Antifungal activities of essential oils and their constituents from indigenous cinnamon (Cinnamomum osmophloeum) leaves against wood decay fungi

Cinnamomum osmophloeum Kaneh is one of the hardwood species indigenous to Taiwan that possesses significant antifungal activity. To examine the antifungal activity of leaf essential oils and dominant constituents from C. osmophloeum, the essential oils of leaves from three clones (A, B, and C) collected from Haw-Lin experimental forest were extracted and their components analyzed by gas chromatography. Results from the antifungal tests demonstrated that the essential oils of both B and C leaves had strong inhibitory effects. The antifungal indices of these two leaf oils at 100 ppm against five strains of white rot fungi and four strains of brown rot fungi were all 100%. Cinnamaldehyde, the major compound in C. osmophloeum leaf essential oils, possessed the strongest antifungal activities compared with the other components. Its antifungal indices against both Coriolus versicolor and Laetiporus sulphureus were 100%. The MIC (minimum inhibitory concentration) of cinnamaldehyde against C. versicolor and L. sulphureus was 50 and 75 ppm, respectively. In addition, comparisons of the antifungal indices of cinnamaldehyde's congeners proved that cinnamaldehyde exhibited the strongest antifungal activities.     

竹叶花椒果实精油对两种蚊虫的毒杀活性研究

采用浸液法测试了竹叶花椒果实的水蒸汽蒸馏精油对白纹伊蚊和致倦库蚊幼虫的毒杀效果,并用三角瓶密闭熏蒸法研究了精油对这两种成蚊的熏杀活性;此外,采用GC-MS分析了该精油的化学成分。研究结果:(1)精油对白纹伊蚊和致倦库蚊的Ⅰ、Ⅱ、Ⅲ、Ⅳ龄期幼虫及蛹的LC50值分别为25.634/61.472、31.763/76.431、52.356/110.172、258.497/121.884和198.263/162.048mg.L-1;(2)精油对白纹伊蚊和致倦库蚊成蚊的LC50值分别为24.957和29.517μg.cm-3;(3)在147.52μg.cm-3熏杀剂量下,精油对白纹伊蚊和致倦库蚊成蚊的KT50值分别为3.493和2.993min,24h致死率均为100%;(4)共鉴定出18种化合物,其中萜烯类10种,占精油总量的67.122%,为竹叶花椒果实精油的主要成分。竹叶花椒果实精油对白纹伊蚊和致倦库蚊均有明显的致死作用,且作用速度快,具有开发为植物源杀蚊剂的潜力。     

Terminating red imported fire ants using Cinnamomum osmophloeum leaf essential oil

Eleven compounds from indigenous cinnamon (Cinnamomum osmophloeum) leaf essential oil were identified by GC-MS and the dominant constituent was trans-cinnamaldehyde (79.85%). The toxicity of leaf essential oil and trans-cinnamaldehyde were then determined to study their effectiveness in controlling the red imported fire ant, Solenopsis invicta Buren. The results of the toxicity tests indicated that both the indigenous cinnamon leaf essential oil and trans-cinnamaldehyde had an excellent inhibitory effect in controlling the red imported fire ant. The LT(50) values for both 2% leaf essential oil and 2% trans-cinnamaldehyde after open exposure were 105.0min and 32.2min; after close exposure were 18.5min and 21.2min, respectively.     

Chemical compositions and larvicidal activities of leaf essential oils from two eucalyptus species

In the current study, the mosquito larvicidal activity of leaf essential oils and their constituents from two eucalyptus species (Eucalyptus camaldulensis and Eucalyptus urophylla) against two mosquito species, Aedes aegypti and Aedes albopictus, was investigated. In addition, the chemical compositions of the leaf essential oils were analyzed using gas chromatography-mass spectrometry. Results from the larvicidal tests revealed that essential oil from the leaves of E. camaldulensis had an excellent inhibitory effect against both A. aegypti and A. albopictus larvae. The 12 pure constituents extracted from the two eucalyptus leaf essential oils were also tested individually against two mosquito larvae. Among the six effective constituents, alpha-terpinene exhibits the best larvicidal effect against both A. aegypti and A. albopictus larvae. Results of this study show that the leaf essential oil of E. camaldulensis and its effective constituents might be considered as a potent source for the production of fine natural larvicides.     

Anti-inflammation activities of essential oil and its constituents from indigenous cinnamon (Cinnamomum osmophloeum) twigs

In this study, chemical compositions of hydrodistilled essential oil and anti-inflammatory activities from the twigs of Cinnamomum osmophloeum Kaneh. were investigated for the first time. The chemical constituents of the twig essential oil were further analyzed by GC-MS and they were found to be L-bornyl acetate (15.89%), caryophyllene oxide (12.98%), gamma-eudesmol (8.03%), beta-caryophyllene (6.60%), T-cadinol (5.49%), delta-cadinene (4.79%), trans-beta-elemenone (4.25%), cadalene (4.19%), and trans-cinnamaldehyde (4.07%). The effects of essential oil on nitric oxide (NO) and prostaglandin E2 (PGE2) production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages were also examined. Results of nitric oxide tests indicated that twig essential oil and its major constituents such as trans-cinnamaldehyde, caryophyllene oxide, L-borneol, L-bornyl acetate, eugenol, beta-caryophyllene, E-nerolidol, and cinnamyl acetate have excellent activities. These findings demonstrated that essential oil of C. osmophloeum twigs have excellent anti-inflammatory activities and thus have great potential to be used as a source for natural health products.     

Antioxidant activities of ethanolic extracts from the twigs of Cinnamomum osmophloeum

Cinnamomum osmophloeum Kaneh. is an indigenous tree species in Taiwan. In this study, phytochemical characteristics and antioxidant activities of ethanolic extracts from the twigs of C. osmophloeum were investigated for the first time. The extracts were obtained successively using liquid-liquid partition to yield n-hexane (Hex), ethyl acetate (EtOAc), n-butanol (BuOH) and water fractions. The antioxidant activities of C. osmophloeum twig extracts were examined using various antioxidant assays, such as DPPH, NBT, reducing power, lipid peroxidation using mouse brain homogenates, metal chelating ability, and photochemiluminescence (PCL). In addition, total phenolic contents were also determined. Results revealed that the BuOH fraction exhibited the best performance in DPPH assay, NBT assay, reducing power assay and lipid peroxidation using mouse brain homogenates assay. Furthermore, the BuOH fraction has the highest total phenolic contents (496.7 mg of GAE/g). Consequently, kaempferol-7-O-rhamnoside was also isolated from the antioxidative BuOH fraction and its activity was also confirmed. These results demonstrated that ethanolic extracts of C. osmophloeum twigs have excellent antioxidant activities and thus it has great potential as a source for natural health products.     

Larvicidal activity of Tagetes patula essential oil against three mosquito species

Larvicidal activity of Tagetes patula essential oil was tested against the fourth instar larvae of Aedes aegypti, Anopheles stephensi, and Culex quinquefaciatus. Five different concentrations of essential oil were studied and the results were compared with that of synthetic insecticide, malathion. A. aegypti (LC(50) 13.57, LC(90) 37.91) was most susceptible followed by An. stephensi (LC(50) 12.08, LC(90) 57.62) and C. quinquefaciatus (LC(50) 22.33, LC(90) 71.89).     

Chemical polymorphism and antifungal activity of essential oils from leaves of different provenances of indigenous cinnamon (Cinnamomum osmophloeum)

The essential oils isolated from nine geographical provenances of indigenous cinnamon (Cinnamomum osmophloeum Kaneh.) leaves were examined by GC-MS and their chemical constituents were compared. According to GC-MS and cluster analyses the leaf essential oils of the nine provenances and their relative contents were classified into six chemotypes-cinnamaldehyde type, cinnamaldehyde/cinnamyl acetate type, cinnamyl acetate type, linalool type, camphor type and mixed type. In addition, the antifungal activities of leaf essential oils and their constituents from six chemotypes of indigenous cinnamon were investigated in this study. Results from the antifungal tests demonstrated that the leaf essential oils of cinnamaldehyde type and cinnamaldehyde/cinnamyl acetate type had an excellent inhibitory effect against white-rot fungi, Trametes versicolor and Lenzites betulina and brown-rot fungus Laetiporus sulphureus. The antifungal indices of leaf essential oils from these two chemotypes at the level of 200 micro/ml against T. versicolor, L. betulina and L. sulphureus were all 100%. Among them, the IC(50) (50% of inhibitory concentrations) value of the essential oil of cinnamaldehyde type leaf against L. sulphureus was 52-59microg/ml. Cinnamaldehyde possessed the strongest antifungal activities in comparison with other constituents of the essential oils from cinnamaldehyde type leaf, at the level of 100microg/ml its antifungal indices against T. versicolor, L. betulina and L. sulphureus were 100%. The IC50 values of cinnamaldehyde against T. versicolor, L. betulina and L. sulphureus were 73, 74 and 73microg/ml, respectively.     

Anti-termitic activities of essential oils from coniferous trees against Coptotermes formosanus

In this study, the anti-termitic activities of 11 essential oils from three species of coniferous tree against Coptotermes formosanus Shiraki were investigated using direct contact application. Results demonstrated that at the dosage of 10 mg/g, the heartwood and sapwood essential oils of Calocedrus macrolepis var. formosana and Cryptomeria japonica and the leaf essential oil of Chamaecyparis obtusa var. formosana had 100% mortality after 5 d of test. Among the tested essential oils, the heartwood essential oil of C. macrolepis var. formosana killed all termites after 1 d of test, with an LC(50) value of 2.6 mg/g, exhibiting the strongest termiticidal property. The termiticidal effect of heartwood essential oil was due to its toxicity and its repellent action.     

三种植物精油对家蝇成虫的熏蒸活性

【目的】探究香樟Cinnamomum caphora果实精油、天竺桂Cinnamomum pedunculatum叶精油和龙柏Sabina chinensis var.chinensis叶精油对家蝇Musca domestica成虫的熏蒸活性,比较这3种植物精油以及混配精油对家蝇的毒力效果,为植物源灭蝇剂的开发提供理论依据。【方法】利用水蒸汽蒸馏法提取植物精油,采取三角瓶密闭熏蒸法测试植物精油及其混剂对家蝇5日龄成虫的熏蒸毒性和击倒作用。【结果】3种植物精油对家蝇的LC50值(致死中浓)分别为5.28,16.86和14.54μg/cm3。LC90熏蒸剂量下,对家蝇的KT50值(击倒中时)分别为12.03,16.56和13.37 min。天竺桂叶精油和龙柏叶精油混配后对家蝇有增效作用,二者的LC50值配比为9∶1时,增效作用极为显著,共毒系数高达367.95。【结论】香樟果实精油对家蝇成虫有很好的熏杀和击倒作用,龙柏叶精油次之,天竺桂叶精油效果最差。天竺桂叶精油和龙柏叶精油混配后对其对家蝇成虫的熏蒸毒性有增效作用。3种植物精油具备开发环保灭蝇剂的潜力,可深入研究。     

Surfactant-enhanced essential oils as mosquito larvicides

Using laboratory bioassays with fourth-instarCulex pipiens formmolestus larvae, we explored the larvicidal properties of two representative plant-derived oils, eucalyptus oil and turpentine (two grades), and cineole, the main component of eucalyptus oil. Each was larvicidal alone, but efficacy was enhanced when the spreading pressure was increased by adding 1% insoluble surfactant (Arosurf MSF) plus 1% detergent. Cheap turpentine was more effective than more refined turpentine. These mixtures were compared with the familiar surface-active larvicides Arosurf and Golden Bear Oil. At a dose of 2 μl per tub (=0.13 μl cm⁻²), enhanced by surfactants (turpentine:Arosurf:detergent 100:1:1 by volume), refined turpentine acted faster than Arosurf alone, causing higher mortality at 24 and 48 h after treatment but equivalent mortality at 72 h. It immobilised more larvae than Golden Bear Oil in the first three hours, but was less effective over 24 h. Crude turpentine enhanced by surfactants immobilised about as many larvae as Golden Bear Oil over 24 h. These findings indicate that plant essential oils merit further attention as widely available, environmentally benign mosquito larvicides.     

Constituents of the essential oils from three tetraploid species of Chrysanthemum

The chemical constituents of the volatile oils from Chrysanthemum indicum, C. yoshinaganthum and C. cuneifolium, three botanically related tetraploid species, are described. By spectroscopic methods, 42 compounds were identified, including 22 monoterpenoids, 17 sesquiterpenoids and 3 acetylenic compounds. The sesquiterpenoids estafiatin (C. yoshinaganthum) and valeranone (C. indicum) have been found for the first time in Chrysanthemum species.     

Screening the antifungal activity of essential oils against decay fungi from palmyrah leaf handicrafts

Background

The whitish tender leaves of Palmyrah are used for making handicrafts. The problem with these articles is discolouration with time and become more brittle due to fungal attack. This could be prevented by some protective coating. Instead of expensive and harmful chemicals we decided to test natural plant essential oils to control fungal attack. Palmyrah leaf article decay fungi were isolated from two different sites of Jaffna peninsula. In this investigation Antifungal Activity of different plant essential oils from neem (Azadirachta indica), castor (Ricinus communis), citronella (Cymbopogon sp) and camphor (Cinnamomum camphora) obtained from local market have been evaluated against isolated fungi. For screening of Antifungal activity, tests and controls were set to determine minimum inhibitory concentration (MIC) and Percentage of Growth Inhibition.

Results

Morphologically three different types of Palmyrah leaf decay fungi were isolated and characterized as Aspergillus niger, Aspergillus flavus and Penicillium sp. Neem and castor oils have recorded no significant (0.05 > P) antifungal activity while citronella and camphor oils showed significantly different antifungal activity compared with control. Camphor oil and Citronella oil showed 100, 58.13% of average growth inhibition for A. niger. 96.38, 51.32% for A.flavus and 84.99, 72.76% for Penicillium sp respectively. Camphor oil showed highest percentage of growth inhibition at lowest minimum inhibitory concentration compared with citronella oil. Camphor oil was found to be highly antifungal and most effective against A niger, and A. flavus, compared with Penicillium sp and gave 100 percentage of growth inhibitions at 5, 1 and 15 ml/dl minimum inhibitory concentration respectively.

Conclusion

Significantly higher broad-spectrum of antifungal activity was observed in camphor oil than other tested oils because it showed highest percentage of growth inhibition at lowest inhibitory concentration. Therefore it could be used for the development of new environmental friendly antifungal agent for the preservation of leafy handicrafts. Further formulation, field experiments are necessary to achieve this target.     

椿叶花椒果实精油对两种蚊虫的生物活性及成分分析

为筛选环保型的植物源灭蚊活性物质, 研究了椿叶花椒 Zanthoxylum ailanthoides 果实精油对白纹伊蚊Aedes albopictus和致倦库蚊Culex pipiens quinquefasciatus成蚊的熏杀活性, 并测试了精油对这两种蚊幼虫的毒杀效果。此外, 采用GC-MS分析了该精油的化学成分。 结果表明：在102.145 μg·cm^-3熏杀剂量下, 精油对白纹伊蚊和致倦库蚊成蚊的KT50值分别为2.788和3.505 min, 24 h致死率分别为100%和97.53%。该精油对白纹伊蚊和致倦库蚊4龄幼虫的LC50值分别为45.237和20.759 mg·L^-1。从椿叶花椒果实精油中共鉴定出14种化合物, 其中2-十一酮为主要成分, 相对含量为89.86%。结果说明椿叶花椒果实精油对两种蚊虫均有明显的杀虫活性, 具有开发成植物源灭蚊剂的潜力。     

Chemical composition and biological activities of essential oils extracted from Korean endemic citrus species

The aim of this study was to analyze the chemical composition of 14 kinds of citrus oils and to test their biological activities. Citrus essential oils were obtained by steam distillation from immature fruits collected from Jeju Island and were analyzed using gas chromatograph (GC)- flame ionization detectors (FID) and GC-MS. Limonene (55.4% to 91.7%), myrcene (2.1% to 32.1%), alpha-pinene (0.6% to 1.6%) and linalool (0.4% to 6.9%) were the major components in most citrus species. To evaluate in vitro antibacterial activity, all essential oils were tested against Propionibacterium acnes and Staphylococcus epidermidis. Nine out of fourteen citrus oils exhibited antibacterial activity against P. acnes, but not against S. epidermidis. The effects of the citrus oils on DPPH radical scavenging, superoxide radical anion scavenging, nitric oxide radical, and cytotoxicity were also assessed. Three essential citrus oils, Joadeung, Dongjunggyul, and Bujiwha, exhibited potent inhibitory effects on nitric oxide production. Two essential oils, Dongjunggyul and Joadeung, showed potent free radical scavenging activities in the DPPH assay. For future applications in cosmetic products, we also performed MTT assays in a human dermal fibroblast cell line. The majority of the essential oils showed no cytotoxicity. The results indicate that citrus essential oils can be useful natural agents for cosmetic application.     

Antifungal activity of some essential oils against toxigenic Aspergillus species

Increasing attentions have been paid on the application of essential oils and plant extracts for control of postharvest pathogens due to their natural origin and less appearance of resistance in fungi pathogens. Some Aspergillus species are toxigenic and responsible for many cases of food and feed contamination. Some Toxins that produce with some Aspergillus species are known to be potent hepatocarcinogens in animals and humans. The present work evaluated the parameters of antifungal activity of the essential oils of Zataria multiflora, Thymus migricus, Satureja hortensis, Foeniculum vulgare, Carum capticum and thiabendazol fungicide on survival and growth of different species of Aspergillus. Aerial part and seeds of plant species were collected then dried and its essential oils isolated by means of hydrodistillation. Antifungal activity was evaluated in vitro by poisonous medium technique with PDA medium at six concentrations. Results showed that all essential oils could inhibit the growth of Aspergillus species. The essential oil with the best effect and lowest EC50 and MIC (Minimum Inhibitory Concentration) was Z. multiflora (223 microl/l and 650 microl/l, respectively). The chemical composition of the Z. multiflora essential oil was analyzed by GC-MS.     

Superheated water extraction of essential oils from Cinnamomum zeylanicum (L.)

Introduction – Superheated water extraction (SHWE) potentially provides an environmentally friendly and clean extraction technique which uses a minimum or no organic solvent. The scope and limitations of the technique have still to be fully explored. Objective – To investigate the application of SHWE to cinnamon (Cinnamomum zeylanicum L.) bark and leaves as typical plant materials to determine if this extraction method can yield a higher quality oil. Methodology – Samples of cinnamon bark or leaves were extracted at 200°C with water under pressure. The essential oils were obtained from the aqueous solution using a solid phase extraction cartridge and were then examined by GC‐MS. Results – Using superheated water extraction, cinnamon bark oil with over 80% cinnamaldehyde and cinnamon leaf oil containing up to 98% eugenol were obtained. Alternative solvent extraction methods were also studied but led to emulsion formation apparently because of the presence of cellulose breakdown products. Conclusion – Superheated water extraction offers a cheap, environmentally friendly technique with a shorter extraction time than hydrodistillation and yielded a higher quality oil with a higher proportion of eugenol than hydrodistillation. Copyright © 2010 John Wiley & Sons, Ltd.     

Comparative larvicidal activity of essential oils from three medicinal plants against Aedes aegypti L

This work aimed at comparing larvicidal activity of essential oils extracted from the dried leaves of Alpinia speciosa, Cymbopogon citratus, and Rosmarinus officinalis against Ae. aegypti larvae. The larvae were observed for 4 h and at 24 h according to a completely randomized design with three replications and the following concentrations [μl/ml]: 0.25, 0.5, 1.0, 1.5, 2.0, 2.5, and controls were distilled water, and commercial standard citral, camphor, eucalyptol, α‐pinene, and β‐myrcene. The essential oil of C. citratus had the lowest LC₅₀ (0.28) and LC₉₀ (0.56) values, followed by that of A. speciosa (0.94 and 1.2, resp.) and of R. officinalis (1.18 and 1.67, resp.), and only the commercial standards citral and α‐pinene were larvicidal.