水稻秸秆石油醚和乙醇萃取物的组成分析

用石油醚和乙醇在索式萃取器中对水稻秸秆进行了萃取,萃取物用傅里叶转换红外光谱仪（FTIR）和气相色谱 质谱联用仪（GC/MS）分析。 结果表明,乙醇和石油醚的萃取率分别为8%和6%。 萃取物中共检测到40种物质,主要分为醇酚（APs）、醛、酮、酸、酯、烃（HCs）及含氮化合物（ONs）7种类别。 其中,石油醚萃取物中酯、HCs和APs 3类物质含量较高,总的相对含量为91.7%;乙醇萃取物中HCs、酸、酯及APs含量较高,总的相对含量为83.9%。 该研究在开发稻秆的高附加值利用方面具有重要的基础理论意义。     

A UV resonance Raman (UVRR) spectroscopic study on the extractable compounds of Scots pine (Pinus sylvestris) wood. Part I: lipophilic compounds

The wood resin in Scots pine (Pinus sylvestris) stemwood and branch wood were studied using UV resonance Raman (UVRR) spectroscopy. UVRR spectra of the sapwood and heartwood hexane extracts, solid wood samples and model compounds (six resin acids, three fatty acids, a fatty acid ester, sitosterol and sitosterol acetate) were collected using excitation wavelengths of 229, 244 and 257 nm. In addition, visible Raman spectra of the fatty and resin acids were recorded. Resin compositions of heartwood and sapwood hexane extracts were determined using gas chromatography. Raman signals of both conjugated and isolated double bonds of all the model compounds were resonance enhanced by UV excitation. The oleophilic structures showed strong bands in the region of 1660-1630 cm(-1). Distinct structures were enhanced depending on the excitation wavelength. The UVRR spectra of the hexane extracts showed characteristic bands for resin and fatty acids. It was possible to identify certain resin acids from the spectra. UV Raman spectra collected from the solid wood samples containing wood resin showed a band at approximately 1650 cm(-1) due to unsaturated resin components. The Raman signals from extractives in the resin rich branch wood sample gave even more strongly enhanced signals than the aromatic lignin.     

Antioxidant, antimicrobial activities and fatty acid components of flower, leaf, stem and seed of Hypericum scabrum

The hexane extracts of flower, leaf, stem, and seed of Hypericum scabrum, which were collected from northwestern Iran, were obtained by extraction in a Soxhlet apparatus. The fatty acids were converted to methyl esters and determined by gas chromatography/flame ionization detector (GC/FID) and gas chromatography/mass spectrometry (GC/MS) systems. The hexane extract from the flower, leaf, stem, and seed contained 39.1%, 43.2%, 29.0%, and 37.6% of omega-3 fatty acids, respectively. The other main components of the flower extract were tetracosane (12.2%) and palmitic acid (9.3%), and that of the leaf extract was palmitic acid (7.4%). The stem and seed extracts contained bis(2-ethylhexyl)phthalate (18.7% and 35.7%), nonacosane (11.7% and 3.9%) and linoleic acid (6.5% and 6.9%) as major components. The hexane extracts of different parts from H. scabrum represent an important source of omega-3 fatty acids in several Hypericum species. The antioxidant activity of all hexane extracts was evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method. The results indicate that hexane extracts from different parts of H. scabrum possess considerable antioxidant activity. The highest radical scavenging activity was detected in seed, which had an IC50 = 165 microg/mL. The antimicrobial activity of the extracts of those samples were determined against seven Gram-positive and Gram-negative bacteria (Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, S. epidermidis, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae), as well as three fungi (Candida albicans, Saccharomyces cerevisiae, and Aspergillus niger). The bioassay showed that the oil exhibited moderate antimicrobial activity. This study reveals that the all parts of this plant are attractive sources of fatty acid components, especially the essential ones, as well as of effective natural antioxidants.     

Microsporum fulvum IBRL SD3: As Novel Isolate for Chicken Feathers Degradation

Keratinous wastes have increasingly become a problem and accumulate in the environment mainly in the form of feathers, generated mainly from a large number of poultry industries. As keratins are very difficult to degrade by general proteases, they pose a major environmental problem. Therefore, microorganisms which would effectively degrade keratins are needed for recycling such wastes. A geophilic dermatophyte, Microsporum fulvum IBRL SD3 which was isolated from a soil sample collected from a chicken feather dumping site using a baiting technique, was capable to produce keratinase significantly. The crude keratinase was able to degrade whole chicken feathers effectively. The end product of the degradation was protein that contained essential amino acids and may have potential application in animal feed production. Thus, M. fulvum could be a novel organism to produce keratinase for chicken feathers degradation.     

Determination of eighty-one volatile organic compounds in dietary Rumexinduratus leaves by GC/IT-MS, using different extractive techniques

The volatile compounds of Rumexinduratus leaves were studied for the first time. In order to achieve the most complete volatile profile four different extractive techniques (hydrodistillation, solid-phase microextraction, Soxhlet system and direct solvent extraction) were applied. The different extracts were analysed by gas chromatography/ion trap-mass spectrometry (GC/IT-MS) which allowed the identification of 81 compounds, distributed by several chemical classes: esters, terpenes, aldehydes, acids, norisoprenoids, ketones, naphthalene derivatives, steroids derivatives and alcohols, among others. The different techniques lead to different compounds' extraction. Using hexane and dichloromethane, 9 and 4 compounds were extracted, respectively. Hydrodistillation, solid-phase microextraction and Soxhlet extraction allowed the extraction of 43, 24 and 29 compounds, respectively. Hydrodistillation was revealed to be the most effective technique, allowing the extraction of a higher number of compounds, both in the hydrolat (20 compounds) and essential oil (34 compounds), having 11 compounds in common.     

Application of High Temperature High Resolution Gas Chromatography to Crude Extracts of Propolis

The underivatized acetone and hexane fractions from propolis samples (predominant flora Citrus spp. and Vernonia polyanthes) were analyzed by HT-HRGC (high temperature high resolution gas chromatography) and HT-HRGC coupled to mass spectrometry (HT-HRGC-MS). Several compounds, including flavonoid aglycones, phenolic acids, and high molecular weight compounds were characterized in crude extracts by HT-HRGC-MS. HT-HRGC and HT-HRGC-MS were shown to be quick and informative tools for rapid analysis of crude extracts without need for prior derivatization and purification.     

The chemical composition of hexane extract from bark of Juniperus brevifolia

The phytochemical analysis of the bark of Juniperus brevifolia was undertaken for the first time. The GC-MS analysis of the hexane extract from bark of "cedro-do-mato" (J. brevifolia) allowed to identify three rare compounds for the first time in Juniperus genus: 6,7-dehydroferrugin-12-methyl ether, 11-hydroxy-6,7-dehydroferruginol and 6,7-dehydrohinokiol. The results also showed that the chemical composition of the extract were essentially abietane-type diterpenoids with alcohol function (44.9%) and with carbonyl function (8.6%). Fatty acids such palmitic, oleic, stearic and docosanoic acids were the second most abundant family of identified compounds (9.5%) and its value increased (12.7%) after alkaline hydrolysis, mainly due to docosanoic and tetradocosanoic acids. Sterols like sitosterol and stigmast-4-en-3-one, were also present (6.6%), along with esters of sterols (8.4%). Significant quantities of the long-chain aliphatic alcohols (ca 3.7%) were identified in the hexane extract only after alkaline hydrolysis.     

Studies on anti-allergic constituents in the leaves and stems of Anchientia salutaris var. martiana (Violaceae).

The anti-allergic active fractionation of hexane extracts of the leaves and stems of Anchietia salutaris var. martiana (family Violaceae) was performed by monitoring their activities with an in vitro bioassay system measuring the inhibitory effects on induced histamine release from guinea pig lung cells. Three known pentacyclic triterpenes (friedelin, alpha-amyrin, beta-amyrin) were isolated, but these compounds were inactive. Aliphatic hydrocarbons and methyl esters of fatty acids (palmitic, oleic, linoleic, linolenic acids) were detected in active fractions. All compounds isolated were detected for the first time in this medicinal plant.     

Improved method for extraction of aroma compounds in aged brandies and aqueous alcoholic wood extracts using ultrasound

This work presents a rapid method for dichloromethane extraction of aroma compounds from brandies and aqueous-alcoholic wood extracts, in brandy-like ageing conditions, using ultrasound. The dichloromethane extracts were injected in split mode on a gas chromatographic (GC) system, separated on a DB-WAX capillary column and detected by flame ionisation. The method allowed satisfactory quantification of 37 volatile compounds in brandies (alcohols, esters, acids, furanics, aldehydes and phenols) and 16 volatile compounds in aqueous-alcoholic oak extracts. Linear responses were obtained (0.99-1.00). The repeatability and the detection and quantification limits were also evaluated. The analysis of spiked samples showed that matrix effects do not affect the method performance for the majority of the volatile compounds analysed.     

Identification of compounds from Etonia rosemary (Conradina etonia)

Mosquitoes transmit pathogens that result in diseases harmful to human, livestock, and wildlife hosts. Numerous measures can be used to reduce insect-borne disease risk to humans, and one approach is the use of topical repellents to prevent host-seeking arthropods from taking a blood meal. A current emphasis in the development of new repellents is that they be safe. Therefore, natural products sources are increasingly being explored. Compounds from plants of the mint family (Lamiaceae) have been demonstrated to be insect repellents. This study examines compounds from Etonia rosemary (Conradina etonia) to identify compounds for examination as insect repellents. Samples of Etonia rosemary were passively extracted with hexane, dichloromethane, and methanol and analyzed by GC/MS. This extraction method was chosen to eliminate thermal degradation of plant components that can occur during the distillation procedure. Additional headspace volatile compounds from this plant were identified using microscale purge-and-trap GC/MS. A variety of terpenes, terpenic alcohols, ketones, and aldehydes were identified in the extracts with terpenes and short-chained aldehydes detected in greatest abundance.     

三甲基硅化合物复合体系引发1,3-戊二烯阳离子聚合研究

研究了三甲基硅化合物 ,主要是三甲基硅酯和三甲基硅氯化物 (TMSCI)与路易斯酸所形成的复合引发体系引发聚合 ,1,3 戊二烯 (PD)的聚合反应行为 ,考察了引发体系引发PD聚合所得聚合物的产率 ,分子量及分子量分布 ,聚合反应速率和聚合反应机理等 ;研究了多种给电体———醚、酮对聚合反应的影响     

HPLC Analysis of Aldehydes and Ketones in Sherry

Abstract

A method was developed to obtain comparative data on aldehydes and ketones which contain 3-10 carbon atoms in various types of sherry. The method consists of continuously extracting sherry samples with Freon 11 and then treating the concentrated extracts with 2,4-dinitrophenylhydrazine in a hexane-water solvent system. The hexane solution is separated and then extracted with acetonitrile; the acetonitrile solution is submitted to HPLC analysis. Overall recoveries (starting from model sherry solutions) of representative compounds (not containing hydroxy groups) were between 37 and 100 percent.

The method intentionally gives poor recoveries for acetaldehyde which, because of its high concentration in sherry, would otherwise mask less concentrated aldehydes and ketones in the chromatogram.

Comparison of the chromatograms of Fino, Amontillado, and Oloroso sherries reveal that aldehyde/ketone production is clearly associ ated with time in sherry production. Differences between gas chromatograms of the Freon extracts of these sherries are less pronounced.     

GC analysis of extractive compounds in beech wood

Various highly hydrophobic beech wood lipids were characterized and their quantities measured in hexane extracts by GC, using short and long capillary columns. More polar compounds were also identified in acetone extracts. Triglycerides, steryl esters, sterols, unsaturated fatty acids, as well as various monosaccharide units were determined as possible pollutants of papermaking systems.     

Improving GC-MS screening analysis by functional-group-related silica gel fractionation of industrial wastewater extracts

The separation of the components of complex industrial waste water extracts according to their functional groups has been accomplished by use of small silica gel columns eluted with a hexane – dichloromethane – methanol gradient. The six fractions obtained covered a polarity range from aliphatic fatty acids to (aromatic) polyhydroxy and polyether compounds. Recovery of model compounds was between 75 and 105%. Used prior to GC-MS analysis this fractionation substantially enhances chromatographic resolution and facilitates peak identification. The procedure was exemplarily applied to an extract of anaerobically treated tannery waste water. Phenols, aromatic acids, and aromatic and aliphatic (poly)hydroxy acids, in the low ppm range, were determined as main constituents. Since fractionation extends the range of detection, trace substances such as chlorocresol, dichlorobenzoic acid, mercaptobenzothiazole, and mercaptoacetic acid were also detectable at the ppb level.     

Components and antioxidant activity of fruits of Cirsium palustre and C. rivulare

In the hexane extract of C. palustre and C. rivulare fruits, fatty acids, sterols, triterpenes, and volatile compounds were analyzed by the GC-MS-FID method. In the methanolic extracts, total phenol content was estimated. The antioxidant activity of both extracts was measured with DPPH assay and expressed in % scavenged DPPH.     

苦丁茶冬青挥发油成分的GC-MS分析

采用乙醚超声萃取-水蒸气蒸馏方法提取苦丁茶冬青的挥发油，用气相色谱-质谱联用分析，鉴定了挥发油中的57个成分，其中主要成分是醇、醛、酮、醚、脂肪酸、脂肪酸酯及含氧萜类等化合物。     

Identification of volatile components in yak butter using SAFE, SDE and HS-SPME-GC/MS

The volatile components of yak butter were isolated by solvent-assisted flavour evaporation (SAFE), simultaneous distillation extraction (SDE; dichloromethane and diethyl ether as solvent, respectively) and headspace solid-phase microextraction (HS-SPME; CAR/PDMS, PDMS/DVB and DVB/CAR/PDMS fibre extraction, respectively) and were analysed by GC/MS. A total of 83 volatile components were identified under six different conditions, including 28 acids, 12 esters, 11 ketones, 10 lactones, 10 alcohols, 4 other compounds, 2 aldehydes, 2 unsaturated aldehydes, 1 furan, 1 sulphur-containing compound, 1 unsaturated alcohol and 1 unsatruated ketone. Among them, 51 were identified by SAFE, 58 by SDE (45 with dichloromethane as solvent and 41 with diethyl ether as solvent) and 40 by HS-SPME (26 with CAR/PDMS; 26 with PDMS/DVB and 32 with DVB/CAR/PDMS). Three pretreatment methods were compared to show that the volatile components obtained using different methods varied greatly, both in terms of categories and in content. Therefore, a multi-pretreatment method should be adopted, together with GC/MS. A total of 25 aroma-active compounds were detected by gas chromatography-olfactometry, among which 20 aroma-active compounds were found by SDE (14 with dichloromethane as solvent and 14 with diethyl ether as solvent) and 17 by SAFE.     

Selection of methylation procedures for quantitation of short-chain glycerol-bound compounds formed during thermoxidation

Five methylation procedures, including base- and acid-catalyzed methods, were tested in thermoxidized methyl linoleate and trilinolein, in order to quantitate major oxidation short-chain glycerol-bound compounds by gas chromatography. Results indicated that transmethylations using KOH in methanol or CH3ONa-CH3OH in tert.-butylmethyl ether were the most appropriate methods, given the excellent reproducibility and practically complete recovery obtained for the compounds of interest, mainly short-chain fatty acids and aldehydic acids. Also, formation of acids from aldehydes during thermoxidation as well as modifications of aldehydic functions under acidic conditions, such as conversion to acetals, were checked using dodecanal as model aldehyde.     

Content of Phenolic Compounds in Meadow Vegetation and Soil Depending on the Isolation Method

The aim of this paper was to determine the effect of the hydrolysis method on the amounts of phenolic compounds in the plant material in soil and, as a consequence, on the parameters to determine the degree of lignins transformation in soils. The study included the plant material (hay, sward, and roots) and soil—Albic Brunic Arenosol (horizon A, AE, and Bsv) samples. Phenolic compounds were isolated at two stages by applying acid hydrolysis followed by alkaline re-hydrolysis. The quantitative and qualitative analysis of phenolic compounds was performed with high-performance liquid chromatography with a DAD. The content of phenolic compounds in the extracts depended on the hydrolysis method and it was determined by the type of the research material. The amounts of phenolic compounds contained in the alkaline hydrolysates accounted for 55.7% (soil, horizon Bsv)—454% (roots) of their content in acid hydrolysates. In the extracts from acid hydrolysates, chlorogenic and p-hydroxybenzoic acids were dominant. In the alkaline extracts from the plant material, the highest content was recorded for p-coumaric and ferulic acids, and in the extracts from soil, ferulic and chlorogenic acids. A combination of acid and alkaline hydrolysis ensures the best extraction efficiency of insoluble-bound forms of polyphenols from plant and soil material.     

Polycyclic Phosphorus-Containing Oxaboracyclanes

Abstract

The olygomers consisting of regularly repeating heterocyclic fragments were synthesized by the reaction of polycondensation of the ether of p-phenylenediboric acid and tetraoxymethyloldphosphioes obtained from the different diphosphines and aldehydes. The compounds with endocyclic phosphorus atom (I) were obtained in case of using the aliphatic aldehydes, and the compounds with exocyclic phosphoruscontaining group (II) were obtained when using the hydroxyaldehydes.