Emodin–phospholipid complex

Developing the drugs as amphiphilic lipid complexes is a potential approach for improving therapeutic efficacy of the drugs by increasing solubility, reducing drug crystallinity, modifying dissolution behavior (sustained or controlled release), and improving bioavailability. Emodin (1,3,8-trihydroxy-6-methylanthraquinone), an anthranoid derivative, shows several biological effects like antimicrobial, antidiuretic, anti-cancerous, and potent antioxidant but due to poor solubility, the dissolution restrains its valuable importance. To overcome this limitation, the emodin–phospholipid complex was developed and investigated by thermal analysis (differential scanning calorimetry), crystallographic (X-ray diffractography), surface morphology (scanning electron microscopy), spectroscopic methods (FT-IR, ¹H-NMR), solubility, and the dissolution (in vitro drug release) study. The phospholipid complex of emodin was found, fluffy and porous with rough surface morphology in the SEM. FT-IR, ¹H-NMR, DSC, and X-RPD data confirmed the formation of the complex. The water and n-octanol solubility of emodin was improved from 2.25 to 9.97 and 53.45 to 77.62 μg/ml, respectively, in the prepared complex. The improved dissolution was shown by the phospholipid complex. Based on the results of the study, it can be concluded that the phospholipid complex may be considered as promising drug delivery system for improving the overall absorption and bioavailability of the emodin molecule.     

An Efficient Synthesis of O-Methyl Protected Emodin Aldehyde and Emodin Nitrile

An efficient synthesis of tri-O-methylemodin aldehyde was achieved via bromination of tri-O-methylemodin utilizing N-bromosuccinimide yielding the monobromo and dibromo derivatives. Sommelet reaction of the monobromomethyl derivative as well as hydrolysis of the dibromomethyl analog with aqueous silver nitrate afforded the protected aldehyde in good yield. Accordingly, both bromo derivatives can be used even when they are obtained as a mixture of the bromination reaction, which could not be controlled easily to yield the bromo products selectively. From the aldehyde the tri-O-methylemodin nitrile was prepared in a one-pot reaction using hydroxylamine-O-sulfonic acid.     

大黄素衍生物的合成及细胞毒性研究

以天然大黄素为母体, 经化学修饰得到一系列新的含氮衍生物6～14. 通过¹H NMR, IR, MS和元素分析确定了结构. 选择口腔底癌(KB)和乳腺癌(MFC-7)两种人癌细胞株, 采用标准MTT法测定了这类大黄素衍生物的细胞毒性. 研究表明大多数衍生物都有较强的抗癌活性, 其中位置异构体7a和7b的混合物表现出最强的活性, 与母体大黄素相比较, 活性分别提高了174倍(KB)和133倍(MFC-7).     

大黄素的吸附溶出伏安研究

研究了大黄素在甲醇、二氧六环和水的混合溶剂中以１％硼砂为支持电解质在静汞电极上的吸附伏安行为。建立了用微分脉冲吸附溶出伏安法测定其含量的新方法。在－０３０Ｖ（ｖｓＡｇ／ＡｇＣｌ）电位下吸附富集，可得一灵敏的还原溶出峰，峰电位－０７５Ｖ，浓度在５×１０－８～５×１０－９ｍｏｌ／Ｌ范围内与峰电流具有良好的线性关系，最低检出限为１×１０－９ｍｏｌ／Ｌ。该法用于含有大黄素体系的测定简便、快速、可靠。     

反相高效液相色谱法同时测定决明子中芦荟大黄素和大黄素

用反相高效液相色谱法分离并测定了决明子中芦荟大黄素和大黄素，建立了该中药中芦荟大黄素、大黄素分离、测定的色谱方法。色谱条件：ＯＤＳ柱，甲醇－水（８０∶２０Ｖ／Ｖ）为流动相，检测波长２２３ｎｍ。本研究为决明子的质量评价提供了科学依据。     

大黄素的电化学氧化还原机理研究

本文利用循环伏安法(CV)、红外光谱循环伏吸法(CVA)和导数循环伏吸法(DCVA)研究大黄素(Q)在乙腈溶剂中的电子转移机理.Q的还原过程中阴离子自由基Q^?-会结合中性分子Q生成二聚物Q₂^?-.Q₂^?-在更负的电位下进一步还原为Q₂^2-.当扫描范围为-0.2 ~ -2.0 V时,经过一个循环伏安过程,在扫描结束物质并没有回到反应物Q,而是Q₂^2-. Q₂^2-会继续发生电化学反应,经历两步一电子过程,分别生成Q₂^3-. 和Q₂^4-.,对应CV图中峰C₃和C₄.当扫描范围扩大至1.0~-2.0 V时,在更正的电位下,观察到两个新的氧化峰A₁和A₂,该范围内的三圈扫描结果表明,在扫描结束物质重新氧化回到Q.当扫描范围缩小至0.3 ~ -1.4 V,A2峰随着扫描圈数的增加而增大,与A2峰对应的氧化产物Q₂^?-在溶液中不断积累.A1峰对应于Q₂^?-氧化回到Q.     

Combination of Methotrexate and Emodin Interacting with DNA

Abstract

The study on interaction of dsDNA with the combination of methotrexate and emodin demonstrated that emodin and methotrexate can form intermolecular hydrogen bonds that enhance the anticancer effect of methotrexate and decrease the side effects. The results show that a combination of synthetic and herbal medicines in treating cancer is very effective and can be used to select other effective combination uses of antitumor drugs. At the same time, according to different interaction models of methotrexate with dsDNA and ssDNA, methotrexate can be used to discriminate between dsDNA and ssDNA in a DNA biosensor as hybridization indicator.     

大黄素分子印迹整体柱的合成及性能表征

以大黄素分子为模板,甲基丙烯酸为单体,乙二醇二甲基丙烯酸酯为交联剂,甲苯和十二醇为混合致孔剂,用原位聚合法合成了一系列分子印迹整体柱,并考察了模板分子在不同条件下合成的印迹聚合物及参考聚合物上保留因子的变化规律.在优化的合成条件下制得的分子印迹整体柱能有效地分离大黄素及其类似物.对分子印迹聚合物及参比聚合物的孔度分析数据表明:分子印迹聚合物中具有两种不同的孔度分布,而参比聚合物中只有一种.     

大黄素衍生物的合成及抗癌活性

通过对大黄素的C6位进行化学修饰, 设计合成了7个含氮杂环的大黄素衍生物和3个含季铵盐基团的大黄素衍生物. 通过红外光谱、 ¹H NMR和质谱表征了所制备化合物的结构, 并测试了它们对白血病细胞Molt-4和淋巴瘤细胞CA46的体外抑制活性. 其中化合物8, 9a+9b, 20a, 20b和20c均显示出比大黄素更高的抗癌活性, 表明苯并咪唑基团和季铵盐基团是大黄素提高抗癌活性的有效药效团.     

大黄素的化学合成及结构修饰研究进展

大黄素是中药大黄的主要成分,也存在于虎杖、芦荟等药用植物中,是分布广泛的一种羟基蒽醌类化合物.其药理作用表现为抗肿瘤、扩张血管、抗菌、导泻、利尿等,具有很好的临床应用价值.结合本研究组的工作综述了大黄素的化学合成方法、结构修饰和生物活性等方面的新进展.     

循环伏安法研究大黄素的电化学行为

采用循环伏安法研究了大黄素在滴汞电极上的电化学行为,应用线性扫描法提出了药用植物大黄中大黄素不需分离的直接测定方法。大黄素在pH 5.72 B-R缓冲溶液中,在-0.434 V(vs.Ag/AgCl)处产生一灵敏的极谱峰,峰电流与大黄素浓度在1×10-6~1.5×10-5mol.L-1范围内呈线性关系。试验结果表明:该体系属具有吸附性的准可逆过程体系。     

Rohrleitungen aus Glas

Ohne ZusammenfassungDer Text erscheint ausführlich in Die Chemische Fabrik, 1938, Heft 49/50. — Dieser Vortrag trat an die Stelle des von Dr. G. Schott angemeldeten Vortrages: Technische Anwendung von Jenaer Glas in der chemischen Industrie.