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.     

Inhibition of COX-1 activity and COX-2 expression by 3-(4'-geranyloxy-3'-methoxyphenyl)-2-trans propenoic acid and its semi-synthetic derivatives

Oxyprenylated naturally occurring cinnamic acids displayed efficient and promising biological activities. Aim of this study was to characterize the effects of 3-(4'-geranyl-3'-methoxy)phenyl-2-trans propenoic acid and its selected semi-synthetic analogues, on COX-2 expression and activity, and on COX-1 activity, in purified systems or in whole cell systems. The anti-inflammatory activity of title compounds (1) was tested as inhibition of COX-2 on isolated monocytes stimulated with LPS (10 μg/ml). COX-2 expression was completely suppressed when monocytes were incubated with 100 μM of 3-(4'-geranyl-3'-methoxy)phenyl-2-trans propenoic acid (1) or 3-(4'-isopentenyloxy)phenyl-2-trans propenoic acid (4). Moreover compounds (1) and (4) inhibit dose-dependently LPS-induced COX-2 expression.     

Design, synthesis and biological evaluation of 3-substituted 2,5-dimethyl-N-(3-(1H-tetrazol-5-yl)phenyl)pyrroles as novel potential HIV-1 gp41 inhibitors

Based on the structure of HIV-1 gp41 binding site for small-molecule inhibitors, optimization of lead 2 resulted in the discovery of a new series of 2,5-dimethyl-3-(5-(N-phenylrhodaninyl)methylene)-N-(3-(1H-tetrazol-5-yl)phenyl)pyrrole compounds with improved anti-HIV-1 activity. The most active compounds 13a and 13j exhibited significant potency against gp41 6-HB formation with IC(50) values of 4.4 and 4.6 μM and against HIV-1 replication in the MT-2 cells with EC(50) values of 3.2 and 2.2 μM, respectively, thus providing a new starting point to develop highly potent small-molecule HIV fusion inhibitors targeting gp41.     

Synthesis and antiviral evaluation of 9-(S)-[3-alkoxy-2-(phosphonomethoxy)propyl]nucleoside alkoxyalkyl esters: inhibitors of hepatitis C virus and HIV-1 replication

We reported previously that octadecyloxyethyl 9-(S)-[3-hydroxy-2-(phosphonomethoxy)-propyl]adenine (ODE-(S)-HPMPA) was active against genotype 1b and 2a hepatitis C virus (HCV) replicons. This is surprising because acyclic nucleoside phosphonates have been regarded as having antiviral activity only against double stranded DNA viruses, HIV and HBV. We synthesized octadecyloxyethyl 9-(S)-[3-methoxy-2-(phosphonomethoxy)propyl]-adenine and found it to be active in genotype 1b and 2a HCV replicons with EC?? values of 1-2 μM and a CC?? of > 150 μM. Analogs with substitutions at the 3'-hydroxyl larger than methyl or ethyl, or with other purine bases were less active but most compounds had significant antiviral activity against HIV-1 in vitro. The most active anti-HIV compound was octadecyloxyethyl 9-(R)-[3-methoxy-2-(phosphonomethoxy)propyl]guanine with an EC?? < 0.01 nanomolar and a selectivity index of > 4.4 million.     

In-vitro cytotoxicity and cell cycle analysis of two novel bis-1,2, 4-triazole derivatives: 1,4-bis[5-(5-mercapto-1,3,4-oxadiazol-2-yl-methyl)-thio-4-(p-tolyl)-1,2,4-triazol-3-yl]-butane (MNP-14) and 1,4-bis[5-(carbethoxy-methyl)-thio-4-(p-ethoxy phenyl)-1,2,4-triazol-3-yl]-butane (MNP-16)

In the present study, we have tested the cytotoxic and DNA damage activity of two novel bis-1,2,4 triazole derivatives, namely 1,4-bis[5-(5-mercapto-1,3,4-oxadiazol-2-yl-methyl)-thio-4-(p-tolyl)-1,2,4-triazol-3-yl]-butane (MNP-14) and 1,4-bis[5-(carbethoxy-methyl)-thio-4-(p-ethoxy phenyl) -1,2,4-triazol-3-yl]-butane (MNP-16). The effect of these molecules on cellular apoptosis was also determined. The in-vitro cytotoxicity was evaluated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay as well as Trypan blue dye exclusion methods against human acute lymphoblastic leukemia (MOLT4) and lung cancer cells (A549). Our results showed that MNP-16 induced significant cytotoxicity (IC(50) of 3-5 μM) compared with MNP-14. The cytotoxicity induced by MNP-16 was time and concentration dependent. The cell cycle analysis by flow cytometry (fluorescence-activated cell sorting [FACS]) revealed that though there was a significant increase in the apoptotic population (sub-G(1) phase) with an increased concentration of MNP-14 and 16, there was no cell cycle arrest. Further, the comet assay results indicated considerable DNA strand breaks upon exposure to these compounds, thereby suggesting the possible mechanism of cytotoxicity induced by MNP-16. Hence, we have identified a novel molecule (MNP-16) which could be of great clinical relevance in cancer therapeutics.     

The pulmonary pharmacology of [4-methoxy-N1-(4-trans-nitrooxycyclohexyl)-N3-(3-pyridinylmethyl)-1,3-benzenedicarboxamide] (2NTX-99), an anti-atherotrombotic compound with therapeutic potential in pathological conditions that target lung vasculature

The pharmacological activity of 2NTX-99 ([4-methoxy-N1-(4-trans-nitrooxycyclohexyl)-N3-(3-pyridinylmethyl)-1,3-benzenedicarboxamide]) was investigated in vitro in the intact, rat pulmonary vasculature and in guinea pig airways. Rat lungs were perfused at constant flow and changes in vascular tone recorded. Challenge with the TXA? analogue 9,11-dideoxy-9α11α-methanoepoxy ProstaglandinF? (U46619, 0.5 μM) increased vessel tone (32.48±1.5 vs 13.13±0.56 mmHg; n=12). 2NTX-99 (0.1-100 μM; n=5), caused a concentration-dependent relaxation, prevented by 1H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one (ODQ, 10 μM, n=4), an inhibitor of soluble guanylate cyclase. Acetylcholine (0.1-10 μM; n=3) and a reference NO-donor, isosorbide-5-mononitrate (5-100 μM; n=4), were ineffective. Intraluminal perfusion of washed human platelets (2 × 10? cells/ml) increased intravascular pressure after challenge with arachidonic acid (AA, 2 μM; n=5), an increase abolished by acetylsalicylic acid and significantly reduced by 2NTX-99 (40 μM; n=5). TXB? in the lung perfusate was detected after platelet activation, 2NTX-99 inhibited TXA? synthesis (6.45±0.6 and 1.10±0.2 ng/ml, respectively). 2NTX-99 did not alter central or peripheral airway responsiveness to Histamine (0.001-300 μM; n=6), U46619 (0.001-3 μM, n=3) or LTD? (1 pM-1 μM; n=6). 2NTX-99 vasodilates the pulmonary vasculature via the release of nitric oxide (NO) and reduces intraluminal, AA-induced, TXA? formation. The combined activity of 2NTX-99 as an NO-donor and a TXA?-synthesis inhibitor provides strong support for its potential therapeutic use in pathologies of the pulmonary vascular bed (e.g. pulmonary hypertension).     

In-Vitro Cytotoxicity and Cell Cycle Analysis of Two Novel bis-1,2, 4-triazole derivatives: 1,4-bis[5-(5-mercapto-1,3,4-oxadiazol-2-yl-methyl)-thio-4-(p-tolyl)-1,2,4-triazol-3-yl]-butane (MNP-14) and 1,4-bis[5-(carbethoxy-methyl)-thio-4-(p-ethoxy phenyl)-1,2,4-triazol-3-yl]-butane (MNP-16)

In the present study, we have tested the cytotoxic and DNA damage activity of two novel bis-1,2,4 triazole derivatives, namely 1,4-bis[5-(5-mercapto-1,3,4-oxadiazol-2-yl-methyl)-thio-4-(p-tolyl)-1,2,4-triazol-3-yl]-butane (MNP-14) and 1,4-bis[5-(carbethoxy-methyl)-thio-4-(p-ethoxy phenyl) -1,2,4-triazol-3-yl]-butane (MNP-16). The effect of these molecules on cellular apoptosis was also determined. The in-vitro cytotoxicity was evaluated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay as well as Trypan blue dye exclusion methods against human acute lymphoblastic leukemia (MOLT4) and lung cancer cells (A549). Our results showed that MNP-16 induced significant cytotoxicity (IC₅₀ of 3–5 μM) compared with MNP-14. The cytotoxicity induced by MNP-16 was time and concentration dependent. The cell cycle analysis by flow cytometry (fluorescence-activated cell sorting [FACS]) revealed that though there was a significant increase in the apoptotic population (sub-G₁ phase) with an increased concentration of MNP-14 and 16, there was no cell cycle arrest. Further, the comet assay results indicated considerable DNA strand breaks upon exposure to these compounds, thereby suggesting the possible mechanism of cytotoxicity induced by MNP-16. Hence, we have identified a novel molecule (MNP-16) which could be of great clinical relevance in cancer therapeutics.     

AMPA receptor agonists: Resolution,configurational assignment,and pharmacology of (+)-(S)- and (-)-(R)-2-amino-3-[3-hydroxy-5-(2-pyridyl)-isoxazol-4-yl]-propionic acid (2-Py-AMPA)

We have previously shown that whereas (RS)-2-amino-3-(3-hydroxy-5-phenylisoxazol-4-yl)propionic acid (APPA) shows the characteristics of a partial agonist at (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) receptors, (S)-APPA is a full AMPA receptor agonist and (R)-APPA a weak competitive AMPA receptor antagonist. This observation led us to introduce the new pharmacological concept, functional partial agonism. Recently we have shown that the 2-pyridyl analogue of APPA, (RS)-2-amino-3-[3-hydroxy-5-(2-pyridyl)isoxazol-4-yl]propionic acid (2-Py-AMPA), is a potent and apparently full AMPA receptor agonist, and this compound has now been resolved into (+)- and (-)-2-Py-AMPA (ee ≥ 99.0%) by chiral HPLC using a Chirobiotic T column. The absolute stereochemistry of the enantiomers of APPA has previously been established by X-ray analysis, and on the basis of comparative studies of the circular dichroism spectra of the enantiomers of APPA and 2-Py-AMPA, (+)- and (-)-2-Py-AMPA were assigned the (S)- and (R)-configuration, respectively. In a series of receptor binding studies, neither enantiomer of 2-Py-AMPA showed detectable affinity for kainic acid receptor sites or different sites at the N-methyl-D-aspartic acid (NMDA) receptor complex. (+)-(S)-2-Py-AMPA was an effective inhibitor of [³H]AMPA binding (IC⁵⁰ = 0.19 ± 0.06 μM) and a potent AMPA receptor agonist in the rat cortical wedge preparation (EC₅₀ = 4.5 ± 0.3 μM) comparable with AMPA (IC₅₀ = 0.040 ± 0.01 μM; EC₅₀ = 3.5 ± 0.2 μM), but much more potent than (+)-(S)-APPA (IC₅₀ = 5.5 ± 2.2 μM; EC₅₀ = 230 ± 12 μM). Like (-)-(R)-APPA (IC₅₀ > 100 μM), (-)-(R)-2-Py-AMPA (IC₅₀ > 100 μM) did not significantly affect [³H]AMPA binding, and both compounds were week AMPA receptor antagonists (K_i = 270 ± 50 and 290 ± 20 μM, respectively). Chirality 9:274–280, 1997. © 1997 Wiley-Liss, Inc.     

A novel synthetic compound, (Z)-5-(3-hydroxy-4-methoxybenzylidene)-2-iminothiazolidin-4-one (MHY773) inhibits mushroom tyrosinase

As part of continued efforts for the development of new tyrosinase inhibitors, (Z)-5-(substituted benzylidene)-2-iminothiazolidin-4-one derivatives (1a – 1l) were rationally synthesized and evaluated for their inhibitory potential in vitro. These compounds were designed and synthesized based on the structural attributes of a β-phenyl-α,β-unsaturated carbonyl scaffold template. Among these compounds, (Z)-5-(3-hydroxy-4-methoxybenzylidene)-2-iminothiazolidin-4-one (1e, MHY773) exhibited the greatest tyrosinase inhibition (IC₅₀ = 2.87 μM and 8.06 μM for monophenolase and diphenolase), and outperformed the positive control, kojic acid (IC₅₀ = 15.59 and 31.61 μM). The kinetic and docking studies demonstrated that MHY773 interacted with active site of tyrosinase. Moreover, a melanin quantification assay demonstrated that MHY773 attenuates α-melanocyte-stimulating hormone (α-MSH) and 3-isobutyl-1-methylxanthine (IBMX)-induced melanin contents in B16F10 melanoma cells. Taken together, these data suggest that MHY773 suppressed the melanin production via the inhibition of tyrosinase activity. MHY773 is a promising for the development of effective pharmacological and cosmetic agents for skin-whitening.     

Synthesis, biological evaluation, and molecular docking studies of benzyl, alkyl and glycosyl [2-(arylamino)-4,4-dimethyl-6-oxo-cyclohex-1-ene]carbodithioates, as potential immunomodulatory and immunosuppressive agents

The immunomodulating properties of functionalized [2-(arylamino)-4,4-dimethyl-6-oxo-cyclohex-1-ene] carbodithioates and 6,6-dimethyl-4-(2-(propan-2-ylidene)hydrazinyl)-6,7-dihydro-2H-indazole-3(5H)-thione compounds have been investigated. Four of them, 13, 18, 19 and 20 inhibited PBMC proliferation induced by phytohemagglutinin (PHA) in a dose dependent manner with an IC(50) of ≤ 20 μM. The Th-1 cytokine, interleukin-2 (IL-2) in PHA/PMA-stimulated peripheral blood mononuclear cells (PBMCs) is significantly inhibited by 13, 19 and 20 with an IC(50) of 8.4 ± 0.4, 5.34 ± 0.15 and 4.9 ± 0.7 μM, respectively. They also inhibited the PMA/lipopolysaccharide-induced proinflammatory cytokines, IL-1β and TNF-α production in human monocytic leukemia cells (THP-1), by 86%, 46% and 59.2% for IL-1β and by 83.8%, 48.2% and 58.7% for TNF-α, respectively. Only 20 showed significant suppressive activity against the phagocyte oxidative burst in a dose dependent manner, with an IC(50) of 23.8 μM. LPS-induced nitrites in mouse macrophages were found to be inhibited by compounds 6, 8, 13-15 and 19 with an IC(50), which range between 7.7 and 63 μM. The cytotoxicity for the active compounds was also studied on Rat Wistar Hepatocyte cell line, CC1 and the Mouse Fibroblast cell line 3T3 NIH in the presence of compounds using a standard MTT assay. Furthermore, structural-activity relationship using automated docking software revealed that active compounds 7, 13 and 19, adapted the same binding mode, however the most active compound 20 is found deeply inserted within the ligand binding site of IL-2, as multiple hydrophobic and hydrophilic key interactions stabilize the compound inside the binding site, thus contributing higher activity.     

Synthesis,characterization and preliminary screening of regioisomeric 1-(3-pyridazinyl)-3-arylpyrazole and 1-(3-pyridazinyl)-5-arylpyrazole derivatives towards cyclooxygenase inhibition

In a search for novel compounds with analgesic and anti-inflammatory activity, a series of regioisomeric 1-(3-pyridazinyl)-3-arylpyrazole (5a–f, 6a–f) and 1-(3-pyridazinyl)-5-arylpyrazole (7a–f, 8a–f) derivatives were synthesized. The structure of these regioisomers was confirmed by spectral techniques. The compounds were preliminarily screened at 8 μM concentration for their inhibitory activity against cyclooxygenase enzymes, COX-1 and COX-2, using a human whole blood test. The tested derivatives showed inhibitory activity for both enzymes and are worthy of further investigation for developing better leads.     

14-3-3 proteins activate a plant calcium-dependent protein kinase (CDPK)

Plants and protozoa contain a unique family of calcium-dependent protein kinases (CDPKs) which are defined by the presence of a carboxyl-terminal calmodulin-like regulatory domain. We present biochemical evidence indicating that at least one member of this kinase family can be stimulated by 14-3-3 proteins. Isoform CPK-1 from the model plant Arabidopsis thaliana was expressed as a fusion protein in E. coli and purified. The calcium-dependent activity of this recombinant CPK-1 was shown to be stimulated almost twofold by three different 14-3-3 isoforms with 50% activation around 200 nM. 14-3-3 proteins bound to the purified CPK-1, as shown by binding assays in which either the 14-3-3 or CPK-1 were immobilized on a matrix. Both the 14-3-3 binding and activation of CPK-1 were specifically disrupted by a known 14-3-3 binding peptide LSQRQRSTpSTPNVHMV (IC₅₀=30 μM). These results raise the question of whether 14-3-3 can modulate the activity of CDPK signal transduction pathways in plants.     

Synthesis, biological evaluation and 3D-QSAR studies of 3-keto salicylic acid chalcones and related amides as novel HIV-1 integrase inhibitors

HIV-1 integrase is one of the three most important enzymes required for viral replication and is therefore an attractive target for anti retroviral therapy. We herein report the design and synthesis of 3-keto salicylic acid chalcone derivatives as novel HIV-1 integrase inhibitors. The most active compound, 5-bromo-2-hydroxy-3-[3-(2,3,6-trichlorophenyl)acryloyl]benzoic acid (25) was selectively active against integrase strand transfer, with an IC(50) of 3.7 μM. While most of the compounds exhibited strand transfer selectivity, a few were nonselective, such as 5-bromo-3-[3-(4-bromophenyl)acryloyl]-2-hydroxybenzoic acid (15), which was active against both 3'-processing and strand transfer with IC(50) values of 11±4 and 5±2 μM, respectively. The compounds also inhibited HIV replication with potencies comparable with their integrase inhibitory potencies. Thus, 5-bromo-2-hydroxy-3-[3-(2,3,6-trichlorophenyl)acryloyl]benzoic acid (25) and 5-bromo-3-[3-(4-bromophenyl)acryloyl]-2-hydroxybenzoic acid (15) inhibited HIV-1 replication with EC(50) values of 7.3 and 8.7 μM, respectively. A PHASE pharmacophore hypothesis was developed and validated by 3D-QSAR, which gave a predictive r(2) of 0.57 for an external test set of ten compounds. Phamacophore derived molecular alignments were used for CoMFA and CoMSIA 3D-QSAR modeling. CoMSIA afforded the best model with q(2) and r(2) values of 0.54 and 0.94, respectively. This model predicted all the ten compounds of the test set within 0.56 log units of the actual pIC(50) values; and can be used to guide the rational design of more potent novel 3-keto salicylic acid integrase inhibitors.     

Design and Synthesis of (3-Phenylisoxazol-5-yl)methanimine Derivatives as Hepatitis B Virus Inhibitors

Series of (3-phenylisoxazol-5-yl)methanimine derivatives were synthesized, and evaluated for anti-hepatitis B virus (HBV) activity in vitro. Half of them more effectively inhibited HBsAg than 3TC, and more favor to inhibit secretion of HBeAg than to HBsAg. Part of the compounds with significant inhibition on HBeAg were also effectively inhibit replication of HBV DNA. Compound (E)-3-(4-fluorophenyl)-5-((2-phenylhydrazineylidene)methyl)isoxazole inhibited excellently HBeAg with IC₅₀ in 0.65 μM (3TC(Lamivudine) in 189.90 μM), inhibited HBV DNA in 20.52 μM (3TC in 26.23 μM). Structures of compounds were determined by NMR and HRMS methods, and chlorination on phenyl ring of phenylisoxazol-5-yl was confirmed by X-ray diffraction analysis, and the structure–activity relationships (SARs) of the derivatives was discussed. This work provided a new class of potent non-nucleoside anti-HBV agents.     

Synthesis and antimycobacterial evaluation of N-substituted 3-aminopyrazine-2,5-dicarbonitriles

A series of 14 new compounds related to pyrazinamide were synthesized, characterized with analytical data and screened for in vitro antimycobacterial activity against Mycobacterium tuberculosis, Mycobacterium kansasii and two types of Mycobacterium avium. The series comprised of N-substituted 3-aminopyrazine-2,5-dicarbonitriles derived from 3-chloropyrazine-2,5-dicarbonitrile by nucleophilic substitution of chlorine by various non-aromatic amines (alkylamines, cycloalkylamines and heterocyclic amines). Noteworthy antimycobacterial activity against M. tuberculosis was found among the alkylamino derivatives, for example, 3-(heptylamino)pyrazine-2,5-dicarbonitrile inhibited M. tuberculosis at MIC=51 μmol/L. 3-(Hexylamino)pyrazine-2,5-dicarbonitrile inhibited M. kansasii at MIC=218 μmol/L. Basic structure-activity relationships are discussed. A comparison between calculated and experimentally determined lipophilicity parameters within the series is included.     

Synthesis and evaluation of 1-(substituted)-3-prop-2-ynylureas as antiangiogenic agents

Novel urea derivatives of alkynes have been designed, synthesized, and evaluated as potential cancer therapeutics leads. The most active 1-((3-chloromethyl)phenyl)-3-prop-2-ynylurea (1) exhibited cytotoxic effect against HELA and MCF-7 cell lines with IC(50) values of 1.55 μM and 1.48 μM, respectively. Further investigation on tube formation assay in human vein umbilical cells (HUVEC) demonstrated that 1 and methyl 4-(3-(3-ethynylureido)benzyloxy) benzoate (6) possess antiangiogenic activity, with minimum effective dose of 25 nM (for 1) and 6.25 μM (for 6). The ED(50) of 1 and 6 were found to be 0.26 μM and 17.52 μM, respectively. The results from in vitro tyrosine kinase assay indicated the EGFR inhibition of 1 over other kinases (VEGFR2, FGFR1 and PDGFRβ). The cytotoxicity of 1 against EGFR overexpressing cell line A431 (IC(50) 36 nM) was comparable to that of erlotinib. The binding mode of 1 from docking simulation in the EGFR active site revealed that the urea motif formed hydrogen bonding with Lys745, Thr854 and Asp855 in hydrophobic pocket of EGFR. Compound 1 is considered as a potential lead for further optimization.     

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.     

Synthesis and biological evaluation of 3-[4-(amino/methylsulfonyl)phenyl]methylene-indolin-2-one derivatives as novel COX-1/2 and 5-LOX inhibitors

Fourteen new 3-[4-(amino/methylsulfonyl)phenyl]methylene-indolin-2-one derivatives were synthesized. Six compounds displayed potent inhibitory activities against COX-1/2 and 5-LOX with IC(50) in the range of 0.10-9.87 μM. Particularly, 10f exhibited well balanced inhibitory action on these enzymes (IC(50)=0.10-0.56 μM). More importantly, 10f and several other compounds had comparable or stronger anti-inflammatory and analgesic activities, but better gastric tolerability in vivo, as compared with darbufelone mesilate and tenidap sodium. Therefore, our findings may aid in the design of new and safe anti-inflammatory reagents for the intervention of painful inflammatory diseases, such as rheumatoid arthritis at clinic.     

Cytotoxic steroids from Monascus purpureus-fermented rice

Bioassay-guided fractionation of an EtOH extract of Monascus purpureus-fermented rice led to the isolation of two new steroids (22S, 23R, 24S)-20β,23α,25α-trihydroxy-16,22-epoxy-4,6,8(14)-trienergosta-3-one (1), the first example of a steroid possessing both a conjugated triene ketone system and a fused 4H-furan ring side chain within one molecule, and (22E, 24R)-3β,5α-dihydroxyergosta-23-methyl-7,22-dien-6-one (2), as well as two known compounds (22E, 24R)-3β,5α-dihydroxyergosta-7,22-dien-6-one (3) and (22E, 24R)-6β-methoxy-ergosta-7,22-diene-3β,5α-diol (4). Their structures were assigned by detailed interpretation of HRESIMS, 1D and 2D NMR spectroscopic data. The absolute stereochemistry of 1 was determined by single-crystal X-ray crystallography while the absolute stereochemistry of 2 was established by CD. Compounds 1-4 showed cytotoxic activity against the lung adenocarcinoma (A549) with IC(50) values of 0.08, 0.94, 12.6 and 13.5 μM, respectively. In addition, compounds 1 and 2 exhibited moderate activities against human ovarian cancer (A2780), with IC(50) values of 2.8 and 5.1 μM.     

Synthesis, characterization, antiamoebic activity and cytotoxicity of new pyrazolo[3, 4-d]pyrimidine-6-one derivatives

A new series of pyrazolo[3,4-d]pyrimidine-6-one derivatives (2a-2j) were prepared by using the Biginelli multicomponent cyclocondensation of 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one (1a), different aromatic aldehydes, and urea with a catalytic amount of HCl at reflux temperature. These compounds were characterized by IR, (1)H NMR, (13)C NMR, and Mass spectral data. In vitro antiamoebic activity was performed against HM1:IMSS strain of Entamoeba histolytica. The results showed that the compounds 2b, 2i, and 2j with IC(50) values of 0.37 μM, 0.04 μM, and 0.06 μM, respectively, exhibited better antiamoebic activity than the standard drug metronidazole (IC(50)?=?1.33 μM). The toxicological studies of these compounds on human breast cancer MCF-7 cell line showed that the compounds 2b, 2i, and 2j exhibited >80% viability at the concentration range of 1.56-50 μM.