Identification of antibacterial and antioxidant constituents of the essential oils of Cynanchum chinense and Ligustrum compactum

The aim of this research was to determine the chemical composition, antioxidant and antibacterial properties of the essential oils from Cynanchum chinense and Ligustrum compactum and isolation of antioxidant and antibacterial constituents from the essential oils. Thirty-eight components were identified in essential oils. Based on bioactivity-guided fractionation, guaiacol, linalool and 2-phenylethanol were isolated and identified as active constituents. Both L. compactum flower oil and 2-phenylethanol showed high antibacterial performance, with inhibition zone from 22.8 ± 0.8 to 11.9 ± 2.0 mm at highest concentration, and minimum inhibitory concentration values ranging from 0.25% to 1%. In both DPPH and ABTS assay, the active constituent guaiacol (IC₅₀ = 4.15 ± 0.72 and 9.12 ± 0.98 μg mL^? 1, respectively) exhibited high antioxidant activity, and the oils showed moderate antioxidant activity. These results indicate potential efficacy of active constituents and essential oils of L. compactum and C. chinense to control food-borne pathogenic and spoilage bacteria.     

Chemical composition and insecticidal activity against Sitophilus zeamais of the essential oils derived from Artemisia giraldii and Artemisia subdigitata

The aim of this research was to determine the chemical composition and insecticidal activity of the essential oils derived from flowering aerial parts of Artemisia giraldii Pamp. and A. subdigitata Mattf. (Family: Asteraceae) against the maize weevil (Sitophilus zeamais Motsch.). Essential oils of aerial parts of A. giraldii and A. subdigitata were obtained from hydrodistillation and investigated by GC and GC-MS. A total of 48 and 33 components of the essential oils of A. giraldii and A. subdigitata were identified, respectively. The principal compounds in A. giraldii essential oil were β-pinene (13.18%), iso-elemicin (10.08%), germacrene D (5.68%), 4-terpineol (5.43%) and (Z)-β-ocimene (5.06%). 1,8-Cineole (12.26%) and α-curcumene (10.77%) were the two main components of the essential oil of A. subdigitata, followed by β-pinene (7.38%), borneol (6.23%) and eugenol (5.87%). The essential oils of A. giraldii and A. subdigitata possessed fumigant toxicity against the maize weevils with LC50 values of 6.29 and 17.01 mg/L air, respectively. The two essential oils of A. giraldii and A. subdigitata also exhibited contact toxicity against S. zeamais adults with LD50 values of 40.51 and 76.34 μg/adult, respectively. The results indicated that the two essential oils show potential in terms of fumigant and contact toxicity against grain storage insects.     

Chemical composition and insecticidal activities of essential oils against diamondback moth,Plutella xylostella (L.) (Lepidoptera: Yponomeutidae)

Five Himalayan plants namely, Acorus calamus, Cedrus deodara, Aegle marmelos, Tagetes minuta and Murraya koenigii were used for the extraction of essential oils through hydrodistillation and the major volatile constituents as identified by GC and GC–MS techniques were β-asarone (91.1%), β-himachalene (45.8%), limonene (59.5%), Z-ocimene (37.9%) and α-pinene (54.2%), respectively. Essential oils were tested for their insecticidal properties against larvae of diamondback moth, Plutella xylostella (L.) (Lepidoptera: Yponomeutidae). Results showed that A. calamus was most toxic (LC_50?=?0.29 mg mL^?1) to P. xylostella followed by C. deodara (LC_50?=?1.08 mg mL^?1) and M. koenigii (LC_50?=?1.93 mg mL^?1) via residual toxicity bioassay. Per cent feeding deterrence index and growth inhibition was significantly higher in A. calamus (42.20 and 68.55, respectively) followed by C. deodara (35.41 and 52.47). In repellent activity studies, C. deodara showed high repellence (64.76%) followed by A. calamus (55.05%).     

Insecticidal properties of essential oils against Tribolium castaneum (Herbst) and their inhibitory effects on acetylcholinesterase and adenosine triphosphatases

Essential oils from 20 Egyptian plants were obtained by using hydrodistillation. The chemical composition of the isolated oils was identified by gas chromatograph/mass spectrometer. Fumigant and contact toxicities of the essential oils were evaluated against the adults of Tribolium castaneum. In fumigation assays, the oil of Origanum vulgare (LC₅₀ = 9.97 mg/L air) displayed the highest toxicity towards the adults of T. castaneum. In contact assays, the oils of Artemisia monosperma (LC₅₀ = 0.07 mg/cm²) and O. vulgare (LC₅₀ = 0.07 mg/cm²) were the most potent toxicants against the adults of T. castaneum. Biochemical studies showed that the tested oils caused pronounced inhibition of acetylcholinesterase (AChE) and adenosine triphosphatases (ATPases) isolated from the larvae of T. castaneum. The oil Cupressus macrocarpa (IC₅₀ = 12.3 mg/L) was the most potent inhibitor of AChE, while the oil of Calistemon viminals (IC₅₀ = 4.4 mg/L) was the most potent inhibitor of ATPases.     

Chemical composition and insecticidal activity of the essential oil of Artemisia eriopoda against maize weevil, Sitophilus zeamais

In our screening program for new agrochemicals from local wild plants, Artemisia eriopoda was found to possess insecticidal activities against the maize weevil, Sitophilus zeamais. The essential oil of the aerial parts of A. eriopoda was obtained by hydrodistillation and investigated by GC and GC-MS. The main components of the essential oil are germacrene D (21.6%) and eucalyptol (14.2%). The essential oil possesses fumigant toxicity against S. zeamais adults with a LC50 value of 11.5 mg/L air and also shows contact toxicity against S. zeamais adults with a LD50 value of 24.8 microg/adult, respectively.     

Volatile chemical composition and bioactivity of six essential oils against the stored food insect Sitophilus zeamais Motsch. (Coleoptera Dryophthoridae)

Essential oils (EOs) of Achillea millefolium, Myrtus communis, Rosmarinus officinalis, Helichrysum italicum, Foeniculum vulgare and Lavandula angustifolia were analysed with GC-FID and GC-MS in order to define their aromatic profiles and then their toxicity and repellent activity against Sitophilus zeamais Motsch. (Coleoptera Dryophthoridae) with specific bioassays were evaluated. Results from topical applications on insects showed that all EOs had variable and significant insecticidal activity. Mortality rate never exceeded 76%. Results of repellency tests are indicated for M. communis and L. angustifolia EOs, displaying high repellent activity to S. zeamais adults.     

Chemical constituents and biological activities of Viburnum macrocephalum f. keteleeri

Three new compounds (1–3) and seven known compounds (4–10) have been isolated from the ethanolic extract of Viburnum macrocephalum f. keteleeri using bioactivity-guided fractionation and identified as methyl (2-α-L-rhamnopyranosyloxy)acetate (1), methyl (2R-3-α-L-rhamnopyranosyloxy)glycerate (2), methyl (3R-4-α-L-rhamnopyranosyloxy-3-hydroxy)butanoate (3), bridelionoside B (4), (6S,7E,9R)-roseoside (5), linarionoside A (6), 3,7,11-trimethyl-1,6-dodecadien-3,10,11-triol (7), (+)-8-hydroxylinalool (8), β-sitosterol (9) and daucosterol (10). The structures of 1–3, including absolute configurations, were determined by spectroscopic data (¹H and ¹³C NMR, HSQC, HMBC and ORD) and chemical methods. In addition, compounds 1–8 were assayed for their insecticidal and antimicrobial activities. Compounds 7 and 8 exhibited moderately insecticidal effects against Mythimna separata with LD₅₀ values of 180 and 230 μg g^?1, respectively. Compounds 2, 3, 7 and 8 showed varying antimicrobial activities with IC₅₀ values ranging from 125 to 529 μM.     

Chemical composition,antimicrobial and insecticidal activities of the essential oils of Conyza linifolia and Chenopodium ambrosioides

Two essential oil-containing plants growing wildly in Egypt: Conyza linifolia (Willd.) Täckh. (Asteraceae) and Chenopodium ambrosioides L. (Chenopodiaceae) were subjected to essential oil analysis and biological investigation. The essential oils from both plants were prepared by hydrodistillation, and GC/MS was employed for volatiles profiling. This study is the first to perform GC/MS analysis of C. linifolia essential oil growing in Egypt. C. linifolia essential oil contained mainly sesquiterpenes, while that of C. ambrosioides was rich in monoterpenes. Ascaridole, previously identified as the major component of the latter, was found at much lower levels. In addition, the oils were investigated for their antimicrobial activity against two Gram positive and two Gram negative bacteria, and one fungus. The insecticidal activities of both oils, including mosquitocidal and pesticidal potentials, were also evaluated. The results of biological activities encourage further investigation of the two oils as antimicrobial and insecticidal agents of natural origin.     

Fumigant and repellent activities of essential oil extracted from Artemisia dubia and its main compounds against two stored product pests

The major chemical constituents of the essential oil extracted from Artemisia dubia wall. ex Bess. (Family: Asteraceae) were found as terpinolene (19.02%), limonene (17.40%), 2,5-etheno[4.2.2]propella-3,7,9-triene (11.29%), isoelemicin (11.05%) and p-cymene-8-ol (5.93%). Terpinolene and limonene were separated as main components from the essential oil. The essential oil showed fumigant toxicity against Tribolium castaneum and Liposcelis bostrychophila with LC₅₀ values of 49.54 and 0.74 mg/L, respectively. The essential oil and isolated compounds of A. dubia showed repellency activities against both insects. Terpinolene and limonene showed the fumigant toxicity against T. castaneum. Terpinolene showed obvious fumigant toxicity against L. bostrychophila. The results indicated that the essential oil of A. dubia had potential to be developed into natural insecticides for controlling stored product pests.     

顶空气相色谱-质谱法分析补骨脂挥发油化学成分

采用顶空气相色谱-质谱(Headspace/GC-MS)联用技术对补骨脂挥发油化学成分进行分析,确认出65种组分,并用峰面积归一化法测定,其质量分数占总挥发性组分峰面积的93.30%。主要成分为:乙酸乙酯(1.61%)、芳樟醇(3.56%)、反-石竹烯(26.8%)、白菖油烯(4.48%)、α-律草烯(3.28%)、1s,顺-卡拉烯(3.16%)、石竹烯氧化物(9.83%)和异补骨脂素(3.02%)。     

Insecticidal and α-glucosidase inhibitory activities of chemical constituents from Viburnum fordiae Hance

The ethanolic extract of the stems of Viburnum fordiae Hance showed insecticidal and α-glucosidase inhibitory activities and then was fractionated by bioactivity-guided fractionation to obtain a rare C₁₃-norisoprenoid (1), together with a new phenolic glycoside (2), and seven known compounds, alangionoside C (3), pisumionoside (4), koaburaside (5), 3,5-dimethoxy-benzyl alcohol 4-O-β-d-glucopyranoside (6), 3,4,5-trimethoxybenzyl-β-d-glucopyranoside (7), arbutin (8), and salidroside (9). The previously undescribed compounds were elucidated as (3R,9R)-3-hydroxy-7,8-didehydro-β-ionyl 9-O-α-d-arabinopyranosyl-(1→6)-β-d-glucopyranoside (1) and 2-(4-O-β-d-glucopyranosyl)syringylpropane-1,3-diol (2) by spectroscopic data (¹H and ¹³C NMR, HSQC, HMBC, ¹H-¹H COSY, HSQC-TOCSY, HRESIMS, IR and ORD) and chemical methods. Compound 1 showed potent insecticidal effect against Mythimna separata with LD₅₀ value of 140 μg g^?1. Compounds 2, 5, 6, 8 and 9 showed varying α-glucosidase inhibitory activity with IC₅₀ values ranging from 148.2 to 230.9 μM.     

Phytochemical analysis of Saponaria officinalis L. shoots and flowers essential oils

Phytochemical analysis by GC and GC/MS of the essential oil samples obtained from fresh shoots and flowers of Saponaria officinalis L. allowed the identification of 96 components in total, comprising 94.7% and 86.0% of the total oils compositions, respectively. Regarding the shoots essential oil, the major of 87 identified volatile compounds were phytol (14.1%), tricosane-6,8-dione (13.4%), patchouli alcohol (7.9%) and tricosane (7.2%), whereas patchouli alcohol (20.0%), heneicosane (11.5%) and tricosane (8.4%) were dominant among the 66 volatiles in the flower oil. Nonterpenoid compounds had the highest contribution in S. officinalis shoots essential oil (53.7%), while in the flower oil, constituents were almost evenly distributed between the oxygenated sesquiterpenoid (41.2%) and nonterpenoid compounds (39.5%).     

Toxicological Stability of Ocimum basilicum Essential Oil and Its Major Components in the Control of Sitophilus zeamais

Essential oils (EOs) are widely recognized as efficient and safe alternatives for controlling pest insects in foods. However, there is a lack of studies evaluating the toxicological stability of botanical insecticides in stored grains in order to establish criteria of use and ensure your efficiency. The objective of this work was to evaluate the toxicological stability of basil essential oil (O. basilicum) and its linalool and estragole components for Sitophilus zeamais (Motschulsky) adults in corn grains by fumigation. The identification of the chemical compounds of the essential oil was performed with a gas chromatograph coupled to a mass selective detector. Mortality of insects was assessed after 24 h exposure. After storage for six (EO) and two months (linalool and estragole) under different conditions of temperature (5, 20, and 35 °C) and light (with and without exposure to light), its toxicological stability was evaluated. Studies revealed that the essential oil of O. basilicum and its main components exhibited insecticidal potential against adults of S. zeamais. For greater toxicological stability, suitable storage conditions for them include absence of light and temperatures equal to or less than 20 °C.     

Comparison of the components of the essential oils from leaves and fruits of Grammosciadium platycarpum

The composition of the hydrodistilled essential oils obtained from dried leaves and fruits of Grammosciadium platycarpum Boiss. & Hausskn. were determined by GC and GC/MS. Twenty-five compounds (87.0%) and sixteen constituents (96.2%) were identified in the leaf and fruit oils, respectively. Linalool (26.1 and 53.9%), (E,E)-α-farnesene (24.1 and 20.4% ) and (Z)-β-santalol (10.6 and 10.9%) were the major components in the leaf and fruit oils. Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 559–560, November–December, 2006.     

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%.     

Chemical composition of the essential oils and headspace volatiles of Ferulago sylvatica (Besser) Reichenb. from Serbia

Abstract

Chemical composition of the headspace volatiles and essential oils isolated from different parts of Ferulago sylvatica was determined by GC and GC/MS analyses. The results showed that headspace volatiles obtained from the aerial parts and roots were similar regarding the number of identified compounds and main components. However, essential oils obtained from different plant organs showed significant differences in chemical composition. Myrcene was the most abundant component of the inflorescences and shoots volatiles, while α-pinene make up over 50% of the root volatiles. Only three components were identified in the root essential oil with 2,3,6-trimethyl benzaldehyde (92.7%) as the main component. In the shoots sample the terpenoid fractions represented 56% of the oil, unevenly distributed between monoterpenoids and sesquiterpenoids with germacrene D (32.5%) recognized as the main constituent. On the other hand, more than 94% of the inflorescences oils were monoterpenoids with myrcene as the most abundant contributor (29.2%).     

Chemical composition,cytotoxicity, antimicrobial and antifungal activity of several essential oils

Essential oils (EOs) are known and used for their biological, antibacterial, antifungal and antioxidant properties. Numerous studies have shown that EOs exhibit a large spectrum of biological activities in vitro. The incidence of drug-resistant pathogens and the toxicity of antibiotics have drawn attention to the antimicrobial activity of natural products, encouraging the development of alternative treatments. The aim of this study was to analyse the phytochemical and the cytotoxic characteristic of 36 EOs; we then evaluated the antimicrobial activity of the less-toxic EOs on Gram-positive, Gram-negative and fungi strains. The results showed low cytotoxicity in seven EOs and good activity against Gram-negative and Candida spp. strains. Based on our results, EOs could be proposed as a novel group of therapeutic agents. Further experiments are necessary to confirm their pharmacological effectiveness, and to determine potential toxic effects and the mechanism of their activity in in vivo models.     

Chemical diversity and anti-acne inducing bacterial potentials of essential oils from selected Elsholtzia species

Essential oils from the aerial parts of four Elsholtzia species; Elsholtzia stachyodes, Elsholtzia communis, Elsholtzia griffithii and Elsholtzia beddomei were obtained by steam distillation and their chemical components were analysed by gas chromatography-mass spectrometry (GC-MS). Principle Component Analysis was used to identify the chemical variations in the essential oils from these plants, which could be categorised into two groups according to their main chemical components which are acylfuran derivatives and oxygenated monoterpenes. Additionally, the anti-acne inducing bacterial activity against Staphylococcus aureus and Staphylococcus epidermidis were evaluated. The oil from E. stachyodes was the most efficacious against the growth of S. aureus and S. epidermidis having MIC values of 0.78 and 1.56 μL/mL, respectively, and exhibited five times more effective than erythromycin (standard antibiotic).     

Chemical composition and insecticidal activity of the essential oil from Helichrysum faradifani endemic to Madagascar

Helichrysum faradifani (Asteraceae) is a perennial shrub growing in rocky and sandy places of Madagascar. The plant is used in the Malagasy traditional medicine as a wound-healing agent, disinfectant and for the treatment of syphilis, diarrhea, cough and headache. In the present work, we analysed the chemical composition of the essential oil distilled from the aerial parts of H. faradifani by GC-MS and evaluated its insecticidal activity against 2nd, 3rd and 4th instar larvae of the lymphatic filariasis vector Culex quinquefasciatus by acute toxicity assays. The most sensitive were 2nd instar (LC₅₀ = 85.7 μL L^?1) larvae. For the 3rd and 4th instar larvae, the estimated LC₅₀ were 156.8 and 134.1 μL L^?1, respectively. Monoterpene hydrocarbons (51.6%) were the major fraction of the essential oil, with the bicyclic α-fenchene (35.6%) as the predominant component. Sesquiterpene hydrocarbons (34.0%) were the second major group characterising the oil, with γ-curcumene (17.7%) as the most abundant component.     

Chemical constituents,anticancer, antimicrobial and antioxidant activities of essential oil from Anaphalis lacteal grown in Qinghai-Tibet Plateau

The chemical constituent of the essential oil from Anaphalis lacteal was determined; 31 compounds, representing 93.91% of the total oil, were identified by gas chromatography–mass spectrometry analysis. Three Gram-positive bacteria species, three Gram-negative bacteria species and four fungi were used to determine antimicrobial activity; the results revealed that the essential oil had a remarkable antimicrobial effect against bacteria and a susceptive effect against fungus. The oil also possessed more efficient free-radical scavenging activities than butylated hydroxytoluene (BHT) with 50% inhibitory concentration (IC₅₀) value 31 μg/mL (40 μg/mL for BHT). MTT assay illustrated that the oil expressed certain effect in inhibiting the growth of HeLa and Hep-6 cancer cells.