Comparative analysis of essential oil components of two Cryptomeria species from China

The essential oils obtained by hydrodistillation from leaves of Chinese native Cryptomeria japonica and Cryptomeria fortunei were analyzed by GC and GC-MS. Fifty-seven compounds were identified in the essential oils of C. japonica with α-elemol (20.12%), kaur-16-ene (14.84%), β-phellandrene (5.97%), β-elemene (5.87%), α-eudesmol (5.62%) and β-eudesmol (5.03%) as main constituents. Forty components were identified in the oil of C. fortunei with kaurene (34.04%), α-elemol (13.34%), γ-eudesmol (10.80%), β-eudesmol (10.16%), α-pinene (2.75%) and γ-cadinene (1.92%) as the most abundant components. This study demonstrated the occurrence of α-elemol chemotype in C. japonica and kaurene chemotype in C. fortunei from China. The essential oil compositions of two Cryptomeria samples were shown that they can be used for green plant protection, pharmaceutical, perfume and food industries.     

Chemical composition and antioxidant and antimicrobial activity of essential oil of Artemisia annua L. from Bosnia

Hydrodistilled volatile oil obtained from the aerial parts of Artemisia annua L., cultivated near Sarajevo, Bosnia, was analyzed by GC-MS. More than one hundred compounds were identi?ed, representing 95.5% of the total oil. The major constituents of essential oil were oxygenated monoterpenes, artemisia ketone (30.7%) and camphor (15.8%). Isolated essential oil was tested for radical-scavenging ability using the stable DPPH radical, the ABTS radical, for reducing power ability with a test based on the reduction of ferric cations, for reducing ability of hydroxy radical in ORAC assay, and for metal chelating ability using the ferrozine assay. In all tests oil did not show a prominent antioxidant activity, but still comparable with thymol, an already known antioxidant. The screening of antimicrobial activity of oil was individually evaluated against representatives of Gram-positive, Gram-negative bacteria and fungi, using the agar diffusion method. All tested microorganisms were inhibited by essential oil. To the best of our knowledge, this is the first report of antimicrobial activity of essential oil of A. annua against Haemophilus influenzae, Enterococcus faecalis, Streptococcus pneumoniae, Micrococcus luteus and Candida krusei microbial strains. The antioxidant, antibacterial and antifungal activity of essential oil of A. annua from Bosnia is presented here for the first time and extends our knowledge in the range of valuable biological activities and possible roles in therapy associated with this medicinal herb.     

Variations in essential oil yield and composition during Cinnamomum cassia bark growth

To extract essential oil for industrial use, the yields and compositions of bark oil during Cinnamomum cassia growth (1-3 years old for the branch bark; 5-12 years old for the stem bark) were determined. The branch bark fraction had a higher essential oil yield than the whole branch. The essential oil yield from branch bark varied within 2.70-3.11% (w/w), while that from stem bark was 0.41-2.61% (w/w) due to differences in age and segment (top, center and lower) of the tree. There were 41 volatile compounds identified in bark oil, among which the majority presented high fluctuations in percentage of composition both in different growth stages and segments. Variations in oil yields did not present the same pattern as the percentages of trans-cinnamaldehyde. The results suggest that choosing bark according to trees’ growth stages and separating stem barks into top, center and lower sections within a tree should significantly improve the extraction efficiency.     

Chemical composition of the essential oil and antioxidant activity of methanolic extracts from fruits and flowers of Hypericum lydium Boiss.

This study was conducted to evaluate the essential oil composition and antioxidant activity of methanolic extracts from fruits and flowers of Hypericum lydium Boiss., a wild growing species of the Turkish flora. The antioxidant activities were determined through several biochemical assays. Both extracts showed an inhibitory effect against the formation of TBARS in a phosphatidylcholine liposome model system, moderate scavenging effect on DPPH and superoxide radicals, prominent reducing power and inhibitory effect on deoxyribose degradation in both the nonsite and site-specific assay, but a greater hydroxyl radical scavenging activity was observed in the non-site specific assay, suggesting that the extracts were better at scavenging hydroxyl radicals than at chelating iron. Correlation analysis indicated that there was a linear relationship between antioxidant potency, free-radical scavenging activity, reducing power and the content of flavonoids of fruits and flowers extracts. The essential oils obtained by hydrodistillation were analyzed by GC and GC-MS. In total forty-three compounds were identified. The most abundant components were monoterpenes hydrocarbons represented principally by α-pinene. The tested oil showed no antioxidant activity.     

Composition of essential oil, concrete, absolute and SPME analysis of Tagetes patula capitula

The chemical compositions of essential oil, concrete, absolute from the capitula of Tagetes patula (family Asteraceae) were analysed by GC-FID and GC/MS. The major compounds identified were (Z)-β-ocimene, (E)-β-ocimene, terpinolene, (Z)-ocimenone, (E)-ocimenone and δ-elemene. In addition, the volatiles of live and plucked capitula (flowers) were analysed by SPME technique using PDMS/DVB/CAR fiber. The SPME-GC-FID analyses of live capitula showed that the volatiles were rich in monoterpenoids in comparison to the plucked capitula. On the other hand, the plucked capitula recorded with significant increase in sesquiterpenoids in comparison to the living capitula.     

European pennyroyal (Mentha pulegium) from Portugal: Chemical composition of essential oil and antioxidant and antimicrobial properties of extracts and essential oil

There is a growing interest of industry to replace synthetic chemicals by natural products with bioactive properties from plant origin. The aim of this study was to determine the chemical composition of European pennyroyal (Mentha pulegium) essential oil and to characterize the in vitro antioxidant and antimicrobial activities of its water (hot and cold) and ethanolic extracts and of the essential oil. The essential oil revealed menthone, pulegone and neo-menthol as the main constituents, comprising 35.9, 23.2 and 9.2% of the essential oil, respectively. The hot water extract exhibited the highest antioxidant activity and phenol content. In contrast, the extracts were not very effective to inhibit the growth of the seven foodborne spoilage and pathogenic bacteria tested, but the essential oil showed antibacterial activity against all bacterial strains. In conclusion, extracts and essential oil of M. pulegium from Mediterranean origin have huge potential as an alternative to chemical additives for the food industry.     

Improvement of essential oil yield of oil-bearing (Rosa damascena Mill.) due to surfactant and maceration

The essential oil content of the oil-bearing rose (Rosa damascene Mill.) is relatively low, around 0.3-0.4 mL kg⁻¹ in fresh flowers. There is a need to increase essential oil yield of oil-bearing rose. The objective was to examine the effect of Tween 20 (polyoxyethylene sorbitan monolaurate) applied with, or without, maceration of flowers on oil content and composition of oil-bearing rose harvested at beginning of flowering, full bloom, and end of flowering. Addition of Tween 20 at 1000 mL L⁻¹ and 2500 mL L⁻¹ increased essential oil yield by 26% (to 0.44 mL kg⁻¹) and 54% (to 0.54 mL kg⁻¹) respectively relative to the untreated control that gave 0.35 mL kg⁻¹ yield. Maceration, in combination with the addition of Tween 20 at 1000 mL L⁻¹ and Tween 20 at 2500 mL L⁻¹, increased oil yield by 69% (to 0.59 mL kg⁻¹) and 94% (to 0.68 mL kg⁻¹) respectively. Among the three phenological phases of harvest, harvesting at the beginning of flowering gave the highest yield followed by the full bloom and then by the end of flowering phases. Since the interaction effect was not significant, the differences obtained among the treatments were regardless of the phase, and vice versa. Treatments did not significantly alter composition of the essential oil. Postharvest pre-extraction application of Tween 20 in combination with maceration could be used in the rose industry for increasing the essential oil yield.     

Variation in essential oil and fatty acid composition in different organs of cultivated and growing wild Ruta chalepensis L.

The essential oil and fatty acid composition of two provenances of Ruta chalepensis from four organs (leaves, flowers, stems and fruits) was determined. The effect of the plant part on total fatty acid contents, essential oil yields, fatty acid and volatile constituents was significant.Fatty acid profiles varied significantly among the studied provenances and organs. Linolenic acid had the highest amount in leaves of the two provenances. From R. chalepensis, in all organs, the main fatty acids were palmitic (13.10-25.31%), followed by palmitoleic (0-15.72%), stearic (1.03-6.85%), oleic (1.90-24.04%), arachidic (0.11-4.03%), eicosatetraenoic (0.10-5.60%) and behenic (0.47-6.09%) acids. Saturated fatty acids had the highest amounts in growing wild R. chalepensis flowers, and cultivated R. chalepensis stems were characterized by the predominance of polyunsaturated fatty acids. Oil composition of all studied organs has a healthy and nutritionally value. Essential oil yields varied from 0.39% to 2.46% and showed a remarkable variation with plant organs. Thirty-six volatile compounds were identified in different analyzed essential oils; 2-undecanone, 2-nonanol and 2-dodecanone had the highest percentages.     

Mathematical modeling for extraction of essential oil from Baccharis spp. by steam distillation

Baccharis (Compositae-Asteraceae) is a large genus of plants distributed from the USA to Argentina, of which 90% are located in South America. In recent decades, species of the genus have been studied, due to their importance as sources of novel active components with possible applications in the pharmaceutical and chemical industries. This work studied three species of Baccharis: Baccharis uncinella DC, Baccharis anomala DC and Baccharis dentata (Vell) G.M. Barroso collected in São Francisco de Paula in southern Brazil. The aim of this work is the evaluation of the aromatic potential of the essential oil obtained by steam distillation method and the simulation of the extraction data by means of a mathematical model. A mathematical model based on mass transfer fundamentals is developed and applied to correlate the experimental data. This model is based on the existence of the broken and intact cells, in which the oil located in the broken cells is rapidly extracted and the oil from intact cells diffuses slowly to the surface of the vegetal material. The analysis of the essential oil was carried through by GC-MS and the major compounds identified to both processes were α-pinene, β-pinene, and spathulenol (B. uncinella), spathulenol, β-caryophyllene, and β-selinene (B. anomala), and germacrene-D, caryophyllene oxide, and spathulenol (B. dentata).     

Antifungal and antiaflatoxigenic efficacy of Caesulia axillaris Roxb. essential oil against fungi deteriorating some herbal raw materials, and its antioxidant activity

The study deals with evaluation of antifungal and antiaflatoxigenic Caesulia axillaris Roxb. essential oil (EO) against herbal raw materials deteriorating fungi and its free radical scavenging activity. During mycoflora analysis these herbal raw materials were found to be severely contaminated by different fungi and aflatoxins. A total of nine different fungal species were isolated from three herbal raw materials. Aspergillus flavus LHPtc was recorded as the highest aflatoxin B1 producing strain. EOs of some plants were tested for their fungitoxicity against the toxigenic strain A. flavus LHPtc, and C. axillaris EO was found as potent fungitoxicant. C. axillaris EO was chemically characterized through GC-MS analysis which depicted the presence of 18 compounds, dl-limonene and Euasarone being the major components. The EO exhibited broad spectrum of fungitoxicity against fungi causing postharvest deterioration of herbal raw materials. At 1.0 μl ml⁻¹ the oil showed complete inhibition of fungal growth and aflatoxin B₁ production was inhibited at 0.8 μl ml⁻¹. Free radical scavenging activity of the oil was also recorded by 2,2-diphenyl-1-picrylhydrazyl assay, and its IC₅₀ value was found 18 μl ml⁻¹. The safety limit of the EO was determined in terms of LD₅₀ on mice, which was 9166.6 μl kg⁻¹, suggesting its non mammalian toxicity. The EO of C. axillaris may be recommended as a plant based preservative in enhancement of shelf life of herbal raw materials by preventing their lipid peroxidation as well as biodeterioration due to fungal and aflatoxin contamination.     

Dual extraction of essential oil and podophyllotoxin from Juniperus virginiana

The leaves (needles) of eastern red cedar (Juniperus virginiana L.) contain two important natural products: essential oil and podophyllotoxin. The hypothesis of this study was that it may be possible to extract both essential oil and podophyllotoxin from the leaves of the tree, by using a dual extraction method. Podophyllotoxin was obtained from the leaves following steam distillation of the leaves to produce the essential oil, indicating that steam distillation did not degrade podophyllotoxin. Furthermore, a product with 6% purity podophyllotoxin was obtained from the steam-distilled plant material, demonstrating the possibility for the establishment of an industrially economic protocol for dual extraction of these two natural products. Our study demonstrated that J. virginiana leaves, currently a waste-product from the timber industry, could be sequentially extracted for essential oil and podophyllotoxin and utilized as a by-product instead. We also found that the J. virginiana heartwood (a traditional source for cedarwood essential oil) does not contain podophyllotoxin. This is the first study to report both podophyllotoxin and essential oil in J. virginiana, and the first report on the dual extraction of these two natural products from the same biomass samples.     

Advances in the identification and agrochemical importance of sesquiterpenoids from Bulnesia sarmientoi essential oil

Bulnesia sarmientoi Lorentz ex Griseb volatile oil was characterized by GC × GC-TOF-MS analysis. Major components were guaiol and bulnesol, followed by hanamyol. The enhanced sensitivity and superior resolution of GC × GC resulted in the identification of thus-far unreported oil constituents as β-guaiene, guaioxide, elemol, germacrene-B, eudesm-5-en-11-ol, γ-eudesmol, α-eudesmol and (−)-hanamyol. The insecticidal effect of B. sarmientoi oil and its main constituents (guaiol, bulnesol and hanamyol) on Spodoptera littoralis, Rhopalosiphum padi and Myzus persicae was studied. Guaiol affected the aphids in a dose-response fashion, showing low efficiency, while bulnesol and hanamyol were inactive. Both the oil and its constituents were also assayed for antifungal action against Fusarium spp. and phytotoxicity to Lactuca sativa. Among the pure compounds tested, bulnesol had a low-moderate effect on Fusarium moniliforme while hanamyol had a strong effect on Fusarium solani. Neither the oil nor the tested compounds affected L. sativa germination or radicle length, indicating that B. sarmientoi is not phytotoxic.     

Insecticidal formulation based on Xylopia aethiopica essential oil and kaolinite clay for maize protection

Insecticidal formulations based on the essential oil of Xylopia aethiopica (Annonaceae) and kaolinite-clay (particles size less than 50 μm) are efficient in protecting stored grains. Ingestion-contact insecticide tests have been conducted using the maize weevil Sitophilus zeamais (Motsch.) (Curculionidae). Residual action of terpenic constituents adsorbed on clay was assessed. Bioassays indicated that S. zeamais adult mortality increased with the quantity of active ingredient. The formulation based on essential oil and clay produced mortality rates ranging from 22% at 2.5% (w/w) to 100% at 10% (w/w). The lethal concentration producing a 50% mortality rate (LC50) was 4.35% (w/w). Efficacy also depended on storage conditions and duration of the formulation, decreasing from 91 to 37% for formulation stored in closed boxes and from 91 to 17% for formulation stored in open boxes, after 1 and 15 days respectively.     

Chemical characterization of barks from Picea abies and Pinus sylvestris after fractioning into different particle sizes

The composition of Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) barks was studied after grinding and fractioning into different particles sizes.Both barks fractionated well and with similar fraction yield profile. The yield of fines was low and the major fractions were larger particles, i.e. 2.4% and 3.1% of particles under 0.425 mm and 66.0% and 50.3% of particles over 2 mm, respectively for spruce and pine bark.The chemical composition of spruce and pine barks, as a mass weighed average of all granulometric fractions was, respectively: ash 3.3 and 4.6%; total extractives 21.6 and 18.8% (hydrophilic extractives were dominant), lignin 27.9 and 33.7% and holocellulose 42.7 and 37.6%. Suberin accounted for 1.3% and 1.6% of spruce and pine bark, respectively. The non-cellulosic monosaccharides showed in both barks predominance of arabinose followed by xylose and mannose.Ash elemental composition showed that N represented about 35% of the total inorganics, Ca 35% and K 17%. Zn, Cu, Ni, Cr and Pb were present in both barks at levels under 1% of the total inorganics. Spruce bark had in average higher contents compared to pine bark, except for Pb and Cr.Size reduction of spruce and pine bark did not apply randomly to the different components and instead resulted into partial separation of the inorganic and organic matter into different size particles. Fine particles concentrated higher amounts of inorganic material and of extractives.     

Use of essential oil of Laurus nobilis obtained by means of a supercritical carbon dioxide technique against post harvest spoilage fungi

The aspects of the antifungal activity of essential oil of laurel (Laurus nobilis) obtained by means of a supercritical carbon dioxide (SFE-CO₂) technique against post harvest spoilage fungi, have been studied in this research work by tests performed under in vitro and in vivo conditions. The measurement of antifungal activity of the oil, for its potential application as botanical fungicide, is very useful to find alternatives to synthetic fungicides. The present paper reports, for the first time, the results about the antifungal activity of laurel oil, obtained by a semi-industrial process that utilize a SFE-CO₂ technique, against three plant pathogenic fungi. The determination of the main active substances was carried out by gas chromatography analysis: laurel oil was characterized by high content (≥10%) of 1.8-cineole, linalool, terpineol acetate, methyl eugenol and a low content (<10%) of linalyl acetate, eugenol, sabinene, β-pinene, α-terpineol. The inhibition of the mycelial growth of Botrytis cinerea, Monilinia laxa and Penicillium digitatum was evaluated in vitro at the concentration range of 200, 400, 600, 800 and 1000 μg/mL. M. laxa was totally inhibited by application of the oil at the lowest concentration, B. cinerea was completely inhibited at the highest concentration, and a fungistatic action was observed in both cases. P. digitatum was only partially inhibited at all the concentration ranges. The activity of the oil, placed in the form of spray on the fruit skin at the concentration range of 1, 2 and 3 mg/mL, was studied by biological tests. Both curative and protective activities of the oil have been evaluated on peaches, kiwifruits, oranges and lemons artificially inoculated with M. laxa, B. cinerea and P. digitatum, respectively. A very good antifungal activity has been found on kiwifruits and peaches when the oil was placed before the inoculation at a concentration of 3 mg/mL (68 and 91% of decay inhibition respectively). The same activity has been found on peaches when the oil was placed after the infection (76% of decay inhibition). The application of the oil did not caused any phytotoxic effect and kept any fruit flavour, fragrance or taste. This study has demonstrated that the essential oil of L. nobilis extracted by a SFE-CO₂ technique, is one potential and promising antifungal agent which could be used as botanical fungicide in the postharvest protection of peaches and kiwifruits against M. laxa and B. cinerea.     

The effects of onion and salt treatments on essential oil content and composition of Rosa damascena Mill

Due to the low oil content of Rosa damascena Mill., on one hand, and the wide spectrum of its application, on the other hand, it is desirable to find ways to increase the oil yield and also its quality. Therefore, in the present study the effects of chopped onion (1.0, 1.5, 2.0 and 4.0 g per 220 g of rose flower) and sodium chloride (11.0, 15.5, 22.0 and 30.0 g per 220 g of rose flower) which were added to rose flowers before distillation, were investigated on the quality and quantity of the oil. The quantity was measured as the ratio of oil to rose flower (w/w, %) and the quality was evaluated using the oil composition especially the content of monoterpene alcohols and hydrocarbons. Compared with corresponding control sample, treating with 1.5 g of chopped onion increased the oil content by 41% but it resulted in a lower quality; whereas in the presence of 1.0 g of onion, an increase of 30% and a decrease of 18% were observed in the percentage of monoterpene alcohols and hydrocarbons, respectively without any considerable change in the oil content. However, the effect of sodium chloride was somehow different from that of onion; such that in the optimal amount (22.0 g), the salt had no considerable effect on the quality but an increase of 21% in the oil yield.     

Chemical composition of oleo-gum-resin from Ferula gummosa

The chemical composition of oleo-gum-resin from Ferula gummosa collected in the northern part of Iran has been studied. The fraction of oleo-gum-resin soluble in ethanol (ca 67 wt.%) is composed by three major fractions: (i) monoterpenes and monoterpenoids (ca 15 wt.% fraction), (ii) sesquiterpenes and sesquiterpenoids (ca 30 wt.%) and (iii) triterpenes and triterpenoids (ca 55 wt.%). The major families of terpenes and terpenoids were identified employing gas chromatography coupled with mass spectrometry detector (GC-MS). Almost 25 wt.% of oleo-gum-resin was insoluble in ethanol and, according to wet chemistry analyses, assigned to arabinogalactane structurally associated with protein complex (AGP). This arabinogalactan possessed the molecular weight of ca 30 kDa, as revealed by size exclusion chromatography, and the main backbone was constituted by β-(1 → 3)/β-(1 → 3,6)-linked d-galactopyranosyl residues ramified predominantly by terminal α-l-arabinofuranosyl and β-d-glucuronopyranosyl residues, as assessed by 1D/2D ¹H NMR.     

Chemical composition of solid waste and effect of enzymatic oil extraction on the microstructure of soybean (Glycine max)

The solid wastes were obtained from enzymatic extraction of soybean oil using four enzyme systems (Alcalase/Celluclast or Alcalase/Viscozyme L) each with two pH conditions: controlled or not controlled. This last option gave a better oil extraction, regardless of the enzymes used. The ash levels were higher for the enzyme systems subjected to controlled pH, depending on the buffer solutions used. The others constituents presented similar values between each other. The monosaccharides with highest concentrations were galactose, followed by glucose and arabinose. The physical analysis showed that the waste residues had good oil binding capacity. The SEM and epifluorescence microscopy revealed the microstructure of the beans and raw materials, as well as the changes caused by the extraction procedures.     

Activities of essential oils from Asarum heterotropoides var. mandshuricum against five phytopathogens

Some secondary metabolites of plants function as antimicrobial products against phytopathogens and constitute an increasingly important class of pesticides. In the present study, the essential oil of Asarum heterotropoides var. mandshuricum was analyzed by GC/MS and its antimicrobial activity was evaluated against five phytopathogenic fungi. Major components of the oil were methyleugenol (59.42%), eucarvone (24.10%), 5-allyl-1,2,3-trimethoxybenzene (5.72%), and 3,7,7-trimethylbicyclo(4.1.0)hept-3-ene (4.93%). The essential oil and the most abundant component, methyleugenol, were separately assayed for inhibition of 5 pathogens: Alternaria humicola, Colletotrichum gloeosporioides, Rhizoctonia solani, Phytophthora cactorum and Fusarium solani. Both the oil and methyleugenol strongly inhibited the growth of the test pathogens (IC₅₀ values <0.42 μg ml⁻¹) except F. solani, with the best activity against P. cactorum (IC₅₀ values = 0.073 and 0.052 μg ml⁻¹, respectively). It is concluded that the essential oil of A. heterotropoides var. mandshuricum has a broad antiphytopathogenic spectrum, and that methyleugenol is largely responsible for the bioactivity of the oil. The mode of action of methyleugenol against P. cactorum is discussed based on changes in the mycelial ultrastructure.     

In vitro activity of eighteen essential oils and some major components against common postharvest fungal pathogens of fruit

The development of natural crop protective products as alternatives to synthetic fungicides is currently in the spotlight. In vitro experiments are valuable precursors to more costly in vivo trials, allowing the identification of effective essential oils and establishing the concentrations required for inhibition of a specific, or spectrum of decay pathogens. In this study, the antifungal properties of eighteen essential oils were evaluated in vitro by addition to the fungal growth medium of five pathogens (Lasiodiplodia theobromae, Colletotrichum gloeosporioides, Alternaria citrii, Botrytis cinerea and Penicillium digitatum) isolated from mango, avocado, citrus, grapes and cactus pear. The inhibitory properties of some of the major compounds of the oils, identified and quantified by gas chromatography-mass spectroscopy and gas chromatography-flame ionization detection were also determined. Most of the oils were selected on the basis of commercial availability and for containing a predominant compound. Visual inspection of fungal growth was done and the lowest concentration where fungal growth was completely inhibited on all replicates was recorded. Thyme oil proved to be the most effective inhibitor, totally inhibiting all of the pathogens tested at concentrations of 1000 μl/l and lower, with the exception of a resistant Penicillium strain. Cinnamon oil, rich in eugenol (81.2%), demonstrated good fungicide potential, while the carvone-rich oils displayed promising activity against the citrus pathogens. Oils characterized by high concentrations of S-carvone were less effective than those containing the R-enantiomer. Essential oil of Lippia citriodora was active against all of the pathogens, excluding L. theobromae from avocado. These essential oils, applied alone or in combination, are good candidates for further in vivo testing and for investigations concerning their modes of action.