Palladium (0) Nanoparticles: A Novel and Reusable Catalyst for the Synthesis of Various Pyran Derivatives

A ligand free, Palladium nanoparticles catalyzed synthesis of pyran derivatives using C-H activated compound, malononitrile and aryl aldehyde via Knoevenagel condensation followed by Michael addition reaction using Palladium nanoparticles as catalyst in one-pot is described herein. The advantages of this method lie in its simplicity, low catalyst loading, cost effectiveness and easy to handle. The Palladium Nanoparticles can be reused without loss of activity even after recycling four times. The palladium nanoparticles were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM). The present method also allows us to synthesize highly functionalized title compounds from simple and readily available inputs.

老鼠生物碱A羧酸衍生物抗炎镇痛活性的研究

目的研究老鼠簕生物碱A羧酸衍生物的抗炎镇痛活性,筛选具有良好抗炎、镇痛药理活性的老鼠簕生物碱A衍生物。方法采用二甲苯致小鼠耳肿胀模型评价羧酸衍生物的抗炎活性,采用醋酸诱导的小鼠扭体法和热板法评价羧酸衍生物的镇痛活性。结果二甲苯致小鼠耳肿胀实验显示,老鼠簕生物碱A羧酸8个化合物对小鼠耳肿胀均有抑制作用,其中化合物2、化合物3、化合物4、化合物8对小鼠耳肿胀的抑制作用与阿司匹林相当;化合物1、化合物5、化合物6、化合物7对小鼠耳肿胀的抑制作用比阿司匹林小。热板法镇痛实验显示,8个衍生物对热刺激引起的疼痛均无抑制作用。小鼠醋酸扭体实验显示,8个化合物对醋酸所致小鼠的扭体反应均有抑制作用,其中化合物3的外周镇痛作用比阿司匹林强,其他7个化合物发挥的外周镇痛作用与阿司匹林相当。结论化合物2、化合物3、化合物4和化合物8等4个羧酸衍生物具有较好的抗炎和镇痛活性,值得进一步研究。