Sesquiterpene hydrocarbons from Lentinus lepideus

Several sesquiterpene hydrocarbons, mainly of the cadinane skeleton, have been identified in cultures of the brown rot fungus Lentinus lepideus. The main compounds are δ-cadinene, α- and γ-muurolene.     

Sesquiterpene Deterrence of a Leaf-Tying Lepidopteran, Stenoma ferrocanella, on Hymenaea stigonocarpa in Central Brazil

Study of two populations of Hymenaea stigonocarpa in the central Brazilian cerrado (savanna/woodland) shows attack by a leaf-tying lepidopteran, Steoma ferrocanella, occurred after inferred peak concentration (% of leaf dry wt) of sesquiterpene leaf resins during leaf development. Also a highly statistically significant relationship existed between leaf-tier attack and level of caryophyllene in one population and γ-muurolene in the other population. The data from one population are consistent with laboratory experiments demonstrating highly significant dose-dependent effects of caryophyllene in Hymenaea leaf resin on mortaility of the lepidopteren Spodoptera exigua. Results from both populations support other evidence that changes in the amount of single terpenes in the mixture constituting the resin may have significant antiherbivore effects and, concomitantly, that herbivory may be a source of some of the leaf resin variation.     

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.     

Essential oil of Psiadia salviifolia

Utilizing GLC, IR, combined GC-MS, the following constituents were identified in the essential oil of Psiadia salviifolia; β-pinene, limonene, γ-terpinene, p-cymene, α-copaene, linalool, β-bourbonene, α-himachalene, γ-cadinene, δ-cadinene, -γ-elemene, and a hydroxy derivative of calamenene. A new monoterpene hydrocarbon was also isolated which from MS and IR evidence was named as 7-methyl-3-methylene-octa-1,4-diene.     

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.     

Insecticidal effects of Flourensia oolepis Blake (Asteraceae) essential oil

Flourensia oolepis Blake (Asteraceae) essential oil had a complex chemical composition with τ-muurolene (6.14%), santolinetriene (6.22%), 2-methylene-4,8,8-trimethyl-4-vinyl-bicyclo[5.2.0]nonane (10.15%), δ-cadinene (10.27%) and γ-gurjunene (20.69%) comprising more than 50% of the oil. This oil had repellent and toxic effects on Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) adults, acting as a contact toxin. Myzus persicae (Sulzer) (Homoptera: Aphididae) and Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae) adults showed behavioral sensibility to this oil.     

Foliage sesquiterpenes of Dacrydium cupressinum: identification,variation and biosynthesis

The major sesquiterpenes in the foliage of Dacrydium cupressinum are α-longipinene, longifolene, longibornyl acetate, caryophyllene, caryophyllene oxide, humulene, α- and β-selinene, β- and δ-elemene, aromadendrene and the rare 9βH-caryophyllene. Sesquiterpene levels vary greatly from tree to tree. As this variation is largely independent of environmental factors, genetic control is proposed. Longifolene and α-longipinene levels are closely correlated, as are those of caryophyllene and humulene. The biosynthetic implications of these correlations are discussed.     

The propolis of stingless bees: terpenes from the tibia of three Frieseomelitta species

The posterior tibia of foraging workers of three species of Frieseomelitta (Hymenoptera: Meliponinae) stingless bees have been shown to carry complex mixtures of plant-derived mono-, sesqui-, di- and tri-terpenes. These subtances were not found on the fore- or mid-legs, nor on other parts of the hind legs. F. silvestrii and F. silvestrii languida, when collecting, appear to exploit different plants for their resin even when housed in the same area. F. varia were found to be not collecting resin at the time of the initial sampling and were therefore sampled later. Mature foragers carry the resin. In the samples studied here, particularly prominent were the monoterpene α-pinene, the sesquiterpenes β-caryophyllene, α-cubebene, α- and γ-muurolene, γ-cadinene, germacrene-D, and elemol and the diterpenes manool and totarol The collected material is used for the resin placed around the entrance to their nests and is also mixed with wax, to produce the cerum used for the structures in the nest.     

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.     

Studies on the Chemical Constituents of the Hydrocarbon Fraction of the Essential Oils from Caryopteris tangutica and C. Glutinosa

The chemical constituents of the hydrocarbon fraction of essential oils of Caryopteris tangutica Maxim. and C. glutinosa Rehd were examined by means of GC-MS-COM and GC retention time data on a 45 m capillary column coated with OV- 101. 21 components have been saparated and identified, i.e. α-thujene, α-pinene, cam- phene, sabinene, β-pinene, β-myrcene, α-terpinene, p-cymene, limonene, β-ocimene-y, β- phellandrene, α-terpinolene, α-cubebene, α-copaene, α-cedrene, β-caryophyllene, γ-cadinene, 1-aromadendrene, α-humulene, β-bisabolene and δ-cadinene. The quantitative determination of these components was carried out by GLC also.     

Inhibitor and substrate activities of sesquiterpene olefins toward (+)-δ-cadinene-8-hydroxylase, a cytochrome P450 monooxygenase (CYP706B1)

Several lines of evidence indicate that (+)-δ-cadinene-8-hydroxylase (CYP706B1) plays an important role in biosynthesis of gossypol in Gossypium arboreum L. ( [Luo et al., 2001] and [Wang et al., 2003]). The catalytically active enzyme has been expressed in yeast microsomes. Some microsomal preparations conjugated the hydroxylated (+)-δ-cadinene to a moiety that has not yet been identified. However, when microsomes were treated with n-octyl-β-d-glucoside (OG), a non-ionic detergent, (+)-δ-cadinene was reproducibly converted to the free alcohol, 8-hydroxy-(+)-δ-cadinene. OG had little effect on K_m and slightly stimulated apparent V_max. Enzymic activity was more than 10-fold more sensitive to inhibition by the N-substituted imidazole clotrimazole than to miconazole. Sesquiterpene olefins (−)-δ-cadinene, (−)-α-cubebene, (−)-α-muurolene, α-humulene, and a mixture of (−)- and (+)-α-copaene were inhibitory to hydroxylation of (+)-δ-cadinene. In addition, (−)-α-cubebene, (−)-α-muurolene, α-humulene, and, to a smaller extent, (−)-δ-cadinene served as alternative substrates for (+)-δ-cadinene-8-hydroxylase and were converted to mono-hydroxylated products. Of the five olefins tested, α-humulene and α-copaene are found in lysigenous glands of cotton (Elzen et al., 1985), which are also the site of gossypol accumulation ( [Bell et al., 1978] and [Mace et al., 1976]) and the probable site of its biosynthesis.     

Novel vitamin E forms in leaves of Kalanchoe daigremontiana and Phaseolus coccineus

In the present study, we isolated novel tocochromanols from green leaves of Kalanchoe daigremontiana and primary leaves of etiolated seedlings of Phaseolus coccineus that were identified as β-, γ-, and δ-tocomonoenols with unsaturation at the terminal isoprene unit of the side chain. The content of γ-tocomonoenol in leaves of etiolated bean increased gradually with the age of seedlings, reaching 50% of the γ-tocopherol level in 40-day-old plants. The content of this compound in leaves was increased by short illumination of etiolated plants and by addition of homogentisic acid, a biosynthetic precursor of tocopherols. These data indicated that γ-tocomonoenol is synthesized de novo from homogentisic acid and tetrahydro-geranylgeraniol diphosphate, a phytol precursor. Based on these results, a biosynthetic pathway of tocomonoenols is proposed.     

Stuies on the Chemical Constituents of the Essential Oils from the Leaves of Aglaia odorata Lour

This paper shows the chemical constituents of the essential oils from the leaves of Aglaia odorata Lout. grown in Zhangzhou. By the aid of GC-MS-DS., IR., the following components have been separated and identified: linalool, hendecane, α-copaene, β-elemene, β-caryophyllene, α-humulene, aromadendrene, γ-cadinene, α-himachalene, δ-cadinene, β-guaiene, γ-gurjunene, γ-elemene, humulene epoxide-Ⅰ, humulene epoxide-Ⅱ, β-elemene-9β-ol, β-humulene-7-ol, nerolidol, earyophyllenol-1, farnesol, β-santalol, elemol. This will provide scientific basis for further develophment of the essential oils of the plants of Aglaia Lour.     

Chemical variability of the volatiles from the leaves of Eugenia protenta McVaugh (Myrtaceae) growing wild in the North of Brazil

Leaf volatiles of eight samples of individual plants of Eugenia protenta from three municipalities in the Northeastern Pará, Brazil, were obtained by hydrodistillation (HD) and investigated by gas chromatography/flame ionization detector (GC/FID) and gas/chromatography/mass spectrometry (GC/MS). Dimethylxanthoxylin, selin-11-en-4α-ol, β-elemene, germacrene D, bicyclogermacrene and δ-cadinene were the principal constituents. The results of the oil compositions were processed by Hierarchical Component Analysis (HCA) allowing the establishment of three groups of essential oils differentiated by the content of dimethylxanthoxylin (Type A), selin-11-en-4α-ol/β-elemene (Type B) and germacrene D accomplished by bicyclogermacrene and δ-cadinene (Type C). Dimethylxanthoxylin is being cited for the first time in the genus Eugenia, however it was previously identified in other genera of the family Myrtaceae (Melaleuca and Austromyrtus).     

Sesquiterpenes from Artemisia princeps

Copaene, cyperene, caryophyllene, β-farnesene, α-himachalene, γ-humulene and farnesyl acetate were isolated from the root of Artemisia princeps. As a result of isomerization studies on γ-humulene, the main constituent, a preferred conformation was proposed.     

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.     

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.     

Terpenes from Cantinoa (Lamiaceae) native to Rio Grande do Sul,South Brazil

Cantinoa althaeifolia, C. heterodon, C. mutabilis, C. stricta and C. sylvularum were investigated for the essential oil and exudate composition. The essential oils of these species, previously placed in the genus Hyptis, demonstrated the presence of at least 46 compounds, being β-pinene, δ-3-carene, β-caryophyllene, bicyclogermacrene, caryophyllene oxide and globulol the compounds present in higher amounts. Besides monoterpenes and sesquiterpenes, three species presented diterpenes. Kaurenoic acid was isolated from C. heterodon exudate and detected by gas chromatography in C. stricta and C. mutabilis. Although kaurane diterpenes are widely found in nature, their occurrence in Lamiaceae seems to be restricted to few genera.     

GmTMT2a from soybean elevates the α-tocopherol content in corn and Arabidopsis

Tocochromanol, or vitamin E, plays a crucial role in human and animal nutrition and is synthesized only by photosynthetic organisms. γ-Tocopherol methyltransferase (γ-TMT), one of the key enzymes in the tocopherol biosynthetic pathway in plants, converts γ, δ-tocopherols into α-, β-tocopherols. Tocopherol content was investigated in 15 soybean cultivars and GmTMT2 was isolated from five varieties based on tocopherol content. GmTMT2a was expressed in E. coli and the purified protein effectively converted γ-tocopherol into α-tocopherol in vitro. Overexpression of GmTMT2a enhanced α-tocopherol content 4–6-fold in transgenic Arabidopsis, and α-tocopherol content increased 3–4.5-fold in transgenic maize seed, which correlated with the accumulation of GmTMT2a. Transgenic corn that is α-tocopherol-rich may be beneficial for animal health and growth.     

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.