Die Cyclopropylcarbinyl-Cyclobutyl-Homoallyl-Umlagerung. I. Teil. Synthese von Tricyclo[3.2.1.02,7]octan-3-ol,endo- und exo-Tricyclo[3.2.1.03,6]octan-4-ol und exo-Bicyclo[3.2.1]-oct-2-en-7-ol

Tricyclo[3.2.1.0^2,7]octan-3-ol ( 1 ) and its 4-isomer 7 were obtained by hydroboration of tricyclo[3.2.1.0^2,7]oct-3-ene ( 5 ). The former alcohol 1 is quantitatively converted to the isomeric alcohol exo-bicyclo[3.2.1]oct-2-en-7-ol ( 3 ) by treatment with aqueous acid. Photolysis of 1-diazo-3-(cyclopent-3-enyl)-propan-2-one ( 12c ) gave a high yield of tricyclo[3.2.1.0^3,6]octan-4-one ( 10a ). Reduction of the latter ketone produced a mixture of endo- and exo-tricyclo[3.2.1.0^3,6]octan-4-ol 2 and 9 , respectively. Oxidation of these secondary alcohols with silver carbonate in benzene furnished a mixture of the ketone 10a and the lactone 14 of 6-hydroxy-bicyclo[2.1.1]heptane-2-carboxylic acid. The latter is thought to be formed by oxydation of the hydrate of the strained ketone 10a .     

Production of natural fruity aroma by Geotrichum candidum

Based on its aromatic potential, Geotrichum candidum isolated from olive vegetation water was tested for the production of volatile compounds. When G. candidum was cultivated on media with glucose as the carbon source, flavor volatile compounds were produced and accumulated in the broth. Fruity flavoring compounds (pineapple-like) such as esters and alcohols were analyzed by gas chromatography coupled to mass spectrometry, including ethyl esters of acetic acid and butyric acid, methyl-3-butan-1-ol, and methyl-2-propan-1-ol. Their synthesis corresponded to the stationary growth phase of the strain. Production of the volatile compounds reached 9.5 g/L of 2-hexanoic acid ethyl ester and 1.6 g/L of benzaldehyde as the main concentrated molecules. Ethyl alcohol seems to be an intermediate metabolite in this pathway.     

Synthesis of 2,7-Diazabicyclo[3.3.0]octane and 2,7-Diazabicyclo[3.3.0]oct-4-ene Derivatives via Cyclization Reaction and Julia Reaction

2,7-Diazabicyclo[3.3.0]octan-4-ol (1) and 2,7-diazabicyclo[3.3.0]oct-4-ene (2) are synthesized by the desulfonylation using Mg-HgCl₂(cat.) of β-hydroxy sulfone derivatives which have been prepared via cyclization of sulfone ester derivative.     

Characterization of Aromatic Liquor by Gas Chromatography and Principal Component Analysis

The differentiation of aromas of Chinese liquor is important for their unique flavors. In this work, aromas of Chinese liquor were characterized by gas chromatography and chemometrics. Ten representative aroma compounds, including three alcohols, four esters, two organic acids, and acetal in 16 Chinese liquor were determined by gas chromatography with flame ionization detection. The relationship between these compounds and six classic aromas was investigated using principal component analysis and k-means clustering. The cumulative contribution of the first three principal components reached up to 84.607%, which effectively differentiated the liquors. The variables with the highest loading absolute value were acetal and ethyl acetate for principal component 1, ethyl butanoate and ethyl hexanoate for principal component 2, and the hexanoic acid and ethyl butanoate for principal component 3. The aromas of the liquors were characterized by k-means clustering with the first three principal component scores, indicating that the acetal, ethyl acetate, ethyl butanoate, ethyl hexanoate, and hexanoic acid are important for the aroma of Chinese liquors. This work demonstrated that the gas chromatography with chemometrics is effective for the characterization of aromatic liquor.     

Use of a Complete Factorial Experiment for Designing a Gas Sensor Based on Extracts of <Emphasis Type="Italic">Pleurotus ostreatus</Emphasis> Mycelium Mushroom

A gas sensor was developed on the basis of extracts of mycelium mushroom Pleurotus ostreatus for determining phenol in air. The procedure of sensor preparation was optimized using a complete factorial experiment. The quantitative and kinetic parameters were found for the adsorption of some organic compounds (alcohols, ketones, alkyl acetates, phenols, aromatic amines) on films with a biological modifier.__________Translated from Zhurnal Analiticheskoi Khimii, Vol. 60, No. 7, 2005, pp. 759–764.Original Russian Text Copyright © 2005 by Silina, Kuchmenko, Korenman, Tsivileva, Nikitina.     

Synthesis and transformations of di-endo-3-aminobicyclo-[2.2.2]oct-5-ene-2-carboxylic acid derivatives

all-endo-3-amino-5-hydroxybicyclo[2.2.2]octane-2-carboxylic acid (13) and all-endo-5-amino-6-(hydroxymethyl)bicyclo[2.2.2]octan-2-ol (10) were prepared via dihydro-1,3-oxazine or g-lactone intermediates by the stereoselective functionalization of an N-protected derivative of endo-3-aminobicyclo[2.2.2]oct-5-ene-2-carboxylic acid (2). Ring closure of b-amino ester 4 resulted in tricyclic pyrimidinones 15 and 16. The structures, stereochemistry and relative configurations of the synthesized compounds were determined by IR and NMR.     

Quantitative Determination of BTEX and Total Aromatic Compounds in Gasoline by Comprehensive Two-Dimensional Gas Chromatography (GC×GC)

Comprehensive two-dimensional gas chromatography (GC×GC) has been applied to the quantitative analysis of benzene, toluene, ethylbenzene, xylenes (BTEX), and all heavier aromatic compounds in gasoline. The two-dimensional chromatographic separation used volatility selection on the first-dimension column and polarity selection on the second-dimension column. In the resulting GC×GC chromatogram, aromatic species were resolved from other compound classes. Moreover, structurally related aromatics were grouped in a manner that facilitated identification and integration. The response of a flame ionization detector to each major aromatic group in gasoline was calibrated using internal standards. Quantitation produced results directly comparable with ASTM standard methods. The present GC×GC method can be expanded to analyze other gasoline components.     

Confirmation of the E and Z attribution to the isomers of 3-ethylidene-1-azabicyco-[2,2,2]octane by CMR spectroscopy

CMR spectra of the following bicyclo[2,2,2]octane compounds were measured: 1-azabicyclo[2,2,2]octan-3-one ( 3 ), 2-azabicyclo[2,2,2]octan-3-one ( 5 ), bicyclo[2,2,2]octaone ( 4 ), 3-ethyl-1-azabicyclo[2,2,2]oct-2-ene ( 6 ) and of the Z and E isomers of 3-ethylidene-1-azabicyclo-[2,2,2]octane ( 1 and 2 ). The attribution of the signals and confirmation of the Z and E configuration of isomers ( 1 ) and ( 2 ) is described.     

新型碳纳米管色谱固定相制备的研究进展

碳纳米管（CNTs）作为一种新型的功能材料,具有优异的物理、化学和机械性能,已经在分析化学领域得到了广泛的关注和应用。通过填充法或原位化学气相沉积法,可制备CNTs气相色谱固定相;将CNTs沉积在硅胶微球或有机聚合物基质微球表面,可制备填充式CNTs液相色谱固定相;通过包埋共聚法将CNTs嵌入聚合物整体柱内,可制备毛细管CNTs液相色谱整体柱。本文主要综述了近年来CNTs（单壁碳纳米管和多壁碳纳米管）用于色谱固定相制备的研究现状,包括气相色谱及液相色谱,并对该领域今后的发展进行展望。     

Seasonal Variability of Volatilome from Dictyota dichotoma

Dictyotaceae, the large family of brown algae with the genus Dictyota as the richest one among them, produce a significant number of secondary metabolites, like diterpenes. The aim of this study was to investigate the variations in the composition of the volatile organic compounds (VOCs) of the brown alga Dictyota dichotoma collected from the Adriatic Sea. For the first time, both seasonal changes and the impact of air drying were examined. Headspace solid-phase microextraction (HS-SPME) on two fibres with different polarities and hydrodistillation (HD), followed by gas chromatography and mass spectrometry (GC-MS) analysis, was performed on both fresh (FrDd) and air-dried (DrDd) D. dichotoma. The major compounds of HS-FrDd were pentadecane and oct-1-en-3-ol. The percentage of pentadecane in HS-DrDd was increased up to 7.8 times in comparison with HS-FrDd. Principal component analysis (PCA) identified differences between the variability of data among fresh and dried samples over months and clearly dissociated the fresh May samples from the others in the HS-SPME results. The most abundant group of VOCs in HD were terpenes, with diterpenes isopachydictyol A and cembra-4,7,11,15-tetraen-3-ol as the major compounds. Diterpene pachydictyol A was also found and among sesquiterpenes and gleenol was the most abundant. Based on the dominant compound analyses, the PCA showed distinct separation of the fresh and dried samples, indicating similarities between the samples and allowing the establishment of typical VOCs significant for the chemotaxonomy of D. dichotoma.     

Determination of specific volatile organic compounds synthesised during Tuber borchii fruit body development by solid-phase microextraction and gas chromatography/mass spectrometry

Fruit body development is a particular phase of the Tuber life cycle, characterised by the aggregation of different types of hyphae, i.e., vegetative hyphal cells and highly specialised reproductive hyphae (asci). In order to identify the volatile organic compounds (VOCs) produced in different stages of the Tuber borchii ripening fruit body, solid-phase microextraction with gas chromatography and mass spectrometry was used. The volatile organic compounds were extracted using a DVB/CAR/PDMS 50/30 microm fiber placed for 10 min at room temperature in the truffle headspace. The results obtained reveal 49 compounds each of which was present only in a particular stage of maturation. 1-octen-3-ol, aromadendrene, alpha-farnesene and other terpenoid compounds were of particular interest, and their possible biological roles are discussed. The production of aromadendrene in the completely unripe fruit body suggests the existence of communication events in the early stage of ascomata formation between the fungus and the host plant. alpha-Farnesene could represent a chemotactic attractant to saprophytic organisms in order to disperse the fungal spores in the environment. The identification of the VOCs produced by truffles during their maturation could give information about the processes underlying this phase of Tuber life cycle.     

Structure-type separation of diesel fuels by solid phase extraction and identification of the two- and three-ring aromatics by capillary GC-mass spectrometry

A simple and effective solid phase extraction (SPE) method using silica gel micro glass columns has been developed for the separation of diesel fuel into groups of aliphatic, and mono-, di- and polyaromatic hydrocarbons. It is based on a stepwise gradient of dichloromethane in n-pentane. The resulting fractions were analyzed by capillary gas chromatography with a flame ionization detector and coupled gas chromatography-mass spectrometry. Commercially available standards, and retention indices and mass spectra were used for identification of individual aromatic compounds. The principal polycyclic aromatic hydrocarbons (PAHs) in diesel fuel are naphthalene, biphenyl, fluorene, phen-anthrene and their alkylated derivatives. Sulfur-containing PAHs are mainly represented by methyl-substituted dibenzo-thiophenes.     

Cyclam complexes of Cu(II) and Co(II) as stationary phases for gas chromatography

New macrocyclic stationary chemically bonded phases were synthesized and tested in gas chromatography conditions. The complexes of 1,4,8,11-tetraazacyclotetradecane with Cu(II) and Co(II) were bonded to the silica support through the (3-chloropropyl)triethoxysilane reactant. The packings obtained were analyzed by diffuse-reflectance ultraviolet–visible spectroscopy (DRUV–Vis), differential thermal gravimetry (DTG), porosimetry, and elementary analysis. Preliminary study of the novel silica gas chromatography (GC) stationary phases containing cyclam complexes was carried out using packed 1/8 in. i.d. columns. The study was conducted on: cyclic, linear and branched olefins, aromatic hydrocarbons and ethers. Characterization of interactions between the compounds mentioned and new stationary phases was based upon analysis of Kováts retention indices (I), difference between retention indices for two phases (ΔI), and molecular retention indices (ΔM_e). Results have shown that the new stationary phases interact sufficiently strongly with molecules of high electron density and can be applied in capillary gas chromatography for the analysis of light hydrocarbons.     

Volatile Organic Compound Profiles of Cystoseira corniculata (Turner) Zanardini 1841 and Ericaria amentacea (C.Agardh) Molinari and Guiry 2020 (ex. Cystoseira amentacea (C.Agardh) Bory de Saint-Vincent, 1832)

The volatile organic compounds (VOCs) of fresh (FrCC) and air-dried (DrCC) Cystoseria corniculata and fresh (FrEA) and air-dried (DrEA) Ericaria amentacea from the Adriatic Sea were investigated by headspace solid-phase microextraction (HS-SPME) and hydrodistillation (HD) and analysed by gas chromatography and mass spectrometry (GC-MS). In HS-FrCC and HS-DrCC, aliphatic compounds were dominant, with decan-5-ol as the most abundant in HS-FrCC, but in HS-DrCC pentadecane dominated. Monoterpenes (β-cyclocitral, β-citral, and β-cyclohomocitral) and sesquiterpenes (cubenol) were abundant in HS-FrCC. Notable differences between fresh and air-dried samples were found for benzene derivatives. Fatty acids and their derivatives were the most abundant in HD-FrCC and HD-DrCC. In HS-FrEA and HS-DrEA, saturated aliphatic compounds as well as unsaturated aliphatic compounds (particularly hexan-1-ol and (Z)-hex-3-en-1-ol) predominantly showed decrements after drying. Pentadecane, heptadecane, pentadecanal, and hexan-1-ol were predominant in HD-FrEA, and their percentage decreased in HD-DrEA. The percentage of monoterpenes decreased after drying, but the percentages of diterpenes and especially sesquiterpenes increased. δ-Selinene was the major terpene and the most abundant in HD-DrEA. A significant increment after drying could be noticed for fatty acids and their derivatives. The great diversity of identified VOCs among these two macroalgae supports their different botanical classifications.     

Separation of the mineral oil aromatic hydrocarbons of three and more aromatic rings from those of one or two aromatic rings

An analytical method was developed for the quantitation of the mineral oil aromatic hydrocarbons in cosmetic raw materials separating those of one or two aromatic rings from those of three and more aromatic rings. Normal phase high performance liquid chromatography was used with donor‐acceptor complex chromatography. The composition of both fractions and the quantities of respective compounds were determined by comprehensive two dimensional gas chromatography with time of flight mass spectrometry and by liquid chromatography coupled to gas chromatography with flame ionization detection.     

Studies on the Constituents of Ganoderma Lucidum

The methanolic extract of fruit bodies of cultivated Ganoderma lucidum was separated by silica gel column chromatography and preparative thin-layer chromatography to give ten compounds. On the basis of spectral analysis, chemical procedures and gas chromatography, d-mannitol (1), ergosta-7, 22-dien-3β-yl palmitate (2), ergosterol (3), ergosta-7, 22-dien-3β-ol (4), 5α-lanosta-7,9(11),24-trien-3β,26-diol (5), ergosterol peroxide (6), 24,25,26-trihydroxy-5α-lanosta-7,9(11)-dien-3-one (7), 5α-lanosta-7,9(11)-dien-3β,24,25,26-tetraol (8) and 8,9-epoxyergosta-5,22-dien-3β,15-diol (9) were identified. Among these compounds, 8,9-epoxyergosta-5,22-dien-3β,15-diol was first separated from Ganoderma lucidum.     

Searching for Potential Markers of Glomerulopathy in Urine by HS-SPME-GC×GC TOFMS

Volatile organic compounds (VOCs) exiting in urine are potential biomarkers of chronic kidney diseases. Headspace solid phase microextraction (HS-SPME) was applied for extraction VOCs over the urine samples. Volatile metabolites were separated and identified by means of two-dimensional gas chromatography and time of flight mass spectrometry (GC × GC TOF MS). Patients with glomerular diseases (n = 27) and healthy controls (n = 20) were recruited in the study. Different VOCs profiles were obtained from patients and control. Developed methodology offers the opportunity to examine the metabolic profile associated with glomerulopathy. Four compounds found in elevated amounts in the patients group, i.e., methyl hexadecanoate; 9-hexadecen-1-ol; 6,10-dimethyl-5,9-undecadien-2-one and 2-pentanone were proposed as markers of glomerular diseases.     

Study of operational variables in the submerged growth ofPleurotus ostreatus mushroom mycelium

Pleurotus ostreatus mushroom mycelium was cultivated in submerged culture in shake-flask experiments with acid extract from peat and yeast extract as nutrient sources. Different concentrations of water-diluted peat extract were tested in an attempt to overcome the effect of growth inhibitors apparently present in nondiluted peat extracts. The best results were obtained with a ratio of one part of peat extract diluted with one part of water. Several operating variables were studied to optimize the growth of mycelial biomass ofP. ostreatus. The best results produced approximately 5 g/L dry biomass with a yield of 60% and an efficiency of 33%. These results were obtained in 8 d at 5% (v/v) inoculum ratio, 28°C, pH of 5.0, and 150 rpm.     

光皮木瓜果实中香气成分的GC-MS分析

以成熟光皮木瓜为试样,采用顶空固相微萃取与气质联用方法分析检测木瓜果实中的香气成分,共鉴定出43种香气成分,占总峰面积的92.89%。含量较高的依次为2-己烯醛、反式-2-甲基-环戊醇、(E,E)-2,4-己二烯醛、2-丁酮、(Z)-3-己烯醛、醋酸乙酯、(E)-3-己烯-1-醇、茶香螺烷等。其中C6化合物占总量的70%以上,因此可以确定C6化合物是构成光皮木瓜果实清香味的主要成分。