Naturally occurring phenanthroindolizidine and phenanthroquinolizidine alkaloids (PIAs and PQAs) are two small groups of herbal metabolites sharing a similar pentacyclic structure with a highly oxygenated phenanthrene moiety fused with a saturated or an unsaturated N-heterocycle (indolizidine/quinolizidine moieties). Natural PIAs and PQAs only could be obtained from finite plant families (such as Asclepiadaceae, Lauraceae and Urticaceae families, etc.). Up to date, more than one hundred natural PIAs, while only nine natural PQAs had been described. PIA and PQA analogues have been applied to the development of potent anticancer agents all along because of their excellent cytotoxic activity. However, in the last two decades, other great biological properties, such as anti-inflammatory and antiviral activities were revealed successively by different pharmacological assays. Especially because of their potent antiviral activity against coronavirus (TGEV, SARS CoV and MHV) and tobacco mosaic virus, PIA and PQA analogues have attracted much pharmaceutical attention again, some of them have been used to present interesting targets for total or semi synthesis, and structure–activity relationship (SAR) study for the development of antiviral agents. In this review, natural PIA and PQA analogues obtained in the last two decades with their herbal origins, key spectroscopic characteristics for structural identification, biological activity with possible SARs and application prospects were systematically summarized. We hope this paper can stimulate further investigations on PIA and PQA analogues as an important source for potential drug discovery.
目的观察比较镍铬合金烤瓷冠(Ni-Cr based porcelain-fused-metal crown)修复患牙与牙周健康对照牙龈下菌斑微生物分布、龈沟液总蛋白水平及牙周临床指标的差异。方法选择临床病例13例,前牙区咬合关系基本正常。采用镍铬合金烤瓷冠修复上颌切牙17颗,对侧同名健康天然牙作为对照。烤瓷冠戴入6~8个月后复诊,进行牙周健康状况的临床检查,分别取患牙、对照牙龈沟液及龈下菌斑盐水涂片。龈沟液定量并检测总蛋白水平。龈下菌斑涂片革兰染色,分类计数革兰阴性球菌、杆菌、弯曲菌、螺旋体及革兰阳性球菌、杆菌,共计数200个细菌。结果修复患牙与对照牙比较探诊深度、龈沟出血指数、龈沟液量、龈沟液总蛋白水平、龈下菌斑中革兰阴性杆菌增加,革兰阳性球菌减少,差异均有显著性(P〈0.05)。而菌斑指数及其他形态的细菌数差异无显著性。结论临床合格的镍铬合金烤瓷冠修复亦使患牙龈下菌群分布发生变化,可能是导致患牙牙龈炎症的原因之一;龈沟液量及总蛋白水平增加;牙周临床指标显示不良改变。 相似文献