Synthesis,Anticancer Activity,Structure-Activity Relationship and Mechanistic Investigations of Falcarindiol Analogues

Forty samples of optically active falcarindiol analogues are synthesized by using the easily available C2 symmetric (R)- and (S)-1,1’-binaphth-2-ol (BINOL) in combination with Ti(OⁱPr)₄, Zn powder and EtI. Their anticancer activities on Hccc-9810, HepG2, MDA-MB-231, Hela, MG-63 and H460 cells are assayed to elucidate their structure-activity relationships. These results showed that the falcarindiol analogue (3R,8S)- 2 i with the terminal double bond has the most potent anti-proliferation effect on Hccc-9810 cells with IC₅₀ value of 0.46 μM. The falcarindiol analogue (3R,8S)- 2 i can induce obvious Hccc-9810 cell apoptosis in a concentration-dependent manner by Hoechst staining and flow cytometry analysis. The proposed mechanism suggests that the falcarindiol analogue (3R,8S)- 2 i increases LDH release and MDA content, and reduces the levels of SOD activity, which lead to the accumulation of oxidative stress and induce apoptosis in Hccc-9810 cells.     

Antioxidant activities of enzymatic‐hydrolysed proteins of dromedary (Camelus dromedarius) colostrum

This work investigated the antioxidant activities of dromedary colostrum proteins before and after hydrolysis by pepsin, trypsin, α‐chymotrypsin, pancreatin and papain. The enzymatic hydrolysis affected the degrees of hydrolysis, electrophoretic profiles, molecular weight distribution and hydrophobic/hydrophilic properties of the generated peptides. The antioxidant activities were evaluated using four antioxidant assays, including 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) radical‐scavenging activities, ferric reducing power and ferrous ion chelating activity. Interestingly, the antioxidant activities of dromedary colostrum proteins were enhanced after enzymatic hydrolysis. The highest antioxidant potential was obtained by pancreatic hydrolysates (P ≤ 0.05). These results suggest that dromedary colostrum protein hydrolysates are an important source of natural antioxidant peptides.     

鲣鱼蛋白肽谱效关系研究

采用鲣鱼为原料,以蛋白质回收率为指标,酶解制备不同工艺条件的样品。通过测定其黄嘌呤氧化酶(XOD)抑制活性、ORAC值、分子质量分布图谱和总氨基酸含量,构建鲣鱼蛋白肽体外化学活性与其分子质量分布图谱、总氨基酸含量图谱之间的谱效关系。结合超高效液相-质谱联用(LC-MS/MS)方法研究其降尿酸肽和抗氧化肽的分布。研究表明,鲣鱼蛋白肽的XOD抑制活性与其ORAC值具有显著的相关性。由多肽分子质量<1ku所占含量的分布区段和脂肪族氨基酸的含量可初步预测鲣鱼蛋白肽的化学活性。质谱分析表明,纯化组分的质谱基峰图在不同时间段的信号强度与鲣鱼蛋白肽的降尿酸活性和抗氧化活性具有明显的相关性。     

食源性致病菌单增李斯特菌检测技术的研究进展

单增李斯特菌是一种兼性厌氧性食源性致病菌,对低温、高盐及消毒剂的抵抗力很强,感染后可能产生低热、高热或其他全身性疾病,免疫力低下的人可能会引起肠胃炎、孕妇流产、早产或死产,甚至会产生脑膜炎。LM的传统检测方法是先进行增菌,再经过氧化氢酶试验、溶血试验、血清学试验等进行鉴定,操作性强、灵敏度高、成本低,但是检测周期长达7 d,无法对目标食物进行快速检测。本文综述了振动光谱学检测方法、免疫学检测方法、分子生物学检测方法、代谢组学检测法、生物传感器等食源性单增李斯特菌的检测方法,并比较其优缺点,以期为食品中LM的快速检测方法的研究提供参考。     

鸭骨骼肌肌钙蛋白I单克隆抗体的制备及其特性

提取鸭骨骼肌肌钙蛋白I（skeletal muscle troponin I，sTnI）用于制备单克隆抗体，并对抗体性能进行 评价。将鸭骨骼肌提取后经十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（sodium dodecyl sulfate polyacrylamide gel electropheresis，SDS-PAGE）测定，取凝胶条带免疫小鼠，融合后经筛选获得分泌抗鸭sTnI的杂交瘤细胞株，用 酶联免疫吸附测定法检测抗体效价、亚型及特异性等特性。结果表明：鸭骨骼肌提取物经SDS-PAGE后出现2 条 颜色较深的条带，取分子质量24 kDa条带用于免疫；筛选后获得2 株单克隆抗体，其中3E7特异性较好，效价在 1∶1.0×105以上，为IgG1亚型，亲和常数（Ka）为5.9×105 L/mol；免疫印迹结果显示，抗体3E7能与鸭骨骼肌提取 物反应，与牛、羊、鸡、鱼骨骼肌提取物无明显反应。