蔗汁酒精废液色素的提取及其抗氧化活性研究

针对蔗汁酒精废液中含有的大量色素物,采用大孔树脂吸附提取色素,对蔗汁酒精废液中色素的提取工艺及其抗氧化活性进行了研究。通过静态吸附实验筛选出吸附树脂D101及对应的洗脱溶剂乙醇。最佳流速为3BV/h,最佳洗脱条件为40%的乙醇在pH6～7范围内进行洗脱。经测定,色素的黄酮含量为茶多酚的27.2%,但对自由基的抑制率却为茶多酚的88.06%,表明蔗汁酒精废液中提取的色素具有较高的抗氧化活性。     

大孔吸附树脂分离纯化枣渣中三萜酸的研究

研究枣渣中三萜酸的分离纯化工艺条件,为枣渣二次开发利用提供依据.筛选合适的大孔树脂,并对大孔树脂分离纯化的条件进行考察.初步确定了树脂分离纯化的条件,上样浓度为3.5mg/mL,洗脱剂为pH值为10的90%乙醇溶液,回收率65%以上,纯度达80%以上.此工艺安全,环保,提取物纯度较高,适用于工业化生产.对X-5树脂吸附总三萜酸的动力学研究表明吸附速率同时受液膜扩散和颗粒扩散控制.     

大孔树脂吸附分离速溶茶副产品中茶多酚的研究

通过静态试验比较了不同树脂对速溶茶副产品中茶多酚的吸附和解析特性,筛选出对茶多酚有较好的吸附率和解析率的NKA-9型树脂。动态试验确定了最佳的吸附和解析参数:上样流速为0.8mL/min、上样液温度为60℃、pH为5,洗脱流速为0.9mL/min、乙醇浓度为80%、洗脱剂用量为3BV。经过NKA-9纯化后速溶茶副产品中茶多酚含量达到58.7%,得率为14%。     

PA／XDA膜包络复合树脂对茶多酚、咖啡碱的吸附分离

研制了XDA负载PA膜包络体的复合树脂,并用于茶叶提取液中茶多酚、咖啡碱的分离。通过对复合工艺,如溶剂配比、PA担载量及添加剂加入量的研究,提出了复合树脂制备的优惠工艺条件。该复合树脂具有良好的吸附、洗脱性能。将溶解度参数理论用于脱附剂的选择,实验结果与理论分析相一致。     

大孔吸附树脂LX-20从发酵液中分离纯化维生素B_(12)

对从脱氮假单胞菌发酵液中分离纯化维生素B12的方法进行了研究。通过对11种弱极性大孔树脂进行筛选,确定LX-20为最适合树脂;对饱和树脂进行静态洗脱和动态洗脱,确定75%甲醇水溶液为洗脱剂,加入醋酸有利洗脱。利用薄层法对粗品进行精制。最终建立工艺路线为发酵液预处理后,LX-20吸附饱和,含醋酸的75%甲醇洗脱,经适当放大后结果仍好。此法洗脱高峰集中,产品纯度达90%,回收率可达98%以上,所得精品经HPLC检测纯度为97.8%。     

离子交换法分离固相合成胸腺素α1

胸腺素α1是一种重要的免疫增强剂,广泛应用于病毒性慢性肝炎以及恶性肿瘤的临床辅助治疗.本文采用离子交换法对固相合成的胸腺素α1进行了分离纯化研究,考察了pH值、进样量、洗脱方法以及树脂种类对纯化效果的影响,建立了一套基于SourceTM 15Q阴离子交换树脂的纯化方案.利用上述方法纯化Tα1纯度可达95.53%,收率60.4%,经ESI-MS分析,产品分子量与Tα1吻合.该技术可满足规模化、低成本纯化固相合成胸腺素α1的需要.     

大孔树脂分离纯化丹酚酸的研究

比较了D301R、D392、D380大孔阴离子交换树脂和X-5.AB-8、NKA-9、SP825大孔吸附树脂对丹参水溶性成分的吸附和解吸能力,筛选出效果较好的SP825进行分离纯化丹酚酸的研究.实验表明,大孔吸附树脂SP825能分离出纯度为95.32%的丹参素,在梯度洗脱条件下可得到以丹参素(水洗脱)和丹酚酸B(乙醇洗脱)为主的产品.在最佳吸附与解吸工艺参数下,丹参素、紫草酸、迷迭香酸、丹酚酸A和丹酚酸B的收率分别为:36.92%、80.39%、82.45%、43.07%和41.03%.     

离子交换树脂去除氯化铝溶液中铁和镓工艺研究

本文采用离子交换树脂去除“一步酸溶法”提取氧化铝工艺中氯化铝溶出液的铁和镓杂质,考察了四种离子交换树脂去除杂质的能力。试验表明,D201MBP型离子交换树脂的杂质吸附率最高,最佳反应条件为树脂和溶出液质量比为1:10,反应温度70℃,反应时间30min,溶出液浓度1～1.2(原溶出液浓度设为1),Fe和Ga的吸附率可达93%和98%,且Al的损失率仅为3.9%。在室温下,用0.5%盐酸溶液洗脱饱和树脂,可达到良好的再生效果。     

离子交换法从发酵液中提取α-酮基-L-古龙酸的工艺研究

本文就离子交换法从发酵液中提取α-酮基-L-古龙酸(以下简称KGA)的可行性进行了研究。比较系统地研究了大孔阴离子交换树脂对发酵液中KFA的静态和动态交换吸附性能及影响因素,并对洗脱条件进行了探索。实验结果表明,用离子交换法从发酵液中提取KGA的工艺是切实可行的。     

聚丙烯腈—硫脲螯合树脂的合成及吸银性能研究

本文以聚丙烯腈和硫脲反应合成了含硫螯合树脂。研究了该树脂对银的螯合性及洗脱性能，还研究了对银的吸附速率。结果表明，该树脂对银的螯合容量可达５６９．１６ｍｇ／ｇ干，氧化－还原当量棕达３．６８９ｍｅｑ／ｇ干。两种洗脱工艺都可以很有效地洗脱树脂吸附的银。１小时内即可达到吸附平衡。     

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.     

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.     

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.     

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.     

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.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.