大孔阴离子树脂分离纯化微生物转化液中5-氟尿苷的研究

探寻从微生物转化液中分离纯化5-氟尿苷(5-FUR)的工艺条件。先后尝试了大孔吸附树脂、大孔弱碱性阴离子交换树脂以及硅胶柱色谱的分离方法,首先利用大孔弱碱性阴离子交换树脂吸附,然后用1mol/L NaCl动态洗脱得到含量较高的两种含氟化合物,最终通过硅胶柱色谱,采用正己烷-乙酸乙酯(含10%醋酸)为流动相进行洗脱,得到了纯度为100%的纯品。在目标化合物和杂质理化性质极其相似,含量极其悬殊的条件下,成功去除含量极高的杂质,实现了5-FUR的分离纯化,圆满地达到了预期的目的。     

大孔树脂-高速逆流色谱法分离纯化地黄中毛蕊花糖苷

该文建立了大孔树脂-高速逆流色谱分离中药材地黄中有效成分毛蕊花糖苷的方法。考察了4种大孔树脂对地黄粗提物中毛蕊花糖苷的静态吸附与解吸情况,其中D101大孔树脂对目标成分的吸附率与解吸率最理想,实验结果表明体积分数为10%的乙醇洗脱得到的毛蕊花糖苷含量最高,目标成分含量从4.9%提高到32.6%。最后,部分纯化的样品（165 mg）采用高速逆流色谱进一步纯化,两相溶剂系统由乙酸乙酯-正丁醇-水（1：4：5,v/v/v）组成,分离得到45 mg纯度为96%的毛蕊花糖苷。     

大孔树脂吸附裸花紫珠苯乙醇苷的动力学与热力学研究

考察不同类型大孔树脂吸附裸花紫珠苯乙醇苷的动力学与热力学特性,为该类化合物的分离纯化提供参考。以吸附率、解吸率为综合评价指标,通过静态吸附-解吸附试验从6种大孔树脂中筛选出最适合纯化裸花紫珠苯乙醇苷类成分的大孔树脂类型,建立大孔树脂纯化裸花紫珠苯乙醇苷的吸附动力学模型和等温吸附模型,探究其吸附过程。根据初步筛选结果,选择SP-827、SP-207和X-5型大孔树脂进一步考察,3种树脂具有大致一样的吸附过程：0～60 min为快速吸附阶段;60～360 min为缓慢吸附阶段;360～1080 min为吸附平衡阶段。准二级动力学方程能很好地模拟3种型号的大孔树脂对裸花紫珠苯乙醇苷的吸附动力学过程,吸附速率受液膜扩散和颗粒内扩散共同影响;Langmuir模型和Freundlich模型都能较好地拟合吸附等温线数据,3种类型的大孔树脂对裸花紫珠苯乙醇苷都具有良好的吸附性能,吸附过程属于“优惠吸附”。动力学模型与热力学模型都能很好地拟合这3种类型大孔树脂纯化裸花紫珠苯乙醇苷的吸附过程,其中国产树脂X-5可以用来代替进口树脂SP-825或SP-207用于裸花紫珠苯乙醇苷类成分的分离和纯化研究,也是纯...     

大孔树脂-高速逆流色谱法分离纯化地黄中毛蕊花糖苷（英文）

该文建立了大孔树脂-高速逆流色谱分离中药材地黄中有效成分毛蕊花糖苷的方法。考察了4种大孔树脂对地黄粗提物中毛蕊花糖苷的静态吸附与解吸情况,其中D101大孔树脂对目标成分的吸附率与解吸率最理想,实验结果表明体积分数为10%的乙醇洗脱得到的毛蕊花糖苷含量最高,目标成分含量从4.9%提高到32.6%。最后,部分纯化的样品(165 mg)采用高速逆流色谱进一步纯化,两相溶剂系统由乙酸乙酯-正丁醇-水(1∶4∶5,v/v/v)组成,分离得到45 mg纯度为96%的毛蕊花糖苷。     

烟草烘丝尾气收集液分级装置构建与评价

本文构建了一种基于FLASH色谱技术的烟草烘丝尾气收集液的分级装置。该装置采用阳离子交换柱、阴离子交换柱和大孔吸附树脂柱串联的方法分级烟草烘丝尾气收集液,优化分离条件,结合气相色谱/质谱(GC/MS)分析对烟草烘丝尾气收集液分级装置进行评价。结果显示,烟碱吸附于732型的阳离子交换树脂中,而717型阴离子交换树脂和AB-8型大孔吸附树脂富集了乙酰基吡咯、二氢猕猴桃内酯、β-二氢大马酮等烟草中的多种致香成分。     

大孔吸附树脂分离纯化昆仑雪菊总黄酮工艺的研究

筛选分离纯化昆仑雪菊总黄酮的大孔吸附树脂并建立纯化工艺条件。以大孔吸附树脂对昆仑雪菊总黄酮的吸附量、吸附率和解吸率等为指标,考察了11种型号的大孔吸附树脂进行分离纯化,并确定了该树脂分离纯化最佳工艺参数。结果显示NKA-9型大孔吸附树脂对昆仑雪菊总黄酮分离纯化效果好,其工艺条件为:以pH值为5.0的原料液上柱吸附,70%浓度的乙醇洗脱、洗脱速度3mL·min-1,在此条件下总黄酮的的静态吸附率为95.74%,解吸率为98.9%。     

基于大孔树脂与制备液相色谱技术快速分离野地瓜茎中的绿原酸

建立了基于大孔吸附树脂快速富集,制备高效液相色谱高效分离野地瓜茎中绿原酸的制备方法:AB-8,D101,HPD600,CN206和NKA-Ⅱ5种树脂中,经静态吸附-解吸附试验发现NKA-Ⅱ型大孔树脂对目标化合物具有较好的吸附率和解析率;采用NKA-Ⅱ型大孔树脂,经4倍柱体积(bed volume,BV)5%(V/V)乙醇除杂后,用7 BV 10%(V/V)乙醇洗脱得到目标化合物组分,HPLC分析目标化合物的峰面积比达到80.8%;由制备高效液相色谱对目标化合物做进一步纯化并开发了重复进样分离模式,提高了分离效率,经纯化后目标化合物纯度达到98.6%;1H NM R和13C NM R鉴定目标化合物为绿原酸。该方法适合于野地瓜中绿原酸化合物的大规模制备。     

大孔吸附树脂分离纯化迷迭香酸的研究

采用大孔吸附树脂法研究迷迭香酸的精制工艺。筛选出适合的大孔吸附树脂,并对其分离纯化的条件进行考察。使用静态吸附法确定大孔吸附树脂NK109最适于迷迭香酸的精制。通过动态吸附性能的考察,确定最佳迷迭香酸上柱浓度838.6mg/L,流速为2.0BV/h上柱。通过动态解吸性能的考察,使用乙酸乙酯作为洗脱液,确定洗脱速度为1.0BV/h。利用大孔吸附树脂,迷迭香酸得到了较好的富集和纯化。纯化后的迷迭香酸纯度可以达到90%以上。     

Diaion HP–20大孔吸附树脂分离纯化含羞草种子中的黄酮类物质

研究Diaion HP–20大孔吸附树脂分离纯化含羞草种子中黄酮类物质的工艺条件。用海南含羞草种子为原料,以含羞草种子中总黄酮吸附量和解吸率为评价指标,考察上样流量、洗脱液种类、柱径比、洗脱液流量等影响因素。Diaion HP–20大孔吸附树脂分离纯化含羞草种子中黄酮类物质的最佳工艺条件:上样流量3 m L/min,洗脱液为40%乙醇溶液,柱径比为1∶10,洗脱液流量为4 m L/min。该方法简单,可行,能够有效分离纯化含羞草种子中黄酮类物质,且大孔吸附树脂可重生,利用率高。     

大孔吸附树脂结合酶解法分离纯化虎杖中白藜芦醇的研究

研究了大孔吸附树脂结合酶解法提取和纯化虎杖中白藜芦醇的方法,采用HPLC法测定虎杖中白藜芦醇的含量,考查了β-糖苷酶对虎杖药材酶解前后白藜芦醇含量的变化,并经静态吸附考察了4种树脂,最后确定以H1020作为提取分离白藜芦醇的树脂.此树脂吸附量较高,脱附容易,有利于得到质量较好的白藜芦醇产品,经该树脂吸附解吸,饱和吸附量可达51.4mg/g,解吸率达92.5%.大孔树脂分离纯化白藜芦醇的含量可达71.5%,而上柱前粗提物中白藜芦醇含量为8.71%,说明采用本法分离纯化虎杖中白藜芦醇是可行的.     

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.