Thesis title: Sustainable Extraction and Analytical Methodologies for Investigating Bioactive Compounds and Health Benefits of Medicinal Plants
Medicinal plants have been used for thousands of years in several cultures for the treatment and prevention of numerous diseases. These natural organisms synthesize secondary metabolites such as polyphenols, terpenes, and alkaloids, which give them antioxidant, anti-inflammatory, antimicrobial, and neuroprotective properties, among many others.
In the context of modern scientific research, advanced extraction techniques and analytical methodologies have been developed to identify and quantify these compounds, facilitating the integration of medicinal plants into therapeutic treatments.
This thesis is focused on the analysis of bioactive compounds extracted from medicinal plants and the evaluation of their biological activity, with particular attention to changes induced by different plant growing conditions. The study integrates a detailed chemical characterization by advanced analytical methodologies such as NMR, HPLC-DAD, HPLC-MS/MS and GC-MS, and an evaluation of biological properties, with a specific focus on antioxidant and anti-Alzheimer's activities.
Medicinal plants: sources of bioactive compounds.
Medicinal plants are a valuable source of natural compounds that provide therapeutic functions, derived primarily from secondary metabolites. These compounds are produced as an adaptive response to environmental and biotic stresses and differ significantly depending on external factors, such as climate and agronomic techniques. The chemical complexity of these metabolites has led to the discovery of numerous compounds with potential pharmaceutical applications, contributing to the formulation of new drugs and supplements.
The ability of these plants to synthesize these compounds is affected by several factors, such as soil type and cultivation techniques, making it necessary to study their behaviour in different environments.
Approaches to the extraction of bioactive compounds.
The extraction of bioactive compounds from medicinal plants represents one of the main challenges in this field, as the selection of extraction conditions can significantly influence the quality and quantity of the metabolites obtained.
The use of pressurized methods (pressurized liquid and supercritical fluid extractions) allows the isolation of bioactive compounds with higher efficiency than traditional techniques. Parameters such as temperature, pressure, and type of solvent can significantly influence the chemical profile of the extracts. This study aims to investigate how these factors affect the yield and composition of extracts of different medicinal plants
Chemical characterization and biological tests.
Chemical analysis of extracted metabolites is crucial to identify and quantify the compounds responsible for biological activity. Advanced analytical techniques such as NMR, HPLC-DAD, HPLC-MS/MS and GC-MS are used to determine the structure and concentration of the metabolites. This work uses these techniques to study the chemical profile of various plant extracts.
Parallel to chemical characterization, it is essential to evaluate the biological activity of the extracts. Biological assays performed in this work include tests to evaluate antioxidant activity, such as DPPH and ORAC, as well as tests to measure anti-Alzheimer's activity, with a focus on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition. These assays provide insight into the therapeutic efficacy of the extracts and are useful in determining the optimum extraction conditions.
Impact of cultivation conditions.
One of the main issues in this research is the study of the influence of cultivation conditions on the chemical composition of plant extracts. Environmental conditions and agronomic techniques can influence the biosynthesis of bioactive compounds and thus the therapeutic potential of medicinal plants. This thesis explores the effect of different ecotypes and cultivation methods on the phenolic content and biological activity of extracts, providing useful information for the optimal production of plants for therapeutic purposes.