Discovery of 4-((E)-3,5-dimethoxy-2-((E)-2-nitrovinyl)styryl)aniline derivatives as potent and orally active NLRP3 inflammasome inhibitors for colitis.

NLRP3 inflammasome activation plays a key role in a variety of inflammatory diseases as IBD. Here a series of pterostilbene derivatives were designed and synthesized based on previous SAR, leading to discovery of new effective NLRP3 inflammasome inhibitors with metabolic stability. Among them, the most effective compound 27 showed high inhibitory efficacy (against IL-1 ß: IC50 = 1.23 µM) and almost no toxicity (against L02: IC50 > 100 µM). Further mechanism studies have shown that compound 27 directly targets the NLRP3 and affects the assembly of inflammasomes to inhibit the activation of NLRP3 inflammasomes. More importantly, in vitro experiments show that compound 27 has a significant therapeutic effect on DSS-induced colitis in mice with good metabolic stability to liver microsomes (t1/2 = 138.6 min). This research encourages the further development of more effective NLRP3 inflammasome inhibitors based on this chemical scaffold.

Discovery of Novel Pterostilbene-Based Derivatives as Potent and Orally Active NLRP3 Inflammasome Inhibitors with Inflammatory Activity for Colitis.

Studies have shown that the abnormal activation of the NLRP3 inflammasome is involved in a variety of inflammatory-based diseases. In this study, a high content screening model targeting the activation of inflammasome was first established and pterostilbene was discovered as the active scaffold. Based on this finding, total of 50 pterostilbene derivatives were then designed and synthesized. Among them, compound 47 was found to be the best one for inhibiting cell pyroptosis [inhibitory rate (IR) = 73.09% at 10 µM], showing low toxicity and high efficiency [against interleukin-1ß (IL-1ß): half-maximal inhibitory concentration (IC50) = 0.56 µM]. Further studies showed that compound 47 affected the assembly of the NLRP3 inflammasomes by targeting NLRP3. The in vivo biological activity showed that this compound significantly alleviated dextran sodium sulfate (DSS)-induced colitis in mice. In general, our study provided a novel lead compound directly targeting the NLRP3 protein, which is worthy of further research and structural optimization.

Discovery and development of novel pyrimidine and pyrazolo/thieno-fused pyrimidine derivatives as potent and orally active inducible nitric oxide synthase dimerization inhibitor with efficacy for arthritis.

In order to discover and develop drug-like anti-inflammatory agents against arthritis, based on "Hit" we found earlier and to overcome drawbacks of toxicity, twelve series of total 89 novel pyrimidine, pyrazolo[4,3-d]pyrimidine and thieno[3,2-d]pyrimidine derivatives were designed, synthesized and screened for their anti-inflammatory activity against NO and toxicity for normal liver cells (LO2). Relationships of balance toxicity and activity have been summarized through multi-steps, and title compounds 22o, 22l were found to show lower toxicity (against LO2: IC50 = 2934, 2301 µM, respectively) and potent effect against NO release (IR = 98.3, 97.67%, at 10 µM, respectively). Furthermore, compound 22o showed potent iNOS inhibitory activity with value of IC50 is 0.96 µM and could interfere stability and formation of the active dimeric iNOS. It's anti-inflammatory activity in vivo was assessed by AIA rat model. Furthermore, the results of metabolic stability, CYP, PK study in vivo, acute toxicity study and subacute toxicity assessment indicated this compound had good drug-like properties for treatment.

Novel phthalide derivatives: Synthesis and anti-inflammatory activity in vitro and in vivo.

Phthalide is a promising chemical scaffold and has been proved to show potent anti-inflammatory efficacy. In this study, three series, total of 31 novel phthalide derivatives were designed and synthesized, their anti-inflammatory activities were screened in vitro and in vivo. The anti-inflammatory activity of all the compounds were screened on LPS induced NO production to evaluating their inhibitory effects. Structure-activity relationship has been concluded, and finally 3-((4-((4-fluorobenzyl)oxy)phenyl)(hydroxy)methyl)-5,7-dimethoxyisobenzofuran-1 (3H)-one (compound 9o) was found to be the active one with low toxicity, which showed 95.23% inhibitory rate at 10 µM with IC50 value of 0.76 µM against LPS-induced NO over expression. Preliminary mechanism studies indicated that compound 9o activated Nrf2/HO-1 signaling pathway via accumulation ROS and blocks the NF-κB/MAPK signaling pathway. The in vivo anti-inflammatory activity shown that compound 9o had obvious therapeutic effect against the adjuvant-induced rat arthritis model.

Synthesis and biological evaluation of myricetin-pentadienone hybrids as potential anti-inflammatory agents in vitro and in vivo.

Some important pro-inflammatory cytokines such as interleukin-6, tumor necrosis factor-α and nitric oxide are thought to play key roles in the destruction of cartilage and bone tissue in joints affected by rheumatoid arthritis. In the present study, a series of new myricetin-pentadienone hybrids were designed and synthesized. Majority of them effectively inhibited the expressions liposaccharide-induced secretion of IL-6, TNF-α and NO in RAW264.7. The most prominent compound 5o could significantly decrease production of above inflammatory factors with IC50 values of 5.22 µM, 8.22 µM and 9.31 µM, respectively. Preliminary mechanism studies indicated that it could inhibit the expression of thioredoxin reductase, resulting in inhibiting of cell signaling pathway nuclear factor (N-κB) and mitogen-activated protein kinases. Significantly, compound 5o was found to effectively inhibit Freund's complete adjuvant induced rat adjuvant arthritis in vivo.

Synthesis and in vitro and in vivo anti-inflammatory activity of novel 4-ferrocenylchroman-2-one derivatives.

A series of novel 4-ferrocenylchroman-2-one derivatives were designed and synthesised to discover potent anti-inflammatory agents for treatment of arthritis. All the target compounds had been screened for their anti-inflammatory activity by evaluating the inhibition effect of LPS-induced NO production in RAW 264.7 macrophages. Among them, 4-ferrocenyl-3,4-dihydro-2H-benzo[g]chromen-2-one (3h) was found to be the most potent compound in inhibiting the productions of NO with low toxicity. This compound also exhibited significant inhibition of the productions of IL-6 and TNF-α in RAW 264.7 macrophages. Preliminary mechanism studies indicated that compound 3h could inhibit the activation of LPS-induced NF-κB and MAPKs signalling pathways. The in vivo anti-inflammatory effect of this compound was determined in the rat adjuvant-induced arthritis model.

Novel resveratrol-based flavonol derivatives: Synthesis and anti-inflammatory activity in vitro and in vivo.

In order to discover novel anti-inflammatory agents, total thirty-seven new resveratrol-based flavonol derivatives were designed and synthesized. All compounds have been screened for their anti-inflammatory activity by evaluating their inhibition effect of LPS-induced NO production in RAW 264.7 macrophages. Their toxicity was also assessed in vitro. Structure-activity relationships (SARs) have been concluded, and finally 2-(2,4-dimethoxy-6-(4-methoxystyryl)phenyl)-3-hydroxy-4H-chromen-4-one was found to be the most active scaffold with low toxicity. This compound could significantly decrease productions of NO, IL-6 and TNF-α with IC50 values of 1.35, 1.12 and 1.92 µM, respectively in RAW 264.7 macrophages. Preliminary mechanism studies indicated that it could inhibit the expression of TLR4 protein, resulting in activation of the NF-ĸB cell signaling pathway. The in vivo anti-inflammatory activity of this compound could reduce pulmonary inflammation by mouse model of LPS-induced acute lung injury (ALI). We believe these findings would further support studies of rational design of more efficient acute lung injury regulatory inhibitors.

Design and synthesis of novel pyrazolo[4,3-d]pyrimidines as potential therapeutic agents for acute lung injury.

Four series of total 35 new pyrazolo[4,3-d]pyrimidine compounds were designed, synthesized and evaluated for their inhibitory activity against LPS-induced NO production in RAW264.7 macrophages. Among them, compound 4e was found to be the most potent inhibitor, which decreased the production of cytokines in vitro, such as NO, IL-6 and TNF-α, with IC50 values of 2.64, 4.38 and 5.63 µM, respectively. Further studies showed that compound 4e inhibited cytokines secretion of macrophages through suppressing TLR4/p38 signaling pathway. Additionally, compound 4e showed in vivo anti-inflammatory activity in LPS-induced model of acute lung injury. These data suggested that compound 4e may be a promising lead structure for the treatment of ALI.

Novel Pyrazolo[4,3- d]pyrimidine as Potent and Orally Active Inducible Nitric Oxide Synthase (iNOS) Dimerization Inhibitor with Efficacy in Rheumatoid Arthritis Mouse Model.

In order to discover novel anti-inflammatory agents for treatment of arthritis and based on preliminary structure-activity relationships, four series (A-D) of total 90 new pyrazolo[4,3- d]pyrimidine compounds were designed and synthesized. All the compounds have been tested for their anti-inflammatory activities by inhibiting of LPS-induced NO production. A clear structure-activity relationship has been concluded step by step, and finally 3,4,5-trimethoxystyryl-1 H-pyrazolo[4,3- d]pyrimidine was found to be the most active scaffold. Among them, compound D27 was discovered as the most potent anti-inflammatory agent (IC50 = 3.17 µM) with low toxicity and strong inhibitory of NO release (IR = 90.4% at 10 µM). This compound also showed potent inhibition of iNOS with IC50 value of 1.12 µM. Preliminary mechanism studies indicated that it could interfere with the stability and formation of active dimeric iNOS. The anti-inflammatory effect of this compound was determined by adjuvant-induced arthritis in rat model. We believe these findings would further support the study of rational design of more efficient iNOS inhibitors in the future.

New pentadienone oxime ester derivatives: synthesis and anti-inflammatory activity.

To develop novel anti-inflammatory agents, a series of new pentadienone oxime ester compounds were designed and synthesized. The structures were determined by IR, 1H NMR, 13 C NMR, and HRMS. All compounds have been screened for their anti-inflammatory activity by evaluating their inhibition against LPS-induced nitric oxide (NO) release in RAW 264.7 cell. Among them, compound 5j was found to be one of the most potent compounds in inhibiting NO and IL-6 (IC50 values were 6.66 µM and 5.07 µM, respectively). Preliminary mechanism studies show that title compound 5j could significantly suppress expressions of nitric oxide synthase, COX-2, and NO, IL-6 through Toll-like receptor 4/mitogen-activated protein kinases/NF-κB signalling pathway. These data support further studies to assess rational design of more efficient pentadienone oxime ester derivatives with anti-inflammatory activity in the future.

Discovery of (4-bromophenyl)(3-hydroxy-4-methoxyphenyl)methanone through upregulating hTERT induces cell apoptosis and ERS.

Dominant-negative mutants of telomerase hTERT were demonstrated to have selective effects in tumor cells. However, no any effective and highly selective hTERT inhibitor has been developed so far. We focused on developing new hTERT modulators and synthesized a small molecular compound, named (4-bromophenyl)(3-hydroxy-4-methoxyphenyl)methanone. Our in vitro studies found that title compound showed high inhibitory activity against telomerase, had high antiproliferative capacity on SMMC-7721 cells with IC50 value 88 nm, and had no obvious toxic effect on human normal hepatocyte cells with IC50 value 10 µM. Our in vivo studies showed that this compound significantly inhibited tumor growth in xenograft tumor models. The further molecular mechanisms of title compound inhibition SMMC-7721 cell proliferation by modulating hTERT were explored; the results showed that endoplasmic reticulum stress (ERS) through ER over response (EOR) activates the expression of hTERT, and then induces ERS, which is believed to be intricately associated with oxidative stress and mitochondrial dysfunction, resulting in apoptotic cell death, thereby modulating the expression of downstream signaling molecules including CHOP (CAAT/enhancer-binding protein homologous protein)) and mitochondrion pathway of apoptosis, leading to inhibition of cell proliferation.

New arylpyrazoline-coumarins: Synthesis and anti-inflammatory activity.

To develop new anti-inflammatory agents with improved pharmaceutical profiles, a series of new phenyl-pyrazoline-coumarin derivatives (4a∼4m) were designed and synthesized. Compounds 4a and 4b were determined by X-ray crystallography. All of the compounds have been screened for their anti-inflammatory activity characterized by evaluating their inhibition against LPS-induced IL-6 release. Among them, compound 4m showed the highest anti-inflammatory activity with inhibiting IL-6, TNF-α and nitric oxide (NO) production lipopolysaccharide (LPS)-stimulated. The further study showed that title compound 4m could significantly suppress expressions of nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and the productions of IL-6, TNF-α, NO through NF-κB/MAPK signaling pathway. The anti-inflammatory activity of compound 4m was determined by carrageenan induced paw edema. Furthermore in vivo evaluation results indicated that compound 4m could inhibit AA-induced rat ankle joints.

Diarylpentadienone derivatives (curcumin analogues): Synthesis and anti-inflammatory activity.

A series of new (2E,4E)-1-(substitutedphenyl)-5-(substitutedphenyl)penta-2,4-dien-1-one derivatives were designed and synthesized. Compounds 3i, 3k were determined by X-ray. All of the compounds have been screened for their anti-inflammatory activity characterized by evaluating their inhibition against LPS-induced IL-6 and TNF-α release in cell RAW 264.7 stimulated with LPS. Compound 3i showed the highest anti-inflammatory activity on decreasing IL-6 and TNF-α. The further study showed that title compound 3i inhibited expression of proteins p-p65, iNOS, COX-2 LPS-induced. Immunofluorescence also revealed compound 3i could lightly reduce activation p65 in nuclei. These results indicate that compound 3i anti-inflammatory role may partly due to its inhibitory effect on the NF-κB signaling pathway.

Benzophenone-nucleoside derivatives as telomerase inhibitors: Design, synthesis and anticancer evaluation in vitro and in vivo.

Based on telomerase, thirteen novel phenstatin moiety linked stavudine derivatives (8a∼8e and 11a∼11f) were synthesized. The structures were determined by NMR and TOF-HRMS. The screening results showed that some compounds had better anti-cancer activity in vivo and in vitro. Among them, Compound 8d showed high inhibitory activity against telomerase and showed good antiproliferative activity against SGC-7901 cell with IC50 value 0.77 µM by inducing cell cycle arrest at G2 phase. It also could improve SGC-7901 cell apoptosis, mitochondrial membrane potential assay indicated that the dissipation of MMP might participate in apoptosis induced by title compound. In vivo studies showed that compound 8d displayed potent anticancer activity with inhibition tumor growth.