Design,Synthesis And Anti-Inflammatory Activity Of Novel 4-Phenoxy-Pyridine Derivatives

The inflammatory response is closely related to our lives.The occurrence of inflammation is mainly a pathological process of defense produced by the body to various pathogens.Inflammation in the body’s voluntary defenses is fundamentally good,but when the defenses attack the body’s own tissues or overdefend,harmful inflammation ensues,and it can be life-threatening in severity.There are many kinds of inflammatory responses.Our research focuses on acute lung injury（ALI）,sepsis and colitis.Design 1:Acute lung injury（ALI）is a serious respiratory disease that underlies acute and persistent lung inflammation.Sepsis is a syndrome of organ failure caused by excessive resistance of the host immune system to invading pathogens.Acute lung injury（ALI）and sepsis pose a serious threat to human life due to their high morbidity and mortality.Despite the current clinical efforts to treat ALI and sepsis diseases,the mortality rate of these diseases remains high and treatment drugs are urgently needed.In this paper,the existing anti-inflammatory drugs were analyzed and discussed.Finally,the pharmacophore（Pyridinamide,quinolinone and other structures）commonly used in anti-inflammatory drugs was introduced by molecular splicing strategy,and the amide bond was introduced according to the bioelectron isoarrangement principle.At the same time,the common atoms of drug design were introduced,hoping to obtain small molecular compounds with anti-inflammatory activity.In this paper,28 novel 4-phenoxy-pyridine derivatives were designed and synthesized,and their anti-inflammatory activities were studied.In vitro anti-inflammatory activity（inhibition of LPS-induced inflammatory factor IL-6production）and cytotoxic activity of the target compound were evaluated by enzyme-related immunosorbent assay（ELISA）and MTT assay.J774A.1（mouse mononuclear macrophage）was used as the experimental cell line.The results showed that compounds D2 and D24 had better anti-inflammatory activity than curcumin,and the anti-inflammatory activity of compound D2(IC₅₀=3.001μM)was the best.Mice models of ALI and sepsis were constructed to evaluate the anti-inflammatory effects of compound D2 in vivo.The results were surprising.Compound D2 significantly improved a range of pathological symptoms associated with inflammation and reduced mortality in sepsis mice.According to the mechanism of inflammatory response,it was found that compound D2 could effectively inhibited the excessive release of inflammatory cytokines（e.g.IL-6,TNF-α）and the activation of NF-κB pathway.In order to further explore the mechanism of action of compound D2,we conducted target search and preliminary confirmation of compound D2.It was found that the inhibition of compound D2 on c-Kit is an important mechanism of its anti-inflammatory effect,and this result indicates a new direction of potential therapeutic targets for anti-inflammatory ALI and sepsis.In vivo acute toxicity tests confirmed the safety of compound D2.These results suggest that compound D2 could be a promising candidate for preclinical anti-inflammatory drugs.Design 2:Inflammatory bowel disease（IBD）is a multifactorial inflammatory disease caused by abnormal intestinal mucosal immune system.It is also a clinically intractable disease.The pathogenesis of colitis is complex.Studies have shown that the occurrence and development of IBD is also accompanied by the activation of NF-αB pathway and the overproduction of cytokines（eg.IL-6 and TNF-α）.Therefore,we continue the idea of the first subject to further reform and innovation in order to obtain colitis treatment drugs with better anti-inflammatory activity.According to the rule that the molecular weight of compounds in the Five Principles of drugs is less than 500,we removed quinolones from the structure of the compound in Subject 1 to reduce the molecular weight of the compound.Meanwhile,chemdraw was used to calculate the Log P value of the compound.Finally,28 new4-phenoxy-pyridine derivatives based on the structure of the compound in Subject 1were redesigned and synthesized.The anti-inflammatory effect of the target compounds was evaluated by various pharmacological and animal experiments.Mouse monocyte macrophage leukemia RAW264.7 cell line was used by ELISA to evaluate the anti-inflammatory activities of 28 compounds in Subject 2 in vitro.The results showed that compared with Project 1,the anti-inflammatory activity of the compounds in Project 2 was on the rise,and the inhibition rate of 15compounds on IL-6 release was more than 80%.We selected several active compounds for dose-dependent screening,and found that compounds D31 and D39had dose-dependent effects on IL-6 release,and the IC50 value of compound D31（0.62μM）was better than that of compound D39（1.372μM）.Colitis animal model experiments indicated that compound D31 has obvious therapeutic effect on colitis.To sum up,this study discussed anti-inflammatory drugs and modified them,finally designed two series of 56 new anti-inflammatory small molecule compounds that have not been reported in the literature,and carried out biological evaluation and mechanism discussion of these 56 compounds.This paper provides research ideas for the innovation of therapeutic drugs for acute lung injury,sepsis,colitis and other diseases.