大孔吸附树脂法柚皮果胶脱色工艺研究

比较了AB-8、S-8、X-5、聚酰胺、NKA-Ⅱ、NPD-600等6种大孔吸附树脂对柚皮果胶的脱色效果.在静态吸附试验研究的基础上,筛选出效果较好的树脂进行动态试验研究.实验表明:AB-8型大孔吸附树脂对柚皮果胶提取液具有较好的吸附脱色效果和较低的果胶损失率,该树脂对柚皮果胶脱色的适宜工艺参数为:室温(约20℃),流速3BV/h,溶液处理量为5BV,上柱液pH值为4～6.此工艺对果胶提取液中色素的吸附率约80%.树脂吸附后可用70%乙醇进行洗涤再生,果胶提取液脱色后经喷雾干燥所得的果胶成品质量符合QB2484-2000标准.     

树脂吸附法D-核糖发酵液脱色的研究

首次考察了六种不同树脂对D－核糖发酵液的脱色作用,详细地研究了吸附工艺条件对树脂脱色能力的影响．试验结果表明,在25℃下,以1.0BV／h的流速进行吸附时,NKA－Ⅱ树脂对D－核糖发酵液具有良好的脱色效果,脱色率91％,处理量5.7BV;并对树脂再生的条件进行了较详尽研究。     

川芎多糖脱色方法比较

比较了活性炭、H2O2和大孔吸附树脂对川芎多糖提取液的脱色效果。选用极性大孔树脂S-8在工作液流速为2BV/h,川芎浓度为0.33g/mL时,脱色率为92.7%,多糖保留率为93.0%,表明S-8适合用于川芎多糖提取液脱色。     

香菇多糖脱色工艺研究

研究了6种大孔吸附树脂和2种离子交换树脂对香菇多糖提取液中色素脱除的影响,在静态吸附试验研究的基础上,筛选出效果较好的树脂进行动态试验研究.研究发现,采用树脂DA201-C,在pH值4～6,温度40℃,流速3BV/h的工艺条件下,香菇多糖提取液中的色素脱除率达到87.8%,多糖保留率为85%,蛋白质的去除率为42%,树脂吸附后可先用1%NaOH和5%NaCl溶液浸泡,再用80%乙醇浸泡淋洗再生.     

蚕砂总生物碱提取物的脱色研究

通过动态吸附实验,考察了D296R(-Cl型)、D296R(-OH型)、D2040、X-5、D380(-Cl型)和D380(-OH型)6种树脂对蚕砂提取液的脱色作用,筛选出分离效果较好的树脂并确定了其分离条件,在此基础上使用正交设计法对它进行树脂再生条件的探究。通过对比这6种树脂对色素及活性物质的分离效果,发现D296-R(-Cl型)大孔阴离子交换树脂脱色效果最为理想,以95%乙醇溶液稀释的蚕砂提取液,经该树脂上样分离后,用3BV70%的乙醇溶液洗脱,所得洗脱液吸光度0.1,活性成分保留较多。正交设计法得出该树脂的适宜再生条件:乙醇浓度为80%,流速为3BV/h,NaOH溶液浓度为3%。     

树脂吸附法豆腐柴叶果胶提取液脱色的研究(□)D3520树脂对色素的吸附性能

以大孔吸附树脂D3520对豆腐柴叶色素的吸附行为为研究对象,对色素的吸附平衡和吸附动力学进行研究,以Langmuir公式拟合25□下的吸附等温线,结果表明:D3520树脂对色素吸附规律较好的符合Langmuir吸附等温式.     

吸附树脂法在泽泻提取物的脱色及高纯度泽泻醇制备中的应用研究

将具有脱色和吸附双重功能的新型吸附树脂用于泽泻提取物的脱色和高纯度泽泻醇提取物的制备工艺中,考察了树脂结构对脱色性能和吸附性能的影响熹见律.结果表明,兼具适宜的比表面积和功能基含量的No.2树脂具有最佳的纯化效果,只通过"吸附-解吸"一步工艺,产品纯度即可从1.93%提高到50%以上,泽泻醇的回收率高于95%.初步探讨了树脂的吸附机理,认为树脂对泽泻醇的吸附是单纯的疏水性作用力,而对色素的吸附应为疏水-离子交换双重作用的协同效应.     

维生素B6树脂法脱色初探

合成得到的维生素 B6 ( Vit B6 ) ,粗产品为黄色到棕色粉末 ,必须经 2次活性炭脱色、结晶 ,才能合格 .粉末炭脱色后一般不能回收重复使用 ,部分产品因吸附在活性炭上会造成产品收率降低 ,而且脱色工艺中常需热过滤 ,开放式的操作会对工作环境造成污染 .大孔吸附树脂用于天然产物的提取分离 ,近年来发展十分迅速 ,在药物、抗生素提纯、工业废水、废液的净化等方面也得到广泛应用 ,在天然色素的提取[1 ,2 ] ,产品的脱色方面也显示出了独特的作用[3,4] .本文探讨了用吸附树脂法对 Vit B6的脱色纯化 .Vit B6标样和粗品由上海新亚药厂提供 ,H…     

树脂吸附法豆腐柴叶果胶提取液脱色的研究 (Ⅰ) D3520树脂对色素的吸附性能

以大孔吸附树脂D3520对豆腐柴叶色素的吸附行为为研究对象,对色素的吸附平衡和吸附动力学进行研究,以Langmuir公式拟合25℃下的吸附等温线,结果表明:D3520树脂对色素吸附规律较好的符合Langmuir吸附等温式。     

交联聚苯乙烯氨基树脂的结构与脱色性能研究

通过改变交联度、致孔剂以及胺化试剂合成了一系列大孔氨基吸附树脂。详细研究了树脂孔结构、功能基结构与树脂脱色性能的关系。     

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.