Anti-proliferative activity of phlorotannin extracts from brown algae Laminaria japonica Aresch

In this study,we evaluated the anti-proliferative activity of phlorotannins derived from brown algae Laminaria japonica Aresch extracts on the human hepatocellular carcinoma cell (BEL-7402) and on murine leukemic cells (P388) by MTT assay.Cells were incubated with 100 μg/mL of the phlorotannin extract (PE) for 48 h.The inhibitory rate of PE on BEL-7402 and P388 cells was 30.20±1.16% and 43.44±1.86%,respectively,and the half-inhibitory concentration of PE (IC50) on P388 and BEL-7402 cells was 120 μg/mL and >...     

Anti-proliferative activity of phlorotannin extracts from brown algae Laminaria japonica Aresch

In this study, we evaluated the anti-proliferative activity of phlorotannins derived from brown algae Laminaria japonica Aresch extracts on the human hepatocellular carcinoma cell (BEL-7402) and on murine leukemic cells (P388) by MTT assay. Cells were incubated with 100 μg/mL of the phlorotannin extract (PE) for 48 h. The inhibitory rate of PE on BEL-7402 and P388 cells was 30.20±1.16% and 43.44±1.86%, respectively, and the half-inhibitory concentration of PE (IC₅₀) on P388 and BEL-7402 cells was 120 μg/mL and >200 μg/mL, respectively. Microscopic observation shows that the morphologic features of tumor cells treated with PE and 5-fluorouracil are markedly different from the normal control group. The inhibitory rate of fraction A₂ isolated from PE by sephadex LH-20 for BEL-7402 and P388 cells at the sample concentration of 70.42 μg/mL was 61.96±7.02% and 40.47±8.70%, respectively. The apoptosis peak for fraction A₂ was the most profound of all fractions used in the flow cytometry assay. The results indicate that the anti-proliferative of this algal extract is associated with the total phlorotannin content.     

风味蛋白酶水解金枪鱼(Eleotridae)碎肉蛋白的动力学模型研究

本文对风味蛋白酶水解金枪鱼碎肉蛋白的特性进行了研究, 采用测定不同底物浓度下的瞬时速率的方法来测定米氏常数Km值, 探讨了水解时间、底物浓度与水解速率及水解度的关系, 并拟合出水解时间与水解度之间关系的数学模型。结果表明: 该酶解反应的米氏常数Km=0.0098, 酶解过程的动力学方程为DH = 8.621 ln (1 + 0.053t?0.0003[S]t)。通过动力学方程求得当酶浓度为200U/g时, 最大临界初始底物浓度[S]为176.81g/L。验证实验表明此模型的可信度高(R2=0.99), 实际值与拟合值基本吻合, 可以用于模拟风味蛋白酶水解金枪鱼碎肉蛋白制备活性肽的反应过程和酶解条件的工艺优化。     

双酶分步水解金枪鱼(Eleotridae)碎肉制备高F值酶解液的工艺研究

以金枪鱼碎肉为原料, 采用双酶分步水解法制备高F值酶解液, 通过Box-Behnken试验设计, 分别确定两步酶解的最佳条件, 酶解液经活性炭静态吸附去除游离芳香族氨基酸, 对脱芳后的酶解液进行氨基酸组成分析并测定F值。结果表明, 胃蛋白酶为第一步水解用酶, 酶解的最佳工艺条件为酶用量650U/g, 料水比1∶7(g/mL), 温度35.9℃; 风味蛋白酶为第二步水解用酶, 酶解的最佳工艺条件为酶用量50700U/g, pH 6.51, 温度51℃, 最终水解度达到36.87%±0.54%; 酶解液在pH 3.0, 温度35℃条件下, 经5%(质量体积分数)的活性炭吸附时间3h后, 脱芳率达到63.18%, F值为30.33, 符合高F值肽的要求。