富硒金针菇子实体中硒多糖的分离纯化技术及红外光谱研究

对富硒金针菇子实体中硒多糖(Se-containing polysaccharide,Se-P)的分离、纯化进行了优化研究,并采用苯酚-硫酸法、ICP-MS法对硒多糖中多糖及硒含量进行了测定.确定硒多糖的最佳提取条件为:浸提温度80℃、浸提时间3 h、料液比1:50、提取3次合并滤液;其中多糖含量为12.48%,硒含量为7.97μg/g.将粗多糖经Sephadex G-100柱层析系统分离纯化,所得精硒多糖进行红外光谱分析表明:可溶性硒多糖均为糖苷键连接的吡喃多糖,其中水溶性硒多糖与普通多糖结构相似,而碱溶性硒多糖中由于硒酸酯的形成改变了原有多糖的吡喃环糖苷键的构型,进一步证明在金针菇的富硒培养过程中,硒参与了硒多糖的合成.     

多糖及多糖衍生物水处理剂的研究进展

叙述了国内外多糖及多糖衍生物水处理剂的现状,简单地介绍了多种新型多糖及多糖衍生物水处理剂的原料、合成方法及其在水处理中的应用,并对多糖及多糖衍生物水处理剂的发展方向进行了展望。     

分子活化分析研究铁芒萁叶中稀土结合多糖

利用分子活化分析技术初步研究了铁芒萁叶中稀土结合多糖的状态.铁芒萁叶经过提取和生化分离后,得到冷水溶性多糖,热水溶性多糖,酸溶性多糖和碱溶性多糖 将所得到的多糖脱蛋白后通过凝胶柱,比色法测定多糖的吸收曲线,并用中子活化法(NAA)测定多糖中的8个稀土元素(La,Ce,Nd,Sm,Eu,Tb,Yb和Lu)的含量.研究结果表明,铁芒萁体内稀土元素与多糖有紧密结合.经分子量测定,与稀土元素(REE)结合的多糖为小分子量多糖(1～2)×10~4u.     

大叶金花草中碱溶性多糖提取工艺的研究

蕨类多糖复合物具有多种生理活性和药理活性,如抗肿瘤、免疫促进、抗凝血、抗补体、抗溃疡、抗炎、抗病毒和降血糖等[1]。目前对蕨类植物多糖的研究较少,主要有紫萁多糖[2,3]、芒萁多糖[4]、半边旗多糖[5]、毛叶蕨多糖[6]、海金沙多糖[7]等。大叶金花草是鳞始蕨科植物乌蕨(Sten     

富硒蛹虫草的抗氧化活性研究

采用现代分离技术从富硒蛹虫草中提取硒多糖,然后以苯酚-硫酸法、电感耦合等离子体质谱（ICP—MS）法对硒多糖中多糖含量和硒含量进行测定;在Fenton体系的最佳实验条件下,研究了硒多糖对羟自由基的清除作用及硒多糖对支撑磷脂双层膜（Supported Bilayer Lipid Membranes,s—BLM）的保护作用。结果表明：硒多糖清除羟自由基的效果比与之相同浓度的无机硒、多糖都要明显。其中硒多糖对羟自由基的最高清除率可达38．02％,硒多糖具有很强的抗脂质过氧化、保护支撑磷脂双层膜的作用。     

阴离子交换树脂分离香菇多糖中蛋白质

香菇多糖是从香菇中提取分离出的一种药用活性成分,具有抗肿瘤,抗病毒,提高人体免疫力等功能,在临床上具有很好的应用前景[1~3]。多糖的药效与多糖的纯度有很大关系,要得到较纯的多糖,工艺复杂,成本很高,因此市场上大多香菇多糖产品纯度较低。香菇多糖中难分离的杂质主要是蛋白     

白芷多糖的分析

研究了白芷多糖的结构和单糖组成。采用紫外光谱和红外光谱法对白芷多糖进行定性分析。结果表明,白芷多糖具有多糖特征性的紫外和红外吸收峰,其分子中存在酰胺结构;凝胶渗透色谱法测定结果表明,白芷多糖的峰值分子量为88538;采用气相色谱法测定白芷多糖中单糖的种类和构成比例,结果表明,白芷多糖由鼠李糖、阿拉伯糖、木糖、甘露糖、葡萄糖和半乳糖等7种单糖组成,并计算出其中6种单糖的摩尔组成比例。     

正交试验与响应面法优化微波提取地黄多糖工艺研究（英文）

为了获得微波提取地黄多糖的最佳条件,采用正交试验法和响应面法分别优化微波提取地黄多糖工艺,以地黄多糖得率为指标,采用微波提取地黄多糖,苯酚-硫酸法测定地黄多糖的含量,以微波提取时间、提取温度和料液比进行三因素分析,根据单因素试验结果设计正交试验和响应面试验,进一步优化微波提取地黄多糖工艺。微波提取地黄多糖工艺通过正交试验法优化的结果表明,最佳条件为微波提取时间150 s,提取温度80℃,料液比1 g∶10 mL,该条件下的地黄多糖得率为72.10%。响应面法优化微波提取地黄多糖工艺的结果表明,修正后的最佳工艺条件为微波提取时间137 s,提取温度89℃,料液比1 g∶8 mL,该条件下的地黄多糖得率为74.41%。经过两种优化方法的比较,响应面法适合优化微波提取地黄多糖工艺,能够有效提高地黄多糖得率。     

不同产地金线莲根茎和叶中多糖含量对比

考察了不同产地金线莲根茎和叶中多糖含量。应用超声辅助法和微波-超声协同萃取法提取金线莲根茎和叶中多糖,用苯酚-硫酸法测定其含量。微波-超声协同萃取法提取优于超声辅助法提取,金线莲根茎部的多糖含量高于叶中多糖含量,福建华安产金线莲多糖含量最高。金线莲中多糖含量为0.8509%～6.400%,具有开发药用的价值。     

苯酚硫酸法测定迷果芹多糖的含量

测定迷果芹中多糖的含量以及4种迷果芹粗多糖中的多糖含量.采用硫酸.苯酚比色法于波长490 nm处测定吸收度.结果表明,迷果芹中的原药材中的多糖含量为4.04%.迷果芹粗多糖醇沉1次、醇沉2次、醇沉3次和醇沉3次脱脂所测得的迷果芹粗多糖中的多耱含量分别为54.90%,53.40%,45.73%,50.90%.     

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.     

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.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.