SÍNTESE VERDE DE ABIETATO DE SÓDIO POR SALIFICAÇÃO DA RESINA DE Pinus elliottii E PREPARO DO OXOVANÁDIO(IV)-bis(ABIETATO): APLICAÇÃO COMO AGENTES ANTIMICROBIANOS

Abstract

This work presents an alternative and renewable source for the synthesis of complexes, also aiming at a low cost, and minimizing the generation of disposable waste. The source chosen was Pinus resin, which provides practical means of obtaining and using it. Pinus is a reforestation tree, therefore, it is easy to find large areas of plantation and exploitation of its raw materials, including in the Guarapuava region; but there are species of this tree all over the world. After obtaining and purifying the resin, salification synthesis was carried out to form a carboxylic salt, called sodium abietate salt (Na-abietate), with NaOH as precursor. After preparing the salt, it was recrystallized and used in the synthesis of the V-abietate complex. Several techniques were used to characterize the Na-abietate salt and V-abietate complex; highlighting the use of mass spectrometry indicating the formation of the vanadium complex with two abietate ligands (C20H29O2-), forming the oxovanadium(IV)bis(abietate). The application was directed to the area of microbiology, investigating the ability of the compounds as their antimicrobial activity using the CIM, CBM, and CFM tests and also diffusion disk. The results showed efficiency of both the salt and the complex in inhibiting the growth of fungi and bacteria. The Na-abietate solution stood out in inhibiting Salmonella enterica Typhimurium with an activity index >100% in the disk diffusion test. The V-abietate complex had good bacteriostatic action for Gram-positive bacteria (S. aureus and L. monocytogenes) with a minimum inhibition concentration of 62.5 μmol L-1; in addition to fungicidal activity for C. albicans and C. tropicalis at a minimum concentration of 15.6 and 62.5 μmol L-1, respectively. In the disk diffusion method, the V-abietate solution showed the best inhibition activity for L. monocytoges with 81%. The complex was also dispersed in white paint to evaluate its antimicrobial properties with a view to its use in coatings and paints. Its greatest inhibition activity was for E. coli with a halo of 10.88 ± 0.13 mm; then S. aureus (8.81 ± 0.26 mm); S. enterica Typhimurium (8.13 ± 0.07 mm) and L. monocytogenes (7.70 ± 0.12 mm). For the yeast strain C. tropicalis there was no growth of colonies during the time established for the test (48 h). Therefore, it is emphasized that Na-abietate salt showed better inhibition activity against bacteria; while the V-abietate complex showed better action against fungi.