Discovery of Novel Peptidomimetics as Irreversible CHIKV NsP2 Protease Inhibitors Using Quantum Mechanical‐Based Ligand Descriptors

Chikungunya virus (CHIKV) is a mosquito‐borne alphavirus. Recent outbreaks of CHIKV infections have been reported in Asia, Africa, and Europe. The symptoms of CHIKV infection include fever, headache, nausea, vomiting, myalgia, rash, and chronic persistent arthralgia. To date, no vaccines or selective antiviral drugs against this important emerging virus have been reported. In this study, the design, synthesis, and antiviral activity screening of new topographical peptidomimetics revealed three potential prototype agents 3a , 4b, and 5d showing 93–100% maximum inhibition of CHIKV replication in cell‐based assay having EC₉₀ of 8.76–9.57 μg/mL. Intensive molecular modeling studies including covalent docking, lowest unoccupied molecular orbital energies, and the atomic condensed Fukui functions calculations strongly suggested the covalent binding of peptidomimetics 3a , 4b, and 5d to CHIKV nsP2 protease leading to permanent enzyme inactivation via Michael adduct formation between α/β‐unsaturated ketone functionality in our designed peptidomimetics and active site catalytic cysteine1013. Furthermore, small molecular weight peptidomimetics 3a and 4b satisfied the Lipinski rule of five for drug‐likeness and showed promising intestinal absorption and aqueous solubility via computational admet studies making them promising hits for further optimization.     

Ex Vivo and In Situ Evaluation of ‘Dispelling‐Wind’ Chinese Medicine Herb–Drugs on Intestinal Absorption of Chlorogenic Acid

This study aims to investigate the additive or synergistic effects and mechanism of intestinal absorption of extracts from two commonly used ‘dispelling‐wind’ TCM botanical drugs [roots of Angelica dahurica (Hoffm.) Benth. & Hook. f. ex Franch. & Sav. (RAD) and Saposhnikovia divaricata (Turcz.) Schischk. (RSD)] using chlorogenic acid as a marker substance. Ex vivo everted intestinal sac and in situ single pass perfusion methods using rats were employed to investigate the effects of two TCM botanical drugs extracts on the intestinal absorption of chlorogenic acid. Both the extracts of RAD and RSD showed synergistic properties on the intestinal absorption of chlorogenic acid. The verapamil (a P‐gp inhibitor) and intestinal dysbacteriosis model induced by norfloxacin increased the P_app and K_a of intestinal absorption of chlorogenic acid. These synergistic effects on intestinal absorption in a rat model can be correlated with the inhibition of P‐gp and regulation of gut microbiota. This experimental approach has helped to better understand changes in the absorption of chlorogenic acid under different conditions. Copyright © 2015 John Wiley & Sons, Ltd.     

外翻肠囊法研究丹参水提物在大鼠肠内的吸收

研究丹参水提物在大鼠肠内的吸收特征,采用大鼠肠外翻模型,选择丹参水提物中具有代表性的原儿茶醛(protocatechuic aldehyde,PAL)、迷迭香酸(rosmarinic acid,RA)和丹酚酸B(salvianolic acid B,SAB)3种成分为考察对象,建立其超高效液相(UPLC)测定方法并测量其累积吸收量,阐明各成分在不同肠段的吸收特征。实验结果显示,RA,SAB在回肠内为被动吸收,符合一级速度过程;RA,SAB在空肠内低、中剂量时为零级速度过程,高剂量时为一级速度过程,是一种主、被动同时存在的吸收方式;PAL在空肠、回肠内均为被动吸收。小肠不同部位的吸收实验表明,空肠可能为RA和SAB的主要吸收部位,回肠可能为PAL的主要吸收部位。丹参水提物中PAL,RA,SAB 3种成分在小肠均有吸收,但各成分的吸收速率及其机制不尽相同,提示小肠对丹参水提物各成分的吸收具有选择性,并不是简单地半透膜渗透过程。     

外翻肠囊法研究葫芦素B胆盐磷脂混合胶束大鼠肠吸收动力学

研究葫芦素B胆盐磷脂混合胶束(Cu B-SDC/PLC-MMs) 在大鼠不同肠段的吸收动力学特征,并与葫芦素B混悬液进行对比。该研究采用外翻肠囊法制备离体肠吸收模型,高效液相色谱法测定葫芦素B的含量,研究Cu B-SDC/PLC-MMs在大鼠十二指肠、空肠、回肠、结肠的吸收状况,并考察不同质量浓度对肠吸收的影响。结果显示Cu B-SDC/PLC-MMs在不同肠段不同浓度下的吸收均为线性吸收(R²均大于0.9),符合零级吸收,且各肠段的吸收速率常数K_a随着药液中葫芦素B质量浓度的增加而增加,提示其吸收机制可能为被动吸收。Cu B-SDC/PLC-MMs在回肠段吸收最好,且各肠段的吸收均高于葫芦素B混悬液。磷脂胆盐混合胶束能显著增强葫芦素B的肠吸收,该肠吸收的研究为其进一步合理固化提供依据。     

外翻肠囊法评价黄连-大黄药对不同提取工艺中生物碱的肠吸收特性

采用水煎和醇提2种工艺,通过大鼠肠外翻模型评价黄连-大黄配伍药对中生物碱的体外肠吸收特征。以小檗碱、巴马汀、黄连碱、表小檗碱4种主要生物碱成分为代表,采用一测多评法对其进行定量分析,计算吸收速率常数,进而评价2种工艺中,4种生物碱成分在大鼠不同肠段的体外吸收特征。结果显示:2种不同工艺提取物中上述4种成分的高、中、低剂量在小肠段均为线性吸收,R²大于0.99,符合零级吸收速率,小肠部位的吸收速率常数(K_a)表现为水煎组>醇提组。     

基于药物仿生系统分析雷公藤双层片的释药特征

目的: 应用药物溶出/吸收仿生系统(DDASS)研究雷公藤双层片的体外释放和跨膜透过特征,并考察其与该制剂在Beagle犬体内过程特征的体内外相关性。 方法: 以雷公藤定碱为指标成分,考察雷公藤片及雷公藤双层片在转篮法中的释药特征,研究其在DDASS模型体外连续、动态、实时的释放和跨膜透过特征;考察2种制剂在Beagle犬体内的药代动力学特征及其相应的体内外相关性。 结果: 雷公藤双层片中雷公藤定碱在转篮法和DDASS中释药过程均符合一级动力学方程,呈溶蚀释放机制。与雷公藤片相比,雷公藤双层片中雷公藤定碱在Beagle犬体内具有明显的缓释作用,相对生物利用度174.88%。在DDASS模型释放/跨膜透过特征与Beagle犬体内吸收特征存在极显著的相关性,优于转篮法溶出特征与Beagle犬体内吸收特征之间的相关性。 结论: DDASS模型可有效评价雷公藤双层片中雷公藤定碱的体外释放及体内吸收动力学特征。     

星点设计-效应面法优选糖肾宁颗粒的成型工艺

目的:优选糖肾宁颗粒的成型工艺。方法:以成型性、溶解性、吸湿性及吸湿后外观为指标,通过单因素试验确定辅料种类,采用星点设计-效应面法优选辅料配合比例、用量、润湿剂浓度等成型工艺参数。结果:最佳成型工艺为提取物-糊精-甘露醇(4∶3∶3),加入75%乙醇制软材,干燥温度55℃。总评"归一值"(overall desirability,OD)平均值0.786,与模型方程理论预测值(0.78)的偏差0.8%。制备的颗粒剂合格收率88.44%,溶化时间0.5 min,临界相对湿度约70%,休止角34.8度,堆密度0.49 g·m L-1。结论:优选的成型工艺稳定可行,制备的糖肾宁颗粒具有合格率高、溶化性好、抗吸湿性强的特征,为该制剂的大生产提供参考。     

改装滚轮微针促进人增生性瘢痕皮肤对醋酸曲安奈德的吸收

目的考察改装滚轮微针在人增生性瘢痕皮肤中对醋酸曲安奈德的促透作用。方法采用亚甲蓝和H-E染色法观察不同针长的微针刺入人增生性瘢痕皮肤的形态;建立高效液相色谱法测定醋酸曲安奈德含量;采用洗脱法、匀浆法分别考察给药1、12h时增生性瘢痕皮肤醋酸曲安奈德在体吸收特性;采用经皮水分流失(TEWL)测量法、激光多普勒血流量法考察其皮肤刺激性。结果所优选的针长500μm滚轮微针能有效穿透角质层,形成的微孔分布相对均匀;微针处理1、12h后,分别有27.42%、60.64%药物吸收进入皮肤。给药12h,皮内注射醋酸曲安奈德皮肤中滞留药量较给药1h下降至45.98%,而微针、直接涂布醋酸曲安奈德乳膏分别增加到2.73、4.18倍,微针组皮肤中滞留药量是直接涂布乳膏组的3.56倍(P<0.05)。皮内注射12h皮肤药量分布并不均匀,均值为(4.83±5.51)μg,微针组均值为(0.93±0.14)μg,分布相对均匀。TEWL法显示微针处理与皮内注射的皮肤刺激性差异无统计学意义,但激光多普勒血流量法显示皮内注射的皮肤刺激性是微针处理的8.40倍。结论改装滚轮微针处理后涂布醋酸曲安奈德乳膏较皮内注射醋酸曲安奈德在人增生性瘢痕中吸收均匀、皮肤刺激性较小,但其瘢痕治疗效果尚有待进一步验证。     

大孔吸附树脂纯化胡芦巴提取物中4-羟基异亮氨酸的研究

目的：优选出纯化胡芦巴提取物中4-羟基异亮氨酸的大孔树脂,并确定相应的最佳工艺条件。方法：以胡芦巴提取物中4-羟基异亮氨酸含量为评价指标,采用柱前衍生-高效液相色谱法检测24种型号大孔树脂静态吸附试验前后4-羟基异亮氨酸（4-HIL）含量变化来考察其纯化效果。结果：24种型号大孔树脂对4-HIL吸附容量均很低,但ADS-5型大孔树脂可用于胡芦巴提取物中4-HIL初步纯化,最佳工艺条件为采用ADS-5型大孔树脂,上样液浓度为0.04g?mL^-1,上样量为60mL,上样流速为2BV?h^-1,收集续滤液蒸干可得。结论：ADS-5大孔树脂可用于其初步除杂。     

Metabolism of Chinese Materia Medica in Gut Microbiota and Its Biological Effects

The drug metabolism in gut microbiota draws increasing attentions. After interacting with the gut bacteria, the biological effects of drugs might be altered, leading to toxicity or detoxification, production of potential bioactivities, regulating intestinal absorption, etc. In this review, we will focus on the metabolism of Chinese materia medica(CMM) in mammal gut microbiota and its biological effects to learn the interaction between gut bacteria and drugs through oral route in CMM.