Biomedical subjects

C A Montanari

Publications and source records attributed to C A Montanari.

3 recordsLinked to original sources

PubMed2006

The role of molecular interaction fields on enantioselective and nonselective separation of chiral sulfoxides.

The separation of a series of 23 asymmetric sulfoxides, including the three proton pump inhibitors (PPI) omeprazole, lansoprazole and pantoprazole was investigated by HPLC, under reversed-phase elution with amylose tris(3,5-dimethylphenylcarbamate), amylose tris[(S)-1-phenylethylcarbamate] and amylose tris(3,5-dimethoxyphenylcarbamate) chiral stationary phases, CSP1-3, respectively. The whole set of sulfoxides showed better enantioselectivity and enantioresolution on CSP1. However, the three PPI were enantioseparated only when using CSP1 and CSP3. It was observed an improved enantioselectivity and enantioresolution on CSP3. The mechanisms of retention were evaluated by molecular interaction fields (MIF) generated via GRID force field, which yielded the geometric reasons leading to the scenario outlined. The enantioselective and nonselective interactions are discussed in terms of the reported selectivity. The steric structural outline of the CSP nonselective interaction sites is of major importance to deliver the sulfoxides to the chiral selective sites where the enantioselective interactions take place.

Models, Molecular↗

PubMed2000

QSAR based on biological microcalorimetry.

In this paper we describe a QSAR based on biological microcalorimetry for a set of antimicrobial hydrazides acting against Saccharomyces cerivisiae and Escherichia coli. Results show that an extrathermodynamic relationship exists based upon partitioning (log P(TA)) and microcalorimetrically measured biopotencies using the same cell systems. Moreover, the extrathermodynamic relationship between drug potencies for these two cell systems shows that both cellular systems appear to behave in the same way with respect to the importance of partitioning. This means that the same set of congeneric compounds experience a similar environment in the two systems. This represents a lateral validation of the method and discloses the validity of the QSAR model.

Anti-Bacterial Agents↗

PubMed1996

Determination of receptor-bound drug conformations by QSAR using flexible fitting to derive a molecular similarity index.

Results are presented for a QSAR analysis of bisamidines, using a similarity index as descriptor. The method allows for differences in conformation of bisamidines at the receptor site to be taken into consideration. In particular, it has been suggested by others that pentamidine binds in the minor groove of DNA in a so-called isohelical conformation, and our QSAR supports this suggestion. The molecular similarity index for comparison of molecules can be used as a parameter for correlating and hence rationalising the activity as well as suggesting the design of bioactive molecules. The studied compounds had been evaluated for potency against Leishmania mexicana amazonensis, and this potency was used as a dependent variable in a series of QSAR analyses. For the calculation of similarity indexes, each analogue was in turn superimposed on a chosen lead compound in a reference conformation, either extended or isohelical, maximising overlap and hence similarity by flexible fitting.

Animals↗