Inhibitors of NF-kappaB derived from thalidomide

A series of compounds originally derived from thalidomide were synthesized and evaluated. The most potent compounds in this series, 5HPP-33 and compound 20, inhibited NF-kappaB activation in HeLa cells. Preliminary study indicated that the mechanism of inhibition of NF-kappaB activation is through inhibition of its translocation from the cytoplasm to the nucleus.     

Potent, selective spiropyrrolidine pyrimidinetrione inhibitors of MMP-13

Explorations in the pyrimidinetrione series of MMP-13 inhibitors led to the discovery of a series of spiro-fused compounds that are potent and selective inhibitors of MMP-13. While other spiro-fused motifs are hydrolytically unstable, presumably due to electronic destabilization of the pyrimidinetrione ring, the spiropyrrolidine series does not share this liability. Greater than 100-fold selectivity versus other MMP family members was achieved by incorporation of an extended aryl-heteroaryl P1'group. When dosed as the sodium salt, these compounds displayed excellent oral absorption and pharmacokinetic properties. Despite the selectivity, a representative of this series produced fibroplasia in a 14 day rat study.     

Preparation of 5-aryl-3-alkylthio-l,2,4-triazoles and corresponding sulfones with antiinflammatory-analgesic activity

In this study, a series of 5-aryl-3-alkylthio-1,2,4-triazoles and corresponding sulfones were prepared with the objective of developing better analgesic-antiinflammatory compounds with minimum ulcerogenic risk. The structures of the compounds were elucidated by spectral and elemental analysis. The compounds were assayed per os in mice for their antiinflammatory and analgesic activity as well as the ulcerogenic risk and acute toxicity. Several of these compounds showed significant activity. Alkylsulfone derivatives were found to be much more potent analgesic-antiinflammatory agents than the corresponding alkylthio analogs. Compounds 9 and 11 were the most active of the series in both analgesic and antiinflammatory activity tests. In contrast to reference compound acetyl salicylic acid, these compounds did not induce gastric lesions in the stomach of experimental animals at the doses that exhibited analgesic/antiinflammatory activity.     

Identification of pyrrolo[2,3-g]indazoles as new Pim kinase inhibitors

The synthesis and Pim kinase inhibition potency of a new series of pyrrolo[2,3-g]indazole derivatives is described. The results obtained in this preliminary structure–activity relationship study pointed out that sub-micromolar Pim-1 and Pim-3 inhibitory potencies could be obtained in this series, more particularly for compounds 10 and 20, showing that pyrrolo[2,3-g]indazole scaffold could be used for the development of new potent Pim kinase inhibitors. Molecular modeling experiments were also performed to study the binding mode of these compounds in Pim-3 ATP-binding pocket.     

New high affinity H3 receptor agonists without a basic side chain

In this study, we replaced the basic amine function of the known histamine H(3) receptor agonists imbutamine or immepip with non-basic alcohol or hydrocarbon moieties. All compounds in this study show a moderate to high affinity for the cloned human H(3) receptor and, unexpectedly, almost all of them act as potent agonists. Moreover, in the alcohol series, we consistently observed an increased selectivity for the human H(3) receptor over the human H(4) receptor, but none of the compounds in this series possess increased affinity and functional activity compared to their alkylamine congeners. In this new series of compounds VUF5657, 5-(1H-imidazol-4-yl)-pentan-1-ol, is the most potent histamine H(3) receptor agonist (pK(i) = 8.0 and pEC(50) = 8.1) with a 320-fold selectivity at the human H(3) receptor over the human H(4) receptor.     

3,3′-Disubstituted bipolar biphenyls as inhibitors of nuclear receptor coactivator binding

A series of bipolar biphenyl compounds was synthesized as proteomimetic analogs of the LXXLL penta-peptide motif responsible for the binding of coactivator proteins to the nuclear hormone receptor coactivator binding domain. These compounds were subjected to multiple in vitro assays to evaluate their effectiveness as competitive binding inhibitors. The results from this initial study indicate that these proteomimetics possess the ability to inhibit this protein-protein interaction.     

Design and synthesis of aminoester heterodimers containing flavone or chromone moieties as modulators of P-glycoprotein-based multidrug resistance (MDR)

In this study, a new series of heterodimers was synthesized. These derivatives are N,N-bis(alkanol)amine aryl esters or N,N-bis(ethoxyethanol)amine aryl esters carrying a methoxylated aryl residue combined with a flavone or chromone moiety. The new compounds were studied to evaluate their P-gp modulating activity on a multidrug-resistant leukemia cell line. Some of the new compounds show a good MDR reversing activity; interestingly this new series of compounds does not comply with the structure-activity relationships (SAR) outlined by previously synthesized analogs carrying different aromatic moieties. In the case of the compounds described in this paper, activity is linked to different features, in particular the characteristics of the spacer, which seem to be critical for the interaction with the pump. This fact indicates that the presence of a flavone or chromone residue influences the SAR of these series of products, and that flexible molecules can find different productive binding modes with the P-gp recognition site. These results support the synthesis of new compounds that might be useful leads for the development of drugs to control P-gp-dependent MDR.     

Analysis of the pharmacological properties of clozapine analogues using molecular electrostatic potential surfaces

Molecular electrostatic potential surfaces have been used to study a series of neuroleptic compounds, clozapine and clozapine analogues, with similar structures but two rather different pharmacological profiles. Using the electrostatic potential surfaces, the compounds studied could be assigned to one of two distinct categories corresponding to the two pharmacological classes. The results of this study suggest that the molecular electrostatic potential surfaces may be useful in the a priori prediction of pharmacological properties of untested clozapine analogues.     

Structure-activity relationships in platelet-activating factor. Part 13: synthesis and biological evaluation of piperazine derivatives with dual anti-PAF and anti-HIV-1 or pure antiretroviral activity

HIV-1 infection of the brain and PAF neurotoxicity are implicated in AIDS dementia complex. We previously reported that a trisubstituted piperazine derivative is able to diminish both HIV-1 replication in monocyte-derived macrophages and PAF-induced platelet aggregation. We report in this work new compounds obtained by modifying its piperazine substituents. The structure-activity relationship study shows that a better dual activity or even pure antiretroviral compounds can be obtained in this series.     

Anti-infective and herbicidal activity of N-substituted 2-aminobenzothiazoles

In this study, a series of N-substituted 2-aminobenzothiazoles was prepared according to a recently developed method. Twelve compounds were tested for their activity related to the inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. Primary in vitro screening of the discussed compounds was also performed against fungal, bacterial and mycobacterial species. The biological activities of some compounds were comparable or higher than the standards phenoxymethylpenicillin or pyrazinamide. The most effective compounds demonstrated insignificant toxicity against the human monocytic leukemia THP-1 cell line. For all compounds, the structure-activity relationships are discussed.     

Evidence for the mechanism of the irreversible inhibition of oestrone sulphatase (ES) by aminosulphonate based compounds

In our search for the mechanism of the enzyme oestrone sulphatase (ES) we have synthesised and evaluated a number of compounds that were predicted to possess some inhibitory activity. Some of these compounds were indeed found to be inhibitors of ES, whilst other compounds were not. From a consideration of the structure–activity relationship (SAR) of the inhibitors and non-inhibitors of this enzyme, we discovered a factor which we now believe is the main inhibitory moiety within the aminosulphonated inhibitors. We therefore report the results of our study into a series of phenyl and alkyl sulphamated compounds as inhibitors of ES. The results of the study show that the substituted phenyl sulphamates are potent inhibitors, whereas the alkyl compounds are, in general, non-inhibitors. Using the results of our SAR study, we postulate the probable mechanism for the irreversible and reversible inhibition of ES, and rationalise the role of the different physicochemical factors in the inhibition of this crucial enzyme.     

Numerical analyses of some common errors in chemosystematics

The effects of random and nonrandom errors were analyzed. Four types of nonrandom errors were simulated and examined in detail: 1. misidentification of compounds; 2. unresolved components; 3. errors in the quantification of individual compounds; and 4. errors in the quantification of a series of analyses. These cases were compared using data from studies inJuniperus. Misidentification of 1 of 40 components had only a slight effect on the resulting classification even when that error accounted for 20% of the total character weights. Unresolved components also had only a slight effect. Nonrandom errors in the quantification of individual compounds (throughout a study) were shown to have no effect on the similarity measure used in this study. Errors in the quantification of a series of analyses (such as encountered in seasonal variations) appeared to be the most serious source of error and were shown to be of considerable importance in chemosystematic studies. Several preventative procedures are suggested.     

Synthesis and biological activity of quinolinone and dihydroquinolinone p38 MAP kinase inhibitors

Synthesis and biological activities of some quinolinone and dihydroquinolinone p38 MAP kinase inhibitors are reported. Modifications to the dihydroquinolinone pharmacophore revealed that dihydroquinolinone may be replaced with a quinolinone pharmacophore and lead to enhanced p38 inhibitory activity. From a study of C-7 substitutions by amino acid side chains, a very potent series of compounds in the p38 enzyme assays was identified. Translation of the in vitro activity into reasonable whole blood activity can be improved in this series of compounds by judicious modification of the physical properties at appropriate regions of the lead.     

Lead optimization of a sulfonylurea-based piperazine pyridazinone series of glucan synthase inhibitors

The structure-activity relationship studies of a novel sulfonylurea series of piperazine pyridazine-based small molecule glucan synthase inhibitors is described. The optimization of PK profiles within the series led to the discovery of several compounds with improved pharmacokinetic profiles which demonstrated in vitro potency against clinically relevant strains. However, the advancement of compounds from this series into a non-lethal systemic fungal infection model failed to show in vivo efficacy.     

Synthesis,stereochemical assignment and biological activity of a novel series of C-4" modified aza-macrolides

Modification of the cladinose C-4" position via manipulation of the corresponding keto derivatives afforded two stereochemically pure series of compounds. The synthesis and structure determination of these compounds is described within. The in vitro and in vivo biological activity of this novel series of C-4" modified macrolides is also described.     

Synthesis, structure-affinity relationships, and molecular modeling studies of novel pyrazolo[3,4-c]quinoline derivatives as adenosine receptor antagonists

This paper reports the study of new 2-phenyl- and 2-methylpyrazolo[3,4-c]quinolin-4-ones (series A) and 4-amines (series B), designed as adenosine receptor (AR) antagonists. The synthesized compounds bear at the 6-position various groups, with different lipophilicity and steric hindrance, that were thought to increase human A(1) and A(2A) AR affinities and selectivities, with respect to those of the parent 6-unsubstituted compounds. In series A, this modification was not tolerated since it reduced AR affinity, while in series B it shifted the binding towards the hA(1) subtype. To rationalize the observed structure-affinity relationships, molecular docking studies at A(2A)AR-based homology models of the A(1) and A(3) ARs and at the A(2A)AR crystal structure were carried out.     

Discovery of a substituted 8-arylquinoline series of PDE4 inhibitors: structure-activity relationship, optimization, and identification of a highly potent, well tolerated, PDE4 inhibitor

The discovery and SAR of a new series of substituted 8-arylquinoline PDE4 inhibitors are herein described. This work has led to the identification of several compounds with excellent in vitro and in vivo profiles, including a good therapeutic window of emesis to efficacy in several animal models. Typical optimized compounds from this series are potent inhibitors of PDE4 (IC(50)<1nM) and also of LPS-induced TNF-alpha release in human whole blood (IC(50)<0.5microM). The same compounds are potent inhibitors of ovalbumin-induced bronchoconstriction in conscious guinea pigs (EC(50)<0.1mg/kg ip) but require a dose of about 10mg/kg po in the squirrel monkey to produce an emetic response. From this series of compounds, 23a (L-454,560) was identified as an optimized compound.     

ERbeta ligands. Part 2: Synthesis and structure-activity relationships of a series of 4-hydroxy-biphenyl-carbaldehyde oxime derivatives

A series of biphenyl carbaldehyde oximes (6) was prepared and shown to have significant selectivity for the estrogen receptor-beta (ERbeta). The exploitation of the oxime moiety as a hydrogen bond donating group, which mimicked the C-ring of genistein makes these compounds unique. Molecular modeling studies showed the oxime moiety hydrogen bonding to the histidine residue, which was supported by the structure-activity relationships. The most potent compounds in this study had IC50 values in a radioligand binding assay of between 8-35 nM. Among the most selective compounds were 6i and 6s (49- and 31-fold ERbeta selective, respectively).     

Antioxidative activity of some quaternary ammonium salts incorporated into erythrocyte membranes

The antioxidative activity of two series of amphiphilic compounds from a group of quaternary ammonium salts has been investigated. They were so-called bifunctional surfactants synthesized to be used as common pesticides or as antioxidants. The latter application was to be ensured by providing the compounds studied with an antioxidant group. Studies on antioxidative possibilities of those compounds were performed on pig erythrocytes. Due to their hydrophobic parts, they anchor in the erythrocyte membrane and influence the degree of lipid oxidation in the erythrocyte membrane subjected to UV radiation. It was found that compounds of both series decreased the oxidation of the membrane lipids. The inhibition of this oxidation increased with the length of their hydrophobic chains up to fourteen carbon atoms. The compounds of the longest hydrophobic chains showed a somewhat weaker antioxidative activity. Of the two series studied compounds were more effective having bromide ions as counterions. The corresponding compounds of a second series (chlorides) protected erythrocyte significantly weaker against oxidation. The effect of the compounds on fluidity of the erythrocyte membrane has been studied in order to explain the oxidation results. Change in fluidity of the erythrocyte ghost membranes was found also dependent on length of the hydrophobic part of the compounds and was more pronounced in the case of bromide surfactants. The final conclusion is that the compounds studied can be succesfully used as antioxidant agents of good efficacy.