Synthesis And Biological Evaluation Of4,4-dimethyl Cholic Acid Deriveatives As Novel Inhibitors Of Protein Tyrosine Phosphatase1B And Synthesis Of MADCB

This thesis includes two parts:(1) Design and synthesis of series of4,4-dimethyl cholic acid derivatives and study on their structure-activity relationship in order to develop novel small molecule PTP1B inhibitors;(2) The synthesis of methyl2-amino-4-((2,5-dichlorophenyl)carbamoyl)benzoate.1. Design and synthesis of4,4-dimethylcholic acid derivatives and study their inhibitory activity on PTP1B/TCPTP.In order to get the PTP1B inhibitor with high inhibitory and selective activities as lead compounds of some new drugs of diabetes, series of small molecule library have been designed and synthesized starting with lithocholic acid(LCA).1) We have designed and synthesized several compounds which contain double bond in A ring and two methyl groups at C-4position. The inhibitory effect on PTP1B showed that the double bond between C-l and C-2position or between C-4and C-5position would weaken the inhibitory activity obviously and two methyl groups at C-4position can improve the selective activity dramatically.2) Eight new compounds with two methyl groups at C-4position have been synthesized by modifying4,4-dimethyl cholic acid at C-24position. The evaluation of inhibition on PTP1B showed that the esterification of carboxyl group will decrease the inhibitory activity.3) In order to improve the inhibitory activity and selective activity, at the same time ameliorate physical and chemical properties, series of heterocycles were introduced in the C-2and C-3position. Nine new compounds have been synthesized, including pyrazine, isoxazole, pyrazole, pyrimidine cycles fused at A ring. Active testing results showed that C-2and C-3heterocyclic not only can improve PTP1B inhibitory activity, but also can improve the selectivity of homology enzyme TCPTP. All the nine compounds indicated that the better inhibitory activity than the LCA, and the inhibitory activity of pyrazole-fused derivatives are better than that of other heterocycle-fused compounds. Compared with the parent compound LCA, the most potent inhibitor compound9a (IC50=0.64±0.03μM) increased nearly8times on the inhibitory activity and14times selective activity on PTPIB over TCPTP. Most of these heterocyclic compounds contain carboxyl group so that they can be transformed into their organic or inorganic acid salt, which can overcome the hydrophobic property of steroids and improve the bioavailability and drug-likeness.2. Synthesis of methyl2-amino-4-((2,5-dichlorophenyl)carbamoyl)benzoateWe optamized the routs and synthesized4-(methoxycarbonyl)-3-nitrobenzoic acid and high-purity methyl2-amino-4-((2,5-dichlorophenyl)carbamoyl)benzoate (MADCB), respectively, from p-phthalic acid in a higher yield by using the economic and suitable method.1) In nitration reaction, the dosage of acid been reduced and the yield been increased nine percent by bringing down the reaction temperature;2) In regio-selectivity hydrolysis reaction, the optimum reaction conditions been found out by investigating the dosage and types of alkali, reaction temperature and reaction time. Besides, the unreacted material, by-products and solvent were recovered with simple method and reused. By condensation and reduction, we obtained the MADCB from the4-(methoxycarbonyl)-3-nitrobenzoic acid. And then, we used the MADCB for the synthesis of dye188and got a satisfactory result.