神经节苷脂的高效液相色谱－化学衍生方法进展

神经节苷脂的高效液相色谱－化学衍生方法进展徐桂芸，常理文（中国科学院化学研究所北京１０００８０）１前言神经节苷脂（Ｇａｎｇｌｉｏｓｉｄｅ）是一类含有唾液酸（Ｓｉａｌｉｃａｃｉｄ）的酸性鞘氨醇糖脂，由鞘氨醇（Ｓｐｈｉｎｇｏ－ｓｉｎｅ）、脂肪酸、寡糖链三...     

R—四氢噻唑—2—硫酮—4—羧酸同R.S—氨基醇的手性识别反应

Ｒ－四氢噻唑－２－硫酮－４－羧酸同Ｒ．Ｓ－亮氨醇、Ｒ．Ｓ－蛋氨醇、Ｒ．Ｓ－苯丙氨醇和Ｒ．Ｓ－色氨醇反应分别得到光学活性非对映体过剩的铵盐；Ｒ－四氢噻唑－２－硫酮－４－羧酸．Ｓ－色氨醇，同时分离出光学活性对映体过剩的Ｒ－亮氨醇，Ｓ－氨蛋醇，Ｓ－苯丙氨醇及Ｒ－色氨醇，用半经验的量子化学ＰＭ３方法研究了氨基醇的最优构型和电子结构，得到了铵盐的最优几何构型。     

高效液相色谱法测定人尿中神经鞘氨醇和二氢神经鞘氨醇

建立了一种检测人尿中神经鞘氨醇（So）和二氢神经鞘氨醇（Sa）的高效液相色谱方法（HPLC）。离心分离尿样中的片状剥落细胞,裂解后用乙酸乙酯萃取、邻苯二甲醛衍生,在HPLC系统中通过梯度洗脱用Nova-PakC18－RP色谱柱（15cm×3．9mm,4μm）分离、荧光检测器检测。So和Sa的检出限均为0．05ng（女性尿样0,075μg/L、男性尿样0．005μg/L）。分析从我国一个村在采集的40份尿样,女性尿样中So、Sa和Sa／So比值分别为1．29－13．58μg/L、0．25－3．13μg/L和0．15－0．25,男性尿样中分别为0．075~3．07μg/L、0.019－0．50μg/L和0．028～0．26。     

新型侧链液晶聚氨酯扩链剂的合成与表征

本文合成了用以制备侧链型液晶聚氨酯的扩链剂二醇－４（４－甲氧基苯酰氧基）苯甲酸－双（β－羟乙基）氨基乙酯（ＩＶ），并以ＨＮＭＲ。ＦＴＩＲ、元素分析等测试手段对此二醇进行了表征，测试结果与设定结构相一致     

6,7—取代—1H—苯并（de）异喹啉—1,3（2H）二酮的合成

从二氢苊出发合成了６－溴－７－氨基２－（２′，４′－二甲基）苯基－１Ｈ－苯并（ｄｅ）异喹啉－１，３（２Ｈ）－二酮，６－甲氧基－７－氨基－２－（２′，４′－二甲基）苯基－１Ｈ－苯并（ｄｅ）异喹啉－１，３（２Ｈ）－二酮和６，７－二氨基－２－（２′，４′－二甲基）苯基－１Ｈ－苯并（ｄｅ）异喹啉－１，３（２Ｈ）－二酮，测定了它们的荧光量子产率，讨论了分子内重原子溴和给电子基对化合物荧光性质的影响。     

新型手性β－氨基醇用于不对称催化醛类烷基化反应

将自己研制的一种新型β－氨基醇（Ⅰ）作为手性源用于醛类的不对称催化烷基化反应。考察了在这种手性β－氨基醇（催化量）存在时各种醛和二乙基锌作用生成相应的手性仲醇的光学收率。考察了几种反应条件参数对于苯甲醛的这种不对称催化反应的影响，其中最佳结果为１－苯基丙醇的光学收率达７４．１％，而其化学产率达９３．８％。     

N—羟基琥珀酰亚胺—间于甲氨基苯甲酸酯柱前衍生HPLC分离荧光检测？…

用Ｎ－羟基琥珀酰亚胺－间二甲氨基苯甲酸酯为柱前衍生试剂,Ｃ１８柱,含ｐＨ为４．０为１０ｍｍｏｌ／Ｌ柠檬酸－磷本氢二钠缓冲溶液的４０％的甲醇－水（Ｖ／Ｖ）溶液为流动相,反相高效液相色谱（ＲＰ－ＨＰＬＣ）分离荧光检测了氨、甲胺和乙胺,检出限分别为５．０、０．５和１．０ｐｍｏｌ,方法简便、快速。     

低价钛引起的（30氧代—1,3—二芳基）丙基丙二腈的还原环化反应

报道了低价钛试剂与（３－氧代－１，３－二芳基）丙基丙二腈的反应。研究发现，低价钛可引起（３－氧代－１，３－二芳基）丙基丙二腈的成环反应，生成２－氰基－３，５－二芳基－１－氨基环戊烯，反式和顺式２－氨基－３－氰基－１，４－二芳基－２－环戊烯－１－醇３种产物，     

基于超高效液相色谱-四极杆飞行时间质谱的缺血性脑卒中的代谢组学研究

采用基于超高效液相色谱-四极杆飞行时间质谱的代谢组学方法,研究缺血性脑卒中患者和健康人群的血浆,分析了缺血性脑卒中的生物标志物.实验收集30例缺血性脑卒中患者和17例健康志愿者的血浆样品,采用主成分分析和正交偏最小二乘判别分析,研究了缺血性脑卒中患者组和健康对照组血浆中的代谢物差异,并进行了代谢通路分析.实验结果表明,患者组血浆中的二氢神经鞘氨醇、植物鞘氨醇等物质含量升高,谷氨酰胺、焦谷氨酸和2-酮丁酸等物质含量降低.结果表明,脑卒中不仅影响了鞘脂类和氨基酸的代谢,还对能量代谢产生了显著的影响.     

新型手性氨基醇的合成及其用于不对称催化醛类烷基化反应

制备了一种由糖类化合物衍生的新型手性氨基醇（Ⅰ），并将其作为手性源用于醛类的不对称烷基化反应．考察了在手性氨基醇的存在下，各种醛和二乙基锌作用生成相应的手性仲醇的光学收率及化学收率．结果表明，该催化剂对于芳香醛的烷基化更为有效．并考察了几种反应条件对于苯甲醛的不对称催化烷基化反应的影响，其中最佳结果为１－苯基－１－丙醇的光学收率达８２．７％，而化学收率达５８．８％．     

瓯柑石油醚提取物的GC-MS分析

为了研究瓯柑的挥发性成分和脂溶性成分, 采用GC-MS分析法进行分离鉴定, 并用面积归一法确定各成分的质量分数. 从瓯柑果肉石油醚提取物中分离鉴定出11种成分, 占总提取物的97.43%, 其主要成分为(Z, Z)-9, 12-十八碳二烯酸(37.46%)、γ-谷甾醇(22.91%);从瓯柑皮石油醚提取物中分离鉴定出10种成分, 占总提取物的99.79%, 其主要成分为柠檬烯(86.39%).     

广西产马尾松与湿地松针叶精油化学成分的比较

用水蒸气蒸馏法从广西产马尾松和湿地松的针叶中提取精油,探索了松针投料量和提取时间对产油率的影响,确定了最佳工艺条件为：松针投料量700 g,提取时间5 h。在此最佳条件下马尾松和湿地松针叶的产油率分别为0.45%和0.19%。用气相色谱（GC）和气相色谱-质谱（GC-MS）等方法分别对两树种的针叶精油进行了定量和定性分析,从马尾松针叶精油中分离出64种化学成分,鉴定了其中的20种成分,占挥发油总量的98.59%;从湿地松针叶精油中分离出73种化学成分,鉴定了其中的29种成分,占挥发油总量的94.23%。两树种针叶精油的主要化学成分大致相同,但在含量上有较大差别。马尾松针叶精油中α-蒎烯的含量约为湿地松的2.6倍,但其β-蒎烯含量低于后者。单萜和倍半萜是构成马尾松和湿地松针叶精油的主要成分。     

GC-MS方法分析杨梅果实精油中香气成分

采用气相色谱一质谱联用技术分析鉴定了木叶、东魁及黑炭3种新鲜杨梅果实精油样品的化学成分,并对三者成分进行对比分析.木叶梅果实精油中鉴定出55个化合物,以单萜类成分为主;东魁梅果精油中鉴定出49个化合物,以倍半萜烯和烷烃类成分为主;黑炭梅果精油中鉴定出化合物48种,以倍半萜烯和烷烃类成分为主.木叶杨梅中富含单萜而缺少倍半萜烯,这可能是其香气浓且易腐烂原因.     

Variability of volatile constituents in Artemisia maritima in western Himalaya

Chemical composition of the essential oil of Artemisia maritima, collected from three different high altitude locations in western Himalaya was studied by gas-chromatography mass spectrometry. Twenty-five constituents were identified in the oil distilled from the sample from Pooh, of which 1,8-cineole (23.8%) and chrysanthenone (17.54%) were the major constituents. Twenty volatile constituents were identified from the sample collected from Rhongtong pass, of which chrysanthenone (38.1%) and 1,8-cineole (37.3%) were the major constituents. In the oil distilled from the sample collected from Lahaul-Spiti 28 constituents were identified, of which 1,8-cineole (44.22%), camphor (9.16%) and borneol (10.94%) were the major constituents. In this sample chrysanthenone was present in very low percentage.     

Comparison of the peptidome released from keratins in Saiga antelope horn and goat horn under simulated gastrointestinal digestion

Goat horn (Caprae Hircus Cornu, GH) has been used as a substitute for Saiga antelope horn (Saigae Tataricae Cornu, SAH) in the clinic and the pharmaceutical industry. In the present study, peptides released from SAH and GH under simulated gastric and intestinal digestion were identified. The results showed that most of the peptides released from SAH and GH under simulated gastrointestinal digestion were hydrophilic, and over 75% of the peptides from keratins (KRTs) were hydrophilic. In total, over 58% of the identified peptides were released from KRTs, and were from the four main regions of KRTs. The peptide features and the peptide release profiles from KRTs in SAH and GH were similar, which may provide a method for the identification of sustainable alternatives to replace the threatened SAH, and provide further evidence of the feasibility of using GH as a replacement for SAH based on their peptidomic analysis.     

Collision-induced fragmentation of negative ions from N-linked glycans derivatized with 2-aminobenzoic acid

N-Linked glycans from bovine ribonuclease B, chicken ovalbumin, bovine fetuin, porcine thyroglobulin and human alpha(1)-acid glycoprotein were derivatized with 2-aminobenzoic acid by reductive amination and their tandem mass spectra were recorded by negative ion electrospray ionization with a quadrupole time-of-flight mass spectrometer. Derivatives were also prepared from 2-amino-5-methyl- and 2-amino-4,5-dimethoxybenzoic acid in order to confirm the identity of fragment ions containing the reducing terminus. Major fragments from the [M - H](-) ions from the neutral glycans retained the derivative (Y-type cleavages) and provided information on sequence and branching. Other major fragments were products of A-type cross-ring cleavages giving information on antenna structure. Singly doubly and triply charged ions were formed from sialylated glycans. They produced major fragments by loss of sialic acid and a series of singly charged ions that were similar to those from the neutral analogues. Doubly charge ions were also produced by the neutral glycans and were fragmented to form product ions with one and two charges. Again, the fragment ions with a single charge were similar to those from the singly charged parents, but branching information was less obvious because of the occurrence of more abundant ions produced by multiple cleavages. Detection limits were around 200 fmol (3 : 1 signal-to-noise ratio).     

Cation-exchange separation of metals in dimethyl sulphoxide-aqueous hydrochloric acid media

The behaviour of bismuth, cadmium, copper, lead, silver, tin and zinc on a cation-exchange resin in a solvent system consisting of dimethyl sulphoxide, hydrochloric acid and water was studied. The distribution coefficients of these metal ions between liquid and resin were determined as functions of the concentration of dimethyl sulphoxide and of hydrochloric acid. On the basis of the distribution coefficients found, predictions were made as to the possibilities of separating these metals from mixtures. Such separations were confirmed experimentally for bismuth from lead, bismuth from copper, zinc from lead, lead from cadmium, silver from copper, silver from lead, lead from cadmium from zinc, bismuth from lead from zinc, and bismuth from zinc from copper.     

一种天然纳米纤维捕鸟蛛丝的物理化学结构表征

蜘蛛丝作为功能性结构材料, 其独特的纤维成型方法与优良的结构和性能引起许多人的关注. 从20世纪80年代开始有关蜘蛛丝的研究报道日益增加[1]. 与高温高压下或由溶剂纺丝成型的合成纤维相比, 蜘蛛丝在空气中凝固成型, 丝纤维成型安全、无害, 从腹部若干不同吐丝器产生不同种类的丝具有不同的用途[2]. 蜘蛛拖曳丝(dragline silk)的比强度大于钢丝, 且具有较大的断裂伸长率(9%～30%)[3,4], 抗张强度1.1～1.4 GPa. 在相对湿度50%和应变速率100%/min的条件下, 模量值可达10～50 GPa. 在所有已知纤维品种中, 蜘蛛丝的断裂能是最高的. 此外, 蜘蛛丝在许多方面的综合性能优于最优良的人造纤维. 另外, 蜘蛛丝的细度为已知纤度最小的天然有机纤维, 这种高性能丝具有捕捉昆虫甚至鸟类的功能, 因此蜘蛛丝是具有特异功能的天然纤维材料. 目前, 蜘蛛丝结构和性能的研究主要包括其化学组成[5]、结晶结构[6,7]、结构模型[8,9]以及其NMR表征[10]等, 这些研究揭示了蜘蛛丝的氨基酸组成、分子量及其分布、结晶度、晶胞尺寸、链构象以及结构模型等. 这些研究主要集中在少数几种蜘蛛品种上, 如金色圆网织网蛛(Nephila clavipes)、十字圆蛛(A.diadematus)和大腹圆蛛(A.ventrocosus)等. 目前, 已知的蜘蛛种类大于30 000种[11], 以蜘蛛丝为例的生物大分子材料研究是一个挑战性的课题. 国内蜘蛛丝的研究仅有大腹圆蛛拖曳丝蛋白一级结构的研究报道[12,13]. 本文报道了广西捕鸟蛛丝的红外光谱、形貌结构和原子力显微镜的初步研究结果.     

氢化诺卜醇及其烷基醚的合成与表征

由β-蒎烯与多聚甲醛反应制得诺卜醇,然后用Ni(R)催化氢化制得氢化诺卜醇(ROH),再将氢化诺卜醇与亚硫酰氯反应制得氢化诺卜基氯(RCl),由RCl分别与6种醇钠反应合成了6种氢化诺卜基烷基醚,各产物的得率均在92%以上,GC纯度95%以上。各产物都用IR,1H NMR,13C NMR与MS进行了结构表征。     

The emission characteristics of hydrocarbon from Chinese cooking under smoke control

To understand the hydrocarbon emissions in China, the source profile and emission factors of hydrocarbon species from cooking sources were measured. The measured commercial restaurants represented Sichuan cuisine, Zhejiang cuisine, household-style cuisine and Korean-style barbecue, respectively. Forty-one hydrocarbon species were quantified, in which the abundant species were n-butane, iso-butane, 2-methlybutane, pentane, propene, 1-butene, toluene and benzene. The hydrocarbon mixing ratios from Korean barbecue were evidently higher than those from the other Chinese-style restaurants, and the Sichuan-style restaurants had significantly higher emissions of iso-butane and d-limonene. The hydrocarbon source profiles of Chinese cooking were different from the profiles obtained from cooking sources of other cities. While the Korean-style barbecue had abundant species such as light alkanes, propene, benzene and toluene, similar to results for Western barbecue source, the relative percentages of these species were different, probably due to the difference in fuels for cooking. The hydrocarbon emission factors were estimated for Sichuan-style cuisine, which was 0.21g hydrocarbon per kg of meat cooked, much lower than that from the barbecue source.