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槟榔碱主要存在于棕榈科植物槟榔的种子内。槟榔是我国目前亟待开发的天然植物资源,广泛分布于海南、广西、云南、福建及台湾等地。槟榔碱味辛、温,具有杀虫、破积、下气、行水的功能。由于槟榔碱对M—胆碱受体的作用,平时嚼食槟榔,可促使唾液分泌增加、增进 相似文献
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为测定海南产槟榔、沉香及槟榔-沉香(质量比为1∶1)药对中锰的含量与生物利用性,并了解锰的健康效应,采用火焰原子吸收光谱法(FAAS)测定了槟榔、沉香原药及其水煎液中锰的含量,并用体外消化-透析法模拟人体胃肠道消化,研究了锰的生物利用性.结果表明,该法回收率为98.32%~102.40%,RSD为1.24%~1.76%... 相似文献
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薄层色谱法检测槟榔中糖精含量 总被引:3,自引:0,他引:3
肖学成 《理化检验(化学分册)》1997,33(3):118-118,120
在湖南长沙、湘潭等地素有嚼食槟榔的传统习惯,每年要消耗槟榔干果数10t.槟榔在精制过程中,常加入糖精以增加甜度.作为化工产品的糖精,毫无营养价值,对人的致癌性目前尚有争论.我国食品中糖精限量一般为不超过0.159·kg~(-1),故检测槟榔中糖精含量有卫生学意义.糖精的测定方法目前有薄层色谱法、电极法、比色法、紫外光谱法、高压液相色谱法等.但是较简便的方法还是首推薄层色谱法,该法是测定食品中糖精的国标法.我们在已有工作的基础上,参照国标法,选用硅胶GF_(254)作吸附剂,测定了210件槟榔样品中糖精含量,结果满意. 相似文献
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将粉碎后的槟榔样品2.00g用20mL乙腈提取,以100mg N-丙基乙二胺为净化剂分散固相萃取净化萃取液。取上清液以Thermo Accucore aQ C18色谱柱为固定相,以0.005mol·L-1乙酸铵溶液-乙腈混合液为流动相进行梯度洗脱,采用高效液相色谱-串联质谱法测定其中4种黄曲霉毒素的含量。质谱分析中采用电喷雾离子源和多反应监测模式。结果表明:4种黄曲霉毒素的质量浓度均在0.1~10.0μg·L-1内与其峰面积呈线性关系,测定下限(10S/N)为1μg·kg-1。以食用槟榔样品为基质,按标准加入法进行回收试验,回收率为80.0%~99.2%,测定值的相对标准偏差(n=6)为1.5%~9.3%。 相似文献
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以等离子体发射光谱法测定了槟榔中20种微量元素含量.结果表明,广州产槟榔所含11种人体必需微量元素含量与进口摈榔接近,Pb、Cd、As含量较低.槟榔不同部位微量元素含量均有显著差异。未成熟的槟榔种子微量元素含量与成熟种子有显著差异,其Ph含量达2.21×10-6,为成熟种子Pb含量的20倍。 相似文献
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Uroš Grošelj Mojca Žorž Amalija Golobič Branko Stanovnik Jurij Svete 《Tetrahedron》2013,69(52):11092-11108
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. 相似文献
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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. 相似文献
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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%). 相似文献
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Shashikant U. Dighe Surya K. Samanta Shivalinga Kolle Sanjay Batra 《Tetrahedron》2017,73(17):2455-2467
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. 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献
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Jona Mirnik Eva Pušavec Kirar Sebastijan Ričko Uroš Grošelj Amalija Golobič Franc Požgan Bogdan Štefane Jurij Svete 《Tetrahedron》2017,73(24):3329-3337
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 CuI 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). 相似文献
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George E. Magoulas Thomas Garnelis Constantinos M. Athanassopoulos Dionissios Papaioannou George Mattheolabakis Konstantinos Avgoustakis Dimitra Hadjipavlou-Litina 《Tetrahedron》2012,68(35):7041-7049
(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. 相似文献