Design, Synthesis And Biological Activity Of Tetrahydro-oxazine And Pyrrolo [3,4-c] Pyrazoles P53-MDM2 Inhibitors

p53 is one of the important tumor suppressor gene for body. Its function is very frequently inactived either by direct mutation of the p53 gene or by indirect mechanisms.The study is demonstrated that MDM2 protein is the major negative regulator of p53 protein. The amplifcation of MDM2 in human cancer is a major reason for the inactivation of p53 function. Therefore, select the p53-MDM2 pathway as a target provides a new strategy for developing better anticancer therapeutics. There are many approaches to inhibit the p53-MDM2 protein interactions, the main way is to design small molecules that could specifcally block the p53-MDM2 interaction. Numerous small molecules with excellent protein binding activities and in vivo antitumor activities have been discoveryed, eight of which have been further advanced to the stage of clinical trials. The clinical results provide the usefulness of this therapeutic strategy for treatment of human cancers in the near future.Here we report the design and synthesis 64 tetrahydro-oxazine derivatives and pyrrolo[3,4-c]pyrazole derivatives, several of which exhibit good MDM2 binding a?nity and in vitro antiproliferative potency.1. Design, synthesis and biological activity of tetrahydro-oxazinesOur group used a strategy that to find new biological activity of marketed drugs as lead compounds. Molecular pharmacology studies showed that Bepridil had MDM2 protein binding activity. Thirty-two tetrahydro-oxazine esters and triazole-tetrahydrooxazines were derived from scaffold hopping of Bepridil. Most of the compounds had moderate protein binding activities and antitumor activities. In particular, compound A7 d inhibited cell growth with IC50 of about 1 μM in U-2OS, A549, NCI-H1299 cell lines, which was equivalent to the positive control drug. Compound A7 i demonstrated inhibitory activity against U-2OS cells approximately 4.45-fold selectivity over Saos cells. Structure-activity relationships indicated that replaced with a variety of groups to the two phenyl rings, the activity changed slightly. Halogen modi?cated compounds were better than the alkyl-replaced and triazole compounds were superior to esters.2. Design, synthesis and biological activity of pyrrolo-[3,4-c]pyrazolesWe previously reported a series of pyrrolo[3,4-c]pyrazole derivatives as the dual inhibitors of p53-MDM2 and NF-κB pathway with better binding inhibitory activities and antitumor activities. Our continued research for potent and diverse analogues led to get 18 highly active compounds. In particular, 8 compounds, namely B5 a, B5 c, B5 d, B5 f, B5 g, B5 h, B5 i, B5 k, showed better antitumor activity than the lead compound and Nultin-3. Most of the compounds were identi?ed potent p53-MDM2 inhibitory activity. B5 c, B5 e, B5 i emerged as 3 excellent inhibitors with binding activities(Ki = 392 n M, 191 n M, 755 n M). Sulfonamides and azetidine compounds were relatively weak and sulfonamides compounds exhibited moderate antitumor activity. Compound B21 a of azetidine compounds showed similar antitumor activity comparable Nutlin-3 and the remaining compounds were lower than the positive control drug.