Α-terpenyl Acetate Research Articles

Effect of xylanase addition and ultrasonic pretreatment on the yield and volatile profile of bay laurel and sage essential oil

In order to increase the yield of essential oils in hydrodistillation of bay laurel and sage, the effect of pretreatment with ultrasound and enzymes (under different conditions of xylanase pretreatment) was studied. The effects of the optimized conditions (concentration of xylanase 0.20 mg/mL in buffer pH=6.5 at 40°C for 4 h) during the enzymatic pretreatment showed that despite the optimization the activity of xylanase did not significantly affect the quantity and quality of essential oils of bay laurel and sage. Ultrasonic pretreatment prior to enzymatic pretreatment with the addition of optimized xylanase resulted in increased yields of dominant compounds (α-thujone 27.42%, β-thujone 12.15%, and camphor 20.94%) in sage essential oil, while in bay laurel the amount of dominant compounds (1,8-cineole 24.65% and α-terpenyl acetate 11.05%) was not significantly increased. Despite minor changes, ultrasonic and enzymatic pretreatment of the plant materials did not significantly affect the chemical composition of the essential oils of bay laurel and sage compared with the control without pretreatment, as confirmed by the Spearman rank test (p < 0.05). The main advantage of ultrasonic extraction is the reduction in pretreatment time. Ultrasonic pretreatment for only 10 min before enzymatic pretreatment resulted in a 50% increase in sage essential oil yield and a 40% increase in bay laurel essential oil yield.

Volatile Oil Components of Laurel (Laurus nobilis L.) Leaves Obtained from Plants Cultivated under Salinity Stress Conditions

Laurel (Laurus nobilis L.) is a strict endemic species of natural vegetation of the Mediterranean region, which is known for its medicinal, aromatic, forestry, ornamental and culinary properties. This species produces valuable essential oil (EO). The content of EO and its composition depend on different factors, e.g., genetic, cultural practices and environmental conditions. Among these, salt stress is a major limiting factor, which affects almost all plant functions. Similar to essential oils (EOs), biotic and abiotic stresses may stimulate or inhibit the emission of volatile compounds (VCs) in plant materials, suggesting that these substances can be responsible on stress defense strategies. Therefore, an experiment was conducted to assess the effect of different NaCl concentrations (0, 50, 100 and 150 mM) of the irrigation water on VCs of laurel leaves. Our results showed that salt stress affected the volatile metabolites compounds, mainly the major ones. For instance, 1,8-cineole and linalool were negatively affected by high salinity levels, while the opposite was observed for α-terpenyl acetate and methyl eugenol. The proportion of grouped compounds of laurel VCs also differed among the studied treatments. The relative content of oxygenated monoterpenes and monoterpene hydrocarbons, respectively the first and the second largest groups, decreased with increasing NaCl concentration. Differently, the relative amount of sesquiterpene hydrocarbon group increased, especially at 100 mM NaCl. These findings indicate that the cultivation of laurel in marginal lands, characterized by high salinity or low-quality water, must be carefully evaluated because it significantly varies the quality of its products.

Not Only a Weed Plant-Biological Activities of Essential Oil and Hydrosol of Dittrichia viscosa (L.) Greuter.

With the increasing interest in obtaining biologically active compounds from natural sources, Dittrichia viscosa (L.) Greuter (Asteraceae) came into our focus as a readily available and aromatic wild shrub widely distributed in the Mediterranean region. This work provides a phytochemical profile of D. viscosa in terms of parallel chemical composition in the lipophilic fraction (essential oil) and the water fraction (hydrosol). GC-MS analysis identified 1,8-cineole, caryophyllene oxide, α-terpenyl acetate, and α-muurolol as the major components of the essential oil, while in the hydrosol p-menth-1-en-9-ol, 1,8-cineole, linalool, cis-sabinene hydrate, and α-muurolol were the major volatile components. 3,4-Dihydroxybenzoic acid was found to be the predominant compound in the hydrosol composition by HPLC analysis. The antimicrobial potential of both extracts was evaluated against thirteen opportunistic pathogens associated with common skin and wound infections and emerging food spoilage microorganisms. The antimicrobial activity of the essential oil suggests that the volatiles of D. viscosa could be used as novel antimicrobial agents. The antiproliferative results of D. viscosa volatiles are also new findings, which showed promising activity against three cancer cell lines: HeLa (cervical cancer cell line), HCT116 (human colon cancer cell line), and U2OS (human osteosarcoma cell line). The decrease in GSH level observed in hydrosol-treated HeLa cells suggests oxidative stress as a possible mechanism of the antiproliferative effect of hydrosol on tumor cells. The presented results are also the first report of significant antiphytoviral activity of hydrosol against tobacco mosaic virus (TMV) infection. Based on the results, D. viscosa might have the potential to be used in crop protection, as a natural disinfectant and natural anticancer agent.

Characterization of Chemical Components in Organs Emissions of Two Salvia dominica L. Populations from Jordan.

The current investigation reports the chemical composition of volatile organic compounds emitted from the different aerial organs of two populations of Salvia dominica L. from Jordan collected from Mediterranean and Irano-Turanian bio-geographical zones. Oxygenated monoterpenes dominated the emission profiles of most organs from the two populations but with variable qualitative and quantitative differences. Mediterranean samples contained higher content of oxygenated monoterpenes (stems: 88.37%, leaves 89.95%, pre-flowering buds 67.14%, fully opened flowers 79.43%, sepals 90.93% and petals 92.25%) as compared to those from Irano-Turanian origin (range 39.85% to 75.06%). trans-Sabinene hydrate dominated the emission profiles of all organs from Irano-Turanian zone (range 38.54% to 73.24%) in addition to the stem, sepal and petal samples from the Mediterranean zone (51.37% to 86.98%). The other organs from the Mediterranean zone were dominated by α-terpenyl acetate (27.66-54.87%). Cluster and Principle Component statistical analysis classified the two populations into two clusters based on their origin. The current study evidenced the different VOCs composition in the two populations, that was mainly related to climatic and environmental conditions and suggested the presence of two ecotypes of S. dominica L.in Jordan.

Essential oil constituents of Juniperus oxycedrus L. and Cupressus sempervirens L. (Cupressaceae) growing in Aures region of Algeria

The purpose of this study was to determine the chemical composition of essential oils from the aerial parts of two species belonging to the Cupressaceae family growing in the Aures region of Algeria Juniperus oxycedrus and Cupressus Sempervirens. The analysis by GC-MS and GC-FID techniques showed the presence of 38 compounds in J. oxycedrus oil where the major constituents were manoyl oxide (23.5%), pentadecan-2-enone 6Z (12.6%), abietatriene (8.0%), abieta-8,11,13-triene-7-one (6.5%), cubebol (4.6%), epi-torilenol (3.8%) and α-cadinol (2.6%), while, a total of 65 compounds were showed in C. sempervirens oil where the major constituents were α-pinene (68.0%), epi-cedrol (6.1%), α-terpenyl acetate (3.5%) and germacrene D (2.5%). It is the first time that the compounds pentadecan-2-enone 6Z, abieta-8,11,13-trien-7-one, cubebol and epi-torilenol have been identified in our J. oxycedrus and epi-cedrol in C. sempervirens essential oils with high contents, as we noticed the absence of α-pinene in our J. oxycedrus essential oil.

LC-ESI/LTQOrbitrap/MS/MS and GC–MS profiling of Stachys parviflora L. and evaluation of its biological activities

The use of some Stachys genus as herbal remedies is known and the aerial parts have a pharmaceutical interest, being used in Anatolia and Iran as wild tea. In this study, chemical composition, antimicrobial, antioxidant, and antiproliferative activities of the methanolic extract and essential oil (EO) of Stachys parviflora L. (S. parviflora) were evaluated. Qualitative analysis of metabolites of S. parviflora methanolic extract was studied using liquid chromatography coupled to high resolution mass spectrometry (LC-ESI/LTQOrbitrap/MS), evidencing the presence of phenolic acids and flavonoids derivatives. The EO was analyzed using gas chromatography coupled to mass spectrometry (GC/MS). Eighty-seven compounds were characterized in the EO of S. parviflora, of which α-terpenyl acetate (23.6%), β-caryophyllene (16.8%), bicyclogermacrene (9.3%), spathulenol (4.9%) and α-pinene (4.2%) were found to be the major components. The highest antimicrobial effect of EO was found to S. aureus and B. cereus (MIC = 0.01 μg/ml), while the highest activity of extract was against B. cereus (MIC = 125 μg/ml). The methanolic extract exhibited strong antioxidant activity in DPPH (IC50 = 76.87 μg/ml) and β-carotene/linoleic acid assay (BCB, IC50 = 188.47 μg/ml) methods. Furthermore, in vitro cytotoxicity evaluation against three cell lines namely human ovarian carcinoma (A2780), human colon carcinoma (HCT), and mouse melanoma cell line (B16F10), showed an anti-proliferative activity of the EO ranging from IC50 value 30.95 μg/ml to 16.55 μg/ml. The results from this study have demonstrated the promising cytotoxic, antibacterial, and antifungal properties of S. parviflora, which could have wide potential applications in food and pharmaceutical industries.

Identification of volatile components in two Thymus species from Iran and their antioxidant properties

Thymus species are well known to have significant amount of phenolic compounds and exhibit strong antioxidant activities. This study is designed to analyze the essential oils of two Iranian Thymus species, ( T. kotschyanus Boiss. et Hohen and T. pubescense Boiss. et Kotschy ex Celak) obtained by hydrodistillation of aerial part of this plants, using GC-FID and GC/MS and evaluate the in-vitro antioxidant activities in two quantitative methods (namely DPPH. and ABTS.+ assay) to determine the total phenolic content of the species (assayed by colorimetric techniques) and to study the possible compositionantioxidant activity relationship. The major aroma constitutes in the essential oil of T. pubescense were found to be thymol (38.7 %), γ-terpinene (7.5 %), p-cymene (5.5 %), α-terpenyl acetate (3.8 %) and β-bisabolene (3.7 %) while in the essential oil of T. kotschyanus, α-terpineol (16.9 %), 1,8-cineol (14.4 %), linalool (9.6 %), thymol (7.2 %) and geranyl acetate (5.4 %) were the main compounds. Both of the tested essential oils exhibited concentration-dependent antioxidant activity. T. pubescense showed more activity in both DPPH. [IC50= 285.2 (236.5-344.0) μg/mL] and ABTS.+ methods [IC50= 1.956 (1.810-2.113) μg/mL], as well as total phenolic content of T. pubescence [70254 ± 0.0049 μg/mg] was found to be slightly higher than T. kotschyanus [62933 ± 0.0026 μg/mg].

Chemical Composition, Free-Radical-Scavenging and Insecticidal Properties, and General Toxicity of Volatile Oils of Two Artemisia species Growing Wild in Iran

The composition of the volatile oils from the aerial parts of Artemisia spicigera and A. splendens, growing in Iran, was analyzed by GC-MS and GC-FID. A total of 47 constituents from each of the oils (87.6 % and 58.3 % of the total oil of A. spicigera and A. splendens, respectively) were separated and identified. The major components of the A. spicigera oil were cis-chrysanthenyl acetate (24.0 %), camphor (21.0 %), 1,8-cineol (13.9 %) and cis-chrysanthenol (8.5 %), while 1,8-cineol (4.7 %), caryophyllene oxide (3.8 %), valencene (3.5 %) and α-terpenyl acetate (3.4 %) were detected as the major constituents of the oils of A. splendens. The free-radical-scavenging activity of the oils was assessed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Both oils showed weak antiradical effect with RC50 values of 55.6 and 106.4 µg/mL, respectively, for A. spicigera and A. splendens. The oils displayed broad and potent insecticidal activity against Oryzaephilus mercator, but no noticeable toxicity towards brine shrimp.

Volatile-oils composition, and bioactivity of the essential oils of Plectranthus barbatus, P. neochilus, and P. ornatus grown in Portugal.

Volatile-oils chemical composition and bioactivity of the essentail oils from Plectranthus barbatus, P. neochilus, and P. ornatus (Lamiaceae) were assessed. Aerial parts from these three related Plectranthus species were collected from cultivated plants grown in Portugal, during vegetative and flowering phases. Volatiles, isolated by distillation-extraction, were analyzed by GC and GC/MS. Monoterpene hydrocarbons (12-74%) and sesquiterpene hydrocarbons (4-45%) constituted the main fractions in all volatiles. α-Pinene (3; 12-67%), oct-1-en-3-ol (6; traces-28%), β-pinene (7; 0.1-22%), and β-caryophyllene (50; 7-12%) dominated P. barbatus volatiles. P. neochilus major volatile components were α-terpenyl acetate (41; traces-48%), α-thujone (2; 2-28%), β-caryophyllene (50; 2-28%), β-pinene (7; 1-25%), and α-pinene (3; 1-19%). Oct-1-en-3-ol (6; 13-31%), β-pinene (7; 11-24%), α-pinene (3; 11-19%), and β-caryophyllene (50; traces-11%) were the main constituents from P. ornatus volatiles. These chemical compositions were rather different from those previously found for specimens harvested in Africa and Brazil. Moreover, the volatiles from the flowers are herewith reported for the first time. Essential oils, isolated by hydrodistillation from leaves and stems, showed a yellowish color and unpleasant odor, with yields ranging from 0.08% to 0.84% (v/dry weight). Antioxidant and antimicrobial activities of the essential oils were evaluated by DPPH· and TBARS assays, and agar disc-diffusion method, respectively. Results showed low or moderate antioxidant capacity and significant antimicrobial activity against Gram-positive bacteria.

Essential oils and crude extracts from Chrysanthemum trifurcatum leaves, stems and roots: chemical composition and antibacterial activity.

The essential oils from the leaves, stems and roots of Chrysanthemum trifurcatum (Desf.) Batt. and Trab. var. macrocephalum (viv.) were obtained by hydrodistillation and their chemical compositions were analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS), in order to get insight into similarities and differences as to their active composition. A total of fifty compounds were identified, constituting 97.84%, 99.02% and 98.20% of total oil composition of the leaves, stems and roots, respectively. Monoterpene hydrocarbons were shown to be the main group of constituents of the leaves and stems parts in the ratio of 67.88% and 51.29%, respectively. But, the major group in the roots oil was found to be sesquiterpene hydrocarbons (70.30%). The main compounds in leaves oil were limonene (26.83%), γ-terpinene (19.68%), α-pinene (9.7%) and α-terpenyl acetate (7.16%). The stems oil, contains mainly limonene (32.91%), 4-terpenyl acetate (16.33%) and γ-terpinene (5.93%), whereas the main compounds in roots oil were α-calacorene (25.98%), α-cedrene (16.55%), β-bourbobene (14.91%), elemol (7.45%) and 2-hexenal (6.88%). The crude organic extracts of leaves, stems and roots, obtained by maceration with solvents of increasing polarity: petroleum ether, ethyl acetate and methanol, contained tannins, flavonoids and alkaloids. Meanwhile, essential oils and organic extracts were tested for antibacterial activities against eight Gram-positive and Gram-negative strains, using a microdilution method. The oil and methanolic extact from C. trifurcatum leaves showed a great potential of antibacterial effect against Bacillus subtilis and Staphylococcus epidermidis, with an IC50 range of 31.25-62.5 µg/ml.

Compositional characteristics of the essential oil of Myrtus communis grown in the central part of Saudi Arabia

The essential oil obtained from aerial parts of Myrtus communis grown in the central part of Saudi Arabia was analyzed by gas chromatography-based techniques (GC–FID, GC–MS, Co–GC, LRI determination, database, and literature search) using polar as well as non-polar columns, which resulted in the identification of a total of sixty-five components accounting for 98.2% of the total oil composition. The oil composition was found to be dominated by monoterpene components accounting for 89.3% of oil composition. Sesquiterpenes (4.8%) and their oxygenated derivatives (3.5%) were present in lesser amounts. The major compounds of the oil were 1,8-cineole (26.5%), linalool (18.0%), α-pinene (11.6%), α-terpineol (8.9%), and limonene (4.0%). Other constituents which were present in appreciable amounts in this oil are trans-geraniol (3.9%), trans-geranyl acetate (3.9%), α-terpenyl acetate (3.3%), linalyl acetate (2.9%), and δ-cadinene (2.7%).

Effect of enzyme assisted extraction on quality and yield of volatile oil from black pepper and cardamom

The present study investigated the effect of enzyme pre-treatment on extraction of active compounds from spices, namely, black pepper and cardamom. A mixture of enzymes, namely, Lumicellulae (a mixture of cellulase, β-glucanase, pectinase, and xylanase), was used for the pre-treatment of black pepper and cardamom. The pre-treatment of spices with enzyme increased the yield of essential oil. The GC and GC-MS evaluation of the essential oil showed that the major active components in spices, such as, β-caryophyllene in black pepper and α-terpenyl acetate in cardamom, markedly increased from 15.03 to 25.58 and 38.91 to 48.6%, respectively, on enzyme treatment as compared with the untreated control. The improvement in the yield and the major components of essential oil was attributed to the destruction of the cell wall structure by the enzymes pre-treatment which was substantiated with microscopical images using SEM.

Analysis of the essential oil of large cardamom (Amomum subulatum Roxb.) growing in different agro‐climatic zones of Himachal Pradesh, India

The aim of the present study was to investigate variations in the chemical composition of the essential oil from seeds of large cardamom grown at different altitudes in Himachal Pradesh, India. The composition of the essential oil was determined by gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O). The oil components showed qualitative and quantitative variations in the composition. GC and GC-MS analysis led to the identification of 55 compounds representing 98% of total oil. Major components in the oil were 1,8-cineole, α-terpineol, DL-limonene, nerolidol, 4-terpineol, δ-terpineol, δ-3-carene, β-myrcene, germacrene D, α-terpinene and longifolenaldehyde. The oil yields obtained were 9.8-19.5 g kg(-1). Cardamom oil from Himachal Pradesh was found to contain new compounds, viz. 4-terpineol, δ-3-carene, trans-sabinene hydrate, 1-phellandrene, α-terpinene, bicyclo-germacrene, isopinocarveol and ledenoxid-II. α-Terpenyl acetate, the major constituent of small cardamom, was also detected in the oil of large cardamom grown in Himachal Pradesh. Application of aroma extract dilution analysis revealed 35 compounds having aroma impact with the flavour dilution factor ranging from 2 to 1024, and 34 of these compounds were identified. The five most intense aromatic components are dl-limonene, 1,8-cineole, β-myrcene, α-pinene, α-basabolol. This is the first time that the characterisation of odour-active compounds has been carried out on large cardamom. The presence of 4-terpineol, δ-3-carene, trans-sabinene hydrate, 1-phellandrene, α-terpinene, 1-terpineol, bicyclogermacrene, isopinocarveol, ledenoxid-II, longifolenaldehyde and α-terpenyl acetate make the aroma of the oil different from large cardamom oil of Sikkim and could offer potential as a new food flavour.

Bifunctional ultrasound assisted extraction and determination of Elettaria cardamomum Maton essential oil

A new hyphenated extraction method composed of ultrasound assisted extraction (UAE)-optimized ultrasound assisted emulsification microextraction (USAEME) was developed for the extraction and preconcentration of the essential oil of Elettaria cardamomum Maton. The essential oil was analyzed by gas chromatography–mass spectrometry (GC–MS) and optimization was performed using gas chromatography-flame ionization detection (GC-FID). Ultrasound played two different roles in the extraction of the essential oil. First, as a source of sufficient energy to break the oil-containing glands in order to release the oil, and second as an emulsifier to disperse the organic phase within water. The effective parameters (factors) of USAEME including volume of extraction solvent (C2H4Cl2), extraction temperature and ultrasonic time were optimized by using a central composite design (CCD). The optimal conditions were 120μL for extraction solvent volume, 32.5°C for temperature and 10.5min for ultrasonic time. The linear dynamic ranges (LDRs) were 0.01–50mgL−1 with the determination coefficients in the range of 0.9990–0.9999. The limits of detection (LODs) and the relative standard deviations (RSDs) were 0.001–0.007mgL−1 and 3.6–6.3%, respectively. The enrichment factors were 93–98. The main components of the extracted essential oil were α-terpenyl acetate (46.0%), 1,8-cineole (27.7%), linalool (5.3%), α-terpineol (4.0%), linalyl acetate (3.5%).

Essential Oil Composition of the Fruits of Eletteria cardamomum

A steam distilled essential oil obtained from fruits of Eletteria cardamomum was characterized by a high proportion of monoterpenes (87.6%). The main monoterpenes was 1,8-cineole (35.6%) followed by α-terpenyl acetate (27.1%), α-terpineol (4.9%), linalool (4.1%) and thujyl alcohol. Sesquiterpenic constituents amounting to only 1.8 % were represented by t-caryophyllene (0.8 %) and valencene (1%). Other important volatile constituents identified in the oil were α-phellandrene (2.5 %), cis-ocimene (2.4 %) and neryl acetate (1.7 %).

Hydration and acetoxylation of monoterpenes catalyzed by heteropoly acid

The liquid-phase hydration and acetoxylation of limonene ( 1), β-pinene ( 2) and α-pinene ( 3) catalyzed by dissolved or silica-supported heteropoly acid H 3PW 12O 40 (PW) in acetic acid and acetic acid/water solutions have been studied. All three substrates give α-terpineol ( 4) as the main product along with α-terpenyl acetate ( 5). The reaction rate increases in the order: limonene<α-pinene<β-pinene. Synthetically useful homogeneous and heterogeneous acetoxylation and hydration of 1, 2 and 3 into 4 and 5 have been developed. At room temperature under optimized conditions, 2 and 3 form a mixture of 4 and 5 with 85% selectivity at 90% substrate conversion. 1 gives 4 and 5 with 85% selectivity at 50% conversion, with the main product being ester 5 in acetic acid ( 4/ 5≈30/70 ) and alcohol 4 in HOAc/H 2O (90/10 v/v) solutions ( 4/ 5≈85/15 ). Virtually no oligomerization of monoterpenes occurs under the optimized conditions. The catalyst can be separated without neutralization and may be reused. The PW shows a much higher catalytic activity than conventional acid catalysts such as H 2SO 4 and Amberlyst-15.

The essential oil ofVitex agnus-castus L. growing in the Amazon region

The essential oils of fresh leaves, flowers and fruits of Vitex agnus-castus L., growing in north Brazil, were obtained by hydrodistillation and their volatile constituents were identified by GC–MS. The most abundant constituents found were 1,8-cineole, (E)-β-farnesene, sabinene, α-pinene, α-terpenyl acetate, β-caryophyllene and bicyclogermacrene. Their compositions were compared with oils from Europe and Nigeria. 1,8-Cineole was an important component in all the samples analysed. Copyright © 1999 John Wiley & Sons, Ltd.

Volatile Components of Stachys Corsica Pers. (Lamiaceae)

Nineteen volatile components were identified by GC/MS from the dichlo-romethane extract of air-dried Stachys corsica. Carvacryl acetate, linalool, α-terpenyl acetate and α-terpineol were the main volatiles.

Palladium-catalyzed oxidation of bicyclic monoterpenes by hydrogen peroxide

The activity of the PdCl 2–CuCl 2 combination in the oxidation of camphene, α-pinene, and β-pinene by dioxygen in acetic acid solutions has been studied. The reactions of α-pinene and β-pinene yield a mixture of carveyl acetate (up to 25% on reacted olefin), α-terpenyl acetate, bornyl chloride, and fenchyl chloride. Camphene undergoes a skeletal rearrangement and an acetic acid/water addition resulting in bornyl acetate as a major product, along with borneol and α-pinene. No oxidation products are detected. In an attempt to develop a CuCl 2-free catalytic system for the selective oxidation of bicyclic monoterpenes, the oxidation of β-pinene and camphene by hydrogen peroxide catalyzed by Pd(OAc) 2 in acetic acid solutions has been studied. β-Pinene gave the allylic oxidation products, i.e., pinocarveol, pinocarveyl acetate and myrtenyl acetate, with selectivity up to 75% at virtually complete conversion, and camphene gave camphene glycol monoacetate with a 90% selectivity at 80% conversion. The oxidation reaction competes with the skeletal rearrangement of monoterpenes accompanied by a nucleophilic addition of hydroxy and acetoxy groups. The introduction of benzoquinone (BQ) in catalytic amounts exerts a beneficial effect on the catalyst stability and selectivity for glycol monoacetate formation. For the Pd(OAc) 2–BQ–H 2O 2 system, more than 200 turnover numbers could be achieved in the acetoxylation of camphene.

Palladium(II) catalyzed oxidation of naturally occurring terpenes with dioxygen

Limonene can be efficiently and selectively oxidized by dioxygen at 60–80°C in glacial acetic acid containing LiCl, in the presence of the PdCl 2CuCl 2 catalytic combination, giving rise to the formation of trans-carveyl acetate as the major product. Several concurrent transformations of limonene occur in the reaction solutions, i.e., isomerization, acetic acid addition, and allylic oxidation. The effect of the reaction variables on the product distribution and reaction rate has been studied. The most favorable conditions for the carveyl acetate synthesis have been found. The reactions of α-pinene and β-pinene under the same conditions yield a mixture of carveyl acetate, α-terpenyl acetate, bornyl chloride, and fenchyl chloride. The activity of the Pd(OAc) 2LiNO 3 combination in the oxidation of limonene, α-pinene, and β-pinene has also been examined.