Synthesis,Characterization And Bioactivity Evaluation Of Phenothiazine And Carbazole Derivatives

Phenothiazines refer to a family of nitrogen-and sulfur-containing tricyclic compounds.Phenothiazine derivatives such as chlorpromazine,trifluoperazine,as a representative antipsychotic drug,it has been found to possesses of various biological activities,such as anti-tumor,anti-inflammation,antioxidant activities etc.Among these phenothiazine compounds,trifluoperazine and thiodarizine have attracted attention thanks to their potential antitumor activities.Carbazole is a tricyclic compound bearing the carbon skeleton of fluorene.It is known that carbazole alkaloids isolated from natural products are interesting drug candidates because of their excellent biological activities,such as anti-tumor and antibacterial activities etc.In recent years,carbazole derivatives have shown potential clinical application in treating pancreatic cancer,breast cancer and other malignant tumors.Among them,the carbazole derivatives such as elliptinium acetate and midostaurin have been approved for cancer therapy in clinic.Carbazole has therefore become one of the important structural units for developing novel anticancer drugs.ZZW-115,a phenothiazine derivative previously developed in our lab is a potential anticancer candidates.It can effectively inhibit the proliferation of pancreatic cancer cells and other tumor cells via targeting the intrinsic disorder protein NUPR1.More importantly,compared with the clinical drug trifluoperazine,ZZW-115 has no obviously neurological side effects when inhibiting tumor growth in mice.Therefore,it is a highly effective anti-tumor drug lead with lower toxicity.Currently ZZW-115 is being actively promoted to clinical application.In the work of this thesis,based on the potential biological activities of phenothiazine and carbazole derivatives,a series of phenothiazine and carbazole derivatives wave been designed and synthesized using ZZW-115 as the lead.The phenothiazine derivative I was obtained by introducing different amines at N-10 position of phenothiazine ring,while the phenothiazine derivative II was obtained by inserting different substituents at C-2position of phenothiazine ring.And the carbazole derivative III was prepared by replacing phenothiazine ring with carbazole ring.Then we assessed the antiproliferation activity of the synthesized phenothiazines and carbazole analogues in different cancer cells.The result showed that both phenothiazine derivatives(I)and(II)exhibited potent antiproliferation activities.Further structure-activity relationship studies show that in compound II,the compound having the methoxy group,methylthio group and ethylthio group at the C-2 position usually showed good to excellent activities.Among compound I and II,the compound II-1e with ethylthio group at C-2 position exhibited the best antiproliferation activity,which set up a foundation for the structural modification of phenothiazines.Carbazole derivative III also showed potential anti-tumor cell proliferation activity.The most active lead compound is compound III-e when the C-2position of the carbazole is substituted with trifluoromethyl and the N-9 position is substituted with pyrrole.Then we evaluated the metabolic stability of II-1e through the liver microparticle metabolic stability test.And the good metabolic stability of II-1e,suggesting that it may not be easily metabolized by the liver in vivo.Importantly,II-1e exhibited potent antitumor activity without any acute toxicity in mice.Further studies on the anticancer mechanism showed that different from that of ZZW-115,compound II-1e not only induced apoptosis by suppressing the expression of Bcl-2,significantly enhancing the expression of the cleavage of PARP and activating tumor suppressor gene p53,but also effectively activate autophagy to promote cancer cell death.Meanwhile,the results of lactate dehydrogenase release(LDH)experiment proved that II-1e may not cause cell membrane rupture and destruction to induce necrosis.Compound II-1e is the first phenothiazine compound bearing the ethylthio group at the C-2 position of phenothiazine and it hence can be used to explore novel anticancer lead compounds with unique mechanisms.In summary,a series of phenothiazine and carbazole derivatives have been designed and synthesized in the work of this thesis.The development of these compounds has enriched the structural diversity of phenothiazine and carbazole compounds.Interestingly,the screened lead compound not only showed good anti-tumor activity via inducing both apoptosis and autophagy.Therefore,these compounds bearing tricyclic structure have the potential to be developed as antitumor lead compound with novel and unique mechanism of action.