A QSAR study has been performed on a series of substituted pyrido[3,2-b]pyrazinones as potent and selective PDE-5 Inhibitors. The compounds in the selected series were characterized by spatial, molecular and electrotopological descriptors using QSAR module of molecular design suite (V-Life MDS^TM 3.5). Correlations between inhibitory activities and calculated predictor variables were established through partial least square regression (stepwise forward) method. The generated QSAR models reveal that the topology of the molecules crucially influences the desired inhibitory activity of pyrido[3,2-b]pyrazinones. PDE-5 inhibition can be well defined by the models generated and the molecules are more selective towards PDE –5 while PDE –6 and PDE –11 inhibitory activities cannot be well delineated by the help of generated QSAR models. So PDE-5 selective compounds can be synthesized based on the assumption of the present QSAR analysis. The best model shows 90% correlation for PDE-5 inhibitory activity which explains good reliability of the model. However cross correlated regression coefficients (Q²) 0.5959 further validate the model significance. The present study imply that the PDE-5 inhibition can be augmented primarily by increasing molecular refractivity and number of carbons connected to the aromatic rings, single bonds and by decreasing number of carbons connected to the double bonds.

Nano-OrderedZn-MCM-41 materials were synthesized using different zinc sources and applied for liquid phase Beckman rearrangement of 4-hydroxyacetophenone oxime to acetaminophen. The reaction conditions such as amount of the catalyst and solvent were optimized to afford acetaminophen in high yields. it Aprotic solvents with high dielectric constant are preferred for this transformation.

A series of per-O-acetyl-b-D-glycosyl thiosemicarbazones 4 and 5 of benzaldehydes and acetophenones were obtained from reaction of per-O-acetyl-b-maltosyl thiosemicarbazide 1 with corresponding carbonyl compounds (2 and 3) in ethanol or acetic acid as solvent using microwave-assisted method. The positions of the magnetic resonance signals in their NMR spectra and the substituent's nature have been indicated by Hammett's regression. The b anomeric configuration of these thiosemicarbazones was confirmed on the basis of the coupling constant J = 9.0–9.5 Hz between proton NH-4 of thiosemicarbazone bond and proton H-1' in maltose component. Structures of thiosemicarbazones were confirmed by spectroscopic methods

A new series of polyoxygenated amido isoborneols has been synthesized and tested on the enantioselective addition of diethylzinc to benzaldehyde and the results compared to a series of related amino isoborneols. The observed different behavior has been explained on the basis of catalytic quelates previously proposed by us

A series of substituted benzaldehyde hepta-O-acetyl-b-lactosyl thiosemicarbazones were synthesized by condensation reactions of hepta-O-acetyl-b-lactosyl thiosemicarbazide with corresponding substituted benzaldehydes. Structures of thiosemicarbazones were confirmed by spectroscopic (IR, NMR) methods. The ¹H and ¹³C NMR spectra of substituted acetophenone peracetylated b-lactosyl thiosemicarbazones have been recorded and discussed. The magnetic resonance signals in their NMR spectra show the relationships between the structure and positions of the substituted groups by Hammett's regression. The b anomeric configuration of these thiosemicarbazones was confirmed on the basis of the coupling constant J = 9.5–8.5 Hz between proton NH-4 of thiosemicarbazone bond and proton H-1' in lactosyl component

Reaction of substituted acetophenone (hepta-O-acetyl-b-lactosyl)thiosemicarbazones with ethyl bromoacetate was performed in the presence of anhydrous sodium acetate using microwave-assisted heating method. The reaction yields were 64-80%. Structure of 2-iminothiazolidin-4-one products was confirmed by spectroscopic methods. Isomer ratios 2 and 2' were determined by ¹H NMR.

Reaction of substituted acetophenone (hepta-O-acetyl-b-maltosyl)thiosemicarbazones with ethyl bromoacetate was investigated. It's indicated that the nature of solvents and the catalysts affected the reaction yields, and that the microwave-assisted heating method gave higher yields of products than the conventional heating one.

Herein we present results of a Quantitative Structure-Activity Relationship (QSAR) studies to classify and design, in a rational way, new antitrypanosomal compounds by using non-stochastic and stochastic bond-based quadratic indices. A data set of 440 organic chemicals, 143 with antitrypanosomal activity and 297 having other clinical uses, is used to develop QSAR models based on Linear Discriminant Analysis (LDA). Non-stochastic model correctly classifies more than 93% and 95% of chemicals in both training and external prediction groups, respectively. On the other hand, the stochastic model shows an accuracy of about the 87% for both series. As an experiment of virtual lead generation, the present approach is finally satisfactorily applied to the virtual evaluation of 9 already synthesized in house compounds. The in vitro antitrypanosomal activity of this series against epimastigote forms of Trypanosoma cruzi is assayed. The model is able to predict correctly the behaviour for the majority of these compounds. Four compounds (FER16, FER32, FER33 and FER 132) showed more than 70% of epimastigote inhibition at a concentration of 100µg/mL (86.74%, 78.12%, 88.85% and 72.10%, respectively) and two of these chemicals, FER16 (78.22% of AE) and FER33 (81.31% of AE), also showed good activity at a concentration of 10µg/mL. At the same concentration, compound FER16 showed lower value of cytotoxicity (15.44%), and compound FER33 showed very low value of 1.37%. Taking into account all these results, we can say that these three compounds can be optimized in forthcoming works, but we consider that compound FER33 is the best candidate. Even though none of them resulted more active than Nifurtimox, the current results constitute a step forward in the search for efficient ways to discover new lead antitrypanosomals.

Phenyl selenol and the zinc-selenolate PhSeZnCl can be conveniently employed for the stereospecific and stereoselective synthesis of vinyl selenides. These reactions occur with moderate to high yields and can be accomplished in eco-compatible conditions using a biphasic acidic system or directly an aqueous suspension.

Esterification reaction of phthalic anhydride with 2-ethyl hexanol was investigated using sulfated titanium dioxide nano catalyst. The influence of reaction time, catalyst amount and alcohol/anhydride molar ratio was studied using a rotatable central composite design (CCD). The optimum values of factors were: 83 min for the time, 9 %wt catalyst, 9:1 alcohol:anhydride molar ratio. The maximum yield of 93% at optimum conditions was obtained.