超高效液相色谱法分析淡豆豉配方颗粒中3种异黄酮

建立超高效液相色谱法同时测定淡豆豉配方颗粒中3种异黄酮(大豆苷元、黄豆黄素、染料木素)的含量。选择Eclipse Plus C₁₈ RRHD色谱柱(100 mm×2.1 mm,1.8μm)，流动相为乙腈-0.1%乙酸溶液，梯度洗脱，流量为0.3mL/min，柱温为30℃，检测波长为260 nm。大豆苷元、黄豆黄素、染料木素的质量浓度分别在18.41～184.14、0.48～4.82、30.65～306.46μg/mL范围内线性关系良好(r≥0.999 9)。样品测定结果的相对标准偏差分别为1.80%、2.20%、1.71%(n=6)，平均加标回收率分别为96.49%、100.93%、98.53%。该方法快速，准确、可靠，可为淡豆豉配方颗粒的质量控制提供参考。     

应用制备高效液相色谱同时制备6种大豆异黄酮单体的方法研究

经大孔吸附树脂纯化大豆异黄酮粗提物后,以制备型高效液相色谱法(PHPLC)分离得到高纯度的大豆异黄酮单体。以SHIM-pack PRC-ODS(20 mm×250 mm,5μm)制备柱,考察了流动相组成及流速、进样量对分离度的影响,确定了最佳色谱条件为乙腈-水流动相梯度洗脱,进样量800μL,流速10 mL/min,在120 min内实现了6种异黄酮单体的基线分离及制备。经超高效液相色谱-串联质谱(UPLC-MS/MS)鉴定,6种异黄酮单体依次为大豆苷、黄豆黄苷、染料木苷、大豆素、黄豆黄素、染料木素。6种产品的纯度分别为95.54%、90.14%、100%、100%、96.27%、100%。方法具有简便易行、稳定性好、产品纯度高等特点,适用于大豆异黄酮标准品的制备。     

反相高效液相色谱法测定豆制品中两种异黄酮甙元的含量

建立了反相高效液相色谱测定异黄酮甙元的方法。采用Hypersil BDS C18色谱柱(250×4.6 mm i.d.,5μm),流动相为甲醇(A)、0.5%乙酸水溶液(B),流速为1.0mL/min,柱温为35℃,检测波长为260 nm,进样量为10μL。结果表明:大豆黄素的线性范围为0.0450~0.3150μg,加标回收率为99.05%,相对标准偏差(RSD)为1.31%;染料木黄酮的线性范围为0.0448~0.3136μg,加标回收率为98.82%,RSD为0.50%。方法可用于豆豉及其它大豆制品中异黄酮甙元的测定。     

应用制备高效液相色谱同时制备6种大豆异黄酮单体的方法研究

经大孔吸附树脂纯化大豆异黄酮粗提物后,以制备型高效液相色谱法(PHPLC)分离得到高纯度的大豆异黄酮单体。以SHIM-pack PRC-ODS(20 mm×250 mm,5 μm)制备柱,考察了流动相组成及流速、进样量对分离度的影响,确定了最佳色谱条件为乙腈-水流动相梯度洗脱,进样量800 μL,流速10 mL/min,在120 min内实现了6种异黄酮单体的基线分离及制备。经超高效液相色谱-串联质谱(UPLC-MS/MS)鉴定,6种异黄酮单体依次为大豆苷、黄豆黄苷、染料木苷、大豆素、黄豆黄素、染料木素。6种产品的纯度分别为95.54%、90.14%、100%、100%、96.27%、100%。方法具有简便易行、稳定性好、产品纯度高等特点,适用于大豆异黄酮标准品的制备。     

人尿中异黄酮的高效液相色谱分析

建立了测定人尿中异黄酮组分(大豆苷原、黄豆黄素、雌马酚、染料木黄酮)含量的反相高效液相色谱法。在尿样中加入黄酮作为内标,异黄酮经酶解后在pH=7.0中性条件下用乙酸乙酯(1∶1)提取,然后用0.02%TFA-M eOH-ACN三元梯度洗脱的方法分离异黄酮。在该条件下,大豆苷原、黄豆黄素、雌马酚、染料木黄酮的检出限分别为12.9 nmol/L、13.9 nmol/L、71.6 nmol/L和11.8 nmol/L;回收率均在89%以上。本方法具有测试步骤简单、准确度高、重现性好等优点,适合大批量样品测定。     

反相高效液相色谱法制备纯化大豆异黄酮糖苷

利用制备高效液相色谱法从大豆总异黄酮提取物中制备出了3种大豆异黄酮糖苷。在Nova-Pak HR C18色谱柱(100 mm×25 mm i.d.,6 μm)上,以甲醇-体积分数为0.1%的乙酸水溶液(体积比为23∶77)为流动相,流速为20 mL/min,采用 等度洗脱方式,制备了3种大豆异黄酮糖苷,经质谱分析,确认它们分别为大豆苷、黄豆苷和染料木苷。高效液相色谱分析 表明,所制备的3种化合物的纯度均达到了99%以上。     

高效液相色谱法测定丰城鸡血藤中四种黄酮类化合物

用HPLC法测定了丰城鸡血藤中的大豆黄素、染料木黄酮、异甘草素、美皂异黄酮含量。鸡血藤中黄酮用80%乙醇溶液(含盐酸10%)提取水解。采用Symm etry C18柱,以0.1%磷酸-乙腈为流动相,梯度洗脱,流速0.8 mL.m in-1,紫外双波长检测:λ1=260 nm(大豆黄素、染料木黄酮、美皂异黄酮)和λ2=370 nm(异甘草素)。大豆黄素、染料木黄酮、异甘草素、美皂异黄酮线性范围分别为2.08~208 mg.L-1(r=0.999 9)、0.96~96 mg.L-1(r=0.999 9)、1.12~44.8 mg.L-1(r=0.999 9)、1.16~116 mg.L-1(r=0.999 9),回收率在92%~103%之间,RSD(n=4)为0.75%~4.69%。实验结果表明该法快速、简便、准确可靠。     

11种心血管保健功效成分的反相高效液相色谱测定

建立了11种心血管保健功效成分(天麻素、吡啶甲酸铬、腺苷、大豆苷元、大豆苷、染料木苷、染料木素、红景天苷、葛根素、芦丁、淫羊藿苷)的反相高效液相色谱同时检测法,采用C18柱,在25℃,1 mL/min流速下,以甲醇-KH2PO4二元流动相梯度洗脱,二极管阵列检测器检测。在单因素实验基础上,采用响应曲面法对提取工艺进行了进一步优化。方法在25 min内实现基线分离,线性相关系数r≥0.9985,检出限范围为0.008~0.20μg/mL,日内精密度≤1.5%,日间精密度≤5.0%,回收率在85.0%~98.2%之间。     

β-环糊精修饰区带毛细管电泳法快速测定染料木甙、染料木素、山柰酚和芦丁

通过研究缓冲溶液的pH和浓度、β-环糊精浓度、十二烷基硫酸钠浓度和毛细管温度等条件,建立了一种β-环糊精修饰区带毛细管电泳法快速测定染料木甙、染料木素、山柰酚和芦丁的方法。在优化的条件下,4种物质在6 min内得到良好分离。染料木甙、染料木素、山柰酚和芦丁峰面积和质量浓度分别在2~400,2~300,2~200和5~500 mg.L-1范围内呈线性关系。染料木甙、染料木素、山柰酚和芦丁的检出限分别为0.8,0.6,0.6和1.4 mg.L-1。方法用于分析生槐角和炙槐角样品并做加标回收试验,回收率结果在93.8%~105.2%。     

反相高效液相色谱法快速检测大豆素火腿中5种防腐剂

建立一种快速检测大豆素火腿中的苯甲酸、山梨酸、脱氢乙酸、羟苯甲酯、羟苯乙酯5种防腐剂含量的反相高效液相色谱法。大豆素火腿样品用水-甲醇(2∶1)超声振荡提取,提取液沉淀蛋白后,用0.45μm滤膜过滤,以Angilent Zorbax SB-C18色谱柱分离,梯度洗脱,用二极管阵列检测器检测。5种防腐剂得到良好的分离,质量浓度在0.1~5.0μg/mL范围内与色谱峰面积线性相关,相关系数(r2)均大于0.995,加标回收率为80.8%~115.2%,方法检出限为0.03~0.17μg/mL,定量限为0.10~0.54μg/mL,重复性相对标准偏差为1.35%~3.78%(n=6)。该方法样品处理简单,准确度高,重复性好,检出限低,适用于大豆素火腿中防腐剂含量的监测。     

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.     

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.     

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.     

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.