反相高效液相色谱法测定人参皂甙Compound-K的含量

人参皂甙compound-K(C-K)在人参中的含量极低,但它是其他含量较高的人参皂甙Rb1和Rb2等在人体肠道内的主要 降解产物和最终吸收形式,具有很高的生物活性。采用反相高效液相色谱法测定了人参总皂甙发酵液中C-K的含量。色谱 条件为:反相C18柱;乙腈-水(体积比为48∶52)溶液为流动相,流速1.0 mL/min;紫外检测波长203 nm;柱温35 ℃;外标法 定量。结果表明:C-K的质量浓度为0.05~0.8 g/L时,其峰面积与质量浓度具有良好的线性关系,相关系数为0.9998。方法 的检测限(S/N=3)为2.5 mg/L,峰面积测定值的相对标准偏差(n=6)为2.20%。测定栽培人参总皂甙及三七茎叶总皂甙微生 物发酵液中C-K的平均加标回收率(n=3)分别为98.6%和99.7%。该方法快速简便,准确可靠,可用于C-K的制备研究及药物 开发。     

发用防晒剂DDABDT的反相高效液相色谱法测定

建立了反相高效液相色谱法测定发用防晒剂二甲基对胺基苯甲酰胺丙基十二烷基二甲胺甲苯磺酸盐(简称DDABDT)的方法.采用的色谱条件为色谱柱Symmetry C8柱,流动相为V(乙腈):V(10 mmol/L NaAc)=65:35溶液(含体积分数0.02%三氟乙酸,pH5.04),流速1.0 mL/min;检测波长305 nm;进样量20μL.DDABDT质量浓度为0.05～1000 mg/L时,其浓度与峰面积呈良好的线性关系(R2＞0.999),检出限为0.02 mg/L(S/N=3).洗发水A中DDABDT的回收率在98.0%～102%之间,发样提取液中DDABDT的平均回收率在85%～108%之间.洗发水中DDABDT浓度测定日内和日间相对标准分别为1.2%,3.4%.头发吸附DDABDT含量测定日内和日间相对标准偏差(RSD)分别为9.1%,9.8%.同时以高效液相色谱-电喷雾离子化质谱对色谱法测定样品的DDABDT峰进行了验证.该方法已用于洗发水及头发吸附DDABDT的分析.     

异硫氰酸苯酯柱前衍生化反相高效液相法同时测定18种氨基酸

 建立了一种利用反相高效液相同时测定 18种氨基酸的方法。以正亮氨酸为内标物 ,异硫氰酸苯酯为柱前衍生剂 ,用C18柱在柱温 38℃下采用二元梯度洗脱 ,于 2 5 4nm波长处检测。氨基酸质量浓度在 3 5mg/L～ 5 5 6mg/L时 ,其峰面积与内标物峰面积的比值和氨基酸的质量浓度的线性相关系数 ,除胱氨酸 (0 96 2 )外均大于 0 99;18种氨基酸的加标回收率在 96 0 %～ 10 2 .4 %。信噪比为 2时 ,亮氨酸最低检测限为 0 5mg/L。应用该方法对小牛血去蛋白注射液中的游离氨基酸含量进行了测定 ,取得了满意的结果。     

反相高效液相色谱法测定烷基糖苷中聚糖

应用反相高效液相色谱法测定烷基糖苷中的聚糖含量。烷基糖苷样品以反相C18色谱柱为分离柱,以甲醇-水(80+20)混合液为流动相,用电雾式检测器检测。聚糖的质量浓度在18.75~300mg·L-1范围内与其峰面积呈线性关系,方法检出限(3s/k)为5mg·L-1。加标回收率在95.0%~109%之间,测定值的相对标准偏差(n=6)在0.9%~1.6%之间。     

反相高效液相色谱法测定荧光增白剂CBS中N,N-二甲基甲酰胺的残留量

建立了反相高效液相色谱外标法检测荧光增白剂CBS(即CF-351)中N,N-二甲基甲酰胺(DMF)残留量的方法。使用Accurasil C18(150 mm×4.6 mm,5 μm)反相液相色谱柱,以甲醇-水为流动相梯度洗脱,流速为1.0 mL/min,检测波长为205 nm,柱温为30 ℃,进样量为5 μL。在上述条件下,在DMF质量浓度为0.19～141 mg/L范围内,其峰面积与质量浓度的线性关系良好。在加标水平（用质量分数表示）为0.2344%和0.4678%时,回收率为98.4%～107.3%。本方法最低检出限(LOD)为0.019%（质量分数）,峰面积的相对标准偏差(RSD)为1.73%。此方法可快速、准确地测定出荧光增白剂CBS中DMF的残留量。     

高效液相色谱法测定全血中骨碱性磷酸酶的活力

 建立了测定全血中骨碱性磷酸酶(BALP)的高效液相色谱法(HPLC)。色谱柱为SpectraPhysicsODS反相柱,以V(0.01mol/L乙酸,pH4.8)∶V(甲醇)=70∶30的溶液为流动相,流速为0.8mL/min,检测波长为275nm。当BALP的质量浓度为8～200mg/L时,其活性对峰面积呈良好的线性关系(r=0.996),检测限为3ng。该方法简便、快速、可靠,可用于临床测定全血中的BALP。     

高效液相色谱法测定橡胶制品中2-巯基苯并噻唑

采用高效液相色谱法测定橡胶制品中2-巯基苯并噻唑的含量。样品经丙酮超声提取两次。采用C18反相色谱柱为分离柱,以甲醇-0.01mol·L-1磷酸二氢钠(80+20)溶液为流动相,在检测波长320nm处进行测定。2-巯基苯并噻唑的质量浓度在0.10~10.0mg·L-1范围内与其峰面积呈线性关系,方法的检出限(3S/N)为0.54mg·kg-1。在0.10,2.0,10.0mg·L-1等3个浓度水平进行加标回收试验,回收率在85.3%~95.4%之间,测定值的相对标准偏差(n=6)在3.1%~5.6%之间。     

高效液相色谱法同时测定植物油中4种甾醇烯

建立了高效液相色谱法同时测定植物油中4种甾醇烯的方法。样品用石油醚提取,硅胶柱净化,反相C30柱(250 mm×4.6 mm i.d,5μm)分离,乙腈-叔丁基甲醚(75∶25,V/V)作流动相,等度洗脱,紫外检测(235 nm)。结果表明:4种甾醇烯的质量浓度在0.025～1.0 mg/L范围内;峰面积与质量浓度呈良好的线性关系,线性相关系数r2>0.999。在加标水平为0.050,0.10和0.50 mg/kg时,4种甾醇烯的加标平均回收率为89.2%～109.8%;相对标准偏差RSD<8%;方法检出限(LOD)为0.010 mg/kg。本方法已应用于实际样品分析。     

反相高效液相色谱法测定合成产物中的双酚芴

建立了采用反相高效液相色谱测定合成的双酚芴含量的方法。采用反相C18烷基柱,以甲醇-水（体积比为85∶15）为流动相,流速为1.0 mL/min,采用UVD170紫外检测器在230 nm处进行检测。双酚芴质量浓度为4～20 mg/L时,其峰面积与质量浓度的线性关系良好,线性相关系数为0.9996;平均回收率高于98.7%,相对标准偏差低于1%。结果表明,所建立的方法简单快速、准确可靠。     

用反相高效液相色谱法测定人体血浆中盐酸氟桂利嗪含量

采用反相高效液相色谱法以桂利嗪为内标测定人体血浆中盐酸氟桂利嗪的含量.以V甲醇:V乙腈:V缓冲液=58:20:22的体系为流动相,用hypersilBDSC8不锈钢色谱柱、紫外检测器(检测波长254nm),血浆样品经乙酸乙酯萃取处理后进样测定.血浆中盐酸氟桂利嗪的含量在5～300μg/L范围内与盐酸氟桂利嗪的峰面积和桂利嗪的峰面积之比呈线性关系(r=0.9997),方法对盐酸氟桂利嗪的平均回收率为83.3%～85.0%,检出限为3μg/L(S/N=3).用该法测定了12名单次口服30mg西比灵(盐酸氟桂利嗪)胶囊的健康志愿者血浆中盐酸氟桂利嗪含量.结果表明,该药在血浆中含量平均达峰时间为(2.67±0.91)h,平均峰质量浓度为(154.9±66.0)μg/L.该法适用于盐酸氟桂利嗪药代动力学的临床监测和研究.     

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.     

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.     

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.     

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.