毛细管电泳高频电导法测定青风藤药材及制剂中青藤碱的含量

青藤碱（Sinomenine)是具有镇痛、消炎、怯风除湿、活血化瘀、增强免疫和抗癌等作用的生物碱单体(结构式见Scheme 1),它存在于防己科植物青风藤和毛青藤的干燥藤茎中,在临床上,已有正青风痛宁片、盐酸青藤碱注射液和毛青藤总片等制剂,用于治疗各种急慢性风湿痛、肿胀以及心率失常等病症．青藤碱含量测定常用非水滴定法,但该法专属性差,实验结果易偏高．此外,     

薄层色谱法测定青藤碱血浆浓度

青藤碱(Sinomenine)系从防已科植物毛青藤(Sinomenium acutum Var.cinereum(Diels) Rehd)中提取的生物碱。经药理实验证实,其具有镇痛、消炎、降压、抗心律失常等作用。为了进行药物动力学研究以及临床药物监测,本实验研究了应用薄层快速分离展开血浆中青藤碱,以锯齿形和直线形薄层扫描法测定其浓度。该方法简便,快速,灵敏度较高。     

盐酸青藤碱在铅笔芯电极上的电化学性质及应用

研究了盐酸青藤碱在1B、2B、4B铅笔芯电极上的电化学行为,发现盐酸青藤碱在2B铅笔芯电极上具有良好的电化学行为。通过考察pH、底液、温度、静置时间等对盐酸青藤碱在2B铅笔芯电极上的电化学行为的影响,建立了以2B铅笔芯电极为工作电极测定盐酸青藤碱的电化学分析新方法。该方法氧化峰电流与盐酸青藤碱在0.146~36.585mg/L范围内呈良好的线性关系,相关系数r=0.9948,检出限为0.049mg/L,可应用于测定盐酸青藤碱肠溶片中盐酸青藤碱含量。进一步探讨了盐酸青藤碱在2B铅笔芯电极上的电化学反应机理。     

β-环糊精修饰碳糊电极测定盐酸青藤碱

研究盐酸青藤碱在β-环糊精(β-CD)修饰碳糊电极上的电化学行为,在此基础上建立了测定盐酸青藤碱的电化学新方法。盐酸青藤碱在β-CD修饰碳糊电极上是受吸附控制的电化学反应过程,在p H 6.6的柠檬酸–柠檬酸钠底液中,盐酸青藤碱在β-CD修饰碳糊电极上产生一对良好的氧化还原峰,峰电位分别为0.458 V和0.086 V。氧化峰电流与盐酸青藤碱的质量浓度在3.658 5~91.462 5 mg/L范围内呈良好线性关系,线性相关系数为0.995 4,检出限为1.229 3 mg/L。该方法应用于正清风痛宁片中盐酸青藤碱含量的测定,测定结果的相对标准偏差为5.82%(n=7),回收率在95.7%~107.4%之间。该方法简便、快速,结果准确,可用于盐酸青藤碱的测定。     

青风藤有效化学成分与环氧合酶的对接研究

将青风藤中23个有效化学成分与COX-2酶对接,有四个化合物具有较低的结合自由能,其中以青藤碱为最低.进一步将这四个化合物与COX-1酶对接,发现这四个化合物与COX-1酶结合能力较弱,预示这四个化合物具有选择性抑制COX-2酶的能力.对青藤碱和COX-2以及COX-1酶的结合模式进行分析,发现青藤碱主要结合于COX-2酶的S′口袋,而COX-1酶的S′结合口袋中第523号残基由COX-2酶中的Val523变成了体积较大的Ile523,使得COX-1酶的S′结合口袋相对COX-2酶的结合口袋要小,从而导致青藤碱分子不能进入COX-1酶S′结合口袋.这成功解释了青藤碱选择性抑制COX-2酶的原因,与早期有关文献报道的实验结果相吻合,充分表明了对接模型的合理性,青藤碱等化合物可作为设计COX-2酶选择性抑制剂的先导化合物.     

基于多源数据融合技术的盐酸青藤碱制备工艺一致性评价方法研究

为考察使用不同提取溶剂制得的盐酸青藤碱的质量差异,探究青藤碱提取工艺变更的可行性,该文运用近红外光谱技术、拉曼光谱技术结合多源数据融合技术,对苯提取和酸水渗漉-氯仿萃取后所制的盐酸青藤碱样品的质量进行系统评价,比较了两种溶剂对产品质量的潜在影响.在低、中、高水平3种融合模式下,分别利用相似度匹配值(SMV)、Hotel...     

青藤碱N-四氮唑和N-噁二唑杂环衍生物的设计与合成

建立了两个新的合成路线,在青藤碱D环的N原子上构建了N-四氮唑和N-1,3,4-噁二唑取代的杂环衍生物,共获得了34个新的青藤碱杂环衍生物.以青藤碱为原料,通过溴化氰取代生成N-CN青藤碱,再与叠氮化钠通过1,3-偶极环加成反应,生成了N-四氮唑青藤碱.苄氯类试剂与四氮唑发生取代反应生成青藤碱N-四氮唑杂环衍生物;酰氯类试剂与四氮唑通过酰化反应和惠思根重排反应生成青藤碱N-1,3,4-噁二唑杂环衍生物.方法简单,条件温和,产率优良.此工作为天然产物结构修饰提供了新的方法,扩大了青藤碱衍生物库,为潜在的青藤碱药物活性研究提供了药物分子设计方法.     

液相色谱-质谱联用测定乌头碱血药浓度及其药代动力学参数的方法学研究

乌头碱(aconitine)是存在于乌头属多种植物中的一种双酯二萜生物碱,具有镇痛、抗炎、抗癫痫、抗肿瘤、提高免疫功能等多种生理活性,但因其具有强烈的心脏毒性和神经毒性,安全系数小,治疗剂量与中毒剂量接近(小鼠LD501.8mg／kg,op;人绝对致死量为2～5mg),限制了对该化合物作为药用的进一步研究,目前仅将其作为致心率失常模型的工具药使用,尚未见其药代动力学的报道。在本文中首次应用液相色谱-质谱联用法对乌头碱在大鼠体内的药代动力学进行了研究。     

从青藤碱制备具有(＋)-C-Normorphinan骨架的化合物

对青藤碱进行Mitsunobu甲基化反应, 得到O-甲基青藤碱(2); 2经过酸性水解、硼氢化还原以及高碘酸钠氧化开环得到O-甲基青藤碱二醛(5); 在哌啶存在下对5进行羟醛缩合反应, 区域选择性地闭环生成具有(＋)-C-normorphinan骨架的化合物(8S,12S,13R)-6,7-didehydro-3,4-dimethoxy-16-methyl-C-normorphinan-7-carboxaldehyde (7); 经过以上五步反应, 7的总收率约35%. 对7进行硼氢化还原得到化合物8; 化合物8以醋酐进行酯化得到化合物9. 化合物7以5% Pd/C为催化剂、1.01×105 Pa下与氢气作用发生双键氢化反应, 立体定向地得到化合物10, 从化合物10出发获得化合物11和12. 通过对化合物11的1H NMR, 13C NMR, 2D-NMR及NOESY等核磁共振分析确定化合物10, 11和12具有7S绝对构型.     

薄层-胶束荧光法测定北豆根中的两种生物碱

本文选用恰当的薄层色谱体系,对秦巴山区所产北豆根中的生物碱类物质粉防已碱和青藤碱进行分离,并用胶束荧光法进行定量,按本文设计的实验方案测出粉防已碱和青藤碱的含量分别为9.94×10~(-3),1.07×10~(-2)g/g,检出限分别为3.5×10~(-12),5.85×10~(-11)g/mL,回收率分别为93.5%,97.2%.     

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%.     

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.     

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

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.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.