牛蒡叶中微量木脂体牛蒡子甙和牛蒡子甙元的分离与鉴定

 建立了分离鉴定牛蒡叶中微量木脂体牛蒡子甙(arctiin)和牛蒡子甙元(arctigenin)的方法。牛蒡叶粗提物经聚酰胺柱提取,浓缩其甲醇洗脱液并于低温下静置析出白色沉淀物。沉淀物用甲醇溶解后经反相高效液相色谱(RP-HPLC)分离,纯化得到两个主要组分。经紫外光谱(UV)、红外光谱(FTIR)及电喷雾质谱(ESI-MS)检测,并与牛蒡子甙和牛蒡子甙元对照品的UV,LC-ESI-MS,HPLC及FTIR图谱比较,鉴定两个主要成分为牛蒡子甙和牛蒡子甙元。     

牛蒡苷与牛蒡苷元的荧光性质及中药牛蒡子中牛蒡苷的荧光法测定

牛蒡苷和牛蒡苷元的三维荧光图谱中均呈现2个荧光峰,激发波长λex分别为230 nm和280 nm,发射波长(λem)均为310 nm。牛蒡苷的荧光远强于牛蒡苷元的荧光。溶液酸度对牛蒡苷和牛蒡苷元的荧光强度有明显影响。在pH13.0时,牛蒡苷的荧光增强,而牛蒡苷元的荧光猝灭。牛蒡子药材的三维荧光图谱和薄层荧光色谱表明,牛蒡子的荧光成分主要为牛蒡苷,而牛蒡苷元及其他共存组分在强碱性条件下对牛蒡苷的荧光无影响。据此,以甲醇为溶剂制备牛蒡子样品提取液,用水适当稀释并调节至pH 13.0,在λex/λem=280 nm/310 nm波长下测定牛蒡苷的含量。在0.014 5~2.03 mg·L-1范围内,荧光强度与牛蒡苷浓度间呈良好线性,其线性方程为IF=2.7+148.7ρ(mg·L-1),相关系数(r)为0.999。用本法测得牛蒡子对照药材中牛蒡苷的含量为6.01%,平均加标回收率为98.1%。用薄层荧光扫描法对本方法进行验证,结果表明,本法结果可靠,可用于牛蒡子药材的质量检验。     

牛蒡苷与牛蒡苷元的荧光性质及中药牛蒡子中牛蒡苷的荧光法测定

牛蒡苷和牛蒡苷元的三维荧光图谱中均呈现2个荧光峰,激发波长λex分别为230 nm和280 nm,发射波长（λem）均为310 nm。牛蒡苷的荧光远强于牛蒡苷元的荧光。溶液酸度对牛蒡苷和牛蒡苷元的荧光强度有明显影响。在pH>13.0时,牛蒡苷的荧光增强,而牛蒡苷元的荧光猝灭。牛蒡子药材的三维荧光图谱和薄层荧光色谱表明,牛蒡子的荧光成分主要为牛蒡苷,而牛蒡苷元及其他共存组分在强碱性条件下对牛蒡苷的荧光无影响。据此,以甲醇为溶剂制备牛蒡子样品提取液,用水适当稀释并调节至pH 13.0,在λex/λem=280 nm/310 nm波长下测定牛蒡苷的含量。在0.014 5~2.03 mg?L-1范围内,荧光强度与牛蒡苷浓度间呈良好线性,其线性方程为IF=2.7+148.7ρ(mg?L-1),相关系数（r）为0.999。用本法测得牛蒡子对照药材中牛蒡苷的含量为6.01%,平均加标回收率为98.1%。用薄层荧光扫描法对本方法进行验证,结果表明,本法结果可靠,可用于牛蒡子药材的质量检验。     

(—)-牛蒡苷元及其对映异构体的不对称合成新方法

(—)-牛蒡苷元属于二苄基丁内酯型木脂素,是中药牛蒡子的主要活性成分.为了研究牛蒡苷元的构效关系,报道了(—)-牛蒡苷元及其对映异构体的不对称合成新方法.以苯丙酸衍生物为起始原料,首先利用噁唑烷酮类手性辅基构建丁内酯β位的手性中心,R构型和S构型β-苄基丁内酯的ee值分别为98%和96%.再利用空间位阻效应在α位构建第二个手性中心,最后脱除保护基得到目标产物.经6步反应,分别以58%、55%的总收率和97%、96%的ee值得到(—)-牛蒡苷元和(+)-牛蒡苷元.为接下来拟进行的结构优化奠定了技术基础.     

酱香型酒香气成分研究：1.珍酒,茅台酒空杯香分离及官能色谱探索

本文系统地研究了酱香型酒主体香的分离方法，摸索出“溶剂萃取－自然挥发－溶解”的酱香型酒空杯香的分离方法，首次从珍酒、茅台酒中分离出典型的空杯香。用在线色谱闻香系统研究了酱香型酒空杯香的化学成分，同时进行色谱测定及嗅闻。结果表明，空杯香是多种成分构成的复合香。     

异戊醇分子印迹聚合物的制备及吸附性能研究

以异戊醇为模板分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,氯仿为致孔剂,采用本体聚合法制备了对异戊醇具有高特异选择性的异戊醇分子印迹聚合物。通过红外光谱、扫描电镜及热重分析仪对聚合物进行表征,并通过动态吸附、静态吸附和选择性吸附实验考察其吸附性能。结果表明,异戊醇分子印迹聚合物对异戊醇呈现出较好的特异性吸附能力,有望作为固相萃取填料应用于白酒中异戊醇的分离、富集和检测。     

气相色谱法测定法国干邑酒中非酒精成分

法国干邑酒是一种葡萄蒸馏酒 ,蒸馏酒经过在橡木桶中陈酿一定的时间 ,然后再用不同酒龄的酒勾兑成具有独特风格的酒饮料。它与我国白酒酿造工艺的最主要区别就是在橡木桶中的陈酿。也正是由于这种陈酿 ,让蒸馏酒经过对橡木的浸出、自身的氧化及水解等过程 ,蒸馏酒的非酒精成分发生了变化 ,成为具有花香和果香、酒质醇和的干邑酒 [1] 。因此干邑酒的非酒精成分的检验在干邑酒的化学分析中也就占有特别的意义。干邑酒的非酒精成分包括甲醇、醛类、酯类、高级醇。其中醛类包括乙醛、异丁醛、乙缩醛、糠醛 ;酯类包括甲酸乙酯、乙酸乙酯、丁酸乙…     

强酸性阳离子交换树脂催化合成马来酸二异戊酯

以强酸性阳离子交换树脂为催化剂催化异戊醇与马来酸酐反应合成了马来酸二异戊酯。在马来酸酐50mmol，异戊醇200mmol和强酸性阳离子交换树脂4.0g，回流分水60min的条件下，马来酸二异戊酯收率达92.2%，树脂重复使用5次，其活性未发生明显的变化。     

聚酰胺柱层析/反相高效液相色谱/电喷雾离子质谱法分离鉴定牛蒡叶中两种黄酮苷

1　引　　言菊科植物牛蒡 (ArctiumlappaL .)富含木脂体 (lignans)、硫乙炔化合物 (sulfur containingacetyleniccompounds)及聚乙炔化合物 (polyacetylenes)、咖啡酰奎尼酸衍生物 (caffeoylquinicacidderivatives)、抑肿瘤因子 (antimutagenicfactor)、可食性纤维(dietaryfiber)、菊粉 (inulin)及牛蒡苦素 (arctiopicrin)等几类具有重要药理作用的化学成分。有关牛蒡化学组成的研究主要取材于牛蒡种子和根。而牛蒡叶的化学组成还甚少报道。本文建立了一种分离、鉴定牛蒡叶中两种黄酮苷、槲皮素葡萄糖鼠李糖苷 (quecertin 3 O rutinoside)…     

超高压辅助离子液体提取/HPLC分析牛蒡子中牛蒡苷与牛蒡苷元

通过离子液体类型与浓度、提取压力、时间、料液比等单因素实验确定了超高压辅助离子液体提取牛蒡子中牛蒡苷和牛蒡苷元的最佳工艺。结果表明,超高压离子液体提取最佳工艺为以0.80 mol/L溴化1-十二烷基-3-甲基咪唑溶液为溶剂,提取压力200 MPa,提取时间2 min,料液比1∶20(g/mL),牛蒡苷和牛蒡苷元的提取率分别为37.15、8.04 mg/g。与传统提取方法相比,超高压提取时间只需2 min,是超声方法的1/15、加热回流方法的1/60,极大地节省了提取时间,提高了工作效率,且不污染环境,是提取牛蒡苷和牛蒡苷元的一种简单有效的方法。     

Microextraction of volatile compounds from wine samples and their determination by GC-FID. The effect of the salts and extraction solvents used

Summary This study describes the optimization of microextraction as a method for extracting volatile compounds from wine. The study has been applied to twelve compounds present in wine: 3-methylbutyl acetate, 3-methyl-1-butanol, ethyl hexanoate, hexanol, ethyl octanoate, butanoic acid, ethyl decanoate, diethyl succinate, hexanoic acid, phenylethanol, octanoic acid, and decanoic acid. These compounds were selected from those identified by GC-MS analysis of a real wine sample. By means of a synthetic wine, the study investigated the influence on extraction yield of the solvents and salts used, the proportion of salts, and the agitation time. The determination was performed by GC with flame ionization detection and an internal standard was used for quantification. The method was applied to samples of white wine from La Rioja.     

Volatile compounds responsible for aroma of Jutrzenka liquer wine

Jutrzenka is a sweet liquer wine produced in Poland from the grape variety of the same name, developed in Poland to withstand the harsh climate of winery regions. Jutrzenka wine has a characteristic aroma with strong fruity and flowery notes, which make it unique among other liquer wines as demonstrated in sensory profile analysis. The work was aimed at characterization of volatile compounds in this wine, with the emphasis on characterization of compounds responsible for its unique aroma. Gas chromatography-olfactometry (GC-O) was applied to identify the key odorants using aroma extract dilution analysis (AEDA) approach. To facilitate free and bound terpenes and C(13)-norisoprenoids identification solid phase extraction (SPE) was used followed by GC/MS. Among identified key odorants β-damascenone was the compound having the highest FD (4096), followed by isoamyl alcohol, 4-mercapto-4-methyl-2-pentanone (FD=2048), methional, linalool, ethyl decanoate (FD=1024) and ethyl hexanoate, furaneol (FD=512). Other significant compounds were ethyl 2-methyl propanoate, ethyl 2-methylbutanoate and phenyl ethyl alcohol. Determination of odor activity values (OAV) showed the highest values for β-damascenone (566), 4-mercapto-4-methyl-2-pentanone (288) ethyl hexanoate (32) and linalool (7). Jutrzenka exhibited also a rich profile of free, and to lesser extent bound terpenes.     

Headspace-solid phase microextraction-gas chromatography as a tool to define an index that establishes the retention capacity of the wine polymeric fraction towards ethyl esters

A headspace-solid phase microextraction followed by gas chromatographic analysis (HS-SPME-GC) was developed to be applied in the study of the interactions between the wine polymeric fraction and the ethyl esters: ethyl hexanoate, ethyl octanoate, and ethyl decanoate. Wine models (WM) were prepared with 10% (v/v) aqueous ethanol at pH 3.5 with distinct wine polymeric concentrations prepared from white wine of Vitis vinifera L. var. Fern?o-Pires: 1.0 g L(-1) (PWM1), with a polymeric concentration approaching the real one in wine; 10.0 g L(-1) (PWM10); and 30.0 g L(-1) (PWM30), saturated with polymeric fraction. A reference wine model (RWM) was prepared without polymeric fraction. Each volatile compound (4.0 mg L(-1)) was added separately to the RWM and to the WM with the three levels of polymeric material (PWM). From the retention index (RI) calculated for each compound using the formula: [RI = 1 - (C(RWM) - C(PWM))/C(RWM)], where C(RWM) is the concentration of the compound in the RWM and C(PWM) is the concentration of the compound in the given PWM, the retention capacity of each wine polymeric fraction towards the three esters was established. The higher retention indexes were observed for ethyl decanoate, the more hydrophobic compound, and for the PWM with higher concentration. Furthermore, this study also suggested that the retained compounds are dosed to the headspace, which may promote the perception of their aroma for a longer period of time.     

Determination of flavone C-glucosides in antioxidant of bamboo leaves (AOB) fortified foods by reversed-phase high-performance liquid chromatography with ultraviolet diode array detection

A sensitive solid-phase microextraction and gas chromatography-pulsed flame photometric detection technique was developed to quantify volatile sulfur compounds in wine. Eleven sulfur compounds, including hydrogen sulfide, methanethiol, ethanethiol, dimethyl sulfide, diethyl sulfide, methyl thioacetate, dimethyl disulfide, ethyl thioacetate, diethyl disulfide, dimethyl trisulfide and methionol, can be quantified simultaneously by employing three internal standards. Calibration curves were established in a synthetic wine, and linear correlation coefficients (R2) were greater than 0.99 for all target compounds. The quantification limits for most volatile sulfur compounds were 0.5 ppb or lower, except for methionol which had a detection limit of 60 ppb. The recovery was studied in synthetic wine as well as Pinot noir, Cabernet Sauvignon, Pinot Grigio, and Chardonnay wines. Although the sulfur compounds behaved differently depending on the wine matrix, recoveries of greater than 80% were achieved for all sulfur compounds. This technique was applied to analyze volatile sulfur compounds in several commercial wine samples; methionol concentrations were found at the ppm level, while the concentrations for hydrogen sulfide, methanethiol, and methyl thioacetate were at ppb levels. Only trace amounts of disulfides and trisulfides were detected, and ethanethiol was not detected.     

Determination of Volatile Compounds in Sultaniye Wine by Solid-Phase Microextraction Techniques

Volatile compounds of wines made from Sultaniye grape varieties grown in Denizli-Turkey were investigated. Volatile compounds in wines were extracted by headspace and immersion solid-phase microextraction (SPME) methods and identified by GC-MS. According to the results of analyses, esters were mainly responsible for the flavor of Sultaniye wine, and among these, ethyl decanoate, ethyl octanoate, ethyl hexanoate, and 3-methylbutyl acetate were found to be dominant. __________ Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 309–310, July–August, 2005.     

A new class of anthocyanin‐procyanidin condensation products detected in red wine by electrospray ionization multi‐stage mass spectrometry analysis

In our previous work, we have identified, in a model wine solution containing malvidin 3‐glucoside, epicatechin and acetaldehyde, a new condensation product – hydroxylethyl‐malvidin‐3‐glucoside‐ethyl‐epicatechin. The objective of this work was to verify the presence of such new condensation products in red wine. For this purpose, red wine was fractionated into various fractions by column chromatography on LiChroprep RP 18 and on Toyopearl 40 (F). The phenolic composition of each fraction was verified by HPLC‐DAD and direct‐infusion ESI‐MSⁿ analysis. In addition to the well‐known anthocyanins and their acetyl and coumaroyl derivatives, and several direct and indirect anthocyanin‐(epi)catechin condensation products, a new class of pigmented products, namely hydroxyethyl‐anthocyanin‐ethyl‐flavanol compounds, have been detected in red wine. The new class of pigmented products would be expected to be the major pigments responsible for the color of aged red wine. Copyright © 2010 John Wiley & Sons, Ltd.     

HPLC study of the efficiency of extraction of phenolic compounds

Summary The rate of extraction of phenolic compounds in two different solvents has been studied by liquid chromatography (HPLC) under reverse phase, gradient elution conditions. The solvents were diethyl ether and ethyl acetate. The method has been applied to two natural samples, a white wine and apple pulp.     

Screening of key odorants and anthocyanin compounds of cv. Okuzgozu (Vitis vinifera L.) red wines with a free run and pressed pomace using GC‐MS‐Olfactometry and LC‐MS‐MS

The principal purpose of the present work is to characterize the aroma, aroma‐active, and anthocyanin profiles of Okuzgozu wines and to observe the effect of the pomace pressing technique on these parameters. A total of 58 and 59 volatile compounds were identified and quantified in free‐run juice wine (FRW) and pressed pomace wine (PW). Alcohols were found as the most dominant group among aroma compounds followed by esters and acids. However, among all these compounds, only 11 and 13 of them could be considered as key odorants in aromatic extracts of FRW and PW, respectively. According to GC‐MS‐O analysis, ethyl octanoate (fruity), phenyl ethyl acetate (fruity), and 2‐phenyl ethanol (flowery) were found as the main contributors to the overall scent of both wines. Beyond the aroma profiles, anthocyanin contents of both types of wines were also investigated, and total 14 and 15 anthocyanins were identified and quantified in FRW and PW. Malvidin‐3‐glycoside and its acetyl and coumaroyl forms were identified as the dominant anthocyanins in both wines. It is worth noting the pressing application (2.0 atm) led to an increase of some unpleasant notes in the aroma providing chemical, pharmacy, and fermented aromas in wine. On the other hand, the wines produced with pressed pomace presented higher amounts of anthocyanins.     

Aroma composition of red wines by different extraction methods and Gas Chromatography-SIM/MASS spectrometry analysis

One hundred and one volatile compounds, reported in literature as powerful odorants of wine, were quantified by Gas Chromatography-Selective Ion Monitoring/Mass Spectrometry (GC-SIM/MS) in Primitivo, Aglianico, Merlot and Cabernet Sauvignon red wines. Wine samples were extracted by 3 different extraction methods: 1) separation of the alcoholic fraction from the aqueous phase by salting-out and subsequent extraction by liquid-liquid micro-extraction with 1,1,2-trichlorotrifluoroethane (Freon 113); 2) extraction by liquid-liquid micro-extraction with dichloromethane; 3) solid phase extraction (SPE cartridge: 800 mg of LiChrolut EN resin) with pentane-dichloromethane (20:1) and dichloromethane. The selection of the ion fragments used for quantification was directly performed on a red wine sample. For each compound the area of the corresponding peak was normalized respect to the peak of the internal standard and then interpolated in a calibration curve obtained analysing a model wine solution (water, ethanol, tartaric acid and known amounts of analytes and of internal standard). The methods showed a good linearity: r2>0.990, except for farnesol (isomer a and c), octanal, decanal, furaneol and phenylacetic acid with 0.966 < or = r2 < or = 0.990. The 7 most powerful odorants were: beta-damascenone, acetaldehyde, maltol, ethyl 2-methylbutanoate, ethyl 3-methylbutanoate, 3-methylbutanoic acid and acetal; 7 other slightly less important were: ethyl hexanoate, ethyl acetate, 1-octen-3-ol, butanoic acid, rose oxide, furaneol and sotolon. The Aglianico wines were characterised by the major fermentation compounds (esters, fatty acids and 2-phenylethanol), beta-damascenone, beta-ionone and linalool. The Primitivo wines were characterized by furaneol, methoxypyrazine, gamma-nonalactone and acetaldehyde, while Cabernet Sauvignon and Merlot wines principally by cask derivates (vanillin, (Z) 3-methyl-gamma-octalactone [(Z) wiskylactone], maltol and eugenol), some aldehydes and 3-isopropyl-2-methoxypyrazine.