Chemical Synthesis Of Protein Tyrosine Phosphatase 1B Inhibitors And Studies Of Activities

Protein tyrosine phosphatase 1B (PTP1B) as a member of protein tyrosine phosphatases (PTPs), is a kind of signaling enzymy regulates insulin signaling by insulin receptor substrate-1 (IRS-1) and insulin receptor substrate -2 (IR.S-2) of the dephosphorylation. Experiments have confirmed that the PTP1B knockout mice can not increase body weight, therefore, the role of PTP1B in signal transduction regarded as a negative regulator of insulin, has become recognized as the treatment of type Ⅱ diabetes and obesity targets.Halogenated phenol compounds extracted from seaweed have diverse biological activities, such as cytotoxic activity, antimicrobial activity, antioxidant activity, antitumor activity and so on. The structural analysis of these compounds by our research group showed that small molecular halogenated phenolic compounds modified by heterocyclic compounds (such as 2,4-thiazolidinedione, Hein, is structured as follows) can produce significant inhibition to PTP1B activity. This thesis is aimed to synthesize a series of structurally similar bromophenol heterocyclic compounds with heterocycyles as followed, using bromophenol compounds as precusors.Synthesis of bromo phenol compounds. A reasonable route and its reaction conditions were determined according to the related references and the target compounds were completedly synthesized with about 70% yields and structurally identified through 1H-NMR,13C-NMR, DEPT spectra characterization. The results show that the synthetic method is of high yield and simple post-treatment. An easy extraction can be used to fufill the isolation of the target compounds with high purity, and silica gel column was seldom needed.The establishment of method of enzyme activity assay and measurement of activity inhibition. The kinetic research of PTP1B catalyzed reaction was studied using pNPP as a substrate through time-course curve, and the activity assay method was established through the parameter optimization such as enzymatic pH and substrate concentration. The results showed that the reaction rate of PTP1B (the slope of the curve plotting to t-OD) remained constant within the first 3 minutes, which displayed zero order reaction ready for the activity measurements; the optimum pH of PTP1B is 6.5;%Inhibition value was utilized as the criteria in the inhibition test for these compounds using the constant concentration of PTP IB-substrate and varied compound concentration. The blanks were made with the 0 min reaction mixture and the reaction mixture using DMSO instead of the test compound within the initial 3 min of the reaction. The inhibiton results for the 12 compounds that synthesized in thesis showed that the 2 of these compounds, that is (5-(5,6-dibromo-3-methoxy-4-hydroxyphenyl-methylene)-2,4-thiazolidinedione, 5-(5,6-dibromo-3-methoxy-4-hydroxyphenyl)-2,4-imidazolidinedione), displayed inhibitory activity with the %Inhibition values of 32.80,27.79, respectively.In vitro inhibition measurement of PTP IB and QSAR studies. Michaelis constant Km was measured with Lineweaver-Burk double reciprocal method. A series of different pNPP substrate concentrations below 16 mM were used for the measurements of Km and Ki. The Km of PTP IB was calculated as 1.4 mM, and Ki values for the positive inhibitor sodium orthovanadate and compound 12 inhibition type were 33μM,60 uM, respectively.