Estudo das interações moleculares entre 1-((2,2-dimetil-1,3 dioxolan-4-il)metil)-4-octil-1H-1,2,3-triazol:2-hidroxipropil-β-ciclodextrina
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Data
2025-03-28
Autores
Silva, Ana Flávia Batista
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Universidade Federal do Espírito Santo
Resumo
Chemical control remains the primary strategy for crop protection. However, its non-rational use can promote fungal resistance to commercial products. To mitigate this issue, the development of new active ingredients for crop protection is essential. The triazole class represents a promising alternative due to its chemical properties and broad spectrum of biological activities. Nevertheless, the low water dispersibility of these compounds limits their biological efficacy. To overcome this limitation, the encapsulation of such compounds using cyclodextrins (CDs) offers an effective approach. This study focused on the preparation and characterization of a solid system composed of 1-((2,2-dimethyl-1,3 dioxolan-4-yl)methyl)-4-octyl-1H-1,2,3-triazole (TLZ) and 2-hydroxypropyl-β-cyclodextrin (HPβCD). The products obtained by kneading (KNHβTLZ) and physical mixing (PMHβTLZ) were prepared in a 1:1 molar ratio, as indicated by the Job’s plot. The aqueous dispersibility of TLZ increased fourfold with increasing HPβCD concentration, as demonstrated by a phase solubility diagram of type AL. The interaction between TLZ and HPβCD was confirmed through FTIR, XRD, TGA/DTG, DSC, and SEM analyses. The FTIR spectrum of KNHβTLZ showed characteristic TLZ bands at 3068 cm⁻¹ (νC–H of the triazole ring) and 1556 cm⁻¹ (νN=N), which disappeared in PMHβTLZ, suggesting the formation of distinct chemical species. Thermal analyses indicated enhanced thermal stability of TLZ in KNHβTLZ, as evidenced by a lower total mass loss in the TGA (83.89% for KNHβTLZ and 95.20% for PMHβTLZ, compared to 99.44% for pure TLZ). Additionally, DTG and DSC analyses revealed a higher degradation temperature for KNHβTLZ (349.9 °C) compared to pure TLZ (335.7 °C) and HPβCD (347.9 °C), whereas PMHβTLZ showed a reduction (328.2 °C). Molecular docking studies demonstrated that TLZ is capable of forming an inclusion complex (IC) with HPβCD, with the molecule remaining inside the cavity in an aqueous medium. However, in DMSO, TLZ did not remain within the HPβCD cavity, indicating a greater affinity for the solvent. This study contributes to a better understanding of the interactions between TLZ and HPβCD, offering insights for the development of formulations that improve the compound’s thermal stability and aqueous dispersibility
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Malaxagem , Dispersibilidade , Estabilidade térmica , Produtos químicos agrícolas , Kneading , Dispersibility , Thermal stability , Agricultural chemicals