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- Sea bass (Dicentrarchus labrax) and sea bream (Sparus aurata) head oils recovered by microwave-assisted extraction: nutritional quality and biological propertiesPublication . Fuente, Beatriz de la; Pinela, José; Calhelha, Ricardo C.; Heleno, Sandrina A.; Ferreira, Isabel C.F.R.; Barba, Francisco Jose; Berrada, Houda; Caleja, Cristina; Barros, LillianMicrowave-assisted extraction (MAE) and Soxhlet extraction (SE) were used to obtain oil from European sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata) heads. The MAE technique allowed the recovery of more than 50% of the total lipid con- tent for both fish by-products in less than 11 min extraction. Based on their fatty acid composition, all fish head oils presented a healthy lipid profile and were found to be a good source of docosahexaenoic acid (DHA, 11–14%). Different lipid quality indices also revealed their cardiovascular protective potential. Oils obtained by MAE showed higher antibacterial and antifungal effects against food pathogens than those extracted by SE. Cellular antioxidant activity (29–35% oxidation inhibition) and anti-inflammatory poten- tial via NO production inhibition (IC50 = 14–21 μg/mL) were evaluated using murine macrophages cells (RAW 264.7). The highest cytotoxic effect (GI50 = 38–46 μg/mL) of fish head oils was observed against breast cancer cells (MCF-7). These results showed that sea bass and gilthead sea bream heads could be exploited for the production of oil with nu- tritional and bioactive properties in line with circular bioeconomy concepts.
- Valorization of Solanum melongena L. crop by-products: Phenolic composition and in vitro antioxidant, antidiabetic, anti-inflammatory, cytotoxic, and antimicrobial propertiesPublication . Añibarro-Ortega, Mikel; Dias, Maria Inês; Petrović, Jovana; Núñez, Sonia; Calhelha, Ricardo C.; Costa, Eduardo M.; Machado, M.; Pintado, Manuela; Soković, Marina; López, Víctor; Barros, Lillian; Pinela, JoséThis study explored the valorization of post-harvest eggplant aerial parts as a sustainable source of value-added ingredients by investigating their phenolic composition and in vitro bioactive properties. HPLC-DAD-ESI/MSn analysis identified chlorogenic acid derivatives as the predominant phenolic compounds (53 % of the phenolic fraction), followed by O-glycosylated kaempferol and quercetin. The extract displayed antioxidant activity in physiologically relevant cell-based assays and significant α-glucosidase inhibitory capacity that far exceeded that of the standard drug acarbose. It also inhibited the formation of advanced glycation end-products (AGEs), suggesting its potential to mitigate diabetes-related complications. Furthermore, the extract showed a modest pancreatic lipase inhibitory effect and capacity to suppress interleukin 6 production. Selective cytotoxicity against human gastric and colon adenocarcinoma cell lines and strong antimicrobial activity against foodborne pathogens were observed. Given the growing demand for natural alternatives to synthetic drugs, these findings position eggplant crop biomass as a promising, sustainable source of active compounds with potential applications in food, nutraceutical, and pharmaceutical formulations for managing type 2 diabetes and other oxidative stress-mediated conditions. This study not only contributes to the valorization of agricultural waste but also expands the research on by-products of Solanaceae crops, offering a pathway for sustainable resource utilization.
- Synthesis of Tricyclic and Tetracyclic Lactone Derivatives of Thieno[2,3-b]pyrazine or Thieno[2,3-b]quinoline: Preliminary Antitumor and Antiparasitic Activity EvaluationPublication . Martins, Maria F.; Ribeiro, Francisco; Borges, Ana Margarida; Calhelha, Ricardo C.; Santarém, Nuno; Cordeiro-da-Silva, Anabela; Queiroz, Maria João R.P.Tricyclic and tetracyclic lactone derivatives of thieno[2,3-b]pyrazine or thieno[2,3-b]quinoline, and 2H-pyrones were prepared using different methodologies. Pd/Cu-catalyzed Sonogashira coupling using Et3N as a base, of methyl 7-bromothieno[2,3-b]pyrazine-6-carboxylate and (het)arylalkynes to yield the Sonogashira ester products, gave also the corresponding tricyclic lactones as minor products. However, the major products did not cyclize with TFA. Tricyclic lactones were then obtained by a tandem one-pot Sonogashira coupling and 6-endo-dig lactonization of 7-bromothieno[2,3-b]pyrazine-6-carboxylic acid with (het)arylalkynes, in good yields. Halogenated tricyclic lactones were synthesized by halocyclization using CuX and NXS. Tetracyclic lactones were synthesized through a Rh(III)-catalyzed formal [4+2] cycloaddition, between thieno[2,3-b]quinoline-2-carboxylic acid and internal alkynes, triggered by C-H activation, with the carboxylic group acting as a directing group. Using the SRB assay, the antitumor activity of both Sonogashira products and lactones was evaluated across five human cancer cell lines (CaCo-2, MCF-7, AGS, HeLa, NCI-H460). The best-performing compound was a Sonogashira product showing a GI50 < 10 µM in all tumor cell lines and low toxicity in PLP2 cells. Additionally, antiparasitic testing against Trypanosoma brucei and Leishmania infantum revealed some compounds with IC50 < 11 µM, though some level of cytotoxicity was observed in THP-1—derived macrophages.
- Anti-Proliferative, Anti-Inflammatory, In Vitro Wound Healing Potentials and Phenolic Content of Phlomis Crinita Cav. ExtractsPublication . Chelgham, Abdelhakim; Borges, Ana Margarida; Calhelha, Ricardo C.; Merouane, Abdelaziz; Noui, Abdallah; Saadi, AbdelkaderPhlomis crinita Cav. (P. crinita), a medicinal plant from the Lamiaceae family, is widely used as a natural remedy in traditional North African and Southern European folk medicine to treat lesions and burns through the application of its leaves This study aimed to investigate its biological activities, including antiproliferative, anti-inflammatory, and wound-healing properties. Hydromethanolic extracts were prepared from the leaves, flowers, and rhizomes. Phytochemical analysis determined total phenolic content (TPC) and flavonoid content (FC). Antiproliferative activity was evaluated using the sulforhodamine B (SRB) assay against five human tumor cell lines (AGS, Caco-2, HeLa, MCF-7, and NCI-H460), each derived from a carcinoma of a distinct organ. Anti-inflammatory activity was assessed by measuring nitric oxide production in LPS-stimulated RAW 264.7 macrophages. The wound-healing potential was evaluated using the scratch assay. Phytochemical analysis revealed significant variations in TPC and FC among the extracts, with the rhizome extract exhibiting the highest levels: TPC: 128.15 μg GAE/mg DW and FC: 46.91 μg QE/mg DW. All extracts demonstrated antiproliferative activity against the tumor cell lines, with the rhizome extract showing the most potent growth inhibition (GI50: 178.11 ± 4.10 μg/mL against AGS). The rhizome extract also exhibited the most potent inhibition of nitric oxide production (IC50: 152.42 ± 10.88 μg/mL) compared to the other extracts tested. In the wound-healing assay, leaf extract demonstrated comparable healing effects to Allantoin, a known wound-healing agent. Our findings support the notion that P. crinita can be considered a promising source of therapeutic bioactive compounds.
- FIG (Ficus Carica L.) Bioresidues as sources of bioactive compounds and natural pigments for the food industryPublication . Shiraishi, Carlos S.H.; Zbiss, Yosra; Roriz, Custódio Lobo; Carocho, Márcio; Domingos, Sara; Calhelha, Ricardo C.; Alves, Maria José; Abreu, Rui M.V.; Prieto Lage, Miguel A.; Heleno, Sandrina A.; Barros, LillianThe 17 goals of sustainable development address several topics, such as: (2) Zero hunger and sustainable agriculture; (9) Industry, Innovation, and Infrastructure; (12) Responsible consumption and production; that are essential for the promotion of the circular economy, product development and conscious production [1]. Fig is a food matrix, cultivated in Portugal and valued by the Portuguese people for consumption in natura, being also used in wines, liqueurs, and jams. As this fruit is very appreciated and consumed, it´s cultivation leads to the production of tons of leaves, usually discarded [2]. Therefore, in the present work, the leaves of five fig varieties (Figure 1), namely Dauphine (Da), Longue d'Aout (La), Pasteliere (Pa), Marseille (Ma) and Bourjassote Noire (Bn), were nutritionally and chemically characterized to detect possible bioactive molecules. The antioxidant and antimicrobial, activities were also analyzed, to provide the food industry with natural additives in alternative to the artificial ones; and at the same time, promote the circular economy. Regarding the nutritional profile of the five leaves, La sample exhibited the highest amount in proteins (18.0±0.6 g/100g dw), while Pa revealed the highest content in fats (2.2±0.1 g/100g dw). The highest moisture content was presented by Da leaves (17.3±0.1 g/100g fw), and for the ashes, La sample was the one that presented the highest value (14.18±0.06 g/100g fw). Concerning the organic acids, these molecules were most abundant in Ma leaves, where it was possible to identify oxalic, malic and citric acids with a total of 139.6±0.4 mg/g dw. For the soluble sugars profiling, in all samples it was possible to identify five sugars, namely, fructose, glucose, sucrose, trehalose, and raffinose in different concentrations; however, Da leaves revealed the higher amount (17±1 g/100g dw). Tocopherols where also analyzed, and in all samples, three of the four isoforms where detected, being Pa sample standing for the predominance of these compounds (4.14±0.05 mg/100 g dw). For the bioactive analysis, different assays were performed, and Pa sample showed the strongest antioxidant potential for the TBARS assay, with an EC50 value of 105±5 mg/mL. For the antimicrobial activity assay, Da leaf extract was the one displaying the best results, by presenting Minimum Inhibitory Concentrations (MIC) ranging from 1.25 to 10 mg/mL against the tested bacterial strains. On the other hand, for the antifungal activity, the samples present very similar profiles, with the exception of the Pa sample, that present the lowest MIC of 5 mg/mL for Aspergillus fumigatus. In general, these leaf extracts can be used in the food industry namely in pastry and bakery products as promising sources of bioactive compounds, and at the same time, this reuse of biowaste promotes circular economy, and reduces the impact of biowaste resulting from the fig industry, thus meeting some of the goals of sustainable development.
- New trends from fungi secondary metabolism in the pharmaceutical industryPublication . Calhelha, Ricardo C.; Shiraishi, Carlos S.H.; Ribeiro, Lúcia Marisa Maia; Carocho, Márcio; Abreu, Rui M.V.; Coutinho, Paula; Barros, Lillian; Vaz, Josiana A.; Ferreira, Isabel C.F.R.Fungi are eukaryotic organisms that can produce a wide range of secondary metabolites with a significant impact on society. Some metabolites are exploited for their activity as antioxidant, anti-inflammatory, antitumor, and anti-microbial agents, and in the production of cancer vaccines, among other pharmaceutical applications. Since the discovery of penicillin, the pharmaceutical industry has been greatly interested in fungi as sources of natural bioactive compounds, and fungi metabolites have made an indispensable contribution to improving human and animal health throughout the last decades. Starting with the development of antibiotics, the pharmaceutical industry has increasingly turned to these compounds for a variety of applications. The increase in the number of patents registered worldwide is a strong indicator that the market realizes the great potential of fungi secondary metabolites. In general, the pharmaceutical industry trend is centered on adopting different strategies to discover new drugs, and fungi secondary metabolites are viewed as having significant potential. This chapter explores the current pharmaceutical applications of secondary metabolites found in fungi. Initially, the most recent mushroom studies and their commercial pharmaceutical and cosmeceutical applications are explored. An overview of the different classes of fungi secondary metabolites with biologically relevant activities is then presented. Recently marine fungi were found to be a rich source of secondary metabolites. Due to the recent relevancy of marine fungi, an overview of marine fungi secondary metabolites with relevant pharmaceutical-related activities is also presented. Finally, the potential of fungi metabolites as a source of natural pigments and the methodologies used to characterize and explore fungi secondary metabolites are also analyzed.
- Methyl 3-[4-(3-arylureido)phenylamino]thieno[3,2-b]pyridine-2-carboxylates as potential inhibitors of VEGFR-2: synthesis and molecular modelling studiesPublication . Peixoto, Daniela; Calhelha, Ricardo C.; Dias, Sofia; Froufe, Hugo J.C.; Abreu, Rui M.V.; Ferreira, Isabel C.F.R.; Queiroz, Maria João R.P.When over expressed or mutated, protein tyrosine kinases become potent oncoproteins that cause deregulated cell growth angiogenesis and metastasis. Because of these characteristics, they are targets for small molecule inhibitors in the treatment of cancer. Recently some thieno[3,2-c]pyridine 1,3-diarylurea derivatives were prepared as VEGFR-2 (vascular endothelium growth factor receptor-2) inhibitors.1 Here we present the synthesis of methyl 3-[4-(3-arylureido)phenylamino]thieno[3,2-b]pyridine-2-carboxylates 2 in excellent yields, by reaction of the methyl 3-(4-aminophenylamino)thieno[3,2-b]pyridine-2-carboxylate 1, prepared also by us, with different arylisocyanates (Scheme).
- Tripleurospermum inodorum – mayweed without scent but with range of bioactivitiesPublication . Ivanov, Marija; Božunović, Jelena; Dias, Maria Inês; Calhelha, Ricardo C.; Barros, Lillian; Ferreira, Isabel C.F.R.; Stojković, DejanTripleurospermum inodorum (L.) Sch. Bip. (Asteraceae), scentless mayweed, is a common weed species, but despite its abundancy it is still underexplored in the terms of its bioactivities. The aim of the study was to explore the bioactivities of scentless mayweed methanolic extract including antimicrobial, antibiofilm, antioxidant, cytotoxic, and antiinflammatory activity and to provide deeper insight into its chemical composition. It was shown that T. inodorum inhibits growth of human pathogenic microorganisms with minimal inhibitory concentration (MIC) in range 3-12 mg/mL, with the lowest MIC noted for the species Candida albicans 475/15, C. albicans 17/15, C. parapsilosis ATCC 22019, Pseudomonas aeruginosa (IBRS P001), Yersinia enterocolitica (ATCC 23715), and Klebsiella pneumoniae (ATCC 13883). Its biofilm potential was promising - application of plant extract (1.5 and 3 mg/mL) reduced C. albicans 475/15 biofilm biomass and biofilm cell viability for more than 50%. Antioxidant assays suggested the plants antioxidant potential at 442.2 mmol GAE (gallic acid equivalent)/100 mg DW (dry weight) as in ABTS+ assay, 277.8 mmol GAE/100 mg DW in DPPH∙, and 204.4 mmol GAE/100 mg DW as recorded in the FRAP assay. Wide cytotoxic potential of the extract was noticed for the range of cells: AGS (gastric adenocarcinoma, GI50 198.7 μg/mL), CaCo2 (colorectal adenocarcinoma, GI50 278.2 μg/mL), MCF-7 (breast adenocarcinoma, GI50 265.7 μg/mL), NCI-H460 (lung carcinoma, GI50 62.9 μg/mL), and VERO (non-tumour cell line, GI50 >400 μg/mL). Likewise, low IC50 (8.4 μg/mL) in the RAW 246.7 anti-inflammatory assay suggests the strong antiinflammatory potential of this weed. The dominant polyphenols in the extract were two apigenin derivatives: apigenin-O-pentoside and apigenin-O-acetylhexoside (5.234 mg/g and 4.929 mg/g extract, respectively). T. inodorum is a rich source of different bioactive polyphenols and its methanolic extract displays a range of bioactive features that should be further examined in order to develop novel herbal medicines
- Bioactivity, proximate, mineral and volatile profiles along the flowering stages of Opuntia microdasys (Lehm.): defining potential applicationsPublication . Chahdoura, Hassiba; Barreira, João C.M.; Fernández-Ruiz, Virginia; Morales, Patricia; Calhelha, Ricardo C.; Flamini, Guido; Soković, Marina; Ferreira, Isabel C.F.R.; Achour, LotfiOpuntia spp. flowers have been traditionally used for medical purposes, mostly because of their diversity in bioactive molecules with health promoting properties. The proximate, mineral and volatile compound profiles, together with the cytotoxic and antimicrobial properties were characterized in O. microdasys flowers at different maturity stages, revealing several statistically significant differences. O. microdasys stood out mainly for its high contents of dietary fiber, potassium and camphor, and its high activities against HCT15 cells, Staphylococcus aureus, Aspergillus versicolor and Penicillium funiculosum. The vegetative stage showed the highest cytotoxic and antifungal activities, whilst the full flowering stage was particularly active against bacterial species. The complete dataset has been classified by principal component analysis, achieving clearly identifiable groups for each flowering stage, elucidating also the most distinctive features, and comprehensively profiling each of the assayed stages. The results might be useful to define the best flowering stage considering practical application purposes.
- Optimization of heat and ultrasound-assisted extraction of Eucalyptus globulus leaves reveals strong antioxidant and antimicrobial propertiesPublication . Lima, Laíres; Pereira, Ana I.; Vaz, Clara B.; Ferreira, Olga; Dias, Maria Inês; Heleno, Sandrina A.; Calhelha, Ricardo C.; Barros, Lillian; Carocho, MárcioThe extraction of phenolic compounds from eucalyptus leaves was optimized using heat and ultrasound-assisted techniques, and the bioactive potential of the resulting extract was assessed. The independent variables, including time (t), solvent concentration (S), and temperature (T) or power (P), were incorporated into a fivelevel central composite design combined with Response Surface Methodology. Phenolic content was determined by HPLC-DAD-ESI/MS and used as response criteria. The developed models were successfully fitted to the experimental data to identify the optimal extraction conditions. Heat-assisted extraction proved to be the most efficient method for phenolic recovery, yielding 27 ± 2 mg/g extract under optimal conditions (120 min, 76.5 ◦C, and 25 % ethanol, v/v). The extracts exhibited a high concentration of phenolic glycoside derivatives, including gallotannin, quercetin, and isorhamnetin. These findings suggest that the extracts hold promise as natural additives in food technology, owing to their moderate antimicrobial activity and strong antioxidant properties.