羟丙基-β-环糊精富集提取射干中异黄酮

利用羟丙基-β-环糊精（HP-β-CD）水溶液对中药射干（Belamcanda chinensis）中功能性成分异黄酮类物质富集提取。 考察了时间、温度等对提取效果的影响,确定了优化的工艺条件;结合紫外光谱、高效液相色谱和液相色谱-质谱联用等检测手段,测定提取源总异黄酮含量及黄酮种类。 在此条件下,对异黄酮类物质的提取总量较纯水浸取提高1倍,鸢尾苷提取量可提高2倍。     

葛花中异黄酮类化学成分的RRLC-Q-TOF MS/MS研究

采用快速分离液相色谱-四极杆-飞行时间质谱联用(RRLC-Q-TOF MS/MS)技术对葛花中的异黄酮类成分进行了研究, 得到了相应化合物的保留时间、 分子量及结构信息. 研究结果表明, 葛花水提取液的主要成分为异黄酮类及其苷类化合物, 并含有皂苷类和酚类化合物. 在葛花中首次发现同属植物狐尾葛特有化合物Alopecuroides A和葛根中的化合物3'-甲氧基大豆苷元-7-O-甲醚. 讨论了异黄酮类化合物的质谱碎裂途径及规律.     

大豆素的结构修饰

大豆素是从大豆中分离出的异黄酮类成分,也是中药葛根中的活性成分之一.它具有雌激素样作用,用于治疗骨质疏松症、降低胆固醇等.异戊烯取代的某些黄酮类化合物具有很强的雌激素样作用,且有很强的抗真菌活性及细胞毒作用[1～3],因此,我们以大豆素为先导物与溴代异戊烯在碳酸钾存在下室温进行醚化反应,然后以N,N-二乙基苯胺为溶剂微波加热进行Claisen重排反应,得到几个异戊烯基取代的异黄酮类衍生物,以便进一步研究它们的生物活性.     

加压毛细管电色谱测定葛根中三种异黄酮类化合物

建立了加压毛细管电色谱(pCEC)检测葛根中异黄酮类化合物葛根素、大豆苷、大豆苷元的方法。采用C18毛细管色谱柱,以NaH2PO4缓冲盐水溶液和甲醇为流动相,优化流动相比例、流动相流速、NaH2PO4缓冲盐水溶液浓度和pH、分离电压等色谱条件。结果表明,在流动相为17.5 mmol/L NaH2PO4缓冲盐水溶液(pH 4.0):甲醇=55:45(V/V),分离电压3 kV,流动相流速80μL/min,检测波长250 nm的条件下,葛根素、大豆苷、大豆苷元质量浓度在200～1000μg/mL范围内线性关系良好,相关系数在0.9960～0.9982之间,平均回收率在98.6%～100.9%之间,RSD为3.1%～3.5%之间。该方法已用于葛根中异黄酮类物质的分离检测。     

液质联用分析葛根提取物及中药片剂中异黄酮类化合物

采用反相C18毛细管液相色谱柱,以乙腈(含0.1%(体积分数,下同)三氟乙酸)和水(含0.1%三氟乙酸)为流动相梯度洗脱,在26 min内分离了葛根异黄酮提取物以及愈风宁心片中的主要成分。采用毛细管液相色谱/四极杆飞行时间串联质谱仪对葛根提取物以及片剂中的几种主要异黄酮类化合物做了结构分析,发现葛根素是主成分(提取物中其平均质量分数是13.32%;片剂中每片含量19.28~24.34 mg)。对微量未知化合物,用它们的子离子谱图与已知化合物的谱图比较,推测其成分为3′-甲氧基葛根素和3′-甲氧基大豆苷。     

胶束毛细管电泳同时分离测定葛根及其制剂中的5种异黄酮

建立了一种新的胶束毛细管电泳方法,用于同时分离检测葛根素、大豆苷、 3’-甲氧基葛根素、 3’-羟基葛根素和4’-甲氧基葛根素5种异黄酮。优化的实验条件为：以40 mmol/LNa₂B₄O₇+4 mmol/L NaOH(pH 9.62)为运行缓冲溶液,5%(V/V)甲醇和14 mmol/L的十二烷基磺酸钠(SDS)为添加剂,分离电压22 kV,检测波长250 nm,进样时间5 s。在优化条件下,葛根素、大豆苷、 3’-甲氧基葛根素、 3’-羟基葛根素和4’-甲氧基葛根素5种异黄酮可在14 min内完成分离检测,各目标组分的峰面积与其浓度之间的线性关系良好。该方法用于葛根及其制剂中5种异黄酮的定量分析,加标回收率范围为95.6%～104.8%,相对标准偏差不超过4.0%。     

野菊花中蒙花苷的提取及其含量的测定

以乙醇为溶剂,采用溶剂回流提取方法结合微波、超声波辅助提取野菊花中的蒙花苷,用HPLC法测定。采用正交试验法研究了野菊花中蒙花苷提取和HPLC实验条件,并比较了采用不同的微波和超声波辅助提取方式对蒙花苷提取结果的影响。结果表明,溶剂回流提取最佳条件为:提取温度80℃,回流时间2.0 h,溶剂用量40 mL。应用于安徽等产地野菊花中蒙花苷的提取分析,结果显示,广东和广西产地药材含量明显更高;在相同的实验条件下采用微波辅助提取可使蒙花苷达到较高的提取率,特别是采用微波辐射药材后再进行溶剂回流提取,提取时间可缩短一半。     

成都生物所发明判断大豆异黄酮糖苷水解的方法

不久前,中科院成都生物所发明的“一种判断大豆异黄酮糖苷是否水解或水解程度的方法”获得国家发明专利授权。大豆异黄酮是大豆等豆科植物生长过程中形成的一类次生代谢产物,具有多种生理功能,它不仅参与调节植物的生长活动,还能对人体发挥有益的生理调节作用。为了得到生物活性高的大豆异黄酮苷元,在工业上大多以大豆豆饼或豆粕为底物,采用酸水解或微生物转化的方法将糖苷转化为苷元。此前,判断大豆异黄酮糖苷是否水解及水解程度,通常是通过水解前后苷元含量的变化来判断,此方法操作过程相对繁琐。成都生物所发明的该种方法,通过商品豆粕经乙醇提取、提取液抽滤除杂质、减压蒸馏浓缩至无乙醇得水相、以水相为底物进行水解、用乙酸乙酯从水解液中萃取大豆异黄酮苷元、萃取液减压浓缩、浓缩相进行薄层层析、在紫外灯下观察层析结果,以此判断大豆异黄酮糖苷是否水解或水解的程度。该方法具有快速、准确等优点,具有良好的应用前景。(仪器信息网成都生物所发明判断大豆异黄酮糖苷水解的方法     

小儿肺热咳喘口服液中苦杏仁苷的提取工艺研究

以小儿肺热咳喘口服液为原料,苦杏仁苷含量为检测指标,以提取溶剂、提取时间、溶剂用量、提取方法为因素,采用四因素三水平L9(34)正交设计优选出苦杏仁苷的最佳提取条件。结果表明,最佳提取条件用30 m L甲醇回流提取30 min,提取率可达98.2%。提取工艺合理可行,稳定可靠。     

HPLC-DAD结合交替三线性分解二阶校正方法进行中药葛根中主要有效成分同时测定

应用高效液相色谱-二极管阵列联用仪(HPLC-DAD)结合基于交替三线性分解(ATLD)算法的二阶校正方法快速测定了中药葛根样中主要活性成分葛根素、大豆苷和大豆苷元的含量,实现了同时定量分析.色谱条件:甲醇-水(体积比为53∶47),检测波长范围为190～380nm,柱温为30℃,流速为1.0mL/min,进样量为20.0μL.预测的实际样中三种目标分析组分葛根素、大豆苷、大豆苷元的含量分别为(0.465±0.023),(0.553±0.015)和(0.098±0.005)mg/g,它们的加标回收率分别为(101.1±3.2)%,(100.4±6.4)%和(100.1±4.9)%.     

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.