Chemical and biological characterization of wild plants and agrifood products
Plant kingdom is a good source of natural preparations containing effective chemical and bioactive compounds which can be used for different applications, particularly as food additives and health promoting compounds in the formulations of functional foods and nutraceuticals. Investigations about plant bioactive compounds have recently regained prominence with the increasing understanding of their biological significance and increasing recognition of the origin and function of their structural diversity. Several substances from plants can be used as alternatives for the treatment of several life-threatening diseases or provide important new drug leads, many of which are approved or are undergoing trials for clinical uses.
An important research line of our group is the evaluation of the biological properties and chemical characterization of extracts from wild plants and agrifood products from the Mediterranean region, namely medicinal plants, wild edible plants with nutraceutical relevance, and beverages (spirits, liqueurs, etc) from different characteristic cultures of the Algarve region and their respective raw materials.
Figure. Extraction and analysis of bioactive compounds from Drosophyllum lusitanicum.
Figure. Separation of fresh and dried fig spirits in relation of major volatile compounds (left); white and dark figs from two typical varieties from the Algarve (right).
Nowadays increased interest in human health, nutrition and disease prevention has enlarged demand for functional foods including plants, fruits and their products. The biological and chemical studies are an important step to find new natural sources of compounds with health benefits, and the valorization and exploration of their potential applications. Essentially, our studies involve thepretreatment of samples for analysis, the evaluation of the biological properties and the chemical characterization.
Pretreatment of samples for analysis
Mineralization is a preliminary step in the determination of minerals necessary to reduce interferences caused by the presence of organic matrix and thus avoiding an increment in optical background. Two are the basic digestion procedures more used, wet mineralization utilizing various mineral acids and temperatures and dried mineralization (calcination) using only high temperatures;
For the extraction of plant compounds we use several solid-liquid extraction techniques such as Soxhlet, Accelerated Solvent Extraction equipment (ASE), Supercritical Fluid Extraction (SFE), ultrasound technique, etc; or liquid-liquid extraction using different organic solvents.
Figure. Recovering plumbagin from micropropagated plants of Drosera intermedia using several extraction methods.
Evaluation of the biological properties
The bioactivity of the extracts, namely antioxidant, antimicrobial, anticholinesterase, antidiabetic and neuroprotective properties, is evaluated using a range of in vitro chemical and cellular models.
Figure. Evaluation of total phenolic contents, and antimicrobial, antioxidant and neuroprotective properties of Lavandula viridis extrats.
Chemical characterization
Development of chromatographic and spectroscopic methods for the identification and quantification of components of interest such as polyphenols, aromas, minerals, etc. using different analytical technique (HPLC-DAD, HPLC-MS, GC-FID, GC-MS, FAAS, FAES, etc).
Figure. HPLC chromatogram monitored at 280 nm of Pinguicula lusitanica methanol extract and structures of the iridoid glucosides and phenylethanoid glucosides assigned.
Relevant publications:
Gonçalves S. & Romano A. 2016. The medicinal potential of plants from the genus Plantago (Plantaginaceae). Industrial Crops and Products, 83: 213-226, DOI: 10.1016/j.indcrop.2015.12.038
RodrÃguez-Solana R., Galego L.R. & Romano A. 2016. Fig spirits: differentiation between fresh and dried figs. XVI Latin-American Congress on Chromatography (XVI COLACRO) e do 9th National Meeting on Chromatography (9ENC), 5-9 janeiro, Lisboa, Portugal, pp. 475-476
Cortés-Diéguez S., Rodriguez-Solana R., DomÃnguez J. M. & DÃaz E. 2015. Impact odorants and sensory profile of young red wines from four Galician (NW of Spain) traditional cultivars. Journal of the Institute of Brewing, 121(4): 628-635, DOI 10.1002/jib.252.
RodrÃguez-Solana R., Salgado J.M., DomÃnguez J.M. & Cortés S. 2014. Estragole quantity optimization from fennel seeds by supercritical fluid extraction (carbon dioxide-methanol) using a Box-Behnken design. Characterization of fennel extracts. Industrial Crops and Products, 60: 186-192, DOI: 10.1016/j.indcrop.2014.05.027
Costa P., Sarmento B., Gonçalves S. & Romano A. 2013. Protective effects of Lavandula viridis L’Hér extracts and rosmarinic acid against H2O2-induced oxidative damage in A172 human astrocyte cell line. Industrial Crops and Products, 50: 361-365.DOI: 10.1016/j.indcrop.2013.07.054
Costa P., Gonçalves S., Valentão P., Andrade P.B., Almeida C., Nogueira J.M.F. & Romano A. 2013. Metabolic profile and biological activities of Lavandula pedunculata subsp. lusitanica (Chaytor) Franco: studies on the essential oil and polar extracts. Food Chemistry, 141: 2501–2506. DOI: 10.1016/j.foodchem.2013.05.055
Gonçalves S. & Romano A. 2013. In vitro culture of lavenders (Lavandula spp.) and the production of secondary metabolites. (Review paper) Biotechnology Advances 31: 166–174. DOI: 10.1016/j.biotechadv.2012.09.006.
Costa P., Gonçalves S., Grosso C., Andrade P.B., Valentão P., Bernardo-Gil M.G. & Romano A. 2012. Chemical profiling and biological screening of Thymus lotocephalus extracts obtained by supercritical fluid extraction and hydrodistillation. Industrial Crops and Products, 36: 246-256. DOI:10.1016/j.indcrop.2011.09.014.
