The Synthesis And Activity Assay Of Tartaric Acid Derivatives As AminopeptidaseN Inhibitors

Aminopeptidase N (APN/identical to CD 13) belongs to a family of zinc depen-dent exopeptidase has become an attractive target for structure-based drug designing in the last decades. It was originally used as a marker for the myeloid differentiation antigen.Aminopeptidase N (APN) is expressed on various mammalian cells including monocytes, myeloid, epithelial cells of the intestine and kidney, fibroblasts, endoth-elial cells and tumor cells. APN has been also proved to behave as a receptor for corona-viruses TEGV and 229E in humans.More impotantly, many researches have shown that APN is involved in the regulation of tumour cell invasion and metastasis. In addition, APN is involved in the processes of immunological regulation, and as a result, many immunologic active materials have been degradated and the ability of macrophage and NK cells to identify and kill tumor cells have been weakened. All these findings make this enzyme an interesting target for possible anti-tumor drugs research, which require the development of potent and more selective inhibitors.Based on the infrastructure of design principles, analysis and summary the structural features of peptide-like APN inhibitors which have been synthesized. Studies have discovered that the binding site of the APN with compouns can be divided to three parts, part A is a hydrophobic pocket which interacts with the phenyl group of Bestatin; part B is the zinc binding group (ZBG) and part C is a hydrophobic pocket on the other side. In this thesis, by the combination of crystal structure of the enzyme and application of computer-aided drug design software, we designed and synthesized three series of 40 novel peptide-like derivatives:tartaric acid derivatives, malic acid derivatives and nicotine acid derivatives. Their structures are confirmed by IR, ESI-MS and 1H NMR. All the targeted compounds are novel without any report by now.Preliminary bioactivity assays are carried out in vitro. The target compounds are evaluated for inhibitory activities toward APN. As a result, most of these newly syn-thesized compounds show good inhibitory activities on APN. The results of experi- ment show that L-tartaric acid derivatives are the most activity inhibitors toward APN, their half inhibitory concentration (IC50) achieved to micromolar range, these new compounds have potent and selective inhibitory activities toward APN.The newly synthesized compounds were evaluated for their in vitro cytotoxicity by growth-inhibition studies using erythrocyte leukeemic cell line (K562). MTT assay was used of them and calculate the rate of inhibition against the tumor cells. Of these compounds, compounds A1,B1,C1 and D2 are the most active compounds. So we choose them as experimental subject, continued to obtain their cytotoxic activity IC50 and we found compound D2 have the best inhibitory activity toward K562 cells.