Browsing by Author "Cruz, Pedro F."
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- Abieta-7,13-Diene in Nematode-Infected Pinewood Pinus pinaster Branch Extracts: Isolation and the Elucidation and Characterization of Its StructurePublication . Gaspar, Marisa C.; Cruz, Pedro F.; Brito, Rui M. M.; Sousa, Hermínio C. de; Braga, Mara E. M.The oleoresin and volatile fraction produced by conifers, such as Pinus pinaster, play a crucial role in plant defence, acting as precursors to resin acids and adapting in response to environmental stress or pathogen attacks. Abietadiene (abieta-7,13-diene), the biosynthetic precursor to abietic acid, has been identified as the most abundant compound in extracts from pinewood nematode (PWN)-infected P. pinaster trees. As abietadiene is not commercially available, this study aimed to achieve, for the first time, its isolation, structure elucidation, and detailed characterization from readily available forestry residues. Abietadiene was successfully isolated using thin-layer chromatography (TLC), and its purity and identity were evaluated using multiple analytical techniques: gas chromatography (GC), liquid chromatography (LC), nuclear magnetic resonance (NMR), and Fourier-transform infrared spectroscopy (FTIR). GC analysis indicated a purity of over 70% for the isolated compound, while LC provided the higher purity value of 98%. The identity of abietadiene was unequivocally confirmed through LC, FTIR, and NMR analysis. This work represents the first isolation and comprehensive characterization of abietadiene from a natural source, making detailed chemical data on this compound available to the scientific community. These findings may be used for future studies on the biological interactions and ecological roles of abietadiene, particularly in the context of plant defence and pathogen resistance.
- Corema album spp: Edible wild crowberries with a high content in minerals and organic acidsPublication . Brito, Catarina; Bertotti, Taciana; Primitivo, Maria João; Neves, Marta; Pires, Cristiana L.; Cruz, Pedro F.; Martins, Patrícia A. T.; Rodrigues, Ana Cristina; Moreno, Maria João; Brito, Rui M. M.; Campos, Maria; Vaz, Daniela C.; Pessoa, Maria Fernanda; Lidon, Fernando; Reboredo, Fernando; Santos Ribeiro, VâniaEdible wild plants are part of the ethnobotanical and gastronomic heritage of different geographical areas. Corema album (L.) D. Don is an endemic species of the dune systems of the Atlantic coast of the Iberian Peninsula. The aerial parts of Corema album are a source of nutrients and antioxidants. The Corema album white berry (Portuguese crowberry) is rich in calcium, iron, and zinc. The plant also shows high phenolic content and antioxidant capacity associated with the leaves, fruit, and flowers. The presence of organic acids, namely phenolic acids, such as hydroxycinnamic acids, and long chain polyunsaturated fatty acids (PUFAs) omega-3 and omega-6 has also been confirmed. Toxicity studies evaluated by cell viability tests with human intestinal epithelium model cells (Caco-2) have shown that, at low concentrations, plant extracts may present beneficial effects.
- DIBMA nanodiscs keep α-synuclein foldedPublication . Adão, Regina; Cruz, Pedro F.; Vaz, Daniela C.; Fonseca, Fátima; Pedersen, Jannik Nedergaard; Ferreira-da-Silva, Frederico; Brito, Rui M. M.; Ramos, Carlos H. I.; Otzen, Daniel; Keller, Sandro; Bastos, Margaridaα-Synuclein (αsyn) is a cytosolic intrinsically disordered protein (IDP) known to fold into an α-helical structure when binding to membrane lipids, decreasing protein aggregation. Model membrane enable elucidation of factors critically affecting protein folding/aggregation, mostly using either small unilamellar vesicles (SUVs) or nanodiscs surrounded by membrane scaffold proteins (MSPs). Yet SUVs are mechanically strained, while MSP nanodiscs are expensive. To test the impact of lipid particle size on α-syn structuring, while overcoming the limitations associated with the lipid particles used so far, we compared the effects of large unilamellar vesicles (LUVs) and lipid-bilayer nanodiscs encapsulated by diisobutylene/maleic acid copolymer (DIBMA) on αsyn secondary-structure formation, using human-, elephant- and whale -αsyn. Our results confirm that negatively charged lipids induce αsyn folding in h-αsyn and e-αsyn but not in w-αsyn. When a mixture of zwitterionic and negatively charged lipids was used, no increase in the secondary structure was detected at 45 °C. Further, our results show that DIBMA/lipid particles (DIBMALPs) are highly suitable nanoscale membrane mimics for studying αsyn secondary-structure formation and aggregation, as folding was essentially independent of the lipid/protein ratio, in contrast with what we observed for LUVs having the same lipid compositions. This study reveals a new and promising application of polymer-encapsulated lipid-bilayer nanodiscs, due to their excellent efficiency in structuring disordered proteins such as αsyn into nontoxic α-helical structures. This will contribute to the unravelling and modelling aspects concerning protein-lipid interactions and α-helix formation by αsyn, paramount to the proposal of new methods to avoid protein aggregation and disease.
- Edible flowers of Helichrysum italicum: Composition, nutritive value, and bioactivitiesPublication . Primitivo, Maria João; Neves, Marta; Pires, Cristiana L.; Cruz, Pedro F.; Brito, Catarina; Rodrigues, Ana C.; Carvalho, Carla C. C. R. de; Mortimer, Megan M.; Moreno, Maria João; Brito, Rui M. M.; Taylor, Edward J.; Millson, Stefan H.; Reboredo, Fernando; Campos, Maria; Vaz, Daniela C.; Santos Ribeiro, VâniaHelichrysum italicum (H. italicum) is a halophyte shrub with bright yellow flowers with a strong curry-like aroma. The essential oils of H. italicum have been used in the production of cosmetics and pharmaceuticals, due to their antiallergic and anti-inflammatory properties. In the agri-food sector, H. italicum flowers can be used for seasoning and flavoring food, and as natural food preservatives. Here, we report on the composition, bioactive compounds, and nutritive value of H. italicum flowers. Flowers were mainly composed of carbohydrates (>80 % dry weight), followed by minerals (6.31 ± 0.95 % dw), protein (5.44 ± 0.35 % dw), and lipids (3.59 % ± 0.53 % dw). High percentages of Fe, Zn, Ca, and K were found in the flower material, along with a high content in antioxidants, polyphenols, and carotenoids, as corroborated by the nuclear magnetic resonance (NMR) data. Flowers were mainly composed of saturated fatty acids (SFAs) (54.50 ± 0.95 % of total FA), followed by polyunsaturated fatty acids (PUFAs) (37.73 ± 1.25 % of total FA) and monounsaturated fatty acids (MUFAs) (7.77 ± 0.34 %), as detected by gas chromatography mass spectrometry (GC–MS). The omega-6 PUFA linoleic acid (22.55 ± 0.76 % of total FA) was the most abundant fatty acid found. Flower extracts showed antimicrobial activity against Saccharomyces cerevisiae and Komagataella phaffii, as well as against Gram-negative (Klebsiella pneumoniae) and Gram-positive (Staphylococcus aureus) bacteria. H. italicum flower material was nontoxic to human intestinal Caco-2 model cells at concentrations up to 1.0 % w/v.
- Nutritive Value and Bioactivities of a Halophyte Edible Plant: Crithmum maritimum L. (Sea Fennel)Publication . Correia, Iris; Antunes, Madalena; Tecelão, Carla; Neves, Marta; Pires, Cristiana L.; Cruz, Pedro F.; Peralta, Claúdia C.; Pereira, Cidália D.; Reboredo, Fernando; Moreno, Maria João; Brito, Rui M. M.; Vaz, Daniela C.; Campos, Maria; Rodrigues, Maria JorgeCrithmum maritimum L. (sea fennel), an edible xerophyte of coastal habitats, is considered an emerging cash crop for biosaline agriculture due to its salt-tolerance ability and potential applications in the agri-food sector. Here, the nutritional value and bioactive properties of sea fennel are described. Sea fennel leaves, flowers, and schizocarps are composed of carbohydrates (>65%) followed by ash, proteins, and lipids. Sea fennel’s salty, succulent leaves are a source of omega-6 and omega-3 polyunsaturated fatty acids, especially linoleic acid. Extracts obtained from flowers and fruits/schizocarps are rich in antioxidants and polyphenols and show antimicrobial activity against Staphylococcus aureus, Staphylococcus epidermis, Candida albicans, and Candida parapsilosis. Plant material is particularly rich in sodium (Na) but also in other nutritionally relevant minerals, such as calcium (Ca), chlorine (Cl), potassium (K), phosphorus (P), and sulfur (S), beyond presenting a potential prebiotic effect on Lactobacillus bulgaricus and being nontoxic to human intestinal epithelial Caco-2 model cells, up to 1.0% (w/v). Hence, the rational use of sea fennel can bring nutrients, aroma, and flavor to culinary dishes while balancing microbiomes and contributing to expanding the shelf life of food products.
- Preserving and hydrogel-matrixing the bioactive properties of aromatic medicinal halophytic herbs from the coastline of the Iberian PeninsulaPublication . Parracho, Tiago; Cruz, Pedro F.; Peralta, Claúdia C.; Silva, Cândida G.; Campos, Maria Jorge; Neves, Marta; Cordeiro, Rachel; Trindade, Daniela; Moura, Carla; Almeida, Zaida L.; Pereira, Cidália D.; Guimarães, Carla; Brito, Rui M. M.; Guerra, Mauro; Reboredo, Fernando; Veríssimo, Paula; Vaz, Daniela C.; Santos Ribeiro, VâniaEdible wild plants are part of the ethnobotanic heritage of a certain geographical area and are important sources of essential oils, antioxidants, minerals, and special flavours. Corema album (Portuguese crowberry), Crithmum maritimum (sea fennel), Eryngium maritimum (sea holly), Helichrysum italicum (curry plant) and Otanthus maritimus (cottonweed) wildly flourish along the sandy dunes of the coast of the Iberian Peninsula. These plants are locally known for their beneficial properties, with important value for food, cosmetics and/or medicinal applications. Hence, leaves of these endemic species were collected at four different locations and submitted to different preserving treatments (oven-drying, freezing, and freeze-drying). Acetonic extracts of the different plants submitted to the different post-harvesting treatments were analysed regarding their antioxidant capacities and phenolic contents. Plant extracts were also analysed by diffusion-ordered nuclear magnetic resonance spectroscopy (DOSY-NMR). In general, freeze-drying was the best method of preserving plant minerals, antioxidants (~4 mgVCEAC/g fw) and polyphenols (~5 mgGAE/g fw). Minerals were quantified via energy-dispersive X-ray fluorescence spectrometry, and despite their location, all plants were rich in Ca, Cl, K, S and P. Hierarchical clustering and principal component analyses (PCA) pointed towards chemical/metabolic proximity between taxonomic families. Alginate hydrogels loaded with 0.1 % and 0.2 % (w/v) of extracts presented homogenous surface properties by scanning electron microscopy, good mechanical tensile strength (~30 MPa) and antibacterial activity against S. aureus. Edible alginate hydrogels enriched with plant extracts hold great nutraceutical potential to be used as natural preservatives for food coating and packaging or as sources of bioactive compounds for biomedical applications.
- Retention of minerals, antioxidants, pigments, and glucosinolates by broccoli florets and green bean pods boiled in alkaline, neutral and acidic watersPublication . Ribeiro, Vânia S.; Cruz, Pedro F.; Almeida, Zaida L.; Silva, Cândida G.; Silva, Maria Isabel; Silva, Inês S.; Santos, Liliana R.; Santos, Marta T.; Guimarães, Carla; Brito, Rui M.M.; Guerra, Mauro; Reboredo, Fernando; Pereira, Cidália D.; Vaz, Daniela C.Given the poor palatability and chewability of crude green bean pods (Phaseolus vulgaris) and broccoli florets (Brassica oleracea var. italica Plenck) these vegetables are generally microwaved, steamed or water boiled. Hence, here, we evaluated the contents of minerals, antioxidants, phenolics, glucosinolates, pigments, colour, texture and flavour of water-boiling broccoli and green bean pods, with four mineral waters with variable composition and pH. Plant matrices were characterized by High Resolution Magic-Angle Spinning (HR-MAS) and plant extracts were analysed by pseudo-2D Diffusion-ordered nuclear magnetic resonance (NMR) spectroscopy. Mineral waters ranging from acidic to neutral and alkaline were used and the colour properties (lightness, greenness/yellowness, colour saturation and hue angles), minerals and bioactive contents retained by the vegetables were compared to microwaved and steamed material. Boiling bean pods for 5 min extracted more polyphenols and antioxidants, particularly with more acidic waters, than 5 min of microwaving or steaming. However, even if boiling broccoli with more acidic water could better preserve glucosinolates, the food material presented lower retention of pigments and poor palatability. Cooking with more alkaline water increased mineral retention and broccoli greenness, also leading to highest scores in “colour”, “texture”, and “flavour”. Hence, samples cooked in more alkaline water presented higher acceptability.