Inhibitory effects of Mannich bases of heterocyclic chalcones on NO production by activated RAW 264.7 macrophages and superoxide anion generation and elastase release by activated human neutrophils

Some chalcones exert potent anti-inflammatory activities. Mannich bases of heterocyclic chalcones inhibited nitric oxide (NO) production in lipopolysaccharide and interferon-γ stimulated RAW 264.7 macrophages. Also Formyl-Met-Leu-Phe and cytochalasin B induced superoxide anion generation (O2·-) and elastase release in human neutrophils. Mannich bases of heterocyclic chalcone analogs exhibited potent inhibitory effects on NO production with IC(50) values ranges between 10.5 and 0.018 μM, O2·- generation (IC(50) 39.87-0.68 μM) and elastase release (IC(50) 39.74-0.95 μM). Compound 29 (IC(50) 0.055 μM) and 34 (IC(50) 0.018 μM) were showed excellent inhibition on NO production. On the other hand, compounds 2 and 8 showed potent inhibition on O2·- generation and elastase release. Therefore, these four compounds may be new leads for development of anti-inflammatory activities. The structure-activity relationships are also discussed.     

Design, synthesis and biological evaluation of pyridine acyl sulfonamide derivatives as novel COX-2 inhibitors

A series of pyridine acyl sulfonamide derivatives (1-24) have been designed and synthesized and their biological activities were also evaluated as potential cyclooxygenase-2 (COX-2) inhibitors. Among all the compounds, compound 23 displayed the most potent COX-2 inhibitory activity with an IC(50) of 0.8 μM. Antitumor and anti-inflammatory assays indicated that compound 23 owned high antiproliferative activity against B16-F10, HepG2 and MCF-7 cancer cell lines as well as COX-2-derived prostaglandin E(2) (PGE(2)) inhibitory activity of murine macrophage RAW 264.7 cell line with IC(50) values of 2.8, 1.2, 1.8 and 0.15 μM, respectively. Docking simulation was performed to position compound 23 into the COX-2 active site to determine the probable binding model.     

6-Nitrobenzimidazole derivatives: potential phosphodiesterase inhibitors: synthesis and structure-activity relationship

6-Nitrobenzimidazole derivatives (1-30) synthesized and their phosphodiesterase inhibitory activities determined. Out of thirty tested compounds, ten showed a varying degrees of phosphodiesterase inhibition with IC(50) values between 1.5±0.043 and 294.0±16.7 μM. Compounds 30 (IC(50)=1.5±0.043 μM), 1 (IC(50)=2.4±0.049 μM), 11 (IC(50)=5.7±0.113 μM), 13 (IC(50)=6.4±0.148 μM), 14 (IC(50)=10.5±0.51 μM), 9 (IC(50)=11.49±0.08 μM), 3 (IC(50)=63.1±1.48 μM), 10 (IC(50)=120.0±4.47 μM), and 6 (IC(50)=153.2±5.6 μM) showed excellent phosphodiesterase inhibitory activity, much superior to the standard EDTA (IC(50)=274±0.007 μM), and thus are potential molecules for the development of a new class of phosphodiesterase inhibitors. A structure-activity relationship is evaluated. All compounds are characterized by spectroscopic parameters.     

Design, synthesis and biological evaluation of benzo[1.3.2]dithiazolium ylide 1,1-dioxide derivatives as potential dual cyclooxygenase-2/5-lipoxygenase inhibitors

3-(4-Bromophenyl)-6-nitrobenzo[1.3.2]dithiazolium ylide 1,1-dioxide (5) was discovered as a new prototype for dual inhibitors of cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX). Thus, the structure-activity relationships of benzo[1.3.2]dithiazolium ylide 1,1-dioxide skeleton were carried out. The 6-NO(2) group played an essential role in the inhibitory activity. In addition, moderate-sized lipophilic substituents at the para-position of the 3-aryl moiety were required for dual COX-2/5-LOX inhibitory activity. Among the identified potent dual inhibitors, 3-(4-tbutylphenyl) derivative 30c (IC(50) values of 0.27 μM and 0.30 μM against COX-2 and 5-LOX, respectively) and 3-(4-biphenyl) derivative 30f (IC(50) values of 0.50 μM and 0.15μM against COX-2 and 5-LOX, respectively) were the most potent dual COX-2/5-LOX inhibitors. Intraperitoneal administration of 30c at 100mg/kg demonstrated potent acute anti-inflammatory activity. As a result, benzo[1.3.2]dithiazolium ylide 1,1-dioxide represented a novel scaffold for the exploitation in developing dual COX-2/5-LOX inhibitors.     

Design, synthesis, and biological evaluation of substituted hydrazone and pyrazole derivatives as selective COX-2 inhibitors: Molecular docking study

New arylhydrazone derivatives and a series of 1,5-diphenyl pyrazoles were designed and synthesized from 1-(4-chlorophenyl)-4,4,4-trifuorobutane-1,3-dione 1. The newly synthesized compounds were investigated in vivo for their anti-inflammatory activities using carrageenan-induced rat paw oedema model. Moreover, they were tested for their inhibitory activity against ovine COX-1 and COX-2 using an in vitro cyclooxygenase (COX) inhibition assay. Some of the new compounds (2f, 6a and 6d) showed a reasonable in vitro COX-2 inhibitory activity, with IC?? value of 0.45 μM and selectivity index of 111.1. A virtual screening was carried out through docking the designed compounds into the COX-2 binding site to predict if these compounds have analogous binding mode to the COX-2 inhibitors. Docking study of the synthesized compounds 2f, 6a and 6d into the active site of COX-2 revealed a similar binding mode to SC-558, a selective COX-2 inhibitor.     

Synthesis and biological evaluation of isoxazolo[4,5-d]pyridazin-4-(5H)-one analogues as potent anti-inflammatory agents

In this study, eighteen new isoxazolo[4,5-d]pyridazin-4(5H)-one derivatives possessing either a 1,3,4-thiadiazole or a 1,2,4-triazole-5-thione moiety were synthesized and tested for anti-inflammatory activity in vitro (COX-1/COX-2, 5-LOX) and in vivo (rat paw edema assay). Compounds 15, 16, 25, 26 and 28-30 showed dual COX-2 (IC(50)'s in the 2.1-10.9 μM range), and 5-LOX (IC(50)'s in the 6.3-63.5 μM range) inhibitory activity. When administered orally to rats, dual COX-2/5-LOX inhibitors showed higher anti-inflammatory activity in vivo (30-45% reduction of the inflammatory response) than the reference drug ibuprofen (18%). Among dual COX-2/5-LOX inhibitors, the most potent compound (28) exhibited the best anti-inflammatory profile by inhibiting both COX-2 (IC(50)=2.1 μM) and 5-LOX (IC(50)=6.3 μM) enzymes. We investigated the binding interactions of compound 28 by an enzyme-ligand molecular modeling (docking) studies, which showed favorable binding interactions in both COX-2 and 5-LOX active sites. Furthermore, the dual acting COX-2/5-LOX compound 28 exhibited a superior gastrointestinal safety profile (ulcer index=0.25) compared to the reference drug ibuprofen (UI=7.0) when administered orally at the same molar dose. These observations suggest that isoxazolo[4,5-d]pyridazin-4(5H)-one analogs represent a new scaffold to design potent, effective, and safe anti-inflammatory agents possessing dual COX-2/5-LOX inhibitory activity.     

Design, synthesis and biological evaluation of novel 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid derivatives as aminopeptidase N/CD13 inhibitors

A series of novel 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid derivatives were designed, synthesized and assayed for their activities against aminopeptidase N (APN/CD13) and MMP-2. The results showed that most compounds exhibited higher inhibitory activities against APN than that of MMP-2. Within this series, compound 12h (IC(50)=6.28 ± 0.11 μM) showed similar inhibitory activities compared with Bestatin (IC(50)=5.55 ± 0.01 μM), and it could be used as novel lead compound for the future APN inhibitors development as anticancer agents.     

Chisopanins A-K, 11 new protolimonoids from Chisocheton paniculatus and their anti-inflammatory activities

Eleven new protolimonoids, chisopanins A-K (1-11), were isolated from the twigs of Chisocheton paniculatus, as well as thirteen known (12-24) protolimonoids. The structures were elucidated on the basis of spectroscopic analysis, X-ray crystallographic analysis, and chemical methods. Chisopanins A and B (1 and 2) possessing uncommon hemiketal tetrahydropyran ring at C-17 showed the most potent inhibitory activities on lipopolysaccharide-stimulated inflammation factor-release with IC(50) values at 5.4 and 7.9 μM for NO, and at 26.9 and 30.7 μM for TNF-α, respectively. In addition, compounds 5-7, 9, 12, 13, and 20 were potent to inhibit NO production with IC(50) value lower than 10 μM.     

Synthesis, anti-inflammatory, analgesic and kinase (CDK-1, CDK-5 and GSK-3) inhibition activity evaluation of benzimidazole/benzoxazole derivatives and some Schiff's bases

A series of N-(acridin-9-yl)-4-(benzo[d]imidazol/oxazol-2-yl) benzamides has been synthesized by the condensation of 9-aminoacridine derivatives with benzimidazole or benzoxazole derivatives. Condensation of 2-hydroxy naphthaldehyde with functionalized diamines leads to the formation of Schiff's bases and not imidazole derivatives. All these compounds were characterized by correct FT-IR, (1)H NMR, MS and elemental analyses. These compounds were screened for anti-inflammatory, analgesic and kinase (CDK-1, CDK-5 and GSK-3) inhibition activities. Compounds 11 and 7e(f) showed good anti-inflammatory (35.8% at 50 mg/kg po) activity and good analgesic activity (60% at 50 mg/kg po), respectively. Compound 3b showed significant in vitro activity against CDK-5 (IC(50)=4.6 microM) and CDK-1(IC(50)=7.4 microM) and compound 3a showed moderate CDK-5 inhibitory activity (IC(50)=7.5 microM). The other compounds showed moderate anti-inflammatory and analgesic activities.     

Synthesis, structure-activity relationships and biological evaluation of caudatin derivatives as novel anti-hepatitis B virus agents

A series of caudatin derivatives were synthesized, and their anti-hepatitis B virus (HBV) activity was evaluated in HepG 2.2.15 cells. Most of the 3-O-substituted caudatin derivatives showed effective anti-HBV activity. Among the tested compounds, six compounds (2e-2h, 2l, 2r) exhibited significantly inhibitory activity against HBV DNA replication with IC(50) values in the range of 2.82-7.48 μM. Interestingly, two compounds (2e, 2f) had potent activity inhibiting not only the secretion of HBsAg (IC(50)=18.68 μM, 21.71 μM), HBeAg (IC(50)=13.16 μM, 33.73 μM), but also HBV DNA replication (IC(50)=7.48 μM, 3.63 μM). The structure-activity relationships (SARs) of caudatin derivatives had been discussed, which were useful for caudatin derivatives to be explored and developed as novel anti-HBV agents.     

Oroxylin A analogs exhibited strong inhibitory activities against iNOS-mediated nitric oxide (NO) production

A number of oroxylin A analogs were prepared and evaluated for their inhibitory activities against iNOS-mediated nitric oxide (NO) production from LPS-stimulated BV2 cells. The analogs were synthesized from purchased 2'-hydroxy-4,5,6-trimethoxyacetophenone and aldehydes in 3 steps. Among the tested compounds, several analogs (3b, 3c, 3d, 3f) exhibited strong inhibitory activities. Especially, the analog with 4-nitrophenyl group (3b) showed stronger inhibitory activity (IC(50)=4.73 μM) than that of wogonin (IC(50)=7.80 μM).     

Synthesis of chalcone-amidobenzothiazole conjugates as antimitotic and apoptotic inducing agents

A series of chalcone-amidobenzothiazole conjugates (9a-k and 10a,b) have been synthesized and evaluated for their anticancer activity. All these compounds exhibited potent activity and the IC(50) of two potential compounds (9a and 9f) against different cancer cell lines are in the range of 0.85-3.3 μM. Flow cytometric analysis revealed that these compounds induced cell cycle arrest at G2/M phase in A549 cell line leading to caspase-3 dependent apoptotic cell death. The tubulin polymerization assay (IC(50) of 9a is 3.5 μM and 9f is 5.2 μM) and immuofluorescence analysis showed that these compounds effectively inhibit microtubule assembly at both molecular and cellular levels in A549 cells. Further, Annexin staining also suggested that these compounds induced cell death by apoptosis. Moreover, docking experiments have shown that they interact and bind efficiently with tubulin protein. Overall, the current study demonstrates that the synthesis of chalcone-amidobenzothiazole conjugates as promising anticancer agents with potent G2/M arrest and apoptotic-inducing activities via targeting tubulin.     

Design, synthesis and CoMFA studies of N1-amino acid substituted 2,4,5-triphenyl imidazoline derivatives as p53-MDM2 binding inhibitors

A series of novel N1-amino-acid substituted 2,4,5-triphenyl imidazoline derivatives was designed and synthesized based on our previous studies. All synthesized target compounds were screened for their p53-MDM2 binding inhibitory activities and anti-proliferative activities against five cancer cell lines. Among them, twelve compounds displayed improved binding inhibitory activities and most compounds showed higher cell growth inhibition activities with IC(50) values in the low micromolar range. Compound 6c exhibited marked p53-MDM2 binding inhibitory activity (IC(50)=0.59 μM) which was eightfold more potent than that of Nutlin-1 (IC(50)=4.78 μM). CoMFA analysis was performed based on obtained biological data and resulted in a statistically significant CoMFA model with high predict abilities (q(2)=0.645, r(2)=0.979).     

2-(3,5-Dihydroxyphenyl)-6-hydroxybenzothiazole arrests cell growth and cell cycle and induces apoptosis in breast cancer cell lines

2-Arylbenzothiazoles are an important class of bicyclic privileged substructures present in various natural or synthetic compounds that have been shown to possess anticancer, antifungal, antibacterial, anti-inflammatory, and antiallergic activities. This study examined the antiproliferative properties of 2-(3,5-dihydroxyphenyl)-6-hydroxybenzothiazole (DH) and its molecular mechanism of action in human breast cancer MDA-MB-231 cells. DH inhibits the growth of MDA-MB-231 cells with an IC(50) value of 25 μM in a dose/time-dependent manner as measured by the microculture tetrazolium method. Cell cycle analysis by flow cytometry showed that DH-induced growth arrest could be associated to apoptosis in MDA-MB-231 cells.     

Design, synthesis, biological evaluation and molecular modeling of novel 1,3,4-oxadiazole derivatives based on Vanillic acid as potential immunosuppressive agents

In present study, a series of novel 1,3,4-oxadiazole derivatives have been designed, synthesized and purified. All of these compounds are reported for the first time, the chemical structures of these compounds were confirmed by means of (1)H NMR, ESI-MS and elemental analyses. Besides, we evaluated their immunosuppressive activity. Most of these synthesized compounds were proved to have potent immunosuppressive activity and low toxicity. Among them, the bioassay results demonstrated that compounds 5c, 5n, 5p, 5o, 6f and 6g exhibited immunosuppressive activities with IC(50) concentration range from 1.25μM to 7.60 μM against the T cells, and the IC(50) of positive control (csa) is 2.12 μM. Moreover, all the title compounds were assayed for PI3K/AKT signaling pathway inhibition using the ELISA assay. We examined the compounds with potent inhibitory activities against IL-1, IL-6 and IL-10 released in ConA-simulated mouse lymph node cells. The results showed compounds 5o and 6f displayed the most potential biological activity against T cells (IC(50)=1.25 μM and 4.75 μM for T cells). The preliminary mechanism of compound 5o inhibition effects was also detected by flow cytometry (FCM). The results of apoptosis and ELISA assay demonstrated that the immunosuppressive activity of compounds 5o and 6f against T cells may be mediated by the inhibition of PI3Kγ/AKT signaling pathway. Molecular docking was performed to position compounds 5o and 6f into PI3Kγ binding site in order to indicate the potential target.     

Synthesis and biological evaluation of 4-[3-chloro-4-(3-fluorobenzyloxy)anilino]-6-(3-substituted-phenoxy)pyrimidines as dual EGFR/ErbB-2 kinase inhibitors

A series of 4-[3-chloro-4-(3-fluorobenzyloxy)anilino]-6-(3-substituted-phenoxy)pyrimidine derivatives were elaborately designed based on the skeleton of Lapatinib, and evaluated for their potential to inhibit epidermal growth factor receptor (EGFR) and ErbB-2 tyrosine kinase activities and antiproliferative activities against A431 and SKOV-3 cell lines. Among these synthesized pyrimidine derivatives, 4-[3-chloro-4-(3-fluorobenzyloxy)anilino]-6-(3-acrylamidophenoxy)pyrimidine (6), 4-[3-chloro-4-(3-fluorobenzyloxy)anilino]-6-(3-cyanoacetamidophenoxy)pyrimidine (9), 4-[3-chloro-4-(3-fluorobenzyloxy)anilino]-6-{3-[6-(4-amino)pyrimidinyl]amino) phenoxy}pyrimidine (11) and 4-[3-chloro-4-(3-fluorobenzyloxy)anilino]-6-(3-phenoxyacetamidophenoxy)pyrimidine (14) could significantly inhibit dual EGFR/ErbB-2 kinase activities (IC(50)=37/29 nM, 48/38 nM, 61/42 nM, 65/79 nM, respectively). And compounds 6 and 11 also showed the most potent antiproliferative activities in vitro, with the IC(50) value of 6 being 3.25 μM for A431 and 0.89 μM for SKOV-3, as for 11, 4.24 μM for A431 and 0.71 μM for SKOV-3, respectively. Docking study was also performed to determine the possible binding model.     

Novel 5-substituted 1H-tetrazoles as cyclooxygenase-2 (COX-2) inhibitors

A series of novel 5-substituted 1H-tetrazoles as cyclooxygenase-2 (COX-2) inhibitors was prepared via treatment of various diaryl amides with tetrachlorosilane/sodium azide. All compounds were tested in cyclooxygenase (COX) assays in vitro to determine COX-1 and COX-2 inhibitory potency and selectivity. Tetrazoles contained a methylsulfonyl or sulfonamide group as COX-2 pharmacophore displayed only low inhibitory potency towards COX-2. Most potent compounds showed IC(50) values of 6 and 7 μM for COX-2. All compounds showed IC(50) values greater 100 μM for COX-1 inhibition.     

Metronidazole acid acyl sulfonamide: a novel class of anticancer agents and potential EGFR tyrosine kinase inhibitors

A series of novel metronidazole derivatives were recently reported as potent anticancer agents targeting EGFR and HER-2 by our group [Qian, Y.; Zhang, H. J.; Zhang, H.; Xu, C.; Zhao, J.; Zhu, H. L. Bioorg. Med. Chem.2010, 18, 4991]. Based on the previous results, we designed and synthesized a new series of metronidazole acid acyl sulfonamide derivatives and a new series of phenylacetyl benzenesulfonamide derivatives and their anticancer activities were evaluated as potential EGFR and HER-2 kinase inhibitors. Among all the compounds, compound 12 displayed the most potent inhibitory activity EGFR and HER-2 (IC(50)=0.39 μM for EGFR and IC(50)=1.53 μM for HER-2) and it also showed the most potent growth inhibitory activity against A549 and B16-F10 cancer cell line in vitro, with an IC(50) value of 1.26 μg/mL for A549 and 0.35 μg/mL for B16-F10. Docking simulation was further performed to position compound 12 into the EGFR active site to determine the probable binding model.     

Lupane-type triterpenoids from the steamed leaves of Acanthopanax koreanum and their inhibitory effects on the LPS-stimulated pro-inflammatory cytokine production in bone marrow-derived dendritic cells

Two new compounds, (20R)-3α-hydroxy-29-dimethoxylupan-23,28-dioic acid (1) and 3α-hydroxylup-20(29)-ene-23,28-dioic acid 28-O-[β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl] ester (2), and eight known lupane-type triterpenoids (3-10), were isolated from steamed leaves of Acanthopanax koreanum. Chemical structures were determined using a combination of spectroscopic analyses and chemical reactivity. Compounds 1-10 were evaluated for their inhibitory activities on lipopolysaccharide (LPS)-stimulated interleukin (IL)-12 production in bone marrow-derived dendritic cells (BMDCs). Compound 1 exhibited inhibitory activity with IC(50) value of 26.5 μM on IL-12 production, compared with IC(50) value of 29.6 μM for the positive control. Compound 1 also showed significant suppression of LPS-stimulated IL-6 and tumor necrosis factor-alpha (TNF-α) production.     

Synthesis of novel Schiff base analogues of 4-amino-1,5-dimethyl-2-phenylpyrazol-3-one and their evaluation for antioxidant and anti-inflammatory activity

4-Aminoantipyrine (4-amino-1,5-dimethyl-2-phenylpyrazole-3-one) and its analogues have been found to be compounds of interest for their anti-inflammatory, analgesic, antiviral, antipyretic, antirheumatic and antimicrobial activities. In the present study, Schiff base analogues of 4-aminoantipyrine were synthesized by the condensation reaction with substituted benzaldehydes and then evaluated for their antioxidant and anti-inflammatory activities. From among the synthesized compounds (3a-m, 4 and 5), 3 k and 3f exhibited the highest antioxidant activity followed by 3g, 3l, 3c, 3i, 5, 3m and 3h. The IC(50) values for compounds 3 k and 3f were found to be 0.44 and 0.93 μM, respectively, comparable to that of ascorbic acid (IC(50) 0.41 μM), a standard antioxidant agent. From the comparisons between the hydroxylated and methoxylated compounds, the rank order of antioxidant activity for the products resulting from benzylidene phenyl ring substitution was 2,4,6-OH>3,4-OH>3-OMe-4-OH>3,5-OMe-4-OH>2,4-OH>3-Me-4-OMe>3,4-OMe>4-OMe>4-OH. The structure-activity relationship study revealed that the position and nature of the substituted group on the benzylidene phenyl ring of the Schiff base analogues of 4-aminoantipyrine play an important role in their antioxidant activity. The anti-inflammatory activity of 3f, which also exhibited excellent antioxidant activity, was evaluated in terms of its inhibition of NO production, an inflammatory modulator, in LPS pretreated RAW 264.7 cells using the Griess method. We also examined whether or not this compound had effect on iNOS and COX-2 mRNA expression in RAW 264.7 cells. It was observed that compound 3f significantly reduced NO production and inhibited LPS-stimulated iNOS and COX-2 mRNA levels in a dose-dependent manner. Overall, 3f showed promising antioxidant and anti-inflammatory activities and may be used as the lead compound in a future study.