石榴皮单宁的超声波-半仿生法提取及抗氧化性分析

采用超声波辅助半仿生法提取石榴皮单宁。利用正交实验方法对提取工艺进行优化,并进行了红外光谱分析和研究抗氧化能力检测。在提取液的pH值分别:1.2、7.6、8.4,溶剂质量分数50%、提取时间45 min、提取温度50℃、超声波功率320 W和超声波频率25KHz的条件下,单宁提取量可达234.6 mg.g-1,远高于无超声波辅助的试样。红外光谱分析表明:石榴皮单宁中含有大量的无色花翠素-3-葡萄糖苷分子结构式类物质;抗氧化能力检测显示:采用超声波辅助半仿生法能够提高单宁对OH.、DPPH.和ABTS+.等自由基的清除能力,与水回流提取法相比,其IC50值分别降低了0.26、0.022和0.41 mg.mL-1。     

超声波强化提取地骨皮中有机酸的研究

用超声波强化提取地骨皮中有机酸,采用单因素和正交试验方法研究了提取温度、提取时间、料液比、超声波功率对地骨皮中有机酸提取量的影响规律。结果表明超声波提取法的最佳工艺条件为提取温度65℃、提取时间35 min、料液比1∶16、超声波功率135 W,在此条件下地骨皮中总有机酸提取率为2.73%。     

柴胡中柴胡皂甙a的超声辅助溶剂提取

以溶剂提取法为基础,以超声波为辅助手段,对柴胡中的有效成分进行了提取.通过对提取液中柴胡皂甙a量的测定,研究了超声功率、提取温度、提取时间和样品浸渍时间等条件对提取效果的影响,优选出超声辅助溶剂提取的最佳条件为超声功率50%、提取温度50 ℃、提取时间20 min、样品浸渍时间24 h.实验结果表明,超声辅助溶剂提取比普通的溶剂提取具有更高的提取效率.     

何首乌中蒽醌类物质的超声波提取工艺优化

采用超声波辅助法提取何首乌中蒽醌类物质.讨论了甲醇体积分数、提取时间、提取温度、料液比和提取功率5个因素对提取效率的影响;通过正交试验确定了何首乌中蒽醌类物质的最佳提取工艺条件,甲醇体积分数为80%,提取时间为1.0h,提取温度为45℃,料液比为1∶15(g∶mL),提取功率为700W.此条件下蒽醌类物质的最大提取率为1.472 9%.     

超声波提取川贝母黄酮类物质的工艺优化

采用超声波提取技术提取川贝母中的黄酮类物质.考察了超声功率、乙醇体积分数、料液比、超声时间和超声温度各因素对黄酮类物质提取效率的影响.在超声功率800 W条件下,通过L_9(3~4)正交试验,确定了川贝母黄酮类物质的超声波最佳提取工艺参数:超声功率为800 W,乙醇体积分数为80%,料液比为1 g∶45 mL,超声时间为2.0 h,超声温度为45℃.在最佳提取工艺条件下进行验证试验,川贝母黄酮类物质的提取率达到77.13 mg/g,RSD值为0.39%.     

川佛手中多酚类物质的微波和超声波联合提取工艺优化

采用微波和超声波提取技术,实现了川佛手中多酚类物质的有效提取.在微波功率800 W和微波提取时间40 min的条件下,通过单因素实验条件优化,考察了超声功率、乙醇浓度、提取温度、超声时间和提取料液比对提取效率的影响;通过正交试验设计,确定了最佳提取工艺条件参数,即超声功率800 W、乙醇体积分数60%、提取温度55℃、超声时间1.0 h和提取料液比1∶20 g/m L;通过验证实验,得到川佛手多酚的提取率约为20.79 mg/g.     

山核桃蒲壳中单宁的提取、检测及其缓蚀性能研究

用响应面法优化山核桃蒲壳中单宁的提取工艺,对单宁类型进行鉴定,还对单宁在HCl溶液中对冷轧钢的缓蚀作用进行探索。通过定性实验,证实山核桃蒲壳中含有缩合类单宁。运用Box-Behnken中心组合实验和响应面法考察了乙醇体积分数、提取时间、提取温度3个因素对单宁提取率的影响,优化提取条件为:乙醇体积分数65%,提取时间61 min,提取温度52℃。在此条件下,单宁提取率为6.73%。失重缓蚀实验结果表明,在酸洗时间为2～12h、酸洗温度20～50℃、HCl浓度0.2～1.0mol/L条件下,单宁提取液有一定的缓蚀作用,但缓蚀率不高。若通过与乌洛托品复配,缓蚀率均可提高到97%以上。     

超声波法辅助提取‘凤丹’丹皮多糖工艺优化

使用超声波法辅助提取‘凤丹’丹皮中的多糖,对超声波功率、提取温度、提取时间作为三个因素进行试验,以多糖得率为响应面指标,设计响应面对超声波法辅助提取‘凤丹’丹皮多糖工艺进行优化。结果显示丹皮中的多糖的最优提取工艺条件组合为:超声波功率为87.0W,提取温度为43.0℃,提取时间为22.0min。实际测得的丹皮中的多糖的得率为(15.40±0.10)mg·g~(-1)。通过响应面实验与常规方法对比,超声波法对多糖提取有较好的辅助作用,能够提高多糖得率,为‘凤丹’丹皮的资源开发提供依据。     

水产品中胂蛋白的提取方法研究

以蛤蜊为研究对象,建立了水产品中胂蛋白的提取方法.采用超声波细胞破碎法以Tris-HCl作为缓冲溶液提取蛤蜊中的胂蛋白;对提取的胂蛋白进行电泳分离纯化,采用氢化物发生-原子荧光光谱法对蛋白条带中As含量进行测定.根据实验结果分析,胂蛋白的最佳提取条件为:超声功率190 W,超声波每次辐射时间/间歇时间为5 s/5 s,...     

正交设计优化木贼多糖的超声提取工艺(英文)

以蒸馏水为溶剂提取,通过单因素实验和正交实验,研究料液比、超声功率、超声提取温度和超声作用时间对木贼多糖提取效果的影响。超声提取法的优化工艺条件为:料液比(g/mL)1∶20,提取温度70℃,超声功率100 W,作用时间50 min。在此条件下,木贼多糖的平均提取率为12.33%,RSD为0.16%。超声波强化提取木贼多糖省时高效。     

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.     

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.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.