Two Brown Algae Polyphenols Physiologically Active Research

Sargassum thunbergii Kuntze and Sargassum Kjellamanianum Yendo are two kinds of common brown algae along Qingdao coast. They are abundant in bioactive constituents, which make them potential resources for advanced pharmaceutical utilization.In this thesis, phlorotannins were extracted from the two brown algae and purified. Experiments were mainly focused on the studies of their bioactivities.The thesis consists of the following four parts:1. The extracting process of phlorotannins was optimized in order to reduce the impurities such as polysaccharides. F-D method which is simple, convenient and has less interference was chosen to determine the total content of phlorotannins. The suitable wavelength is 709nm and the best reaction time is 10min respectively.2. The antibacterial activity of phlorotannins from the two brown algae was investigated by Plate Growth Inhibition Assay. The results showed that the phlorotannins can inhibit the growth of the tested bacteria except Escherichia coli, and the effect was closely related to their concentration and molecular weight. Phlorotannins of high concentration and high molecular weight had stronger inhibition. The inhibition of phlorotannins on marine bacteria is better than other bacteria.3. Animal experiments were carried out in vivo to show the effects of phlorotannins on anticoagulation and reducing blood fat. The results showed that phlorotannins can extend the coagulation time, bleeding time and amount of bleeding of the mice. Phloratannins also has positive effects on decreasing total cholesterol, low density lipoprotein cholesterol and increasing high density lipoprotein cholesterol except increasing a little triglyceride. The results of in vitro experiment of rabbit showed that phiorotannins can extend thrombin time, prothrombin time and activated partial thromboplastin. It showed that phlorotannins can resist blood coagulation in both intrinsic pathway and extrinsic pathway.4. The anticancer activity of phlorotannins was tested with two kinds of cancer cell line. The result showed that the phlorotannins from Sargassum thunbergii Kuntze had strong inhibition on BEL-7420 liver cancer cell line and...