New Arylpyrazoline-coumarins: Synthesis And Anti-inflammatory Activity

Inflammation is a protective attempt of host defense against injury or infection.Redness,swelling,heat,pain,and dysfunction are local features of the inflammatory reaction,accompanied by systemic related reactions such as fever and leukocytosis.However,when inflammation becomes chronic,it has been proven tissue damage and may lead to diseases,such as atherosclerosis and arthritis.And studies have shown that in the process of tumor,accompanied by a large number of chronic inflammation,indicating that chronic inflammation has a role in the promotion of tumorigenesis.It has been reported that Tak1 is traditionally accepted as the primary LPS receptor and critical for the inflammatory response to LPS.Upon stimulation with LPS,Tak1initiates series of signaling cascades that result in activation of NF-?B and mitogen-activated protein kinases?MAPK?to induce the release of pro-inflammatory cytokines.Recent studies found that inhibition of Tak1 could decrease the expressions of IL-6,IL-1b and TNF-a,which were consistent with inflammatory.So,the Tak1signal pathway may be a target in the treatment of inflammatory disease.NF-kB,downstream protein of Tak1,which is a key activator in the inflammatory processes,it turns on transcriptions of inflammatory genes including TNF-a and IL-6.Meanwhile,MAPK?containing JNK,ERK and P38?,were quite significant in the regulation of inflammation because of mediating the production of NO,TNF-a,IL-6,IL-b and other inflammatory mediators.Five membered rings such as pyrazoline and pyrazole are privileged structures used in anticancer and anti-inflammatory activity.Celecoxib,which is formed of diaryl moiety containing central pyrazole ring,is one of the most important extremely marketed COX-2 selective drugs.Based on this diaryl five-member heterocyclic skeleton,containing diphenyloxadiazole/thiadiazole hybrids,a lot of novel compounds with high anti-inflammatory activity were designed and synthesized.Curcumin analogs?containing a,b-unsaturated ketone moiety?,precursors of pyrazolines,show wide anti-inflammatory activity.In addition,compounds containing coumarin scaffold are largely present in natural products and display a variety of biological activities,namely those associated with activation Nrf2/ARE pathway and anti-inflammatory activity.A large number of coumarin derivatives have been prepared by suppressing the DNA binding ability of NF-kB.Motivated by above findings,a series of aryl-pyrazoline-coumarin derivatives were synthesized and evaluated for their anti-inflammatory activity.Based on computer aided drug design,13 novel coumarin-dihydropyrazolo-chromoneskeletonderivativesas potential inflammation inhibitorshavebeen synthesized through KnoevenagelandClaisen-Schmidt condensation reactions,cyclization,acylation,substitution reaction of salicylaldehyde with ehhyl acetoacetate.Structures of the synthesized compounds were confirmed by¹H-NMR?¹³C-NMR?X-ray crystallography.Based on Tak1,we investigated anti-inflammatory activity and preliminary molecular mechanisms using both cell and animal models in this study.First,we used mouse macrophage-like cell?RAW264.7?,which can be stimulated with LPS to mimic a status of infection and inflammation,to investigate the inhibition and molecular mechanisms of compounds on the productions of iNOS/NO,TNF-a and IL-6.Immunofluorescence and western blot experiments will also be performed in an attempt to illustrate above mechanisms.This study was based on TAK1,using cell models and animal models to study anti-inflammatory activity and preliminary molecular mechanism.First,we used LPS to stimulate mouse macrophages?RAW 264.7?to simulate infection and inflammation,and to investigate the inhibitory effects of compounds on iNOS/NO,TNF-a,and IL-6production and their molecular mechanisms.Immunofluorescence and immunoblotting experiments will also try to clarify the above mechanisms.According to the evaluation of anti-inflammatory activity,compound 4m was initially screened as an arylpyrazoline-coumalin derivative with high efficiency,low toxicity,and good selectivity,which laid the foundation for further search for more active lead compounds.