Objective: To explore in vivo transformation form of aqueous extract W-A-80 from Trionycis Carapax through investigating its digestion in simulated gastric fluid(SGF) and simulated intestinal fluid(SIF). Method: Aqueous extract W-A-80 from Trionycis Carapax was prepared by water extraction and alcohol precipitation method

it was digested at 37℃ in SGF and SIF.With yield of oligopeotides as index

effect of different enzyme-substrate ratios and reaction time of pepsin and trypsin on yield change of oligopeptides(interception relative molecular mass<3 500) was investigated by enzyme-linked immunosorbent detector-biuret reaction;Equilibrium dialysis was adopted to determined protein binding rate of prepared oligopeptides with liver tissue of mice in vitro. Result: Optimum enzymatic hydrolysis conditions were determined that digested 3 h with pepsin enzyme substrate ratio of 1:10 at 37℃ in SGF and 11 h with trypsin enzyme substrate ratio of 1:100 at 37℃ in SIF;Protein binding rates of different concentrations of oligopeptides with liver tissue in mice were 31.63%

19.93%

9.65% and 48.75%

47.43%

22.72%

respectively

both significantly more than that of blank control group which were 7.00%

5.31%

4.60%. Conclusion: A large amount of oligopeptides generated when aqueous extract W-A-80 was digested in simulated gastrointestinal fluid

and their activity were significantly stronger than undisposed

so we speculated oligopeptides may be materials basis of Trionycis Carapax for anti-liver fibrosis.