Structure Based Design, Synthesis And Activity Studies Of Small Hybrid Molecules As HDAC And G9a Inhibitors

Objective: Histone deacetylases and histone methyltransferases are two crucial targets that are associated with many cancers, as the researchers reported, multi-targeted drugs can not only improve the therapeutic effect, but also avoid the combination interactions among multi-drugs when multiple drugs use together, reducing side effects and so on, it is important in cancer treatment aspect. This study aims to design and synthesis some novel dual targets anti-cancer compounds that can inhibit the activity of multiple protein targets. This method and compounds can not only be used for the treatment of cancers, but also provide a basis for the development of designing novel multi-targets drugs.Methods: Firstly, “Pharmacophore Combination” approach was used in the compounds designing to design the anti-cancer compounds of dual targets. Secondly, by referring literatures and checking Scifinder website to design synthetic compounds route. Thirdly, in terms of biological activities later, anti-proliferative toxicity testing, In Cell-western and activity studies were chosen to detect toxicity of the compounds as well as the inhibitions for the target enzymes. Finally, the application of computer-aided techniques was chosen to study the possibility to be medicines and the binding mode between the target protein structures and the compounds.Results:In this paper, we used the principle of pharmacophore Combination, by modifying histone methyltransferase inhibitor BIX-01294’s quinazoline nucleus and histone deacetylase inhibitor Vorinostat, we successfully got three series of candidate compounds. By refering literature and surfing Scifinder website, combined the structural characteristics of the compounds, we scheduled five synthetic routes successfully. 2,4-dichloro-6,7-dimethoxy quinazoline and 4-methoxy-2-amino benzoic acid were used as the starting materials to synthesize the final compounds. Finally we successfully synthesized 23 candidate compounds, all new intermediates and the candidate compounds structures were verified using 1H- NMR and 13C-NMR. For the latter part of compounds activity studies, after the anti-proliferative cell toxicity test, In Cell-western and activity studies, the results showed that compound QZ-8(14) have good biological activity screening results, the EC50 for the tumor cell lines(MDA-MB-231, MCF-7, A549, HCT-8) were about 10 μM, 37 μM, 36 μM, 73 μM; the IC50 for HDAC was only about 6 μM; G9 a IC50 for the In Cell-western experiment was only about 7 μM. QZ-8(14) was further tested through computer-aided drug design software Discovery Studio’s ADME prediction module, the results showed it is a good candidate to be a drug; by using Schr?dinger Suite software to dock QZ-8(14) into protein crystal structures, we found the compound QZ-8(14) has good binding modes with the two target enzymes, and can produced good interactions between them.Conclusions: In this study, pharmacophore Combination principle was successfully used to design a number of small hybrid molecules as HDAC and G9 a inhibitors, by referring to the literatures and Sci-finder, we synthesized 23 new compounds successfully, these candidate compounds were screened by a preliminary biological activities, some of the compounds exhibited good pharmacological activities. Drug docking studies and molecular ADME prediction showed that compound 14 has good predition results and interaction with the receptor protein.