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| Author(s): |
Ana Caroline Zanatta Silva
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Araraquara. 2021-09-30. |
| Institution: | Universidade Estadual Paulista (Unesp). Instituto de Química. Araraquara |
| Defense date: | 2021-09-17 |
| Advisor: | Wagner Vilegas |
| Abstract | |
This work describes the study of the extracts of the medicinal plants Byrsonima intermedia A. Juss. (Malpighiaceae), Serjania marginata Casar. (Sapindaceae) and Terminalia catappa L. (Combretaceae) in order to allow the development and characterization of phytopreparations that can be used in the treatment of chronic diseases. For this, it was fundamental to deepen the knowledge of the chemical composition, to evaluate the seasonality, to improve the analytical methods for the quality control of the vegetal raw material and to develop inclusion complexes for the incorporation of the extracts. In the seasonality study, the extracts were analyzed by high-performance liquid chromatography (HLPC) coupled to tandem mass spectrometry (HPLC-ESI-MS/MS). The samples were collected bimonthly during the summer, autumn, winter and spring periods. The HPLC-MS/MS data were analyzed in the GNPS (Global Natural Products Social Molecular Networking) platform, which allowed the annotation of 39 compounds in B. intermedia extracts, 38 compounds in S. marginata extracts and 42 compounds in T. catappa extracts. The clustering of the samples in the molecular networks showed that seasonal factors played an important role in the production of metabolites in each plant species, with temperature, drought and solar radiation conditions being the main factors that affected the variability of substances in each species. The content of total flavonoids, antioxidant and antiglycant capacity were also determined to help study the seasonal chemical variability of these species. In order to contribute to environmental sustainability, for the standardization of S. marginata extract, a green chromatographic method by HPLC-PDA was developed using only ethanol and water as solvents, following a fractional factorial planning in the screening of variables and applying Doehlert matrix was used in the optimization procedure. The developed green method was compared with the literature method, and the chromatographic performance and environmental impact of both were evaluated using metrics, such as GCFR (Green Chromatographic Fingerprinting Response), HPLC-EAT (EAT - Environmental Assesment Tool) and AGREE (Analytical GREEnness metric). The method was validated through the evaluation of the parameters of selectivity, linearity, detection and quantification limits, precision and robustness. The standardization of the extract was performed by quantification of protocatechuic acid and (+)-catechin, (-)- epicatechin and apigenin derivatives. The developed method was accurate and robust and combined with the principles of Green Chemistry was found to be environmentally friendly. Finally, to confer improvements in the chemical and biological properties of the active ingredients of the extracts, we investigated the complexation of each of them with β-cyclodextrin by physical mixing and malaxation. The characterization of these samples by spectroscopy in the infrared region, thermal analysis, X-ray diffraction, scanning electron microscopy and nuclear magnetic resonance, allowed to propose the partial complexation of the metabolites of the extracts in the cavity of β-cyclodextrin. Thus, this study brings new information about the potential of the extracts of B. intermedia, S. marginata and T. catappa contributing to improve the chemical quality control of the vegetal material, to increase its potential of application as a future phytomedicine and collaborating to the implementation of more environmentally friendly analytical marches. (AU) | |
| FAPESP's process: | 16/21044-4 - Standardization of phytomedicines for the treatment of chronic diseases |
| Grantee: | Ana Caroline Zanatta Silva |
| Support Opportunities: | Scholarships in Brazil - Doctorate |