酸提取大豆种皮果胶的工艺研究

果胶的提取方法很多,酸提取乙醇沉淀法与盐析法、离子交换法、微波提取法等相比,具有试剂简单、价廉且操作和工艺条件易于控制、提取率较高等优点。目前,我国每年消耗果胶约1500吨以上,其中约80％需从国外进口。因此寻找新的果胶原料势在必行。大豆种皮作为大豆加工行业的副产品,具有价格低廉、贮存容易,果胶含量较高（高达16％）等特点,是较好的生产果胶的替代原料之一。本文采用酸提取方法对大豆种皮果胶的提取工艺条件进行研究。     

2000年中国稀土产销市场分析

20 0 0年我国稀土行业的发展呈平稳状态 ,稀土矿产品产量约 780 0 0吨 (ＲＥＯ ,下同 ) ,稀土冶炼加工产品产量约 6 5980吨。与我国整个国民经济的发展基本一致 ,呈现 8 2 %的增长。关于 2 0 0 0年稀土矿产品结构大致如下 :包头矿 4 80 0 0吨 (含部分上年库存产品 ) ,四川矿 1450 0吨 ,离子矿 130 0 0吨 ,山东矿 140 0吨 ,独居石10 0 0吨 ,磷钇矿 10 0吨。1　 国内市场2 0 0 0年我国国民经济的发展比较平稳 ,与1999年相比增长幅度约 8 0 %。国内的稀土市场也呈现平稳发展势态 ,但在新材料领域则仍呈高速发展势态。2 0 0 0年我国稀土永磁体生…     

《高等学校化学学报》2001年度总被引频次和影响因子大幅度上升

据美国科技情报所 (ISI)网络版近期公布的消息 ,《高等学校化学学报》 2 0 0 1年度总被引频次为 195 9次 ,比 2 0 0 0年增加了 5 3 8次 ,上升了近 16个百分点 ,居我国科技期刊之榜首 ;影响因子为 0 .90 4,比 2 0 0 0年增加了 0 .3 14 ,上升了 2 1个百分点 ,居我国科技期刊第三位 .现报道 2 0 0 1年 ISI收录我国科技期刊的主要引证指标 .2 0 0 1年 ISI收录我国科技期刊的主要引证指标刊　　　　名总被引频次影响因子即时指标收录文章数半衰期ACTA BIOCH BIOPH SIN(生物化学与生物物理学报 ,中文 ) 2 17 0 .3 990 .0 0 0 12 82 .9A…     

《高等学校化学学报》2001年度总被引频次和影响因子大幅度上升

据美国科技情报所 (ISI)网络版近期公布的消息 ,《高等学校化学学报》 2 0 0 1年度总被引频次为 195 9次 ,比 2 0 0 0年增加了 5 3 8次 ,上升了近 16个百分点 ,居我国科技期刊之榜首 ;影响因子为 0 .90 4,比 2 0 0 0年增加了 0 .3 14 ,上升了 2 1个百分点 ,居我国科技期刊第三位 .现报道 2 0 0 1年 ISI收录我国科技期刊的主要引证指标 .2 0 0 1年 ISI收录我国科技期刊的主要引证指标刊　　　　名总被引频次影响因子即时指标收录文章数半衰期ACTA BIOCH BIOPH SIN(生物化学与生物物理学报 ,中文 ) 2 17 0 .3 990 .0 0 0 12 82 .9A…     

柑橘果肉果胶的流变和结构特性

以柑橘果肉为原料,采用稀酸提醇沉法提取果胶粗品,研究了果胶溶液的浓度及热处理温度对果胶溶液流变学性质的影响.采用DEAE Cellulose-52柱对柑橘果肉粗品进行洗脱得到3个多糖组分(P-0,P-1和P-2),对其分子量、半乳糖醛酸、单糖组成及酯化度等进行分析,并利用红外光谱及核磁共振氢谱等对各组分进行结构特性分析.结果表明,柑橘果肉果胶为典型的剪切稀化型非牛顿流体;P-0,P-1和P-2组分分子量存在显著差异;柑橘果肉果胶为富含糖醛酸的酸性多糖,且是发生部分乙酰化的低酯果胶,其单糖组成以半乳糖醛酸、半乳糖、阿拉伯糖、鼠李糖和岩藻糖居多,且均以Ⅰ型聚鼠李半乳糖醛酸(RG-Ⅰ型)结构为主;3种组分糖环类型均是吡喃糖,糖苷键既有α型,又有β型.     

一种蚕砂中果胶的提取及其含量测定方法

<正>申请公布号:CN107245114A申请公布日:2017.10.13申请人:浙江理工大学摘要本发明涉及蚕砂加工领域,公开了一种蚕砂中果胶的提取及其含量测定方法。该提取方法,以提取过叶绿素的蚕砂滤渣为原料,先粉碎成成粉末,利用PEG修饰的纤维素酶辅助黑曲霉提取蚕砂滤渣中的果胶,再经脱色浓缩、沉淀;抽滤、沉析回收得到果胶,采用咔哩-硫酸法测定提取液中的果胶含量。本发明方法提取得到的果胶分子量大,提取率高,     

脐橙皮中黄酮类化合物与果胶的分离和提取研究

黄酮类化合物是具备主要生物活性的天然产物,果胶是人体7大营养素中膳食纤维的主要成分.实验就黄酮和果胶提取分别作L9(34)和L16(44)正交化实验.工艺条件表明,提取黄酮的较佳工艺条件是:固液比1∶30,超声处理时间55 min,处理温度50℃,浸提液浓缩得到粗黄酮.提取黄酮后的脐橙皮渣中提取果胶的较佳工艺条件是:70℃的温度,提取时间为55 min,pH=2.0,固液提取比为1∶25.     

《高等学校化学学报》2001年度总被引频次和影响因子大幅度上升

据美国科技情报所 (ISI)网络版近期公布的消息 ,《高等学校化学学报》 2 0 0 1年度总被引频次为 195 9次 ,比 2 0 0 0年增加了 5 3 8次 ;影响因子为 0 .90 4,比 2 0 0 0年增加了 0 .3 14 .现报道 2 0 0 1年 ISI收录我国科技期刊的主要引证指标 .2 0 0 1年 ISI收录我国科技期刊的主要引证指标刊　　　　名总被引频次影响因子即时指标收录文章数半衰期ACTA BIOCH BIOPH SIN(生物化学与生物物理学报 ,中文 ) 2 17 0 .3 990 .0 0 0 12 82 .9ACTA BOT SIN(植物学报 ,中文 ) 5 160 .2 840 .0 75 2 2 7 5 .4ACTA CHIM SINICA(…     

高效液相色谱法测定烟草中淀粉和果胶含量

烟草中的淀粉和果胶用盐酸水解,水解产生的葡萄糖和半乳糖醛酸以Waters Sugar Pak Ⅰ钙型阳离子交换柱为固定相,0．05 g·L-1 EDTA钙钠溶液为流动相进行分离,示差折光检测器检测葡萄糖和半乳糖醛酸的含量。由葡萄糖和半乳糖醛酸含量换算为淀粉和果胶含量。方法检出限为葡萄糖2．0 mg·L-1、半乳糖醛酸1．0 mg·L-1,方法用于几种烟草样品中淀粉和果胶含量的测定,结果的相对标准偏差为1．4％-1．8％,标准回收率在96％-105％之间。     

烟草果胶的提取分析研究进展

果胶是自然界广泛存在的一种物质,其含量对烟草的评吸质量有重要的影响。文章主要介绍了果胶的各种提取和分析方法,并对果胶提取分析的发展方向进行了展望。     

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%.     

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.     

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

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.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

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.     

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.