草珊瑚中的一个新倍半萜内酯

草珊瑚为金粟兰科植物Sarcandra glabra(Thumb.)Nakai的全株,又名接骨金粟兰、肿节风、九节风、九节茶、接骨木等。有清热祛风,散瘀接骨之功效,民间用于治疗肺炎、凤湿性关节炎等。近年来做成制剂治疗溃疡病、癌症等。已报导的化学成分有延胡索酸、琥珀酸及异白蜡树定(isofraxidin)等。今从草珊瑚叶中分得一个新的倍半萜内酯,本文鉴定其结构为(—)-istanbulin A。     

Radioimmunoassay for neuropeptide Y (NPY): chromatographic characterization of immunoreactivity in plasma and tissue extracts

A sensitive and specific radioimmunoassay was developed to determine the occurrence and concentration of neuropeptide Y (NPY) in plasma and tissue extracts. Furthermore, NPY-like immunoreactivity (NPY-Li) was characterized by means of three different chromatographic systems. The NPY antiserum used (NI) did not cross-react with related peptides of the pancreatic polypeptide family except avian pancreatic polypeptide (1% cross-reactivity). Unextracted plasma contained high molecular weight proteins which interfered in the assay. Acid ethanol extraction removed this protein interference allowing a 90% recovery of NPY-Li. The content of NPY-Li in human plasma from healthy subjects was close to or below the detection limit (less than 22 pmol/l). Sympathetic nerve stimulation in the cat increased the output of NPY-Li from the splenic vein suggesting the release of this peptide upon sympathetic activation. The major peak of NPY-Li in spleen extracts and splenic vein plasma co-eluted with synthetic porcine NPY and a minor peak with larger Stokes radius was also present. The present radioimmunoassay enables further studies on the physiological and pathophysiological role of NPY.