Chiral azole derivatives. 4. Enantiomers of bifonazole and related antifungal agents: synthesis, configuration assignment, and biological evaluation

The first synthesis, full stereochem. characterization and biol. evaluation of of both enantiomers of bifonazole (I) and the related II, III and IV are described

Sampling protein motion and solvent effect during ligand binding.

An exhaustive description of the molecular recognition mechanism between a ligand and its biological target is of great value because it provides the opportunity for an exogenous control of the related process. Very often this aim can be pursued using high resolution structures of the complex in combination with inexpensive computational protocols such as docking algorithms. Unfortunately, in many other cases a number of factors, like protein flexibility or solvent effects, increase the degree of complexity of ligand/protein interaction and these standard techniques are no longer sufficient to describe the binding event. We have experienced and tested these limits in the present study in which we have developed and revealed the mechanism of binding of a new series of potent inhibitors of Adenosine Deaminase. We have first performed a large number of docking calculations, which unfortunately failed to yield reliable results due to the dynamical character of the enzyme and the complex role of the solvent. Thus, we have stepped up the computational strategy using a protocol based on metadynamics. Our approach has allowed dealing with protein motion and solvation during ligand binding and finally identifying the lowest energy binding modes of the most potent compound of the series, 4-decyl-pyrazolo[1,5-a]pyrimidin-7-one

QCM Measurements of RH with Nanostructured Carbon-Based Materials: Part 2-Experimental Characterization

In this series of two papers, the humidity sensing of a carbon nanotube (CNT) network-based material is transduced and studied through quartz crystal microbalance (QCM) measurements. To this aim, quartzes functionalized with different amounts of sensing material were realized, exposed to different humidity levels, and characterized. In this second paper, the experimental results are presented and discussed. The sensing mechanisms are elucidated exploiting the theory presented in the first paper of this series. The presented results show that the investigated material functionalization induces a large response of QCM to humidity in terms of resonant frequency even at low RH levels, with a sensitivity of about 12 Hz/%RH (at RH < 30% and room temperature and 10 ug of deposited SWCNT solution) and an increase in sensitivity in the high RH range typical of nanostructured film. Regarding the response in terms of motional resistance, a large response is obtained only at intermediate and high humidity levels, confirming that condensation of water in the film plays an important role in the sensing mechanism of nanostructured materials

The novel mu-opioid antagonist, GSK1521498, reduces ethanol consumption in C57BL/6J mice.

RATIONALE Using the drinking-in-the-dark (DID) model, we compared the effects of a novel mu-opioid receptor antagonist, GSK1521498, with naltrexone, a licensed treatment of alcohol dependence, on ethanol consumption in mice. OBJECTIVE We test the ability of GSK1521498 to reduce alcohol consumption and compare its intrinsic efficacy to that of naltrexone by comparing the two drugs at doses matched for equivalent receptor occupancy. METHODS Thirty-six C57BL/6J mice were tested in a DID procedure. In 2-day cycles, animals experienced one baseline, injection-free session, and one test session when they received two injections, one of test drug and one placebo. All animals received GSK1521498 (0, 0.1, 1 and 3 mg/kg, i.p., 30 min pre-treatment) and naltrexone (0, 0.1, 1 and 3 mg/kg, s.c. 10 min pre-treatment) in a cross-over design. Receptor occupancies following the same doses were determined ex vivo in separate groups by autoradiography, using [3H]DAMGO. Binding in the region of interest was measured integrally by computer-assisted microdensitometry and corrected for non-specific binding. RESULTS Both GSK1521498 and naltrexone dose-dependently decreased ethanol consumption. When drug doses were matched for 70-75 % receptor occupancy, GSK1521498 3 mg/kg, i.p., caused a 2.5-fold greater reduction in alcohol consumption than naltrexone 0.1 mg/kg, s.c. Both GSK1521498 and naltrexone significantly reduced sucrose consumption at a dose of 1 mg/kg but not 0.1 mg/kg. In a test of conditioned taste aversion, GSK1521498 (3 mg/kg) reduced sucrose consumption 24 h following exposure to a conditioning injection. CONCLUSIONS Both opioid receptor antagonists reduced alcohol consumption but GK1521498 has higher intrinsic efficacy than naltrexone

Exploiting the Pyrazolo[3,4-d]pyrimidin-4-one ring system as a useful template to obtain potent adenosine deaminase inhibitors,

A number of pyrazolo[3,4-d]pyrimidin-4-ones bearing either alkyl or arylalkyl substituents in position 2 of the nucleus were synthesized and tested for their ability to inhibit adenosine deaminase (ADA) from bovine spleen. The 2-arylalkyl derivatives exhibited excellent inhibitory activity, showing Ki values in the nanomolar/ subnanomolar range. The most active compound, 1-(4-((4-oxo-4,5-dihydropyrazolo[3,4-d]pyrimidin-2- yl)methyl)phenyl)-3-(4-(trifluoromethyl)phenyl)urea, 14d, was tested in rats with colitis induced by 2,4- dinitrobenzenesulfonic acid to assess its efficacy to attenuate bowel inflammation. The treatment with 14d induced a significant amelioration of both systemic and intestinal inflammatory alterations in animals with experimental colitis. Docking simulations of the synthesized compounds into the ADA catalytic site were also performed to rationalize the structure-activity relationships observed and to highlight the key pharmacophoric elements of these products, thus prospectively guiding the design of novel ADA inhibitors

Exploiting the Pyrazolo[3,4-d]pyrimidin-4-one ring system as a useful template to obtain potent adenosine deaminase inhibitors,

A number of pyrazolo[3,4-d]pyrimidin-4-ones bearing either alkyl or arylalkyl substituents in position 2 of the nucleus were synthesized and tested for their ability to inhibit adenosine deaminase (ADA) from bovine spleen. The 2-arylalkyl derivatives exhibited excellent inhibitory activity, showing Ki values in the nanomolar/ subnanomolar range. The most active compound, 1-(4-((4-oxo-4,5-dihydropyrazolo[3,4-d]pyrimidin-2- yl)methyl)phenyl)-3-(4-(trifluoromethyl)phenyl)urea, 14d, was tested in rats with colitis induced by 2,4- dinitrobenzenesulfonic acid to assess its efficacy to attenuate bowel inflammation. The treatment with 14d induced a significant amelioration of both systemic and intestinal inflammatory alterations in animals with experimental colitis. Docking simulations of the synthesized compounds into the ADA catalytic site were also performed to rationalize the structure-activity relationships observed and to highlight the key pharmacophoric elements of these products, thus prospectively guiding the design of novel ADA inhibitors

Nicotinic acetylcholine receptors in the mesolimbic pathway: primary role of ventral tegmental area alpha6beta2 receptors in mediating systemic nicotine effects on dopamine release, locomotion, and reinforcement

\u3b16* nicotinic acetylcholine receptors (nAChRs) are highly and selectively expressed by mesostriatal dopamine (DA) neurons. These neurons are thought to mediate several behavioral effects of nicotine, including locomotion, habit learning, and reinforcement. Yet the functional role of \u3b16* nAChRs in midbrain DA neurons is mostly unknown. The aim of this study was to determine the composition and in vivo functional role of \u3b16* nAChR in mesolimbic DA neurons of male rats. Immunoprecipitation and immunopurification techniques coupled with cell-specific lesions showed that the composition of \u3b16* nAChR in the mesostriatal system is heterogeneous, with (non-\u3b14)\u3b16\u3b22* being predominant in the mesolimbic pathway and \u3b14\u3b16\u3b22* in the nigrostriatal pathway. We verified whether \u3b16* receptors mediate the systemic effects of nicotine on the mesolimbic DA pathway by perfusing the selective antagonists \u3b1-conotoxin MII (CntxMII) (\u3b13/\u3b16\u3b22* selective) or \u3b1-conotoxin PIA (CntxPIA) (\u3b16\u3b22* selective) into ventral tegmental area (VTA). The intra-VTA perfusion of CntxMII or CntxPIA markedly decreased systemic nicotine-elicited DA release in the nucleus accumbens and habituated locomotion; the intra-VTA perfusion of CntxMII also decreased the rate of nicotine infusion in the maintenance phase of nicotine, but not of food, self-administration. Overall, the results of these experiments show that the \u3b16\u3b22* nAChRs expressed in the VTA are necessary for the effects of systemic nicotine on DA neuron activity and DA-dependent behaviors such as locomotion and reinforcement, and suggest that \u3b16\u3b22*-selective compounds capable of crossing the blood\u2013brain barrier may affect the addictive properties of nicotine and therefore be useful in the treatment of tobacco dependence