超临界流体色谱法分析大豆磷脂

 采用以CO2 为流动相的超临界流体色谱方法 ,以含 0 0 5 % (体积分数 )三乙胺的乙醇作为改性剂 ,对具有重要生物功能的大豆磷脂组成进行分析 ,获得了大豆磷脂提取物中 6个重要组分的定性结果 ,并讨论了流动相组成、操作温度和压力对分离的影响。对其中有代表意义的磷脂酰胆碱 (PC)进行了外标法定量分析 ,在PC质量浓度为0 0 2 0 g/L～ 0 0 75 g/L时具有较好的线性关系 ,PC加样回收率为 96 7% (n =5 ) ,重现性好。此方法可用于实际样品的分析。     

高效液相色谱法分析大豆中磷脂酰胆碱的分子种

用高效液相色谱法（HPLC）在正相半制备硅胶柱上将大豆磷脂酰胆碱与其它组分分离，从柱后收集磷脂酰胆碱（PC），然后在反相C18柱上分析其分子种组成，蒸发光散射检测器检测。在25min内将大豆磷脂酰胆碱分离成11个分子种组分，使用易挥发溶剂，可获得各种分子种的纯物质，供进一步分析。分子种根据HPLC峰的脂肪酸组成分析而确定。     

大豆磷脂的高效液相色谱分析

采用正相高效液相色谱法,梯度洗脱程序和蒸发光散射检测器对大豆磷脂组成进行分析,在15min内将大豆膦脂中4种重要组分：卵磷脂,脑磷脂,肌醇磷脂和磷脂酸与其它组分完全分离,用外标法对这4种重要成分进行定量,线性范围为0．2－5．8g/L,回收率为96．7－100．8％;相对标准偏差为0．82％－1．34％,方法用于实际样品测定,获得满意的结果。     

润滑油基础油烃族组成的薄层色谱法测定

采用薄层色谱-火焰离子化检测器测定了不同来源、不同工艺的润滑油基础油，提取了薄层色谱图特征变量，以偏最小二乘法为数学工具，通过洗脱色谱法取得基础数据，建立基础油的薄层色谱—烃族组成模型；采用该模型预测待测样品的烃族组成，并与洗脱色谱法的测定结果比较，饱和烃和芳烃质量分数的相关系数分别为0．9617和0．9611；对于分析结果进行：检验表明，建立的方法与洗脱色谱法的测定结果相一致；另外，薄层色谱法具有分析速度快，重复性好等优点。     

旋转薄层色谱分离聚合物

报道了旋转薄层色谱分级聚合物，及配合直接扫描密度法测定分子量分布的结果．在旋转薄层硅胶板上用混合溶剂成功地分离并直接收集了聚苯乙烯２１个级分，分子量测定结果与ＧＰＣ法基本一致．初步认为旋转薄层色谱以薄层吸附色谱分离机理为基础，采用连续注入流动相和旋转薄层板离心力相结合的方式，改善并加快了分离效果     

红细胞膜上各种磷脂中脂肪酸的测定

应用自制硅胶板的薄层色谱法分离了红细胞膜上四种主要磷脂。将分离后的每种磷脂斑点硅胶涂层刮下，不经萃取，直接在无水甲醇－苯－乙酰氯溶液中进行转移甲基化，然后用毛细管相色谱分离测定其脂肪酸组成和含量。上述方法已成功地用于先天愚型病人和正常人红细胞膜上各种磷脂中脂肪酸轮廓分析，获得有意义的结果。     

气相色谱法测定大豆磷脂中磷脂酰肌醇

将含磷脂酰肌醇的大豆磷脂水解后,进行乙酰衍生化得到肌醇六乙酯,然后用气相色谱法测定肌醇六乙酯,从而计算出大豆磷脂中磷脂酰肌醇的含量。对一大豆磷脂试样,按提出方法测定6次,得磷脂酰肌醇含量的平均值为8.61 mg.g-1,测定结果的相对标准偏差为2.2%。又在此试样的基础上加入不同量的磷脂酰肌醇标准(10.0~110.0 mg)作回收试验,所得回收率结果为95.6%~104.2%。     

氨基酸在薄层原位的傅里叶变换表面增强拉曼光谱

应用表面增强技术将薄层色谱与红外傅里叶变换拉曼光谱联用，在薄层色谱原位获得两种氨基酸光谱。研究表明，在薄层原位微量样品的ＮＩＲ－ＦＴ－ＳＥＲＳ光谱与纯固体样品ＦＴ－Ｒａｍａｎ光谱的主要特征谱带频率基本一致，在银微粒作用下，色氨酸分子中吲哚环环伸缩振动获最大增强，组氨酸分子中Ｃ＝Ｎ双键的伸缩振动是明显增强，对８μｇ样品就能在薄层色谱原位较可靠地反映了分子的结构信息。     

准圆周薄层色谱上行展开的研究

圆周薄层色谱能将样品展开为很细的谱线,具有较高的分辨能力,常用于分析一些难分离的物质。这种色谱方法过去只能采用水平展开方法。我们将普通薄层板修饰成特定形状,用最常见的上行展开法获得近似于圆周薄层的色谱。方法不需要特殊展开装置,应用于皂苷、生物碱的分离鉴定取得很好效果。     

顶空固相微萃取-气相色谱法测定粉状大豆磷脂的丙酮残留

固相微萃取技术(SPME)作为一种样品预处理方法已在食品溶剂残留检测中得到了广泛的应用。大豆磷脂是一种保健品,广泛地应用在食品与医药领域。在我国．粉状大豆磷脂在加工过程中采用丙酮提取杂质。磷脂中丙酮残留不利于人体健康。目前,我国粉状磷酯产品尚无统一的测定方法和溶剂残留标准,大多生产厂家需借鉴国外的     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.