Desenvolvimento e caracterização de complexos moleculares de óleo essencial de Alpinia zerumbet (Pers.) Burtt & Smith com sulfobutil-éter-B-ciclodextrina

Abstract

The present study consists of two distinct chapters. In the first chapter, entitled “Biological activities and pharmacological applications of cyclodextrins complexed with essential oils and their volatile components: a systematic review”, a review with in vitro and in vivo studies that evaluated essential oils (EOs) and their volatile components (VCs) complexed with different cyclodextrins (CDs), the formation of inclusion complexes (ICs) and their influence on different biological activities and pre-clinical trials. The search terms 'Cyclodextrin', 'Inclusion complex', 'Volatile oils', 'Essential oil' and 'Volatile components' were used to retrieve articles from the PUBMED, MEDLINE and SCOPUS databases, resulting in the selection of 38 articles, 22 from in vitro studies and 16 from preclinical studies, which were discussed and it was found that CDs promoted better therapeutic efficacy due to increased solubility, stability and bioavailability of EOs and VCs. The second chapter, entitled “Preparation, characterization and molecular docking of Alpinia zerumbet essential oil complexed with sulfobutylether-β-cyclodextrin”, aimed to extract and identify the components of essential oil of Alpinia zerumbet (EOAz) by gas chromatography coupled mass spectrometry (GC-MS) and evaluate its antimicrobial activity against strains of pathogenic microorganisms (klebsiella pneumoniae ATCC 10031, Escherichia coli ATCC 10536, Staphylococcus aureus ATCC 6538P, Candida parapsilosis ATCC 90018, Candida albicans ATCC 10231 e Candida tropicallis ATCC 750). The OEAz was complexed with sulfobutylether-β-cyclodextrin (SBEβCD) to form ICs. The complexes were prepared by coprecipitation (IC 1 at 24 h and IC 2 at 6 h) and by physical mixture (PM), all in a 1:1 stoichiometric molar ratio (EOAz:SBEβCD) and evaluated by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (CSD) and molecular doking simulation, the latter using the major components of EOAz. As results, EOAz showed terpinen-4-ol (22.37%) and 1.8-cyienol (19.65%) as major constituents and antimicrobial activity against all pathogenic strains tested. In the FTIR analysis, displacements of bands of the OH stretching mode of the SBEβCD spectrum occurred in relation to IC 1 (3446 to 3421 cm-1, 2938 to 2931 cm-1 and 1161 to 1159 cm-1) and disappearance of the 2357 cm-1 band present only in the OEAz spectrum; thermal characterization indicated a decrease in EOAz mass loss from 95.13% to 55.7, 55.8 and 53.78 in IC 1, IC 2 and PM, respectively. Molecular docking data revealed an interaction of 1,8- cienol (ΔEbind = -97.20 Kcal/mol) close to the center of the SBEβCD cavity suggesting formation of an inclusion complex, while terpinen-4-ol (ΔEbind = -120.46 Kcal/mol) interacted outside the cavity. Therefore, the displacement of bands of the spectrum in the FTIR, the increase of the thermal stability with reduction of the mass loss in the thermogravimetric analyzes and the conformation in the molecular docking of one of the major components of the EOAz suggest the formation of molecular complexes in the IC 1 obtained with 24 h, being a potential alternative for the biotechnological development of new formulations for potential therapeutic application.