Event-related delta and theta responses may reflect the valence discrimination in the emotional oddball task.

How emotion and cognition interact is still a matter of debate. Investigation of this interaction in terms of the brain oscillatory dynamics appears to be an essential approach. To investigate this topic, we designed two separate three-stimulus oddball tasks, including emotional stimuli with different valences. Twenty healthy young subjects were included in the study. They completed two tasks, namely: the positive emotional oddball task and the negative emotional oddball task. Each task included the target, non-target, and distractor stimuli. Positive and negative pictures were the target stimuli in the positive and negative emotional oddball task. We asked participants to determine the number of target stimuli in each task. During sessions, EEGs were recorded with 32 electrodes. We found that (negative) target stimuli elicit higher delta (1-3.5 Hz) and theta (4-7 Hz) power responses but not the phase-locking responses compared to (positive) distractor stimuli during the negative oddball task. On the other hand, the same effect was not seen during the positive emotional oddball task. Here, we showed that the valence dimension interacted with the target status. Finally, we summarized our results that the presence of negative distractors attenuated the target effect of the positive stimuli due to the negative bias.

Hit-to-lead optimization on aryloxybenzamide derivative virtual screening hit against SIRT.

Sirtuins (SIRTs) are a class of nicotinamide adenine dinucleotide (NAD+)-dependent protein histone deacetylases (HDACs) that are evolutionarily conserved from bacteria to mammals. This group of enzymes catalyses the reversible deacetylation of lysine residues in the histones or non-histone substrates using NAD+ as a cosubstrate. Numerous studies have demonstrated that the aberrant enzymatic activity of SIRTs has been linked to various diseases like diabetes, cancer, and neurodegenerative disorders. Previously, we performed a pharmacophore-based virtual screening campaign and an aryloxybenzamide derivative (1) displaying SIRT1/2 inhibitory effect was identified as a hit compound. In the current study, the hit-to-lead optimization on the hit compound was explored in order to improve the SIRT binding and inhibition. Fourteen compounds, ten of which were new, have been synthesized and subjected to in vitro biological evaluation for their inhibitory activity against SIRT1-3. By the structural modifications performed, a significant improvement was observed in selective SIRT1 inhibition for ST01, ST02, and ST11 compared to that of the hit compound. The highest SIRT2 inhibitory activity was observed for ST14, which was designed according to compatibility with pharmacophore model developed for SIRT2 inhibitors and thus, providing the interactions required with key residues in SIRT2 active site. Furthermore, ST01, ST02, ST11, and ST14 were subjected to in vitro cytotoxicity assay against MCF-7 human breast cancer cell line to determine the influence of the improvement in SIRT1/2 inhibition along with the structural modifications on the cytotoxic properties of the compounds. The cytotoxicity of the compounds was found to be correlated with their SIRT inhibitory profiles indicating the effects of SIRT1/2 inhibition on cancer cell viability. Overall, this study provides structural insights for further inhibitor improvement.

Novel pyridazinone derivatives as butyrylcholinesterase inhibitors.

In the current study, forty-four new [3-(2/3/4-methoxyphenyl)-6-oxopyridazin-1(6H)-yl]methyl carbamate derivatives were synthesized and evaluated for their ability to inhibit electric eel acetylcholinesterase (EeAChE) and equine butyrylcholinesterase (eqBuChE) enzymes. According to the inhibitory activity results, [3-(2-methoxyphenyl)-6-oxopyridazin-1(6H)-yl]methyl heptylcarbamate (16c, eqBuChE, IC50 = 12.8 µM; EeAChE, no inhibition at 100 µM) was the most potent eqBuChE inhibitor among the synthesized compounds and was found to be a moderate inhibitor compared to donepezil (eqBuChE, IC50 = 3.25 µM; EeAChE, IC50 = 0.11 µM). Kinetic and molecular docking studies indicated that compounds 16c and 14c (hexylcarbamate derivative, eqBuChE, IC50 = 35 µM; EeAChE, no inhibition at 100 µM) were mixed-type inhibitors which accommodated within the catalytic active site (CAS) and peripheral anionic site (PAS) of hBuChE through stable hydrogen bonding and π-π stacking. Furthermore, it was determined that [3-(2-methoxyphenyl)-6-oxopyridazin-1(6H)-yl]methyl (4-methylphenyl)carbamate 7c (eqBuChE, IC50 = 34.5 µM; EeAChE, 38.9% inhibition at 100 µM) was the most active derivative against EeAChE and a competitive inhibitor binding to the CAS of hBuChE. As a result, 6-(2-methoxyphenyl)pyridazin-3(2H)-one scaffold is important for the inhibitory activity and compounds 7c, 14c and 16c might be considered as promising lead candidates for the design and development of selective BuChE inhibitors for Alzheimer's disease treatment.

Study On Synthesis and Biological Activity of Some Pyridopyridazine Derivatives.

In this study, new pyrido[3,4-d]pyridazine derivatives were synthesized and evaluated for their in vitro antibacterial, antifungal and antimycobacterial activities. Among the synthesized compounds, compound 10 (1-(4-benzylpiperazin-1-yl)pyrido[3,4-d]pyridazin-4(3H)-one) and compound 12 (1-(4-benzylpiperidin-1-yl)pyrido[3,4-d]pyridazin-4(3H)-one) were found to have the highest antimycobacterial activity. However, all compounds were found ineffective against tested Gram-positive, Gram-negative bacteria and fungus.

Preliminary results of a novel quorum sensing inhibitor against pneumococcal infection and biofilm formation with special interest to otitis media and cochlear implantation.

The purpose of the study is to assess the effect of a novel quorum sensing inhibitor (QSI), coded as 'yd 47', against otitis media and biofilm formation on Cochlear implants (CIs). Small pieces cut from cochlear implant were implanted under the skin in the retroauricular area on both sides of four guinea pigs. The implant pieces in the study and control sides were implanted in Streptococcus pneumoniae strain solution and saline, respectively. The right and left middle ears were also instilled with a solution containing pneumococci and saline, respectively. The animals were only given an intraperitoneal 'yd 47' twice daily for three months to be assessed later with electron microscopy. Clinical examination with palpation, inspection and otoscopy did not reveal any sign of implant infection or otitis media. In the study and control implant materials, soft tissues around the implant and tympanic membranes, there was no biofilm formation by pneumococci. Contamination by various cells and some rod-shaped bacteria (not diplococcic) were seen in some of the materials. In conclusion, the novel QSI seems promising in the prevention of otitis media and biofilm formation on CIs by pneumococci.

Synthesis and biological evaluation of the salicylamide and salicylic acid derivatives as anti-estrogen agents.

Alkylphenols have xenoestrogenic activity, which mimic the action of physiological estrogens and these mimicking activities are mainly mediated by nongenomic pathway. Nongenomic pathway plays a pivotal role in breast, endometrial and ovarian cancers' growth and development. In this study, various alkylphenol derivatives were prepared and screened for their anti-uterotrophic and uterotrophic activity. Among these compounds, 2-hydroxy-5-nonanoylbenzamide (compound 1b) showed 93.99% inhibitory activity in the anti-uterotrophic test performed, and was found inactive in the uterotrophic activity test. Moreover, all test compounds were examined for the effect on uterine histopathological changes, and plasma 17ß-estradiol (E2) level. Compound 1b was also tested for in vitro anti-cancer activity against ER+, human breast cancer cell line MCF-7, and it reduced cell viability to 74.01% at 50 nM concentration.

Synthesis and biological evaluation of 4,5-diphenyloxazolone derivatives on route towards selective COX-2 inhibitors.

A series of 3-unsubstituted/substituted-4,5-diphenyl-2-oxo-3H-1,3-oxazole derivatives were prepared as selective cyclooxygenase-2 (COX-2) inhibitors. Among the synthesized compounds, 4-(4-phenyl-3-methyl-2-oxo-3H-1,3-oxazol-5-yl)benzensulfonamide (compound 6) showed selective COX-2 inhibition with a selectivity index of >50 (IC(50)COX-1=>100 microm, IC(50)COX-2=2 microm) in purified enzyme (PE) assay. Compound 6 also exhibited selective COX-2 inhibition in human whole blood assay. Molecular docking studies showed that 6 can be docked into the COX-2 binding site thus providing the molecular basis for its activity.

Synthesis and analgesic and anti-inflammatory activity of ethyl (6-substituted-3 (2H)-pyridazinone-2-yl)acetate derivatives.

A number of 6-substituted-3(2H)-pyridazinones and the corresponding methyl (6-substituted-3(2H)-pyridazinone-2-yl)acetate derivatives carrying the arylpiperazinyl structure present in potent antinociceptive agents reported in the literature were synthesized. As part of a programme a series of diverse arylpiperazine derivatives of ethyl (6-substituted-3(2H)-pyridazinone-2-yl)acetate were prepared and tested for their in vivo analgesic and anti-inflammatory activity by using p-benzoquinone-induced writhing test and carrageenan-induced hind paw edema model, respectively. Side effects of the compounds were examined on gastric mucosa. None of the compounds showed gastric ulcerogenic effect compared with reference non-steroidal anti-inflammatory drugs (NSAIDs). On the basis of available data, the structure-activity relationship in the series of ethyl (6-substituted-3(2H)-pyridazinone-2-yl)acetate derivatives was also discussed. When compared to parent 6-substituted-3(2H)-pyridazinones, the new ester derivatives, for example ethyl (6-4-[(2-fluoro)phenyl]piperazine-3(2H)-pyridazinone-2-yl)acetate exhibited better analgesic and anti-inflammatory activity and a lower ulcerogenic effect.

Synthesis and analgesic and anti-inflammatory activity of some new (6-acyl-2-benzoxazolinone and 6-acyl-2-benzothiazolinone derivatives with acetic acid and propanoic acid residues.

In this study for developing potent analgesic and anti-inflammatory compounds, we synthesized 6-acyl-2-benzoxazolinone and 6-acyl-2-benzothiazolinone derivatives with acetic acid and propanoic acid side chain, and performed preliminary screening of their in vivo analgesic and anti-inflammatory activities at a single dose of 100 mg/kg inmice by a p-benzoquinone-induced writhing test and a Carrageenaninduced hind paw edema model, respectively. We also determined their gastric ulceration effects in the tested animals. Propanoic acid derivatives were generally found to have higher analgesic and anti-inflammatory activities, and among them, 3-(6-benzoyl-2-benzothiazolinon-3-yl)propanoic acid (Compound 4 a) exhibited the highest analgesic and anti-inflammatory activity. However, all compounds showed lower anti-inflammatory effects than we observed for indomethacin at 10 mg/kg dose. Consequently, 6-acyl-2-benzoxazolinone/2-benzothiazolinones having propanoic acid side chain might lead to further studies for developing better candidates with potent analgesic and anti-inflammatory effects while acetic acid derivatives do not exhibit comparable satisfactory features.