Estrogen Attenuates Diethylnitrosamine-Induced Hepatocellular Carcinoma in Female Rats via Modulation of Estrogen Receptor/FASN/CD36/IL-6 Axis.

This study was designed to evaluate the potential protective impact of estrogen and estrogen receptor against diethylnitrosamine (DEN)-induced hepatocellular carcinoma (HCC) in rats. The levels of liver injury serum biomarkers, liver content of interleukin-6 (IL-6), relative liver weight and distortion of liver histological pictures were significantly increased in ovariectomized (OVX) rats and SHAM rats that received DEN alone and were further exaggerated when DEN was combined with fulvestrant (F) compared to non-DEN treated rats. The OVX rats showed higher insults than SHAM rats. The tapering impact on these parameters was clear in OVX rats that received estradiol benzoate (EB), silymarin (S) or orlistat (ORS). The immunohistochemistry and/or Western blot analysis of liver tissues showed a prominent increase in fatty acid synthase (FASN) and cluster of differentiation 36 (CD36) expressions in OVX and SHAM rats who received DEN and/ or F compared to SHAM rats. In contrast to S, treatment of OVX rats with EB mitigated DEN-induced expression of FASN and CD36 in liver tissue, while ORS improved DEN-induced expression of FASN. In conclusion, the protective effect against HCC was mediated via estrogen receptor alpha (ER-α) which abrogates its downstream genes involved in lipid metabolism namely FASN and CD36 depriving the tumor from survival vital energy source. In addition, ORS induced similar mitigating effect against DEN-induced HCC which could be attributed to FASN inhibition and anti-inflammatory effect. Furthermore, S alleviated DEN-induced HCC, independent of its estrogenic effect.

Stability studies of endocrine disrupting tributyltin and triphenyltin compounds in an artificial sea water model.

Triorganotins belong to toxic components present predominantly in antifouling paints for marine vessels. Tributyltin/triphenyltin at pico- or nanomolar concentrations in sea water are known to induce an irreversible sexual abnormality in females of over 190 marine species, an "imposex" phenomenon - the superimposition of male genitalia on a female. Moreover, trialkyltins and triaryltins function as potent nuclear retinoid X receptors (RXR) agonists. In mammals, triorganotin compounds induce immunosuppressive, metabolic, reproductive or developmental effects. Toxic effects of triorganotins warrant the need for monitoring of their long-lasting presence in the environment. This study brings novel data on the stability of two triorganotin compounds in artificial sea water model obtained by applying ultra-pressure liquid chromatography (UPLC) and gas chromatography-mass spectrometry (GC-MS) methods. Stability of tributyltin and triphenyltin chlorides was studied for 180 days and the degradation kinetic parameters were obtained. Tributyltin chloride was the less stable with the degradation kinetic parameters Kdeg = 0.00014 day-1 and t1/2 = 4950 days (13.6 years). Kdeg of the more stable triphenyltin chloride was determined to be Kdeg = 0.00006 day-1 with t1/2 = 11550 days (31.6 years). Since similar stability data of triorganotin compounds were not published previously, we report high stability for both tested compounds, which indicates a significant environmental problem when these substances enter sea water and later coastal sediments.

Phenothiazine-derived antipsychotic drugs inhibit dynamin and clathrin-mediated endocytosis.

Chlorpromazine is a phenothiazine-derived antipsychotic drug (APD) that inhibits clathrin-mediated endocytosis (CME) in cells by an unknown mechanism. We examined whether its action and that of other APDs might be mediated by the GTPase activity of dynamin. Eight of eight phenothiazine-derived APDs inhibited dynamin I (dynI) in the 2-12 µm range, the most potent being trifluoperazine (IC50 2.6 ± 0.7 µm). They also inhibited dynamin II (dynII) at similar concentrations. Typical and atypical APDs not based on the phenothiazine scaffold were 8- to 10-fold less potent (haloperidol and clozapine) or were inactive (droperidol, olanzapine and risperidone). Kinetic analysis showed that phenothiazine-derived APDs were lipid competitive, while haloperidol was uncompetitive with lipid. Accordingly, phenothiazine-derived APDs inhibited dynI GTPase activity stimulated by lipids but not by various SH3 domains. All dynamin-active APDs also inhibited transferrin (Tfn) CME in cells at related potencies. Structure-activity relationships (SAR) revealed dynamin inhibition to be conferred by a substituent group containing a terminal tertiary amino group at the N2 position. Chlorpromazine was previously proposed to target AP-2 recruitment in the formation of clathrin-coated vesicles (CCV). However, neither chlorpromazine nor thioridazine affected AP-2 interaction with amphiphysin or clathrin. Super-resolution microscopy revealed that chlorpromazine blocks neither clathrin recruitment by AP-2, nor AP-2 recruitment, showing that CME inhibition occurs downstream of CCV formation. Overall, potent dynamin inhibition is a shared characteristic of phenothiazine-derived APDs, but not other typical or atypical APDs, and the data indicate that dynamin is their likely in-cell target in endocytosis.

Quinolone-1-(2H)-ones as hedgehog signalling pathway inhibitors.

A series of quinolone-2-(1H)-ones derived from the Ugi-Knoevenagel three- and four-component reaction were prepared exhibiting low micromolar cytotoxicity against a panel of eight human cancer cell lines known to possess the Hedgehog Signalling Pathway (HSP) components, as well as the seminoma TCAM-2 cell line. A focused SAR study was conducted and revealed core characteristics of the quinolone-2-(1H)-ones required for cytotoxicity. These requirements included a C3-tethered indole moiety, an indole C5-methyl moiety, an aliphatic tail or an ester, as well as an additional aromatic moiety. Further investigation in the SAG-activated Shh-LIGHT2 cell line with the most active analogues: 2-(3-cyano-2-oxo-4-phenylquinolin-1(2H)-yl)-2-(1-methyl-1H-indol-3-yl)-N-(pentan-2-yl)acetamide (5), 2-(3-cyano-2-oxo-4-phenylquinolin-1(2H)-yl)-2-(5-methyl-1H-indol-3-yl)-N-(pentan-2-yl)acetamide (23) and ethyl (2-(3-cyano-2-oxo-4-phenylquinolin-1(2H)-yl)-2-(5-methyl-1H-indol-3-yl)acetyl)glycinate (24) demonstrated a down regulation of the HSP via a reduction in Gli expression, and in the mRNA levels of Ptch1 and Gli2. Analogues 5, 23 and 24 returned in cell inhibition values of 11.6, 2.9 and 3.1 µM, respectively, making this new HSP-inhibitor pharmacophore amongst the most potent non-Smo targeted inhibitors thus far reported.

Magnetically guided capsule versus conventional gastroscopy for upper abdominal complaints: a prospective blinded study.

OBJECTIVES: Upper gastrointestinal endoscopy is mostly performed under sedation and has a low yield of relevant gastric lesions in patients without alarm symptoms. Simpler screening tests such as capsule endoscopy could be helpful, but gastric visualization is insufficient with the current passive capsules. A magnetically guided gastric capsule was prospectively evaluated in patients with routine indications for gastroscopy. METHODS: A total of 189 symptomatic patients (105 male; mean age 53 y) from 2 French centers subsequently and blindly underwent capsule and conventional gastroscopy by 9 and 6 examiners, respectively. The final gold standard was unblinded conventional gastroscopy with biopsy under propofol sedation. Main outcome was accuracy (sensitivity/specificity) of capsule gastroscopy for diagnosis of major gastric lesions, defined as those lesions requiring conventional gastroscopy for biopsy or removal. RESULTS: Twenty-three major lesions were found in 21 patients. Capsule accuracy was 90.5% [95% confidence interval (CI), 85.4%-94.3%] with a specificity of 94.1% (95% CI, 89.3%-97.1%) and a sensitivity of 61.9% (95% CI, 38%-82%). Accuracy did not correlate with lesion location, gastric luminal visibility, examiner case volume, or examination time. Of the remaining 168 patients, 94% had minor and mostly multiple lesions; the capsule made a correct diagnosis in 88.1% (95% CI, 82.2%-92.6%), with gastric visibility and lesion location in the proximal stomach having significant influence. All patients preferred capsule gastroscopy. CONCLUSIONS: In a prospective and strictly blinded study, magnetically guided capsule gastroscopy was shown to be feasible in clinical practice and was clearly preferred by patients. Improvements in capsule technology may render this technique a future alternative to gastroscopy.

1,8-Naphthalimide derivatives: new leads against dynamin I GTPase activity.

Fragment-based in silico screening against dynamin I (dynI) GTPase activity identified the 1,8-naphthalimide framework as a potential scaffold for the design of new inhibitors targeting the GTP binding pocket of dynI. Structure-based design, synthesis and subsequent optimization resulted in the development of a library of 1,8-naphthalimide derivatives, called the Naphthaladyn™ series, with compounds 23 and 29 being the most active (IC50 of 19.1 ± 0.3 and 18.5 ± 1.7 µM respectively). Compound 29 showed effective inhibition of clathrin-mediated endocytosis (IC50(CME) 66 µM). The results introduce 29 as an optimised GTP-competitive lead Naphthaladyn™ compound for the further development of naphthalimide-based dynI GTPase inhibitors.

Further exploration of the heterocyclic diversity accessible from the allylation chemistry of indigo.

Diversity-directed synthesis based on the cascade allylation chemistry of indigo, with its embedded 2,2'-diindolic core, has resulted in rapid access to new examples of the hydroxy-8a,13-dihydroazepino[1,2-a:3,4-b']diindol-14(8H)-one skeleton in up to 51% yield. Additionally a derivative of the novel bridged heterocycle 7,8-dihydro-6H-6,8a-epoxyazepino[1,2-a:3,4-b']diindol-14(13H)-one was produced when the olefin of the allylic substrate was terminally disubstituted. Further optimisation also produced viable one-pot syntheses of derivatives of the spiro(indoline-2,9'-pyrido[1,2-a]indol)-3-one (65%) and pyrido[1,2,3-s,t]indolo[1,2-a]azepino[3,4-b]indol-17-one (72%) heterocyclic systems. Ring-closing metathesis of the N,O-diallylic spiro structure and subsequent Claisen rearrangement gave rise to the new (1R,8aS,17aS)-rel-1,2-dihydro-1-vinyl-8H,17H,9H-benz[2',3']pyrrolizino[1',7a':2,3]pyrido[1,2-a]indole-8,17-(2H,9H)-dione heterocyclic system.

In silico docking, molecular dynamics and binding energy insights into the bolinaquinone-clathrin terminal domain binding site.

Clathrin-mediated endocytosis (CME) is a process that regulates selective internalization of important cellular cargo using clathrin-coated vesicles. Perturbation of this process has been linked to many diseases including cancer and neurodegenerative conditions. Chemical proteomics identified the marine metabolite, 2-hydroxy-5-methoxy-3-(((1S,4aS,8aS)-1,4a,5-trimethyl-1,2,3,4,4a,7,8,8a-octahydronaphthalen-2-yl)methyl)cyclohexa- 2,5-diene-1,4-dione (bolinaquinone) as a clathrin inhibitor. While being an attractive medicinal chemistry target, the lack of data about bolinaquinone's mode of binding to the clathrin enzyme represents a major limitation for its structural optimization. We have used a molecular modeling approach to rationalize the observed activity of bolinaquinone and to predict its mode of binding with the clathrin terminal domain (CTD). The applied protocol started by global rigid-protein docking followed by flexible docking, molecular dynamics and linear interaction energy calculations. The results revealed the potential of bolinaquinone to interact with various pockets within the CTD, including the clathrin-box binding site. The results also highlight the importance of electrostatic contacts over van der Waals interactions for proper binding between bolinaquinone and its possible binding sites. This study provides a novel model that has the potential to allow rapid elaboration of bolinaquinone analogues as a new class of clathrin inhibitors.

Novel non-cyclooxygenase inhibitory derivatives of naproxen for colorectal cancer chemoprevention.

A structure-based medicinal chemistry strategy was applied to design new naproxen derivatives that show growth inhibitory activity against human colon tumor cells through a cyclooxygenase (COX)-independent mechanism. In vitro testing of the synthesized compounds against the human HT-29 colon tumor cell line revealed enhanced growth inhibitory activity compared to the parent naproxen with 3a showing IC50 of 11.4 µM (two orders of magnitude more potent than naproxen). Selectivity of 3a was investigated against a panel of three tumor and one normal colon cell lines and showed up to six times less toxicity against normal colonocytes. Compound 3a was shown to induce dose-dependent apoptosis of HT116 colon tumor cells as evidenced by measuring the activity of caspases-3 and 7. None of the synthesized compounds showed activity against COX-1 or COX-2 isozymes, confirming a COX-independent mechanism of action. Compound 3k was found to have no ulcerogenic effect in rats as indicated by electron microscope scanning of the stomach after oral administration. A pharmacophore model was developed for elucidating structure-activity relationships and subsequent chemical optimization for this series of compounds as colorectal cancer chemopreventive drugs.

2-Methoxyestradiol ameliorates doxorubicin-induced cardiotoxicity by regulating the expression of GLUT4 and CPT-1B in female rats.

The clinical usage of doxorubicin (DOX) is hampered due to cardiomyopathy. Studies reveal that estrogen (E2) modulates DOX-induced cardiotoxicity. Yet, the exact mechanism is unclear. The objective of the current study is to evaluate the influence of E2 and more specifically its metabolite 2-methoxyestradiol (2ME) on cardiac remodeling and the reprogramming of cardiac metabolism in rats subjected to DOX cardiotoxicity. Seventy-two female rats were divided into groups. Cardiotoxicity was induced by administering DOX (2.5 mg/kg three times weekly for 2 weeks). In some groups, the effect of endogenous E2 was abolished by ovariectomy (OVX) or by using the estrogen receptor (ER) blocker Fulvestrant (FULV). The effect of administering exogenous E2 or 2ME in the OVX group was studied. Furthermore, the influence of entacapone (COMT inhibitor) on induced cardiotoxicity was investigated. The evaluated cardiac parameters included ECG, histopathology, cardiac-related enzymes (creatine kinase isoenzyme-MB (CK-MB) and lactate dehydrogenase (LDH)), and lipid profile markers (total cholesterol (TC), triglyceride (TG), and high-density lipoprotein (HDL)). The expression levels of key metabolic enzymes (glucose transporter-4 (GLUT4) and carnitine palmitoyltransferase-1B (CPT-1B)) were assessed. Our results displayed that co-treatment of E2 and/or 2ME with DOX significantly reduced DOX-induced cardiomyopathy and enhanced the metabolism of the heart through the maintenance of GLUT4 and CPT-1B enzymes. On the other hand, co-treatment of DOX with OVX, entacapone, or FULV increased the toxic effect of DOX by further reducing these important metabolic enzymes. E2 and 2ME abrogate DOX-induced cardiomyopathy partly through modulation of GLUT 4 and CPT-1B enzymes.

Effects of varied substituents on the antibacterial activity of triazolylmethyl oxazolidinones.

A number of 1,2,3-triazolylmethyl piperazino oxazolidinone derivatives with optionally varied substituents at the 4N-piperazine position were synthesized and their antibacterial activity evaluated against a panel of susceptible and resistant Gram-positive and selected Gram-negative bacteria. Substitution with 5-membered heteroaroyl and dinitrobenzoyl moieties potentiated activity against staphylococci and enterococci strains. Furthermore, the compounds having dinitrobenzoyl 7n, 7o, and 5-nitrofuroyl 7t substitutions were four- to eightfold more potent than linezolid against M. catarrhalis. However, substitution of guanidino and other water-solubilizing functionalities at the 4N-piperazine position resulted in compounds that are devoid of antibacterial activity.

Growth Optimization and Secondary Metabolites Evaluation of Anabaena variabilis for Acetylcholinesterase Inhibition Activity.

Cyanobacteria comprise a good natural resource of a potential variety of neuro-chemicals, including acetylcholinesterase inhibitors essential for Alzheimer's disease treatment. Accordingly, eight different cyanobacterial species were isolated, identified, and evaluated on their growth on different standard nutrient media. It was found that the modified Navicula medium supported the highest growth of the test cyanobacteria. The effects of methylene chloride/methanol crude extracts of the test cyanobacteria on acetylcholinesterase activity were examined and compared. Anabaena variabilis (KU696637.1) crude extract recorded the highest acetylcholinesterase inhibition (62 ± 1.3%). Navicula medium chemical components were optimized through a Plackett-Burman factorial design. The biomass of Anabaena variabilis increased significantly when grown on the optimized medium compared to that of control. The chemical analysis of the fractions derived from Anabaena variabilis showed the presence of two compounds in significant amounts: the flavonoid 5,7-dihydroxy-2-phenyl-4H-chrome-4-one and the alkaloid 4-phenyl-2-(pyridin-3-yl) quinazoline. Molecular docking studies revealed that both compounds interact with the allosteric binding site of acetylcholinesterase at the periphery with π-π stackings with Tyr341 and Trp286 with good, predicted partition coefficient. The compounds obtained from this study open the door for promising drug candidates to treat Alzheimer's disease for their better pharmacodynamics and pharmacokinetic properties.

Schiff bases of indoline-2,3-dione: potential novel inhibitors of Mycobacterium tuberculosis (Mtb) DNA gyrase.

In the present study a series of Schiff bases of indoline-2,3-dione were synthesized and investigated for their Mtb gyrase inhibitory activity. Promising inhibitory activity was demonstrated with some of these derivatives, which exhibited IC(50) values ranging from 50-157 mM. The orientation and the ligand-receptor interactions of such molecules within the Mtb DNA gyrase A subunit active site were investigated applying a multi-step docking protocol using Molecular Operating Environment (MOE) and Autodock4 docking software. The results revealed the importance of the isatin moiety and the connecting side chain for strong interactions with the enzyme active site. Among the tested compounds the terminal aromatic ring benzofuran showed the best activity. Promising new leads for developing a novel class of Mtb gyrase inhibitors were obtained from Schiff bases of indoline-2,3-dione.

Assessment of the stability of novel antibacterial triazolyl oxazolidinones using a stability-indicating high-performance liquid chromatography method.

OBJECTIVES: To evaluate the stability of 12 triazolyl oxazolidinone (TOZ) derivatives in simulated gastric and intestinal fluids as well as in human plasma at 37 ± 1°C. MATERIALS AND METHODS: A stability-indicating high-performance liquid chromatography (HPLC) procedure with a C(8) column (250 × 40 mm, 5 µm particle size) and a mobile phase of acetonitrile/H(2)O (50/50 v/v) at 1.0 ml/min was used. Accelerated stability studies were conducted at 37 ± 1°C in 0.1 M HCl solution as simulated gastric fluid and in phosphate buffer solution (pH about 7.4) as simulated intestinal fluid. The stability of TOZs in human plasma at a simulated biological temperature of 37 ± 1°C was evaluated as well. RESULTS: The stability studies indicated that the examined TOZs were stable in the above media, with the exception of compounds 1a [tert- butyl 4-(4-((R)-5-((1H-1,2,3-triazol-1-yl)methyl)-2-oxooxazolidin-3-yl)-2-fluorophenyl)piperazine-1-carboxylate] and 1b [tert-butyl 4-(2-fluoro-4-((R)-5-((4-methyl-1H-1,2,3-triazol- 1-yl)methyl)-2-oxooxazolidin-3-yl)phenyl) piperazine-1-carboxylate], which underwent degradation in simulated gastric fluid. The degradation kinetics revealed degradation parameters (k(deg), t(1/2), t(90)) of 0.180 h(-1), 3.85 h, and 0.58 h for 1a and of 0.184 h(-1), 3.76 h and 0.57 h for 1b, respectively. Furthermore, the degradation products were identified by mass-spectrometric analysis at mass-to-charge ratios 347.5 and 361.5, respectively, and proton nuclear magnetic resonance analysis. CONCLUSION: With the exception of compounds 1a and 1b, the TOZs are stable in simulated gastric and intestinal fluids as well as in human plasma. Being carbamate derivatives, compounds 1a and 1b underwent fast and complete degradation in simulated gastric fluid. The obtained results should be considered for future studies of formulation of structurally related TOZs in oral dosage forms.

Circulating plasmacytoid dendritic cells in acutely infected patients with hepatitis C virus genotype 4 are normal in number and phenotype.

The incidence of hepatitis C virus (HCV) genotype 4 infection in Egypt provides a unique opportunity to study the innate immune response to symptomatic acute HCV infection. We investigated whether plasmacytoid dendritic cells (pDCs) are activated as a result of HCV infection. We demonstrate that, even during symptomatic acute infection, circulating pDCs maintained a similar precursor frequency and resting phenotype, compared with pDCs in healthy individuals. Moreover, stimulation with a Toll-like receptor 9 agonist resulted in an intact inflammatory response. These data support the growing consensus that pDCs are not directly activated by HCV and therefore are viable targets for immunotherapy throughout HCV infection.

Quantitative structure-activity relationship (QSAR) studies on a series of 1,3,4-thiadiazole-2-thione derivatives as tumor-associated carbonic anhydrase IX inhibitors.

A linear quantitative structure-activity relationship (QSAR) study that encodes various aspects of physicochemical, topological and electronic descriptors has been developed for a series of 1,3,4-thiadiazole-2-thione derivatives (1a-r and 2a-c). The carbonic anhydrase IX inhibitory activity of the candidates under study (1a-r and 2a-c) were correlated to the selected parameters using stepwise linear regression analyses to achieve the best QSAR model. Promising results were obtained with the employed tetra-parametric model indicating that the information approach used in the present investigation is quite useful for modeling carbonic anhydrase IX inhibitors.

Determination of novel antibacterial triazolylmethyl oxazolidinones concentrations in human plasma by APCI-LC-MS: application to stability study.

UNLABELLED: Triazolylmethyl oxazolidinones are novel potent antibacterial agents recently synthesized in our laboratory. PURPOSE: Development of a rapid and specific LC-MS method for evaluating the stability of three potentially active antibacterial triazolylmethyl oxazolidinone compounds, namely PH-27, PH-38 and PH-41, in human plasma. METHODS: Ion-trap mass spectrometry using +APCI-MS at m/z 348.1 (PH-27), 389.1 (PH-38) and 451.1 (PH-41) combined with liquid chromatographic analysis using C18 reversed-phase column and a mobile phase consisting of 20 mM ammonium acetate solution and acetonitrile (50:50 v/v) was used. Plasma samples were pre-treated with acetonitrile to precipitate proteins prior to LC-MS analysis. Linezolid was used as an internal standard whose predominant ion at m/z 338.1 was monitored and used to construct the calibration curves. An accelerated stability study under controlled experimental conditions was conducted at -20 oC for a 5-weeks period. RESULTS: Calibration curves of the examined oxazolidinones in human plasma were established (r: 0.99) up to the concentration of 20.0 microg ml-1 with LLQ of 0.1 (PH-27), 0.5 (PH-38) and 1.0 microg ml-1 (PH-41). Validation data showed appropriate intra- and inter-day precision and accuracy as indicated from RSD% 1.3 - 8.6 and % DEVs -12.7 to +11.3, respectively. Stability studies gave the kinetic degradation parameters of kdeg 0.0191- 0.0857 week-1, t1/2 8.1-36.3 weeks and t90 1.2 -5.5 weeks. CONCLUSIONS: The developed +APCI-LC-MS assay is simple, fast and specific method that could be applied for the routine analysis of the selected oxazolidinones during stability and pharmacokinetic studies. The examined compound PH-27 was proved to be relatively more stable and resistant to degradation in human plasma compared to PH-38 and PH-41, as indicated from the kinetics and recovery studies at -20 oC.

A pilot data analysis of a metabolomic HPLC-MS/MS study of patients with COPD.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a heterogeneous condition with multiple clinical faces. Metabolomic profiling studies small molecules present in biological samples by combined use of chromatography with mass spectrometry. OBJECTIVES: The goal of our work was to perform a high performance liquid chromatography combined with tandem mass spectrometry (HPLC-MS/MS) metabolomic study to compare the concentrations of metabolites in COPD patients and in controls. MATERIAL AND METHODS: Participants were recruited at the University Hospital, Hradec Králové, Czech Republic, with the approval of the ethics committee. The analysis of blood samples was performed at Health Sciences Center (HSC) in Kuwait. The blood samples were analyzed for concentrations of acylcarnitines and amino acids by high performance liquid chromatography (Waters 2690 HPLC; Waters, Milford, USA) and a triple-quadruple tandem mass spectrometer (Quattro LC, Micromass, Manchester, United Kingdom). RESULTS: Groups of 10 subjects with COPD and 10 healthy controls were analyzed. Carnitine analysis showed that the free carnitine to acylcarnitine ratio (C0/AC ratio) was significantly lower in COPD (0.58 µM/L) compared to the controls (0.73 µM/L; p = 0.002). The mean C8/C2 ratio in the COPD group was significantly higher (0.03 µM/L) - in the control group it was 0 µM/L (p = 0.03). Amino acid analysis showed lower levels of phenylalanine in the COPD group (22.05 µM/L) compared to the controls (30.05 µM/L; p = 0.008). The alanine concentrations were significantly lower in the COPD group (173 µM/L) than in the control group (253 µM/L; p = 0.001). The pyroglutamate levels were higher in COPD (1.58 µM/L) than in the controls (1 µM/L; p = 0.040). CONCLUSIONS: The carnitine and acylcarnitine levels in COPD subjects in this study possibly indicate a predisposition to atherosclerosis as a result of inadequate ß-oxidation of fatty acids and show the presence of oxidative stress. Furthermore, the high sensitivity to changes in circulating amino acid levels may allow us to detect subclinical malnutrition and take early preventative interventions such as nutritional supplementation and patient education.

Small-Molecule Inhibitors of the NusB-NusE Protein-Protein Interaction with Antibiotic Activity.

The NusB-NusE protein-protein interaction (PPI) is critical to the formation of stable antitermination complexes required for stable RNA transcription in all bacteria. This PPI is an emerging antibacterial drug target. Pharmacophore-based screening of the mini-Maybridge compound library (56 000 molecules) identified N,N'-[1,4-butanediylbis(oxy-4,1-phenylene)]bis(N-ethyl)urea 1 as a lead of interest. Competitive enzyme-linked immunosorbent assay screening validated 1 as a 20 µM potent inhibitor of NusB-NusE. Four focused compound libraries based on 1, comprising 34 compounds in total were designed, synthesized, and evaluated as NusB-NusE PPI inhibitors. Ten analogues displayed NusB-NusE PPI inhibition ≥50% at 25 µM concentration in vitro. In contrast to representative Gram-negative Escherichia coli and Gram-positive Bacillus subtilis species, these analogues showed up to 100% growth inhibition at 200 µM. 2-((Z)-4-(((Z)-4-(4-((E)-(Carbamimidoylimino)methyl)phenoxy)but-2-en-1-yl)oxy)benzylidene)hydrazine-1-carboximidamide 22 showed excellent activity against important pathogens. With minimum inhibitory concentration values of ≤3 µg/mL for Gram-positive Streptococcus pneumoniae and methicillin-resistant Staphylococcus aureus and ≤51 µg/mL for Gram-negative Pseudomonas aeruginosa and Acinetobacter baumannii, 22 is a potent lead for a novel antibacterial target. Epifluorescence studies in live bacteria were consistent with 22, inhibiting the NusB-NusE PPI as proposed.

Synthesis and anti-mycobacterial activity of 4-(4-phenyl-1H-1,2,3-triazol-1-yl)salicylhydrazones: revitalizing an old drug.

The antitubercular drug; para-aminosalicylic acid (PAS) was used as the core scaffold for the design of a series of 1H-1,2,3-triazolylsalicylhydrazones upon coupling with triazole and arylhydrazone moietis to furnish a single molecular architecture. The obtained derivatives were screened against Mycobacterium tuberculosis H37Rv revealing good to high activity for the active compounds (MIC values of 0.39-1.5 µg/mL) compared to the marketed drugs isoniazid, rifampicin and ethambutol. Moreover, the most active analogue N-(1-(4-chlorobenzyl)-2-oxoindolin-3-ylidene)-2-hydroxy-4-(4-phenyl-1H-1,2,3-triazol-1-yl)-benzohydrazide (20) was found to be ten-fold more potent than PAS and equipotent to rifampicin (MIC 0.39 µg/mL), while exhibiting low cytotoxicity with a selectivity index of >128. In addition, this compound was shown to be active against persistent forms of mycobacteria comparable to standard drugs in nutrient starvation model. Accordingly, we introduce compound 20 as a valuable lead for further development. A 3D-QSAR study was also conducted to help in explaining the observed activity and to serve as a tool for further development.