Neutral Constituents of Volatiles in Cultured Broth of Sporobolomyces odorus

Neutral constituents of volatiles in the ether extract of cultured broth of Sporobolomyces odorus AHU 3246 were analyzed by gas chromatography-mass spectrometry and other methods.

Identified compounds were as follows: Methyl, ethyl, isobutyl, n-butyl, isoamyl, n-amyl, benzyl, and β-phenylethyl alcohol; formaldehyde, acetaldehyde, benzaldehyde, phenyl-acetaldehyde, acetone, and methyl ethyl ketone; ethyl formate, ethyl acetate, and di-n-butyl phthalate; γ-decalactone (4-decanolide) and 4-hydroxy-cis-dodecenoic acid γ-lactone (cis-6-dodecen-4-olide). Di-n-butyl phthalate and parts of methyl, ethyl, and n-butyl alcohol and ethyl acetate were thought to be contaminants. γ-Lactones produced by the yeast were determined by GLC.

Although nine strains of six species of carotenoid pigment accumulating yeasts were cultured under the same conditions, neither flavorful smelling nor γ-lactone production detected in their cultured broths.     

Identification of some volatile compounds from Citrullus vulgaris

Volatile compounds from watermelon (Citrullus vulgaris obtained by vacuum steam distillation—extraction of the fruit at 60–70° in a water-recycling apparatus, were separated by gas chromatography and subjected to spectral analyses. Evidence was obtained for the following new constituents, hexanal, trans-2-heptenal, trans-2-octenal, nonanal, trans-2-nonenal, trans,cis-2,6-nonadienal, nonan-1-ol, trans-2-nonen-1-ol, cis-3-nonen-1-ol, trans,cis-2,6-nonadien-1-ol, trans-2-decenal, trans-2-undecenal, geranial and β-ionone.     

Studies on Leaf Oils of Citrus Species

Leaf oil samples of four Japanese citrus species were analysed by gas chromatography to determine the detailed composition of each leaf oil. The following components were identified: α-pinene, α-thujene, camphene, β-pinene, sabinene, β-myrcene, α-terpinene, limonene, β-phellandrene, trans-2-hexen-1-al, γ-terpinene, p-cymene, terpinolene, cis-2-penten-1-ol, n-hexyl alcohol, cis-3-hexen-1-ol, trans-2-hexen-1-ol, p-α-dimethylstyrene linalool, linalyl acetate, β-elemene, terpinen-4-ol, caryophyllene, humulene, α-terpineol, neryl acetate, geranyl acetate, β-selinene, geraniol and thymol. Most components were contained in common in leaf oils of the four citrus species, but relative contents of some of the components; such as γ-terpinene, linalyl acetate, and thymol differed from species to species. For example, γ-terpinene was the major component (33.8%) of Hassaku, whereas it was only a minor component in Daidai. Daidai is characterized by a very high content of linalyl acetate (35%) which is only a trace in the other three species. Kishu-mikan is characterized by a high content of thymol (15%).     

Composition of turpentine from Pinus edulis wood oleoresin

Monoterpenoids and sesquiterpenoid hydrocarbons of Pinus edulis wood oleoresin were analyzed by chromatographic and spectroscopic methods. Monoterpenoid hydrocarbons (20·3%) were composed mainly of α-pinene, with camphene, β-pinene, 3-carene, sabinene, myrcene, limonene, β-phellandrene, trans-ocimene and terpinolene in secondary to trace amounts. Oxygenated terpenoids (0.28%) contained bornyl acetate and verbenone as major constituents, and linalool, camphor, terpinene-4-ol, citronellyl acetate, borneol, neral, α-terpineol, citronellol, nerol, and geraniol in smaller amounts. Oleoresin contained 1·1% of acetogenins, composed mainly of ethyl caprylate. Sesquiterpenoid hydrocarbons were high (5·7%) in oleoresin) and were composed of germacrene D as a major constituent (36·6%), of γ-amorphene, α-copaene, and longifolene as secondary constituents (5–20%), and β-farnesene, α- and γ-murolenes, β₁-, γ-, δ-, and ε-cadinenes, α-amorphene, δ-guaiene, sibirene, α-cubebene, β-copaene, β-ylangene, sativene, cyclosativene, β-bourbonene, α- and γ-humulenes, caryophyllene, α-longipinene and longicyclene in smaller amounts. Composition of P. edulis and of P. monophylla turpentines was found to be similar, with percentage of ethyl caprylate being the best distinguishing criterion.     

Chemical composition of volatiles from cortical oleoresin of Pseudotsuga menziesii

Pseudotsuga menziesii cortical oleoresin was found to contain 1·7% of oxygenated terpenoids and compounds of similar volatility composed of linalool, methylsalicylate, bornyl acetate, citronellol, geranyl acetate, methylthymol, citronellyl acetate, terpinen-4-ol, borneol, isopulegol, anethole, terpinen-4-ol acetate, camphor, geraniol, neryl acetate, and nerol. Sesquiterpenoid hydrocarbons were low (only 0·07%) and contained sibirene and longifolene as main constituents, with β-caryophyllene, γ-muurolene, γ-cadinene (identified by IR), and 20 additional compounds in small amounts. p-Cymen-8-ene was identified in monoterpene hydrocarbon fraction.     

Chemical composition of the cortical essential oil from Abies balsamea

Monoterpenoids and sesquiterpene hydrocarbons of Abies balsamea cortical oleoresin (Canada balsam) were analyzed by a combination of chromatographic and spectroscopic methods. Monoterpene hydrocarbons (21%) were composed of β-pinene, α-pinene, β-phellandrene, limonene, 3-carene, myrcene and camphene (listed in order of decreasing percentages), and oxygenated monoterpenes (0·4%) contained 4,4-dimethyl-2-cyclohepten-1-one, linalool, bornyl acetate, methylthymol, citronellyl acetate, α-terpineol, piperitone, citronellal, borneol, citronellol, two unknowns, and geraniol. From the sesquiterpene hydrocarbon fraction (1·1%) were isolated: longifolene, β-bisabolene, longipinene, an unknown, sativene, cyclosativene, cis-α-bisabolene, β-himachalene, α-himachalene, β-caryophyllene, γ-humulene, farnesene, longicyclene, an unknown, and β-selinene. Both himachalenes have been identified for the first time in Pinaceae outside of Cedrus; their co-occurrence with γ-humulene, longifolene, longipinene and longicyclene supports the biosynthetic mechanism by which all of these compounds arise through initial 1/11 cyclization of tran-cis-farnesylphosphate.     

Analysis of the volatile components of Lavandula canariensis (L.) Mill., a Canary Islands endemic species,growing in Australia

The essential oil of a Canary Islands endemic species, Lavandula canariensis (L.) Mill., gathered from Australia, was extracted by hydrodistillation and solid phase micro-extraction (SPME). The oils have been studied by GC and GC–MS. A total of 38 compounds have been identified in the leaf oil extracted by hydrodistillation, the principal components being carvacrol (23.6%), β-bisabolene (20.8%), (E,E)-α-farnesene (11.3%), β-caryophyllene (7.6%) and carvacrol methyl ether (7.3%), while the oil extracted by SPME showed carvacrol (42.6%) as the principal component with moderate amounts of (E,E)-α-farnesene (9.1%), β-bisabolene (7.5%), cis-hex-3-en-1-ol (5.6%) and carvacrol methyl ether (4.6%). SPME extracts indicated that carvacrol, cis-hex-3-en-1-ol and linalool were in greater concentration in the head space vapours than in the oil. This is the first report describing the essential oil composition of this species.     

Volatiles from spruce trap-trees detected by Ips typographus bark beetles: chemical and electrophysiological analyses

In the search for compounds that contribute to the host or habitat discrimination, antennae of Ips typographus were screened for sensitivity to volatiles released by spruce trap-trees using gas chromatography linked to electroantennography. The antennally active compounds were determined using comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometric detection. Data show that I. typographus antennae respond to compounds emitted by the host. In total, 18 of antennally active compounds were detected: α-pinene, camphene, sabinene, β-pinene, myrcene, Δ-3-carene, p-cymene, limonene, β-phellandrene, 1,8-cineole, γ-terpinene, terpinolene, nonanal, camphor, trans-pinocamphone, cis-pinocamphone, terpinen-4-ol, and verbenone. Unequivocal identification of all active minor compounds is provided and confirmed using synthetic standards. Compounds in minor quantities like 1,8-cineole, β-phellandrene, camphor, cis-pinocamphone, and trans-pinocamphone were more active than major spruce monoterpenes. We hypothesize that the minor spruce compounds may play so far unrecognized role in conveying information about host suitability for I. typographus.     

Identification des constituants de l'essence des aiguilles de Pinus pinaster

The chromatographic analysis of the volatile leaf oil of Pinus pinaster Ait. showed 42% of monoterpene hydrocarbons (α-pinene, camphene, β-pinene, myrcene, 3-carene, limonene, cis-ocimene, terpinolene, para-cymene, 35% of sesquiterpene hydrocarbons (cubebene, copaene, caryophyllene, humulene, germacrene D, α- and γ-muurolenes, δ- and γ-cadinenes) and 23% of oxygenated compounds including esters (linalyl, bornyl, geranyl, neryl and farnesyl acetates), alcohols (cis-hexenol, linalool, α-fenchol, trans-pinocarveol, terpinen-4-ol, α-terpineol, dihydrocarveol, guaiol, junenol and α-cadinol), one aldehyde (hexenal) and one ketone (piperitone). Three non terpenoid phenylethyl esters were also identified: phenylethyl isovalerate, methyl-2 burtyate and 3-3 dimethylacrylate. Some alcohols and mainly α-terpineol and linalool seemed to be formed during the steam distillation process, they were absent when the leaf oil was obtained by maceration of small portions of leaves in the usual solvents of terpenes.     

Electron spin resonance and electron nuclear double resonance studies of cation radicals derived from tocopherol model compounds

Electron spin resonance (ESR) and electron nuclear double resonance (ENDOR) measurements were performed for the cation radicals obtained from the model compounds of α-, β-, γ- and δ-tocopherol (vitamin E) by oxidizing the tocopherol precursors in an AlCl₃-CH₂Cl₂ solution. The proton hyperfine coupling constants g-values were precisely determined. The ENDOR spectra of the cation radicals of α-, β-, γ- and δ-tocopherol models in CH₂Cl₂ at ?100°C clearly show 10, 6, 6 and 12 different proton hyperfine couplings, respectively. By varying the temperature, the ESR spectra of the α- and δ-tocopherol model cations exhibit line-width alternation phenomena characteristic of the hindered rotation of the OH group. However, neither the β- nor the γ-tocopherol model cation radical ESR spectra show any sign of an alternative line-width effect. These results are interpreted by assuming that the β- and γ-tocopherol model cations are stabilized in the trans and cis conformations, respectively. On tocopherol model cations are stabilized in the trans and cis conformations, respectively. On the other hand, both the α- and δ-tocopherol model cations exist as cis and trans isomers.     

Complementary microbial approaches for the preparation of optically pure aromatic molecules

Different strategies for stereoselective microbial preparation of various chiral aromatic compounds are described. Optically pure 2-methyl-3-phenyl-1-propanol, ethyl 2-methyl-3-phenylpropanoate, 2-methyl-3-phenylpropanal, 2-methyl-3-phenylpropionic acid and 2-methyl-3-phenylpropyl acetate have been prepared using different microbial biotransformations starting from different prochiral and/or racemic substrates. (S)-2-Methyl-3-phenyl-1-propanol and (S)-2-methyl-3-phenylpropanal were prepared by biotransformation of 2-methyl cinnamaldehyde using the recombinant strain Saccharomyces cerevisiae BY4741ΔOye2Ks carrying a heterologous OYE gene from Kazachstania spencerorum. (R)-2-Methyl-3-phenylpropionic acid was obtained by oxidation of racemic 2-methyl-3-phenyl-1-propanol with acetic acid bacteria. Kinetic resolution of racemic 2-methyl-3-phenylpropionic acid was carried out by direct esterification with ethanol using dry mycelia of Rhizopus oryzae CBS 112.07 in organic solvent, giving (R)-ethyl 2-methyl-3-phenylpropanoate as major enantiomer. Finally, (R,S)-2-methyl-3-phenylpropyl acetate was enantioselectively hydrolysed employing different bacteria and yeasts having cell-bound carboxylesterases with prevalent formation of (R)- or (S)-2-methyl-3-phenyl-1-propanol, depending on the strain employed.     

Flower scent composition in night-flowering Silene species (Caryophyllaceae)

Floral scent of 13 night-flowering Silene species (Caryophyllaceae) was collected by headspace adsorption and analysed via gas chromatography and mass spectrometry. Benzenoids together with isoprenoids dominated the scent in all species. Among the benzenoids, benzaldehyde (Silene subconica 35.5%, Silene succulenta 23.1%, Silene sericea 15.6%, Silene vulgaris 12.2%, and Silene nutans 9.9%), methylbenzoate (Silene saxifraga 96.1%, S. succulenta 15.2%), benzyl acetate (Silene dichotoma 37.8%, S. nutans 30.1%, Silene italica 9.0%, and Silene latifolia 5.5%), or benzyl alcohol (Silene viscosa 36.1%) occur in the largest amounts. p-Cresol is only found in the floral scent of S. dichotoma (28.5%). Among the isoprenoids, monoterpenes occur in the largest amounts (myrcene 23% in Silene chlorantha, trans-β-ocimene 27.2% in S. nutans and 34.9% in S. sericea, fenchyl acetate 12.7% in S. chlorantha, β-linalool 40.5% in S. chlorantha and 14.5% in S. italica). Relatively high amounts of lilac compounds occur in S. latifolia (49.1%), Silene otites (35.7%), S. subconica (15.2%), and S. vulgaris (59.6%). Higher amounts of sesquiterpenes (isoprenoids) were only found in Silene vallesia with β-bourbonene and γ-muurolene.The vast majority of chemicals identified are common components of a wide array of scented angiosperm flowers. Nevertheless, the results conform most strongly with the findings in other night-blooming and/or moth-pollinated flowers. All investigated Silene species follow the general trend of floral scent compounds typical for moth-pollinated flowers, i.e. flowers having acyclic terpene alcohols (e.g. linalool), aromatic alcohols (benzyl alcohol, 2-phenylethanol) and esters derived from them, and small amounts of nitrogen-containing compounds.     

The leaf oil terpene composition of Juniperus occidentalis

The chemical composition of the volatile oil of 10 trees each of two Oregon populations of the western juniper was determined by a computerized GC-MS method. The identity of the major components, sabinene, α-pinene, α- and γ-terpinene, p-cymene, limonene, terpinen-4-ol and bornyl acetate was confirmed. In addition, tricyclene, α-thujene, camphene, β-pinene, α- and β-phellandrene, car-3-ene, trans-ocimene, linalool oxide, terpinolene, trans-sabinene hydrate, camphor, camphene hydrate, borneol, α-terpineol, p-cymenol, methyl citronellate, citronellyl acetate, carvacrol, cuminic aldehyde, β-bourbonene, several cadinene and cadinol isomers, elemol, γ-, β- and α-eudesmol, and manoyl oxide were identified. Santene, citronellol, and aromatic ethers of the safrole-eugenol type were not found. Tree-to-tree variability of the relative percentages of these terpenes was fairly large and chemosystematic implications are discussed briefly.     

Flavor of Black Tea

Intermediate and high boiling neutral compounds in the aroma concentrate from black tea were isolated by fractional distillation, silica-gel column chromatography and gas chromatography.

Identification of the compounds was verified by the agreement of IR and mass spectra as well as gas chromatographic data with those of authentic compounds.

Eleven compounds; α-muurolene, δ-cadinene, furfuryl alcohol, methyl phenyl carbinol, cadinenol, geranial, pyrrole-2-aldehyde, benzyl formate, phenylethyl formate, cis-3-hexenyl benzoate and indole, were newly identified as constituents of black tea aroma and ten known components; α-terpineol, 3, 7-dimethyl-l, 5, 7-octatrien-3-ol, trans, trans-2, 4-decadienal, 2-phenyl-2-butenal, α- and β-ionone, cis-jasmone, theaspirone, lactone of 2-hydroxy-2, 6, 6-trimethylcyclohexylidene-l-acetic acid and phenylacetonitrile were confirmed. The geometric structure of theaspirone in tea aroma was determined as the cis-form.     

Essential oil composition of four Lomatium Raf. species and their chemotaxonomy

The composition of the essential oils of Lomatium dasycarpum ssp. dasycarpum, Lomatium lucidum, Lomatium macrocarpum var. macrocarpum and Lomatium utriculatum is described. Identification of components was determined from their GC, GC/MS data and many were confirmed by coinjections with authentic samples. Several components were isolated by liquid and gas chromatographic techniques and their structures confirmed from their ¹H and ¹³C NMR spectral data. 2-Methyl and 3-methylbutanoates were the major components of L. dasycarpum fruits as well as stems and leaves oils. β-Phellandrene/limonene, decanal, dodecanal, bornyl acetate, germacrene D, α-humulene and bicyclogermacrene were the major components of the corresponding L. lucidum oils. α-Pinene and β-pinene were the major components of the fruit oil of L. macrocarpum. Its stem and leaf oil was rich in peucenin 7-methyl ether, β-caryophyllene, (Z)-3-hexenol, palmitic acid, linoleic acid and (E)-2-hexenal. Sabinene, (Z)-ligustilide, terpinen-4-ol, β-phellandrene/limonene, β-caryophyllene, myrcene, α-pinene and β-pinene were the major compounds in L. utriculatum fruit oil, while its stem and leaf oil was rich in (Z)-ligustilide, palmitic acid, terpinen-4-ol, linoleic acid and germacrene D. (Z)-Falcarinol was a major component of all the four root oils.     

Studies on the Flavor of Green Tea

By continuing flavor analysis of green tea from a previous paper, further twenty seven compounds were newly identified. These compounds are limonene, α-cubebene, α-copaene, caryophyllene, α-humulene, α- and γ-muurolene, β-sesquiphellandrene, δ-cadinene, calamenene, cubenol, α-cadinol, α-terpineol, n-heptanol, n-nonanol, furfurylalcohol, n-nonanal, N-ethylformylpyrrole, pyrrylmethylketone, 6-methyl-trans-3,5-heptadien-2-one, 2′,2″-dihydro-α-ionone, 6,10,14-trimethyl-2-pentadecanone, cis-3-hexenylcaproate, cis-3-hexenylbenzoate, α-terpinylacetate, coumarin and diphenylamine.

Relative quantities of known compounds in intermediate- and high-boiling fraction were determined.     

Volatile terpenoids from aeciospores of Cronartium fusiforme

Aeciospores of Cronartium fusiforme isolated from slash pine (Pinus elliottii) trees were analyzed for volatile terpenoids by GLC and GLC-MS. α-Pinene, β-pinene, Δ³-carene, myrcene, linonene, β-phellandrene, and δ-terpinene were the major monoterpenoid hydrocarbons present with only traces of camphene. A number of monoterpenoid alcohols were also present of which terpinen- 4-ol predominated. Among the various acyclic sesquiterpenes present, β-farnesene and β-citronellol were identified. Several aromatic compounds were also observed, including o-cresol.     

Sex pheromone of the cotton leafworm, Spodoptera littoralis

cis-9,trans-11-Tetradecadien-1-ol acetate (A) and cis-9,trans-12-tetradecadien-1-ol acetate (B), the same compounds as the female sex pheromone of Spodoptera litura, were identified as major components of the female sex pheromone of the cotton leafworm, Spodoptera littoralis. Compounds A and B were individually active, but the activity was synergistically enhanced by mixing the two compounds. The male response was optimal with mixture ranging from 5 : 1 to 20 : 1 of compounds A and B, respectively. Fifty per cent of the male moths of S. littoralis responded to the 20 : 1 mixture at the 10^?7 μg level; they responded at a concentration 100-fold lower than did male moths of S. litura. A partially purified extract of females of S. litura stimulated male moths of S. littoralis. Similarly a partially purified extract of S. littoralis was also active for the male moths of S. litura. The extract of females of S. litura, however, was 1000 times less active for male moths of S. littoralis than was the exrtact of females of S. littoralis, suggesting that a compound(s) is present in the extract of S. litura that inhibits the response of males of S. littoralis.     

Fusarium infection in maize: volatile induction of infected and neighboring uninfected plants has the potential to attract a pest cereal leaf beetle, Oulema melanopus

Fusarium infection of maize leaves and/or roots through the soil can stimulate the emission of volatile organic compounds (VOCs). It is also well known that VOC emission from maize plants can repel or attract pests. In our experiments, we studied VOC induction responses of Zea mays L. ssp. mays cv. ‘Prosna’ having Fusarium infection (mix of four species) in leaves or roots, then tested for VOC induction of uninfected neighboring plants, and finally examined wind-tunnel behavioral responses of the adult cereal leaf beetle, Oulema melanopus L. (Chrysomelidae: Coleoptera) behavior to four induced VOCs. In the first part of our experiment, we confirmed that several green leaf volatiles (GLVs; (Z)-3-hexenal, (E)-2-hexenal, (Z)-3-hexen-1-ol, (E)-2-hexen-1-ol, (Z)-3-hexen-1-yl acetate, 1-hexyl acetate), terpenes (β-pinene, β-myrcene, Z-ocimene, linalool, β-caryophyllene), and shikimic acid pathway derivatives (benzyl acetate, methyl salicylate, indole) were positively induced from maize plants infected by Fusarium spp. The quantities of induced VOCs were higher at 7 d than 3 d post-infection and greater when plants were infected with Fusarium on leaves rather than through soil. In the second part of our experiment, uninfected maize plants also showed significantly positive induction of several VOCs when neighboring an infected plant where the degree of induction was negatively related to the distance from the infected plant. In the third part of our experiment, a Y-tube bioassay was used to evaluate upwind orientation of adult cereal leaf beetles to four individual VOCs. Female and male O. melanopus were significantly attracted to the GLVs (Z)-3-hexenal and (Z)-3-hexenyl acetate, and the terpenes linalool and β-caryophyllene. Our results indicate that a pathogen can induce several VOCs in maize plants that also induce VOCs in neighboring uninfected plants, though VOC induction could increase the range at which an insect pest species is attracted to VOC inducing plants.     

Free amino acids and γ-glutamyl peptides in seeds of Fagus silvatica

The contents of amino acids and peptides have been investigated in seeds of Fagus silvatica L. (beechnuts). In addition to the common amino acids, the following compounds have been isolated and identified: 4-hydroxyproline (probably the cis-l-isomer), N⁵-acetylornithine, 3-(2-furoyl)-l-alanine, methionine sulfoxide (probably an artefact), pipecolic acid (probably partially racemized d-isomer), l-willardiine (with a small amount of the d-isomer), N-(3-amino-3-carboxypropyl)azetidine-2-carboxylic acid, N-[N-(3-amino-3-carboxypropyl)-3-amino-3-carboxypropyl]azetidine-2-carboxylic acid, 2(S),5(S),6(S)-5-hydroxy-6-methylpipecolic acid, 2(S),5(R),6(S)-5-hydroxy-6-methylpipecolic acid, γ-glutamylalanine, γ-glutamylglutamic acid, γ-glutamylisoleucine, γ-glutamylleucine, γ-glutamylmethionine sulfoxide (probably an artefact), γ-glutamylphenylalanine, γ-glutamyltyrosine, γ-glutamylvaline, glutathione, γ-glutamylwillardiine, and γ-glutamylphenylalanylwillardiine. γ-Glutamylphenylalanine and willardiine are the dominating components of the amino acid fraction.The isolations were performed by use of ion exchange chromatography, taking advantage of the different pK-values of the amino acids, mainly on acid resins in the 3-chloropyridinium form with aq. 3-chloropyridine as eluant and on basic resins in the acetate form with aqueous acetic acid as eluant. These methods in combination with preparative paper chromatography have permitted the isolation and identification of compounds present in amounts as low as 1/6000 of the dominant ninhydrin-reactive component. The implications of the occurrence of this large variety of compounds in the Fagaceae are briefly discussed.