荜茇宁与牛血清白蛋白相互作用的研究

用荧光光谱及紫外光谱法研究生理条件下荜茇宁与生物大分子牛血清白蛋白(BSA)的相互作用.实验结果表明,荜茇宁与BSA形成基念复合物从而猝火BSA的内源性荧光,猝灭原因主要为静态猝灭和非辐射能量转移.根据Forster 偶极-偶极非辐射能量转移理论,确定荜茇宁与BSA有较强的相互作用,可以被蛋白质所储存和运输.荜茇宁与B...     

荜茇宁对小鼠酒精性脂肪肝的预防作用

目的：探讨荜茇成分荜茇宁（piperlonguminine,GBN）对小鼠酒精性脂肪肝肝损伤的预防作用。方法：将成年雄性昆明小鼠随机分为空白对照组、酒精性脂肪肝模型组以及GBN（低、高）剂量组。空白对照组以基础饲料喂养,其余各组以高脂饲料喂养并每天用白酒按0.8 mL/30 g灌胃;GBN低剂量（10 mg/（kg•d））和高剂量组（40 mg/（kg•d））组分别按设计的药物和剂量给予小鼠灌胃,给药体积为0.8 mL/30 g体质量,空白对照组、模型组给予相同体积的水灌胃,连续给药6 周。于实验第6周末,测定各组小鼠体质量、肝脏指数,检测血清丙氨酸氨基转移酶（alanine aminotransferase,ALT）、天冬氨酸氨基转移酶（aspartate aminotransferase,AST）活力、总胆固醇（total cholesterol,TC）和甘油三酯（triglyceride,TG）含量,并做肝脏病理学检查。结果：GBN低、高剂量组肝脏指数分别为（4.42±0.50）%、（4.53±0.44）%,与模型组比较均显著降低;血清ALT与AST活力极显著降低（P＜0.01）;血清TC与TG含量极显著降低（P＜0.01）;同时病理组织学显示GBN能明显改善酒精性脂肪肝小鼠的肝细胞脂肪变性。结论：GBN够有效预防酒精性脂肪肝的发生或发展。     

Insecticidal defenses of Piperaceae from the neotropics

Insecticidal and growth-reducing properties of extracts of 14 species of American neotropical Piperaceae were investigated by inclusion in diets of a polyphagous lepidopteran, the European corn borer,Ostrinia nubilalis. Nutritional indices suggested most extracts acted by postdigestive toxicity.Piper aduncum, P. tuberculatum, andP. decurrens were among the most active species and were subjected to bioassay-guided isolation of the active components. Dillapiol was isolated from the active fraction ofP. aduncum, piperlonguminine was isolated fromP. tuberculatum, and a novel neolignan fromP. decurrens. The results support other studies on Asian and AfricanPiper species, which suggest that lignans and isobutyl amides are the active defence compounds in this family.