Synthesis and biological activity of optically active NCL-1, a lysine-specific demethylase 1 selective inhibitor

Optically active (1S,2R)-NCL-1 and (1R,2S)-NCL-1 were synthesized and evaluated for their lysine-specific demethylase 1 inhibitory activity and cell growth inhibitory activity. In enzyme assays, the (1S,2R)-isomer was approximately four times more potent than the (1R,2S)-isomer. In cell growth inhibition assays, the two isomers showed similar activity in HEK293 cells and SH-SY5Y cells, whereas the (1S,2R)-isomer showed approximately four times more potent activity than the (1R,2S)-isomer in HeLa cells.

Halogenation of 4-hydroxy/amino-3-methoxyphenyl acetamide TRPV1 agonists showed enhanced antagonism to capsaicin

As an extension of our analysis of the effect of halogenation on thiourea TRPV1 agonists, we have now modified selected 4-hydroxy(or 4-amino)-3-methoxyphenyl acetamide TRPV1 agonists by 5- or 6-halogenation on the aromatic A-region and evaluated them for potency for TRPV1 binding and regulation and for their pattern of agonism/antagonism (efficacy). Halogenation shifted the functional activity at TRPV1 toward antagonism with a greater extent of antagonism as the size of the halogen increased (I>Br>Cl), as previously observed for the thiourea series. The extent of antagonism was greater for halogenation at the 5-position than at the 6-position, in contrast to SAR for the thiourea series. In this series, compounds 55 and 75 showed the most potent antagonism, with K(i) (ant)=2.77 and 2.19nM, respectively, on rTRPV1 expressed in Chinese hamster ovary cells. The compounds were thus ca. 40-60-fold more potent than 6'-iodononivamide.

Synthesis and optimization of novel 4,4-disubstituted cyclohexylbenzamide derivatives as potent 11β-HSD1 inhibitors

The synthesis and SAR of a series of 4,4-disubstituted cyclohexylbenzamide inhibitors of 11β-HSD1 are described. Optimization rapidly led to potent, highly selective, and orally bioavailable inhibitors demonstrating efficacy in both rat and non-human primate ex vivo pharmacodynamic models.

Cytotoxic effects of N-(3-chloro-1,4-dioxo 1,4-dihydro-naphthalen-2-yl)-benzamide on androgen-dependent and -independent prostate cancer cell lines

BACKGROUND

Worldwide among men, prostate cancer ranks third in cancer occurrence and sixth in cancer mortality. A number of 1, 4-naphthoquinone derivatives have been identified that possess significant pharmacological effects associated with antitumor activities. In this study, the in vitro effects of N-(3-chloro-1,4-dioxo 1,4-dihydro-naphthalen-2-yl)-benzamide (NCDDNB) were evaluated on androgen-dependent (CWR-22) and androgen-independent (PC-3, DU-145) human prostate cancer cell lines, and on a normal bone marrow cell line (HS-5). Specifically, the in vitro activity of this compound on cell cycle regulation and apoptosis was evaluated.

MATERIALS AND METHODS

Established methods of cell viability, cell cycle, Western blot and apoptosis were used.

RESULTS

The effect of NCDDNB on CWR-22, PC-3, DU-145 and HS-5 cells revealed significant anti-tumor activities with IC(50)s, of 2.5, 2.5, 6.5, and 25 muM respectively. The results of cell cycle analysis showed that NCDDNB arrested PC-3, DU-145, and CWR-22 cells in the G(1)-phase of the cell cycle. The compound showed no effect on the cell cycle progression in the HS-5 bone marrow cell line. These findings were further validated using Western blot analysis. NCDDNB showed the greatest amount of apoptosis in the androgen-independent PC-3 cells in a time-dependent manner with the apoptotic apex at day 5 of treatment. Furthermore, NCDDNB induced-apoptosis in DU-145 and CWR-22 cells peaked at day 3 of treatment.

CONCLUSION

Although the mechanism of action of this compound has not been completely elucidated, the effect on the cell cycle and the induction of apoptosis in different prostate cancer cell lines prompted us to carry out a more in-depth preclinical evaluation. This study suggests that NCDDNB may have an impact on treatment of prostate cancer while protecting the bone marrow.

Design, synthesis and prostate cancer cell-based studies of analogs of the Rho/MKL1 transcriptional pathway inhibitor, CCG-1423

We recently identified bis(amide) CCG-1423 (1) as a novel inhibitor of RhoA/C-mediated gene transcription that is capable of inhibiting invasion of PC-3 prostate cancer cells in a Matrigel model of metastasis. An initial structure-activity relationship study focusing on bioisosteric replacement of the amides and conformational restriction identified two compounds, 4g and 8, with improved selectivity for inhibition of RhoA/C-mediated gene transcription and attenuated cytotoxicity relative to 1. Both compounds were also capable of inhibiting cell invasion with equal efficacy to 1 but with less attendant cytotoxicity.

A novel histone deacetylase inhibitor Chidamide induces apoptosis of human colon cancer cells

Many studies have demonstrated that histone deacetylase (HDAC) inhibitors induce various tumor cells to undergo apoptosis, and such inhibitors have been used in different clinical trials against different human cancers. In this study, we designed and synthesized a novel HDAC inhibitor, Chidamide. We showed that Chidamide was able to increase the acetylation levels of histone H3 and to inhibit the PI3K/Akt and MAPK/Ras signaling pathways, which resulted in arresting colon cancer cells at the G1 phase of the cell cycle and promoting apoptosis. As a result, the proliferation of colon cancer cells was suppressed in vitro. Our data support the potential application of Chidamide as an anticancer agent in treating colon cancer. Future studies are needed to demonstrate its in vivo efficacy.

[Synthesis and anti-tumor activities of N-(aminopyridine) benzamide derivaties]

To explore novel histone deacetylase (HDAC) inhibitors with anti-tumor activity, on the basis of preliminary studies, sixteen N-(2-amino-4-pyridine) benzamide derivaties (class A) and sixteen N-(2-amino-3-pyridine) benzamide derivaties (class B) were designed and prepared, and their structures were confirmed by 1H NMR and HR-MS individually. The results showed that 30 target compounds except V-20 and V-21 had HDACs inhibitory activity and V -13, V -14, V -16 were equal to CI-994 at 200 micromol x L(-1) in vitro. Compounds V-30, V-31 and V-32 exhibited potent inhibitory activities on Hut78, Jurkat E6-1, A549, K562 and MDA-MB-435s.

Structure-based design, synthesis, and biological evaluation of a series of novel and reversible inhibitors for the severe acute respiratory syndrome-coronavirus papain-like protease

We describe here the design, synthesis, molecular modeling, and biological evaluation of a series of small molecule, nonpeptide inhibitors of SARS-CoV PLpro. Our initial lead compound was identified via high-throughput screening of a diverse chemical library. We subsequently carried out structure-activity relationship studies and optimized the lead structure to potent inhibitors that have shown antiviral activity against SARS-CoV infected Vero E6 cells. Upon the basis of the X-ray crystal structure of inhibitor 24-bound to SARS-CoV PLpro, a drug design template was created. Our structure-based modification led to the design of a more potent inhibitor, 2 (enzyme IC(50) = 0.46 microM; antiviral EC(50) = 6 microM). Interestingly, its methylamine derivative, 49, displayed good enzyme inhibitory potency (IC(50) = 1.3 microM) and the most potent SARS antiviral activity (EC(50) = 5.2 microM) in the series. We have carried out computational docking studies and generated a predictive 3D-QSAR model for SARS-CoV PLpro inhibitors.

Discovery and structural analysis of Eph receptor tyrosine kinase inhibitors

The Eph family of receptor tyrosine kinases has drawn growing attention due to their role in regulating diverse biological phenomena. However, pharmacological interrogation of Eph kinase function has been hampered by a lack of potent and selective Eph kinase inhibitors. Here we report the discovery of compounds 6 and 9 using a rationally designed kinase-directed library which potently inhibit Eph receptor tyrosine kinases, particularly EphB2 with cellular EC(50)s of 40nM. Crystallographic data of EphA3 and EphA7 in complex with the inhibitors show that they bind to the 'DFG-out' inactive kinase conformation and provide valuable information for structure-based design of second generation inhibitors.

[Synthesis and anti-tumor activities of N-substituted benzamide derivatives]

To explore novel histone deacetylase (HDACs) inhibitors with anti-tumor activity, MS-275, a HDACs inhibitor, was prepared and used as a lead compound to design new N-substituted benzamide derivatives. MS-275 and eleven target compounds were obtained, and their structures were confirmed by 1H NMR and HR-MS individually. The results showed that the activity of compound 9d was equal to MS-275 in HDACs inhibition tests in vitro and worthy of further investigation. Compound 5c, 5d and 9c displayed obvious dose-effect relationship, which possessed moderate HDACs inhibitory activities. Ten compounds except 9e had selective inhibitory activities on Hut78.

Synthesis and structure-activity relationships of amide derivatives of (4,4-difluoro-1,2,3,4-tetrahydro-5H-1-benzazepin-5-ylidene)acetic acid as selective arginine vasopressin V2 receptor agonists

A series of (4,4-difluoro-1,2,3,4-tetrahydro-5H-1-benzazepin-5-ylidene)acetamide derivatives was synthesized, and their structure-activity relationships were examined in order to identify potent and selective arginine vasopressin V(2) receptor agonists. Attempts to substitute other chemical groups in place of the 2-pyridilmethyl moiety of 1a led to the discovery that potent V(2) binding affinity could be obtained with a wide range of functional groups. This structural tolerance allowed for the manipulation of other attributes, such as selectivity against V(1a) receptor affinity or avoidance of the undesirable inhibition of cytochrome P450 (CYP), without losing potent affinity for the V(2) receptor. Some representative compounds obtained in this study were also found to decrease urine volume in awake rats.

New derivatives of benzylamide with anticonvulsant activity

Previously obtained picolinic acid benzylamide is a potent anticonvulsant with low neurotoxicity. In search for new effective anticonvulsants twelve new benzylamides (1-12) were synthesized and preliminary evaluated in the Anticonvulsant Screening Program (ASP) of Antiepileptic Drug Development Program (ADDP) of NIH. Two of them appeared the most promising: 1-cyclopentenecarboxylic acid benzylamide (1-Cpc-BZA) (9) showed MES ED50 = 85,36 mg/kg (PI = 2,49), scPTZ ED50 = 1,37 mg/kg (PI = 1,37), 6Hz-EST ED50 = 50,29 mg/kg and cyclopentanecarboxylic acid benzylamide (Cpc-BZA) (11) showed pilocarpine ED50 = 154.75 mg/kg and pilocarpine ED97 = 270.95 mg/kg.

Aryl aminopyrazole benzamides as oral non-steroidal selective glucocorticoid receptor agonists

Aryl aminopyrazole amides capped with N-alkylbenzamides 13-16 are selective glucocorticoid receptor agonists. 2,6-Disubstituted benzamides have prednisolone-like potency or better in vitro. Good oral exposure was demonstrated in the rat, with compounds with lower lipophilicity, for example N-hydroxyethyl benzamides (e.g., 16e).

Designing selective, high affinity ligands of 5-HT1D receptor by covalent dimerization of 5-HT1F ligands derived from 4-fluoro-N-[3-(1-methyl-4-piperidinyl)-1H-indol-5-yl]benzamide

We demonstrate here that covalent dimerization of 5-HT 1 ligands is an effective design strategy to modulate affinity and selectivity of 5-HT 1 ligands. This approach was applied to LY-334370, a selective agonist of 5-HT 1F receptor, to generate structurally well-defined divalent molecules. Radioligand binding assays to three cloned 5-HT 1 receptor subtypes (5-HT 1B, 5-HT 1D, 5-HT 1F) demonstrated that the affinity of a series of homologous dimers varied significantly upon exploration of three structural variables (linker length, attachment position, functionality). In particular, the series of C 3-to-C 3 linked dimers derived from a monomer ( 3) showed high binding affinity to 5-HT 1D (for example, K i approximately 0.3 nM for dimer 8) but did not bind to 5-HT 1F ( K i > 0.01 mM), providing >10000-fold subtype selectivity. Results from a functional assay (rabbit saphenous vein contraction) demonstrate that certain dimers are 5-HT 1 receptor agonists.

N-{[(6-Substituted-1,3-benzothiazole-2-yl)amino]carbonothioyl}-2/4-substituted benzamides: Synthesis and pharmacological evaluation

A series of 1,3-benzothiazol-2-yl benzamides (11-30) were prepared in satisfactory yield and evaluated for their anticonvulsant, neurotoxicity, CNS depressant study and other toxicity studies. All the synthesized compounds were in good agreement with elemental and spectral data. Majority of the compounds were active in MES and scPTZ screen and showed the decrease in the immobility time. None of the compounds had shown neurotoxicity or liver toxicity.

Derivatives of aryl-4-guanidinomethylbenzoate and N-aryl-4-guanidinomethylbenzamide as new antibacterial agents: synthesis and bioactivity

AIM

The aim of the present study was to design, synthesize, and evaluate novel antibacterial agents, derivatives of aryl-4-guanidinomethylbenzoate and N-aryl-4-guanidinomethylbenzamide.

METHODS

A total of 44 derivatives of aryl-4-guanidin-omethylbenzoate (series A) and N-aryl-4-guanidinomethylbenzamide (series B) were synthesized and their antibacterial activities were assessed in vitro against a variety of Gram-positive and Gram-negative bacteria by an agar dilution method.

RESULTS

Twelve compounds showed potent bactericidal effects against a panel of Gram-positive germs, including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), vancomycin-intermediate Staphylococcus aureus (VISA), and methicillin-resistant coagulase-negative staphylococci (MRCNS), with minimum inhibitory concentrations (MIC) ranging between 0.5 and 8 microg/mL, which were comparable to the MIC values of several marketed antibiotics. They exhibited weak or no activity on the Gram-negative bacteria tested. In addition, these compounds displayed high inhibitory activities towards oligopeptidase B of bacterial origin.

CONCLUSION

In comparison with the previously reported MIC values of several known antibiotics, the derivatives of aryl-4-guanidinomethylbenzoate and N-aryl-4-guanidinomethylbenzamide showed comparable in vitro bactericidal activities against VRE and VISA as linezolid. Their growth inhibitory effects on MRSA were similar to vancomycin, but were less potent than linezolid and vancomycin against MRCNS. This class of compounds may have the potential to be developed into narrow spectrum antibacterial agents against certain drug-resistant strains of bacteria.

Synthesis of functionalised aromatic oligamide rods

A current goal in synthetic chemistry is the design and synthesis of molecules that adopt well defined conformations-so called foldamers. In this manuscript we describe a modular approach for construction of rod shaped para-oligobenzamide molecules. Our approach permits regiospecific incorporation of side chains through a phenolic ether linkage on the scaffold; a feature that partly restricts the conformation of the rod through intramolecular hydrogen-bonding.

Synthesis of DL-fluorobenzenamides as anticonvulsants

DL-2-Hydroxy-2-phenyl butyramide (1, CAS 52839-87-9), DL-3-hydroxy-3-phenyl pentanamide (2, CAS 131802-69-2) and DL-4-hydroxy-4-phenyl hexanamide (3, CAS 67880-30-2) are anticonvulsants. Searching for more active compounds, some DL-fluorobenzenamides were prepared and tested: DL-2-hydroxy-2-(3'-trifluoromethylphenyl)butyramide (4), DL-2-Hydroxy-2-4'-trifluoromethylphenyl) butyramide (5, CAS 620950-10-9), DL-2-hydroxy-2-[3',5'-bis(trifluoromethyl)phenyl]butyramide (6, CAS 620950-09-6), DL-3-hydroxy-3-(3'-trifluoromethylphenyl) pentanamide (7), DL-3-hydroxy-3-(4'-trifluoromethylphenyl)pentanamide (8), and DL-3-hydroxy-3-[3',5'-bis(trifluoromethyl)phenyl]pentanamide (9, CAS 863976-07-2). Compounds 4-9 exhibited anticonvulsant activity in seizures induced by pentylenetetrazol in mice. Incorporation of trifluoromethyl groups in the phenyl ring of 1, 2 and 3 increased their potency. Compounds 4, 6 and 9 exhibited a similar anticonvulsant activity as the reference drug phenobarbital (CAS 50-06-6).

Synthesis of DL-hydroxybenzenamides as anticonvulsants

The anticonvulsant activity of some DL-hydroxybenzenamides is described. The following compounds from this series were prepared and tested: DL-2-hydroxy-2-(3'-bromophenyl)butyramide (4, CAS 620950-12-1), DL-2-hydroxy-2-(4'-bromophenyl)butyramide (5, CAS 620950-13-2), DL-2-hydroxy-2-(3'-nitrophenyl)butyramide (6, CAS 620950-14-3), DL-2-hydroxy-2-phenyl hexanamide (7, CAS 63002-05-1), DL-2-hydroxy-2-(3',4'-dichlorophenyl)hexanamide (8, CAS 863976-06-1), DL-3-hydroxy-3-(4'-bromophenyl)pentanamide (9, CAS 620950-16-5), DL-3-hydroxy-3-phenyl-heptanamide (10, CAS 863976-08-3) and DL-4-hydroxy-4-(4'-bromophenyl)hexanamide (11,CAS 620950-18-7). Compounds 4, 5, 9 and 11 exhibited significant activity in seizures induced by pentylenetetrazol. Incorporation of bromine in the phenyl ring increased their potency. Compounds 4, 5, 9 and 11 exhibited a similar anticonvulsant activity as the reference drug phenobarbital (CAS 50-06-6).

Design and synthesis of 4-[(s-triazin-2-ylamino)methyl]-N-(2-aminophenyl)-benzamides and their analogues as a novel class of histone deacetylase inhibitors

Inhibition of histone deacetylases (HDAC) is emerging as a new strategy in human cancer therapy. The synthesis and biological evaluation of a variety of 4-(heteroarylaminomethyl)-N-(2-aminophenyl)-benzamides is presented herein. From the different series bearing a six-membered heteroaromatic ring studied, the s-triazine series showed the best HDAC1 enzyme and in vitro anti-proliferative activities with IC(50) values below micromolar range. Some of these compounds can also significantly reduce tumor growth in human tumor xenograft models in mice.

Identification and synthesis of major metabolites of Vasopressin V2-receptor agonist WAY-151932, and antagonist, Lixivaptan®

Small molecule agonists and antagonists of the V(2)-vasopressin receptor have been discovered and have undergone clinical trials. In conjunction with these discovery programs, the synthesis and biological testing of various metabolites associated with these clinical targets were actively pursued. We now report the results of our synthetic efforts and the corresponding biological data generated for several of the metabolites of WAY-151932 and CL-347985 (Lixivaptan).

Discovering benzamide derivatives as glycogen phosphorylase inhibitors and their binding site at the enzyme

A series of novel benzamide derivatives was designed, synthesized, and their inhibitory activities against glycogen phosphorylase (GP) in the direction of glycogen synthesis by the release of phosphate from glucose-1-phosphate were evaluated. The structure-activity relationships (SAR) of these compounds are also presented. Within this series of compounds, 4m is the most potent GPa inhibitor (IC(50)=2.68 microM), which is nearly 100 times more potent than the initial compound 1. Analysis of mapping between pharmacophores of different binding sites and each compound demonstrated that these benzamide derivatives bind at the dimer interface of the rabbit muscle enzyme, and possible docking modes of compound 4m were explored by molecular docking simulation.

In vitro affinities of various halogenated benzamide derivatives as potential radioligands for non-invasive quantification of D2-like dopamine receptors

Benzamide derivatives as radiotracers have played an important role in diagnosing malfunction in dopaminergic neurotransmission. A variety of halogenated and two unsubstituted benzamide derivatives were synthesised and their in vitro affinities to dopaminergic, serotonergic and adrenergic receptors and their lipophilicities were determined. As references IBZM (3), raclopride (4) and FLB457 (5) were tested as well. The two iodinated compounds NAE (27) and NADE (28) displayed K(i) values of 0.68 and 14 nM for the D(2) receptor. The well-established radiotracers FP (1) and DMFP (2) showed affinities in the same range as did the brominated compounds NABrE (29) and NABrDE (30). The log D(7.4) values of 2.91 for NAE (27) and of 2.81 for NADE (28) are in the range of those found for IBZM (3), FP (1) and DMFP (2). These facts allow to expect good properties for the two iodinated compounds NAE (27) and NADE (28) regarding in vivo imaging with SPECT.

Pyrimidine benzamide-based thrombopoietin receptor agonists

A series of pyrimidine benzamide-based thrombopoietin receptor agonists is described. The lead molecule contains a 2-amino-5-unsubstituted thiazole, a group that has been associated with idiosyncratic toxicity. The potential for metabolic oxidation at C-5 of the thiazole, the likely source of toxic metabolites, was removed by substitution at C-5 or by replacing the thiazole with a thiadiazole. Potency in the series was improved by modifying the substituents on the pyrimidine and/or on the thiazole or thiadiazole pendant aryl ring. In vivo examination revealed that compounds from the series are not highly bioavailable. This is attributed to low solubility and poor permeability.