白菜DNA甲基化水平的反相离子对高效液相色谱法研究

建立了反相离子对液相色谱测定白菜的DNA甲基化水平的方法。采用的色谱柱为HypersilBDSC18柱(200mm×4.0mm,5μm),以pH4.0的甲醇-5mmol·L-1庚烷磺酸钠-三乙胺(10:90:0.2,体积比)的混合液为流动相,UV检测器波长为273nm。通过测定DNA水样所产生的胞嘧啶和甲基胞嘧啶的含量,即可得知DNA甲基化程度。胞嘧啶和甲基胞嘧啶回收率分别为99.6%及103.3%,RSD为3.7%(日内)及5.2%(日间)。     

人血清中吗啡含量的高效液相色谱法测定

采用C18 色谱柱 ,体积比70∶30的甲醇 -0.02mol·L-1 磷酸二氢钾缓冲液 (含0.001mol·L-1 三乙胺 ,pH=6.60)作流动相 ,紫外检测波长230nm ,可待因作内标 ,建立了反相高效液相色谱法测定人血清中吗啡含量的方法 ;对流动相、样品预处理和储备液稳定性进行了考察 ,提出用乙酸乙酯直接萃取血清中的吗啡 ,所得样品稳定性好 ,萃取回收率为74 %～80 %;该法快速 ,适于生物样品中吗啡含量的测定。     

反相高效液相色谱法同时测定柚皮中柚皮甙和橙皮甙的含量

采用反相高效液相色谱法同时测定柚皮中柚皮甙和橙皮甙的含量。色谱条件:μ-BondapakC18柱(250mm×4.6mm,5μm),流动相为甲醇-0.5%乙酸溶液(V/V=38/62);流速为0.8mL·min-1;检测波长为283nm,柱温为25℃。柚皮甙和橙皮甙的线性范围分别为20-60mg·L-1和10-30mg·L-1。柚皮甙和橙皮甙的平均回收率分别为99.3%和97.8%。该方法具有快速,结果准确等优点。     

反相高效液相色谱法测定饮料中苯甲醛

建立了反相高效液相色谱法测定饮料中苯甲醛的方法。当苯甲醛的质量浓度在1．0～100．0 mg·L-1范围时,苯甲醛的浓度与色谱峰面积呈线性关系,线性相关系数为0．999 8。苯甲醛的回收率为99．3%-102．6％,相对标准偏差为2．0%～3．4%,方法的检出限为0．1 mg·kg-1。     

微波消化-在线固相萃取富集高效液相色谱法测定饲料用灌木中痕量铅镉汞

研究了用微波消化样品,WatersXterraTMRP18(3.9mm×20mm)色谱柱在线固相萃取富集,二极管矩阵检测器检测,高效液相色谱测定饲料用灌木中痕量铅、镉、汞的方法。铅、镉和汞含量在0.1～100μg·L-1范围内与峰面积呈线性关系,方法检出限(S/N=3)为:铅2.0ng·L-1,镉1.5ng·L-1和汞2.0ng·L-1,方法相对标准偏差为2.0%～3.1%,标准回收率为94%～103%,该方法用于测定饲料用灌木中低含量的铅、镉、汞,结果满意。     

浊点萃取-高效液相色谱法测定痕量镍

以TAN为衍生试剂 ,用TritonX 1 1 4非离子表面活性剂浊点萃取富集镍 (Ⅱ ) ,于ODS柱上 ,用内含 4 5mmol·L- 1十六烷基三甲基溴化铵 (CMTAB)和pH 5 5HAc NaAc缓冲溶液的甲醇 水溶液 [V(CH3OH) +V(H2 O) =70 +3 0 ]作流动相 ,并用分光光度计于 5 90nm处测量 ,发展了一种反相高效液相色谱测定镍 (Ⅱ )的方法。在选定条件下 ,大多数离子不干扰测定 ,镍的检测限为0 1 μg·L- 1。方法用于水样中痕量镍的测定 ,获得满意结果。     

高效液相色谱法测定新除草剂丙草醚

介绍了高效液相色谱外标法测定新型除草剂丙草醚含量的方法.用C8反相柱,甲醇-水(8020)为流动相,紫外检测波长310nm;线性范围1～300μg@ml-1;相关系数为0.9999,RSD为0.36%.回收率为98.5%～101.8%,检出限为8.33ng@ml-1.     

反相高效液相色谱法测定对位酯工业品中的对位酯和对氯苯胺

建立了利用反相高效液相色谱测定工业对位酯中对位酯及其相关杂质对氯苯胺含量的方法。在C_(18)色谱柱(4.6×150 mm,5μm)上通过考察流动相种类、有机调节剂比例、p H等对保留的影响来优化色谱条件。分别建立了同时测定对位酯和对氯苯胺的反相离子对高效液相色谱法、快速测定对氯苯胺的反相高效液相色谱法,并建立了进一步分离对位酯中其他相关杂质的反相高效液相色谱法,可用于对位酯中相关杂质的液相色谱-质谱联用定性分析。在建立的同时测定对位酯和对氯苯胺的反相离子对高效液相色谱法中,对位酯和对氯苯胺分别在0.78~1000.0μg/m L(r=0.9997)和0.31~20.00μg/m L(r=0.9999)的浓度范围内成线性关系,平均回收率(n=3)分别为100.1%(RSD=0.62%)和100.8%(RSD=1.3%);在快速测定对氯苯胺的反相高效液相色谱法中,对氯苯胺在0.25~200.0μg/m L(r=0.9995)的浓度范围内成线性关系,平均回收率(n=3)为102.0%(RSD=0.43%)。     

高效液相色谱法测定单个蟾蜍垂体中精氨酸催产素含量

本文提出了用反相高效液相色谱结合化学衍生化和荧光检测技术测定单个蟾蜍垂体中精氨酸催产素(AVT)含量的方法。AVT经提取后,转化成荧光衍生物,然后在反相ODS术上以水和丙酮作流动相洗脱,荧光检测器检测(λ_(ex2) 340—380nm;λ_(em1) 460nm),最小检出量达1×10~(-12)mol(pmol),回收率为49.5%。     

反相高效液相色谱法测定鬼灯檠中岩白菜素的含量

建立了反相高效液相色谱法测定鬼灯檠中岩白菜素的含量。色谱柱为SymmetryC18柱(5μm,4.6mm×150mm),流动相为甲醇水(1∶3),流速为1.0mL·min-1,柱温30±1℃,检测波长为275nm。该方法线性范围为0.8～4.0μg(r=0.9987),平均加标回收率为100.5%,岩白菜素的相对标准偏差为1.6%(n=6),检出限为0.1ng。方法快速,简单,灵敏度高。     

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.     

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.     

Copper-catalyzed multicomponent reactions of 2-iodoanilines,benzylamines, and elemental sulfur toward 2-arylbenzothiazoles

A relatively cheap copper salt-catalyzed, three-component approach providing 2-arylbenzothiazoles in good to excellent yields from readily available 2-iodoanilines, benzylamines, and sulfur powder is reported. This methodology allows preparation of various classes of 2-arylbenzothiazoles and provides a general, reliable approach.