Studies On Design And Synthesis Of Multi-target Antidiabetic Lead Compounds Based On PTP-1B And PPAR-α,γ,δ

Objective:Diabetes mellitus is a multifactorial endocrine disease that results from defects in a complex pathogenesis,which is associated closely with many enzymes and receptors and affected by heredity and environment.The main type of diabetes mellitus is type Ⅱ diabetes mellitus,which is characterized by insulin resistance and accompanied with a series of complications.Mono-target antidiabetic drug can not make diabetes therapy more effective.Therefore,in order to achieve satisfactory glycaemic control and prevent diabetes and its related complications,a long-term and effective method for diabetes treatment is to prevent insulin resistance and complications through multi-targets therapy.This research is aimed to design and synthesize multi-target antidiabetic lead compounds for protein tyrosine phosphatase-1B(PTP-1B)and peroxisome proliferator-activated receptor-α、γ、δ(PPAR-α,γ,δ),which are chosen from incidence network of type Ⅱ diabetes,by using computer aided drug design(CADD)and the technology of organic synthesis.Theoretical multi-target activity is demonstrated by molecular dynamcs simulation.And it is hope that this study can explore the prospects of multi-target compounds in the treatment of type II diabetes and lay the foundation for the structure modification and activity determination of multi-target antidiabetic lead compounds.Methods:The amino acidic sequences and crystal structure of the human PTP-1B and PPAR-α,γ,δ were retrieved from Brookhaven database.The align of the sequence and 3D structure of different PDB entry of each target was carried out using AlignX in Vector NTI Suite 9.0 and Protein Structure Alignment in Schrodinger Suite 2009.The structure characters of multi-target antidiabetic lead compounds were established by merging the structure of PTP-1B inhibitor and PPAR-α,γ,δpan-agonist and the compounds database was built according to drug likeness,synthetic feasibility and structure character above,using molecular fragment from commercial databases or our studies.Virtual screening of the compounds database was performed by using Glide which was embedded into Schrodinger Suite 2009.In molecular dynamics simulation studies,the crystal structures of PTP-1B and PPAR-α,γ,δ as well as the targets complexed with ligands from phenoxy acetic acid derivatives were used as models for the simulations,respectively.All models were then subjected to carry out 10 ns molecular dynamics simulation by GROMACS 4.0 software package.By searching Beilstein and Sci Finder databases,a series of compounds obtained by virtual screening were synthesized.The preparation of the phenoxy acetic acid and morpholine derivatives were synthesized through nucleophilic substitutions of lipophilic part and polar part.Via condensation of hydantoin and p-hydroxybenzaldehyde by Knoevenagel reaction,imidazolidine-2,4-dione intermediate could be gained,which was then alkylated on nitrogen atom.The hydrogenated product was obtained through hydrogenating of imidazolidine-2,4-dione intermediate before lipohpilic part was added.All compounds were confirmed by 1H NMR and MS.Results:Align results show that each target,the sequence of which is conservative,has a good similarity and identity,and the secondary structure of each protein backbone is aligned well,only with minor difference in non-active domain.A series of phenoxy acetic acid and imidazolidine-2,4-dione derivatives with an aromatic tail group linked by a flexible spacer are obtained through virtual screening of the multi-target antidiabetic compounds database.Molecular docking studies show that these compounds are found to form hydrogen bonds with the key residues of all the targets,which indicates that these compounds have potential characters of multi-target drug and can be recognized as multi-target antidiabetic lead compounds for PTP-1B and PPAR-α,γ,δ.Moreover,the molecular dynamics simulation reveals that receptor-ligand complexes bind correctly and remain stable during the simulations.As an inhibitor,the ligand can form stable hydrogen bonds with Cys215 in P-Loop domain of PTP-1B,which can firmly hold the catalytic site.Meanwhile,fluctuation of residues in WPD-Loop increases and WPD-Loop can not form close-conformation,in order to inhibit the activity of PTP-1B.As an agonist,the ligand shows more flexibility in the ligand binding pockets of PPARs and can form hydrogen bonds with the AF-2 helix of PPARs periodically,which stabilizes the AF-2 helix in an active conformation.Finally,19 compounds are obtained by organic synthesis and the activity is now determined by Tianjin Institute of Pharmaceutical Research.Conclusion:In this research,a series of multi-target antidiabetic lead compounds are obtained by virtual screening.Molecular docking and molecular dynamics simulation studies show that the compounds can inhibit PTP-1B and activate PPARs,which indicates that these compounds have theoretical multi-target activity and multi-target antidiabetic compounds for PTP-1B and PPAR-α,γ,δ are feasible in treatment of diabetes.Meanwhile,some of the compounds are obtained by organic synthesis,which lays the foundation for the structure modification and activity determination of multi-target antidiabetic lead compounds.