Isobornyl Acetate Research Articles

Context effects on odor processing: An event-related potential study

The present study aimed to investigate the effects of cognitive/emotional bias on central nervous odor processing. Forty-five female participants were divided into three groups and were either led to believe the odor was a natural, healthy extract (positive bias), potentially hazardous (negative bias), or a common test odorant (control). The odor (isobornyl acetate) was presented via a constant-flow olfactometer and the EEG was recorded from 60 scalp locations. In the negative bias condition, participants reported reduced well-being and judged the odor as less pleasant. However, neither the thresholds nor the intensity ratings were changed by the context condition. Chemosensory event-related potential (CSERP) analysis revealed that the latencies of the N1 and P2 components were prolonged in the negative bias condition and shortened in the positive bias condition. Current source densities were most prominent in the frontal lobe in negatively biased participants. The findings show that expecting to perceive an emotionally significant odor affects the early encoding of odors.

Chemical Composition of the Volatile Oil from Ferula ovina (Boiss.) Boiss. - Rech. Fruits

Among the Ferula species, Ferula ovina is a sweet-smelling plant. The hydrodistilled essential oil from the dried fruits of Ferula ovina was analyzed by GC-MS. Forty-five components, representing 99.0 % of the oil was characterized. The major components were Ot-pinene (37.4 %), ß-phellandrene (10.8 %), isobornyl acetate (9.2 %), a-fenchene (8.9 %), myrcene (5.8 %), y-elemene (4.6 %) and ß-pinene (4.1 %). The chemical compositions of the oils obtained from aerial parts and fruits were different, especially in the percentage of ot-pinene and in the presences of a-fenchene, isobornyl acetate and y-elemene.

Chemical composition and antimicrobial activity of Chamaecyparis obtusa leaf essential oil

The essential oil obtained from the leaves of Chamaecyparis obtusa was analyzed by GC and GC–MS. α-Terpinyl acetate, sabinene, isobornyl acetate and limonene were found to be the major components. The oil showed relatively strong antibacterial activities against Gram (+) bacteria and some fungi.

Effect of Pt/alumina catalyst preparation method on sensing performance of thermoelectric hydrogen sensor

We fabricated three different Pt/alumina catalysts for micro-thermoelectric hydrogen sensor (micro-THS). In the three Pt/alumina catalysts, two were prepared by impregnation of a commercial alumina with an aqueous solution of platinum (IV) chloride pentahydrate, and the third was prepared by impregnation of commercial alumina and nano-Pt with isobornyl acetate solution. To fabricate the micro-THS, the three Pt/alumina catalysts were integrated on thin membrane of the micro-THS, and its hydrogen sensing properties were investigated. The micro-THS with nano-Pt loaded alumina catalyst showed better sensing performance than those with Pt/alumina catalysts prepared by an aqueous solution of platinum (IV) chloride pentahydrate, because of effectively dispersed nano-Pt metal grain on the surface alumina grain observed by TEM. Its voltage signal was 15.7 mV for hydrogen concentration of 1% in dry air at catalyst temperature of 100°C.

Essential oils of the aerial parts of three Salvia species from Jordan: Salvia lanigera, S. spinosa and S. syriaca

The compositions of the essential oils of three Jordanian Salvia species, S. lanigera and S. spinosa from a desert climate, and S. syriaca from a Mediterranean habitat, were studied. All three oils are rich in monoterpene derivatives (68–73%). S. lanigera and S. spinosa showed a very high content of thymol, 54.9% and 68.9%, respectively. The main constituents of S. syriaca were thymol, α-pinene and isobornyl acetate (15.5%, 12.6% and 12.0%, respectively).

Comparision of volatile oil constituen of two species of kunci pepet (Kaempferia angustifolia Roscue. and K. rotunda Linn.)

Two species of kunci pepet, i.e. K. angustifolia and K. rotunda (Zingiberaceae), had different aromas. We had been analyzed volatile oils of two species by gas chromatography-mass spectrometry (GC-MS). The volatile oils had been got by water-steam distillation. The GC chromatograms of K. angustifolia showed 16 compounds, 5 compounds of them was main compounds, i.e. cycloproazulene (21.86%), alloaromadendrene (20.79%), cyclopropnaphtalene (11.02%), (-)β-elemenene (16.00%), caryophyllene (16.00%), and isobornyl acetate (11.02%). The GC chromatograms of K. rotunda showed 10 compounds, 2 compounds of them was main compound, i.e. tetradecane (26.85%) and benzylbenzoic (55.46%). Based on chemical constituent of volatile oils, the two species of Kaempferia had similarity of 25.00-37.50%. Alloaromadendrene of K. angustifolia and benzylbenzoic of K. rotunda could be used to distinguish the two species of Kaempferia.

Novel Asymmetric Wittig Reaction: Synthesis of Chiral Allenic Esters.

Wittig reactions between 10-(phenylsulfonyl)isobornyl (triphenylphosphoranylidene)acetates (1 and 6) and ketenes resulted in asymmetric induction, with the selective synthesis of allenes with axial chirality. Use of the (1R)-(−)-10-(phenylsulfonyl)isoborneol unit allows the synthesis of allenes with S configuration, whereas use of the (1S)-(+)-10-(phenylsulfonyl)isoborneol unit produces allenes with R configuration. The structure of (1R)-(−)-10-(phenylsulfonyl)isobornyl (S)-5,5-dimethylhexa-2,3-dienoate (2e) was determined by X-ray crystallography. Chirooptical studies of the allenic esters were carried out, confirming that two sets of enantiomeric derivatives were obtained. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Novel Asymmetric Wittig Reaction: Synthesis of Chiral Allenic Esters

AbstractWittig reactions between 10‐(phenylsulfonyl)isobornyl (triphenylphosphoranylidene)acetates (1 and 6) and ketenes resulted in asymmetric induction, with the selective synthesis of allenes with axial chirality. Use of the (1R)‐(−)‐10‐(phenylsulfonyl)isoborneol unit allows the synthesis of allenes with S configuration, whereas use of the (1S)‐(+)‐10‐(phenylsulfonyl)isoborneol unit produces allenes with R configuration. The structure of (1R)‐(−)‐10‐(phenylsulfonyl)isobornyl (S)‐5,5‐dimethylhexa‐2,3‐dienoate (2e) was determined by X‐ray crystallography. Chirooptical studies of the allenic esters were carried out, confirming that two sets of enantiomeric derivatives were obtained. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Full-scale chamber investigation and simulation of air freshener emissions in the presence of ozone.

Volatile organic compound (VOC) emissions from one electrical plug-in type of pine-scented air freshener and their reactions with O3 were investigated in the U.S. Environmental Protection Agency indoor air research large chamber facility. Ozone was generated from a device marketed as an ozone generator air cleaner. Ozone and oxides of nitrogen concentrations and chamber conditions such as temperature, relative humidity, pressure, and air exchange rate were controlled and/or monitored. VOC emissions and some of the reaction products were identified and quantified. Source emission models were developed to predict the time/concentration profiles of the major VOCs (limonene, alpha-pinene, beta-pinene, 3-carene, camphene, benzyl propionate, benzyl alcohol, bornyl acetate, isobornyl acetate, and benzaldehyde) emitted bythe air freshener. Gas-phase reactions of VOCs from the air freshener with O3 were simulated by a photochemical kinetics simulation system using VOC reaction mechanisms and rate constants adopted from the literature. The concentration-time predictions were in good agreement with the data for O3 and VOCs emitted from the air freshener and with some of the primary reaction products. Systematic differences between the predictions and the experimental results were found for some species. Poor understanding of secondary reactions and heterogeneous chemistry in the chamber is the likely cause of these differences. The method has the potential to provide data to predict the impact of O3/VOC interactions on indoor air quality.

Ion exchange resins as catalyst for the isomerization of α-pinene to camphene

Camphene is an industrial intermediate compound for commercial chemicals such as isoborneol, isobornyl acetate and camphor. Industrially, the conventional process for camphene production consists of the isomerization of α-pinene using acidic TiO 2 as catalyst. The use of this catalyst presents problems such as considerable time for preparation, reproducibility and recovery of catalyst from products after the α-pinene isomerization. For the first time, a commercial exchange resin was used as catalyst for this reaction. Based on the concentration of product as a function of the reaction time, the path of the α-pinene transformation to camphene and byproducts is proposed. Temperature and α-pinene/catalyst ratio were studied in order to optimize the yield to camphene production. The obtained results were comparable with those reported for acidic TiO 2.

Composition of the Essential Oil of Xanthium brasilicum Vellozo from Iran

A water-distilled oil obtained from the aerial parts of Xanthium brasilicum Vellozo was analyzed by GC/MS. The oil consisted mainly of monoterpenes and a small percentage of sesquiterpenes. Fifteen compounds were identified, of which borneol (28.9%), fenchone (21.1%) and isobornyl acetate (9.1%) were the major constituents.

The catalytic performance of sulphonated cross-linked polystyrene beads in the formation of isobornyl acetate

The use of three sulphonated cross-linked polystyrene resins (Dowex 50WX8, Amberlyst 15 and Purolite MN500) is reported as heterogeneous Bronsted acid catalysts in the solvent-free liquid-phase hydro-acyloxy-addition reaction of acetic acid ( 1a) to camphene ( 2), giving the pine-fragrance isobornyl acetate ( 3a). As a homogeneous reference catalyst p-toluene sulphonic acid monohydrate was employed. Prior to use, the hygroscopic resins were dried in vacuo, followed by swelling with glacial acetic acid vapour. Since Karl Fischer titrations showed that the drying procedure did not remove all adsorbed water, acetic anhydride was used to eliminate traces of residual water. Ion-exchange reactions provided the number of sulphonic acid groups per gram of resin, while the accessibility of the acid groups was assessed from acid–base titrations and SEM/EDAX. The number of resin beads to be suspended to achieve a desired number of acid sites determined the rate of the reaction. It was demonstrated that transport within the pores of the beads did not affect the rate of the reaction. The conformation of the polystyrene chains determines the accessibility of the acid groups as well as the presence of liquids as dimethylsulfoxide that are able to establish hydrogen bonds with the acid sites. With both the resin catalysts and the homogeneous reference catalyst, the rate of the reaction increased upon addition of small aliquots of water to the reaction mixture. A rise of the proton mobility near the sulphonic acid moieties rationalises the increase of the rate of the reaction by addition of water. The specific absorption of water in the resins also decreased the agglomeration of the sulphonic acid groups of the resins and the shielding of the acid groups by the polystyrene chains, which proceeds with the more flexible (less cross-linked) Dowex 50WX8. The other two resins gave similar reaction rate constants as p-toluene sulphonic acid monohydrate. Since the conversion of camphene ( 2) completely stopped after separation of the resin beads from the reaction mixture, the three different types of resin beads can be effectively applied as heterogeneous solid acid catalysts. By application of a fixed-bed reactor and re-circulating the reactants, the equilibrium is quantitatively shifted to the product isobornyl acetate ( 3a).

Hydration and acetoxylation of camphene catalyzed by heteropoly acid

The liquid-phase acetoxylation and acetoxylation/hydration of camphene ( 1) in homogeneous or heterogeneous systems catalyzed by dissolved or silica-supported heteropoly acid H 3PW 12O 40 (PW) in AcOH/H 2O solutions (0–10 vol.% H 2O) have been studied. Isobornyl acetate ( 2a) and isoborneol ( 3a) are the main reaction products which have been obtained with an almost 100% total selectivity. No oligomerization of camphene has been observed. PW shows a much higher catalytic activity than conventional acid catalysts such as H 2SO 4 and Amberlyst-15. It can be recovered without neutralization and reused.

Alkyl sulphonic acid surface-functionalised silica as heterogeneous acid catalyst in the solvent-free liquid-phase addition of acetic acid to camphene

In search for heterogeneous Brønsted acid catalysts as alternatives for corrosive liquid acid catalysts, silica’s were surface-functionalised with linear alkyl chains containing thiol and thioacetic ester end-groups, which were subsequently converted into sulphonic acids by oxidation with H 2O 2/HOAc. FT-IR, CP/MAS 13 C NMR, XPS, TGA and acid–base titrations established the formation of a surface-bound monolayer of alkyl sulphonic acid groups. The catalytic properties of the surface-functionalised silica’s were evaluated in the solvent-free liquid-phase hydro-acyloxy-addition of acetic acid ( 1) to camphene ( 2), yielding the pine-fragrance isobornyl acetate ( 3). Reaction rates (normalised on the concentration of sulphonic acid groups) were identical to those found using the homogeneous CH 3SO 3H reference catalyst. The equal rates suggest that a similar reaction mechanism is operative. The reaction rate with the solid surface-functionalised silica catalysts increased by two orders of magnitude upon addition of a small amount of water. In the presence of water the alcohol analogue of 3, i.e. isoborneol ( 15), is an important intermediate. Generation of homogeneous alkyl sulphonic acids via hydrolysis followed by leaching from the silica surface does not occur; the formation of 3 stopped after removal of the solid catalyst from the reaction mixture by filtration. Thus, the alkyl sulphonic acid functionalised silica’s act as proper heterogeneous Brønsted acid catalysts.

Variation in volatile compounds from tansy (Tanacetum vulgare L.) related to genetic and morphological differences of genotypes.

Air-dried flower heads of 20 Finnish tansy genotypes were extracted with petroleum ether and analyzed using GC-MS. A total of 55 volatile compounds were detected, and 53 were identified. Of the tansy genotypes studied, 15 were well defined and five were mixed chemotypes. Complete linkage analysis differentiated the populations into six clusters. The most frequently found monoterpene was camphor with or without several satellite compounds such as camphene, 1,8-cineole, pinocamphone, chrysanthenyl acetate, bornyl acetate and isobornyl acetate. In 13 genotypes, camphor concentration exceeded 18.5% and in seven genotypes, camphor was less than 7.2%. Other chemotypes rich in trans thujone, artemisia ketone, 1,8-cineole, or davadone-D were also identified. Davadone-D and a mixed chemotype, containing tricyclene and myrcene, were identified from a Finnish tansy for the first time. Geographically, most chemotypes containing camphor originated from Central Finland, whereas chemotypes without camphor such as artemisia ketone, davadone D and myrcene-tricyclene originated from South or Southwest Finland. Morphologically, the 20 tansy chemotypes based on the groups formed from complete linkage cluster analysis, were compared. The group containing the highest concentration of camphor chemotypes had the tallest shoots. The groups consisting from chemotypes containing davadone-D or artemisia ketone, which originated from Southwest Finland, produced the highest number of flower heads, had the tallest corymb, and were last to flower. Also, the group consisting from chemotypes with a high concentration of camphor and originated from South Finland started to flower late. The correlation between the genetic distance matrices based on RAPD patterns reported previously (Keskitalo et al., 1998. Theo. Appl. Genet. 96, 1141-1150.) and the chemical distance matrices of the present study of the same tansy genotypes was highly significant (0.41, P<0.0001).

Anhydrous zirconium(IV) sulfate and tin(IV) sulfate: solid Lewis acid catalysts in liquid-phase hydro-acyloxy-addition reactions?

Anhydrous zirconium(IV) and tin(IV) sulfate [Zr(SO4)2 and Sn(SO4)2] were prepared from their corresponding metal tetrachlorides and fuming H2SO4/10% SO3. Properties of interest for their potential use as heterogeneous Lewis acid catalysts, such as their susceptibility to undergo hydrolysis, are studied. In the presence of water the metal sulfates are converted into their metal oxides (ZrO2 ·2H2O and SnO2·2H2O) and the Brønsted acid H2SO4, which can also be catalytically active. This is illustrated by the solvent-free liquid-phase hydro-acyloxy-addition of acetic acid (2) to camphene (1) (molar ratio 1: 2 = 1:1) giving the fragrance isobornyl acetate (3). Both anhydrous Zr(SO4)2 and Sn(SO4)2 are inactive as heterogeneous solid Lewis acid catalysts; no conversion of 1 into 3 is found. Upon addition of water, however, 1 is efficiently converted into 3. Moreover, the conversion of 1 into 3 continues even after removal of the solid Lewis acid catalyst by filtration. These results show that after addition of water the reaction becomes homogeneously catalysed by dissolved H2SO4.

Volatile Compounds in Five Starches

ABSTRACTVolatile compounds in commercial wheat, corn, potato, waxy corn, and tapioca starches and in laboratory‐prepared wheat, corn, and potato starches were collected, separated, and identified by a purge and trap concentrator (P&amp;T) interfaced to a gas chromatograph (GC) equipped with a Fourier transform infrared detector (FTIRD) and a mass selective detector (MSD). Hexanal was the most abundant compound in the corn and potato starches and in the laboratory‐prepared wheat starch as determined by total ion chromatogram (TIC) peak areas. Hexanal was the third most abundant compound in commercial wheat starch after 2‐ethyl‐1‐hexanol and benzaldehyde. Among the volatile organics, the level of aldehydes was the highest, followed by alcohols, ketones, benzenes, esters, and terpenes. Specific compounds identified, the majority of which appear to be degradation products of lipid peroxidation, include hexanal, heptanal, octanal, nonanal, decanal, benzaldehyde, 2‐propanone, 2‐propanol, 1‐butanol, 2‐ethyl‐1‐hexanol, methylbenzene, and tetradecane. Waxy corn starch, which released a substantially higher level of total volatiles than all other starches, contained large amounts of pentyl, 2‐methyl‐1‐butyl, benzyl, and isobornyl acetates; and citronella and 1,8‐cineole. Tapioca starch contained few volatiles but did contain an increased level of 2‐propanol. No alcohols occurred in the commercial corn starch. Terpene compounds were detected only in commercial potato, waxy corn, and tapioca starches. Many volatiles detected in wheat and corn starches also were detected in the kernels of their commercial samples.

Chemical Composition of the Flower Oil of Curcuma pierreana Gagnep. from Vietnam

The flowers of Curcuma pierreana Gagnep., Zingiberaceae, were collected in full bloom in Huê, Vietnam. The essential oil was obtained by hydrodistillation of these flowers. The flower oil was analyzed by a combination of high resolution GC and GC/MS. More than 40 components were identified, representing 89% of the oil. The principal constituents were isoborneol (27.3%), camphor (24.1%), isobornyl acetate (7.3%), camphene (6.7%) and α-pinene (5.1%). The oil contained more than 70% of oxygenated compounds, which contributed to its special odor.

Essential oil composition of Bothriochloa pertusa and phyletic relationship in aromatic grasses

Abstract Chemical composition of the essential oil of Bothriochloa pertusa (L) A. Camus, collected from temperate Himalaya, revealed the major categories of terpenoids as monoterpene hydrocarbons (26.45%), oxygenated monoterpenes (7.29%), sesquiterpene hydrocarbons (4.73%) and oxygenated sesquiterpenes (37.05%), in 82.31% of the total volatile constituents identified. Twenty-eight compounds were identified, the major of which are camphene (7.40%), limonene (14.90%), borneol (2.26%), Isobornyl acetate (2.01%), β -caryophyllene (3.10%), intermedeol (24.72%) and acorenone-B (9.80%). B. pertusa contains higher percentage of monoterpene hydrocarbons and oxygenated monoterpenes in comparison to B. bladhi , the only other species of the genus analysed in detail. About 88% of the aromatic grasses are represented by tribe Andropogoneae, that spread globally by late Miocene, possibly a period of the greatest evolutionary diversity in aromatic grasses.

Immature Fruit Oil of Brillantaisia lamium Benth. from Benin

The essential oil of air-dried immature fruit of Brillantaisia laminum (Acanthaceae) from Benin was analyzed by high resolution GC and GC/MS. Almost forty components were identified, representing more than 90% of the oil. The main constituents were isobornyl acetate (66.9%), caryophyllene oxide (5.0%), β-caryophyllene (4.5%) and isoborneol (2.4%).