified as piperitenone (3). The study highlights the plant as a rich source of the flavanone pinocembrin and the volatile aroma compound piperitenone.     

Chemical composition and antimicrobial activity of the essential oils of Onychopetalum amazonicum R.E.Fr.

The essential oils from leaves, twigs and trunk bark of Onychopetalum amazonicum R.E. Fr. (Annonaceae), obtained by hydrodistillation, were analysed by GC and GC–MS, and also were evaluated for in vitro antimicrobial activity. Forty-one compounds, which correspond to 75.0–92.2% of the oil components, were identified. Major compounds were sesquiterpenes, including (E)-caryophyllene, caryophyllene oxide, spathulenol, α-gurjunene, allo-aromadendrene and α-epi-cadinol. The oils were evaluated for antimicrobial activities against four bacteria strains and five pathogenic fungi. The oil of the trunk bark exhibited good activity against Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 10538 and Kocuria rhizophila ATCC 9341, with a minimal inhibitory concentration of 62.5 μg/mL. The essential oil composition and the antimicrobial evaluation are reported for the first time for the genus Onychopetalum.     

Comparative study of volatile oil compositions of two Plectranthus species from northern India

The leaf and inflorescence essential oils of Plectranthus rugosus Wall. (syn. Rabdosia rugosa Wall.) and Plectranthus incanus L. (syn. Plectranthus mollis L.), which grow wild in Uttarakhand, India, were analysed and compared by capillary gas chromatography and gas chromatography-mass spectrometry. The analysis led to the identification of 43 constituents, forming 89.5-93.6% of the total oil compositions. Both leaf and inflorescence oil of P. rugosus were dominated by sesquiterpene hydrocarbons (71.8%, 71.7%) represented by β-caryophyllene (36.2%, 29.8%), germacrene D (25.2%, 28.2%) and α-humulene (6.6%, 8.6%) as the major constituents. Conversely, the leaf and inflorescence oil of P. incanus were dominated by monoterpenoids (74.4%, 65.8%) with piperitenone oxide (44.2%, 38.5%), piperitone (8.6%, 12.2%) and terpinolene (14.5%, 10.2%) as major constituents. Piperitenone oxide, piperitone, cis- and trans-piperitols and trans-piperitol acetate were the marker constituents in P. incanus, which were not noted in the essential oil of P. rugosus.     

Study on essential oils from the leaves of two Vietnamese plants: Jasminum subtriplinerve C.L. Blume and Vitex quinata (Lour) F.N. Williams

The essential oil constituents of the leaves of Jasminum subtriplinerve (Oleaceae) and Vitex quinata (Verbanaceae) cultivated in Vietnam were analysed by gas chromatography – flame ionisation detector (GC–FID) and gas chromatography – mass spectrometry (GC–MS) techniques. The main constituents identified in J. subtriplinerve were mainly oxygenated monoterpenes represented by linalool (44.2%), α-terpineol (15.5%), geraniol (19.4%) and cis-linalool oxide (8.8%). The quantitative significant components of V. quinata were terpene hydrocarbons comprising of β-pinene (30.1%), β-caryophyllene (26.9%) and β-elemene (7.4%). The chemical compositions of the essential oils are being reported for the first time.     

Chromatographic analysis,antimicrobial and insecticidal activities of the essential oil of Phlomis floccosa D. Don.

The present study was conducted to investigate for the first time the chemical composition and insecticidal and antimicrobial properties of Phlomis floccosa D. Don. essential oil isolated by hydro‐distillation of its aerial parts. Qualitative and quantitative analyses of the essential oil on the basis of gas chromatography and mass spectrometry (GC/FID and GC/MS) revealed the presence of 59 organic volatiles representing 86.9% of the total constituents. The major compounds were germacrene‐D (19.7%) followed by β‐caryophyllene (15.5%), caryophyllene oxide (8.3%), hexadecenoic acid (7.9%) and carvacrol (6.1%). The broth microdilution method was conducted to test the antimicrobial activity of the essential oil against five pathogens: Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, Staphylococcus aureus, Bacillus subtilis and the yeast Candida albicans. The oil of P. floccosa D. Don. shows promising activity against the Gram‐positive bacteria S. aureus and B. subtilis and the yeast C. albicans (minimum inhibitory concentration = 625 μg.mL^?1). The effectiveness of the essential oil was assessed on both Tribolium confusum and Sitophilus zeamais pest insects and it was more pronounced against T. confusum, showing a moderate mortality of 47.5%.     

Composition and Antimicrobial Activity of <Emphasis Type="Italic">Helichrysum italicum</Emphasis> Essential Oil and Its Terpene and Terpenoid Fractions

The essential oil of Helichrysum italicum (Roth) G. Don from Croatia has been fractionated into terpene and terpenoid fractions and analyzed using GC/MS. Fifty-two compounds were identified. The main hydrocarbons of the oil were α-pinene (10.2%), α-cedrene (9.6%) aromadendrene (4.4%), β-caryophyllene (4.2%), and limonene (3.8%), while the main oxygen-containing compounds were neryl acetate (11.5%), 2-methylcyclohexyl pentanoate (8.3%), 2-methylcyclohexyl octanoate (4.8%), and geranyl acetate (4.7%). The essential oil and its terpene and terpenoid fractions were evaluated for antibacterial and antifungal activities. The screening of antimicrobial activity was conducted by a disc diffusion test and the minimum inhibitory concentration was determined against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. The essential oil and its terpenoid fraction exhibited higher antimicrobial activity with respect to the terpene fraction. The antimicrobial activities of the oil and its terpenoid fraction were more pronounced against Staphylococcus aureus and Candida albicans.__________Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 29–32, January–February, 2005.     

A study on the seasonal variation of the essential oil composition from Plectranthus hadiensis and its antibacterial activity

The chemical composition and seasonal variation of the essential oil from the aerial parts of Plectranthus hadiensis grown during the rainy and summer seasons in the Western Ghats of India was analysed by GC–MS technique. The analysis of rainy season oil led to the identification of 31 compounds, representing 96.4% of the essential oil and the winter season oil led to 25 compounds, representing 95.1% of the oil. Most of the compounds were sesquiterpenes and oxygenated monoterpenes. The major components of the rainy season oil were L-fenchone (30.42%), β-farnesene (11.87%), copaene(11.10%), 2,3-dimethyl hydroquinone (10.78%), α-caryophyllene(8.41%) and piperitone oxide (3.94%) and of the summer season oil are L-fenchone (31.55%), copaene(11.93%), β-farnesene (10.45%), 1,8-naphthalenedione, 8a-ethylperhydro (10.06%), α-caryophyllene(6.36%), piperitone oxide (5.79%) and limonene(4.63%). Antibacterial activity of the essential oil of P. hadiensis was tested using zone of inhibition and minimum inhibition concentration methods. Both the oils inhibited the organisms and showed the zone of inhibition in the range of 20–35 mm with MIC values between 32 and 64 mg/dL.     

Chemical composition and antimicrobial activities of Perovskia artemisioides Boiss. essential oil

The Perovskia artemisioides Boiss. essential oil obtained by hydrodistillation method of flowers growing wild in the north of Iran. The study led to the identification of 29 compositions by a combination of HP-5 GC–FID and GC–MS analytical techniques. The constituents were identified in P. artemisioides essential oil with 1,8-cineole (29.9%), camphor (29.5%) and α-pinene (7.8%) as main constituents as well as δ-3-carene (5.1%), camphene (3.3%) and β-pinene (2.7%). The oil was identified by a much larger amount of monoterpenes (87.7%) and sesquiterpenes (6.3%). The results of antimicrobial activity exhibit that the extracted essential oil has presented a high inhibiting activity against five microbial strains up to 18 mm. Also, the MIC and MBC results displayed that Staphylococcus aureus, Escherichia coli and Salmonella typhi were inhibited by P. artemisioides essential oil. Therefore, determination of essential oils in this research showed a relatively similar pattern to those published for the other species of Perovskia.     

Comparative essential oil composition of aerial parts of Tanacetum dumosum Boiss. from Southern Zagros,Iran.

The essential oils of leaves and flowers of Tanacetum dumosum Boiss., an endemic medicinal shrub, were extracted by using hydrodistillation method and analysed using GC and GC–MS. A total of 43 and 44 compounds were identified in the essential oils from the leaves and flowers of T. dumosum, respectively. The major chemical constituents of leaves oil were borneol (27.9%), bornyl acetate (18.4%), 1,8-cineol (17.5%), α-terpineol (5.3%), cis-chrysanthenyl acetate (3.3%), camphene (2.7%) and terpinene-4-ol (1.9%), while the main components of the flower oil were isobornyl-2-methyl butanoate (41.1%), trans-linalyl oxide acetate (11.9%), 1,8-cineole (7.7%), thymol (4.2%), linalool (3.9%), camphor (2.9%), isobornyl propanoate (2.9%), α-terpineol (2.1%) and caryophyllene oxide (2.0%). Major qualitative and quantitative variations for some main chemical compounds among different aerial parts of T. dumosum were identified. High contents of borneol, bornyl acetate, 1,8-cineol and linalool in the leaves and flowers of T. dumosum show its potential for use in the food and perfumery industry.     

Essential Oil Composition and Antibacterial Activity of the Leaves of <Emphasis Type="Italic">Stachys schtschegleevii</Emphasis> from Iran

The composition of the essential oil obtained by hydrodistillation from the leaves of Stachys schtschegleevii Sosn. before the flowering stage was analyzed by GC and GC-MS. Forty-five compounds representing 98.7% of the total oil were identified, of which α-pinene (36.4%), germacrene-D (18.6%), limonene (8.2%), and piperitone (6.2%) were the major constituents. Furthermore, antibacterial activity of the entire oil and its two main monoterpenes was evaluated against six Gram-positive and Gram-negative bacteria. The oil exhibited moderate activity against the tested bacteria.__________Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 138–140, March–April, 2005.     

Investigation of the chemical composition–antibacterial activity relationship of essential oils by chemometric methods

The antibacterial effects of Thymus vulgaris (Lamiaceae), Lavandula angustifolia (Lamiaceae), and Calamintha nepeta (Lamiaceae) Savi subsp. nepeta var. subisodonda (Borb.) Hayek essential oils on five different bacteria were estimated. Laboratory control strain and clinical isolates from different pathogenic media were researched by broth microdilution method, with an emphasis on a chemical composition–antibacterial activity relationship. The main constituents of thyme oil were thymol (59.95%) and p-cymene (18.34%). Linalool acetate (38.23%) and β-linalool (35.01%) were main compounds in lavender oil. C. nepeta essential oil was characterized by a high percentage of piperitone oxide (59.07%) and limonene (9.05%). Essential oils have been found to have antimicrobial activity against all tested microorganisms. Classification and comparison of essential oils on the basis of their chemical composition and antibacterial activity were made by utilization of appropriate chemometric methods. The chemical principal component analysis (PCA) and hierachical cluster analysis (HCA) separated essential oils into two groups and two sub-groups. Thyme essential oil forms separate chemical HCA group and exhibits highest antibacterial activity, similar to tetracycline. Essential oils of lavender and C. nepeta in the same chemical HCA group were classified in different groups, within antibacterial PCA and HCA analyses. Lavender oil exhibits higher antibacterial ability in comparison with C. nepeta essential oil, probably based on the concept of synergistic activity of essential oil components.     

Components and insecticidal activity against the maize weevils of Zanthoxylum schinifolium fruits and leaves

In our screening program for new agrochemicals from Chinese medicinal herbs and wild plants, Zanthoxylum schinifolium essential oils were found to possess strong insecticidal activity against the maize weevil Sitophilus zeamais. The essential oils of Z. schinifolium fruits and leaves were extracted via hydrodistillation and investigated by GC and GC-MS. Estragole (69.52%) was the major compound of the essential oil of fresh fruits, followed by linalool (8.63%) and limonene (4.34%) and 94.33% of the total components were monoterpenoids. The main components of the essential oil of fresh leaves were linalool (12.94%), ar-tumerone (8.95%), limonene (6.45%) and elixene (5.43%) and only 50.62% were monoterpenoids. However, the essential oil from purchased fruits contained linalool (33.42%), limonene (13.66%) and sabinene (5.72%), followed by estragole (4.67%), nerol (4.56%) and 4-terpineol (4.27%). Estragole, linalool and sabinene were separated and purified by silica gel column chromatography and preparative thin layer chromatography, and further identified by means of physicochemical and spectrometric analysis. The essential oil from the fresh fruits (LD?? = 15.93 μg/adult) possessed two times more toxicity to the insects compared with that of fresh leaves (LD?? = 35.31 μg/adult). Estragole, linalool and sabinene exhibited contact activity against S. zeamais with LD?? values of 17.63, 13.90 and 23.98 μg/adult, respectively. The essential oils of Z. schinifolium possessed strong fumigant toxicity against S. zeamais adults with LC?? values of 13.19 mg/L (fresh fruits), 24.04 mg/L (fresh leaves) and 17.63 mg/L (purchased fruits). Estragole, linalool and sabinene also exhibited strong fumigant toxicity against the maize weevils with LC?? values of 14.10, 10.46 and 9.12 mg/L, respectively.     

Free and Glycosidically Bound Volatiles of Mentha longifolia Growing in Croatia

The glycosides of volatile compounds and the essential oil were isolated from wild Mentha longifolia. After the enzymatic hydrolysis of glycosides, fourteen volatile aglycones were identified by GC/MS. The main aglycones were eugenol, 2-phenylethanol, benzyl alcohol, lavandulol, trans- and cis-carveol, 3-octanol, and 3-hexen-1-ol. The content of aglycones was 40.85 mg kg^-1 of dried plant material. The main components of the essential oil (yield 0.93 w/w) were carvone, piperitenone oxide, limonene, and -caryophyllene. Eugenol, carveol, 3-octanol, and -terpineol were identified in the aglycones and in the essential oil.     

Chemical composition,antioxidant, antibacterial and cytotoxic activities of essential oil of Leontopodium leontopodioides (Willd.) Beauverd

The essential oil (EO) from the aerial parts of Leontopodium leontopodioides (Willd.) Beauverd was obtained by hydrodistillation and analysed by GC–FID and GC–MS. Sixty-five compounds were identified which represent 96.2% of the total composition of the EO. The major components of the EO were palmitic acid (11.6%), n-pentadecanal (5.7%), linalool (3.8%), β-ionone (3.3%), hexahydrofarnesyl acetone (3.2%), bisabolone (3.2%) and β-caryophyllene (3.2%). The EO exhibited an excellent antibacterial activity against Staphylococcus aureus and Bacillus subtilis according to the MIC values tested by micro-dilution method. It also exhibited a significant cytotoxicity against HepG2 and MCF-7 cell lines with the IC₅₀ values of 67.44 and 70.49 μg/mL according to the MTT assay. However, the antioxidant activity test revealed that the EO exhibited a weak DPPH radical-scavenging activity. In conclusion, the EO of L. leontopodioides could be regarded as a bioactive natural product and deserves further study for its potential therapeutic effects.     

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.     

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.     

Comparison of essential oil components and in vitro anticancer activity in wild and cultivated Salvia verbenaca

The objectives of our research were to study the chemical composition and the in vitro anticancer effect of the essential oil of Salvia verbenaca growing in natural sites in comparison with those of cultivated (Sc) plants. The oil from wild (Sw) S. verbenaca presented hexadecanoic acid (23.1%) as the main constituent, while the oil from Sc plants contained high quantities of hexahydrofarnesyl acetone (9.7%), scarce in the natural oil (0.7%). The growth-inhibitory and proapoptotic effects of the essential oils from Sw and Sc S. verbenaca were evaluated in the human melanoma cell line M14, testing cell vitality, cell membrane integrity, genomic DNA fragmentation and caspase-3 activity. Both the essential oils were able to inhibit the growth of the cancer cells examined inducing also apoptotic cell death, but the essential oil from cultivated samples exhibited the major effects.     

Essential oil composition of Nepeta satureioides from Iran

The essential oil of Nepeta satureioides Boiss. from Iran was isolated by hydrodistillation in yield of 0.06% (w/w). The chemical composition of the essential oil was analyzed by GC and GC-MS. Forty-five compounds accounting for 97.4% of the total oil were identified. The major components were linalool (23.8%), (Z,E)-farnesol (14.7%), linalyl acetate (11.1%), β-caryophyllene (6.6%), lavandulol acetate (6.6%), caryophyllene oxide (6.4%), and (Z)-β-farnesene (3.4%). Oxygenated terpenoids were the main group of compounds. Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 144–145, March–April, 2006.     

Chemical composition of the essential oil from the leaves of Anaxagorea brevipes (Annonaceae) and evaluation of its bioactivity

The essential oil obtained by hydrodistillation from leaves of Anaxagorea brevipes was analysed by gas chromatography fitted with a flame ionisation detector (GC–FID) and coupled to mass spectrometry (GC–MS). Thirty one components were identified, representing around 75.7% of total oil. The major components were β-eudesmol (13.16%), α-eudesmol (13.05%), γ-eudesmol (7.54%), guaiol (5.12%), caryophyllene oxide (4.18%) and β-bisabolene (4.10%). The essential oil showed antimicrobial activity against Gram-positive bacteria and yeast with the MIC values between 25.0 and 100 μg/mL. The highest antiproliferative activity was observed for the oil against MCF-7 (breast, TGI = 12.8 μg/mL), NCI-H460 (lung, TGI = 13.0 μg/mL) and PC-3 (prostate, TGI = 9.6 μg/mL) cell lines, while against no cancer cell line HaCat (keratinocyte) the TGI was 38.8 μg/mL. The oil exhibited a small antioxidant activity assessed through ORAC-FL assay (517 μmol TE/g). This is the first report regarding the chemical composition and bioactivity of A. brevipes essential oil.