Estudos estruturais e conformacionais de polimorfos de um derivado diidroisoxazol

Abstract

The most medicines are produced in the solid state and the dissolution thereof, when ingested , has direct influence on absorption by the body and bioavailability. The properties, that affect drug dissolution, are linked directly with the crystal structure , making it extremely important to study the crystalline form and polymorphism . In this context, this work aims to study the polymorphism of a synthetic compound that possibly shows up as an active inhibitor against the enzyme acetylcholinesterase, which is related to Alzheimer's disease . The compound was recrystallized from various solvents, but only suitable for diffraction in methanol and ethyl acetate crystals were obtained. The compound crystallized from ethyl acetate ( CPISOX02 ) showed orthorhombic crystal system and space group F2dd with the following parameters : a = 14.3320 ( 2 ) Å , b = 14.7242 ( 2 ) Å c = 37.5249 ( 5 ) Å , α = β = γ = 90.000 ° Z = 32 molecules / cell; unique reflections = 4807 , reflections collected = 17393 , R ( obs ) = 0.0350 . The compound crystallized in methanol ( CPISOX04 ) showed monoclinic crystal system and space group Cc with the following parameters : a = 14.3215 ( 4 ) Å , b = 14.7233 ( 3 ) Å c = 20.0773 ( 5 ) Å , β = 110.914 ( 1 ) ° Z = 16 molecules / cell; unique reflections = 9099 , reflections collected = 9104 , R ( obs ) = 0.0476 . From the interpretation of crystallographic data we conclude that the molecules of these polymorphs have different molecular conformation, and which are packaged differently within the unit cell, featuring conformational polymorphism and packagingand CPISOX02 CPISOX04 . Regardless of the type of polymorphism and the distribution of loads , energy and entropy will be different , resulting in significant differences in physicochemical properties . Thus, Raman spectroscopy was performed and calculated and some physico-chemical properties and energies the energies of HOMO and LUMO molecular orbitals with their location, to offer more evidence on the differentiation of these polymorphs.