The main antioxidants present in plant extracts—quercetin, β-carotene, gallic acid, ascorbic acid, hydroxybenzoic acid, caffeic acid, catechin and scopoletin—are able to synthesize silver nanoparticles when reacting with a Ag NO₃ solution. The UV-visible absorption spectrum recorded with most of the antioxidants shows the characteristic surface plasmon resonance band of silver nanoparticles. Nanoparticles synthesised with ascorbic, hydroxybenzoic, caffeic, and gallic acids and scopoletin are spherical. Nanoparticles synthesised with quercetin are grouped together to form micellar structures. Nanoparticles synthesised by β-carotene, were triangular and polyhedral forms with truncated corners. Pentagonal nanoparticles were synthesized with catechin. We used Fourier-transform infrared spectroscopy to check that the biomolecules coat the synthesised silver nanoparticles. X-ray powder diffractograms showed the presence of silver, AgO, Ag₂O, Ag₃O₄ and Ag₂O₃. Rod-like structures were obtained with quercetin and gallic acid and cookie-like structures in the nanoparticles obtained with scopoletin, as a consequence of their reactivity with cyanide. This analysis explained the role played by the various agents responsible for the bio-reduction triggered by nanoparticle synthesis in their shape, size and activity. This will facilitate targeted synthesis and the application of biotechnological techniques to optimise the green synthesis of nanoparticles.

The European Entrepreneurship Competence Framework (EntreComp) offers a comprehensive description of the knowledge, skills, and attitudes that people need to develop for an entrepreneurial mindset. The use of the framework as a self-assessment tool has garnered attention, but there is scarce presence of instruments that address the whole set of competencies proposed by Entrecomp. In view of the lack of specific tools, the objective of this research was to assess the evidence of validity and reliability of a new questionnaire. The sample was composed of 742 college students from several Spanish universities between 17- and 64-years-old, with 34.6% being men and 65.4% being women. To evaluate the validity based on relationships with other measures, the Entrepreneurial Intention and Entrepreneurial Self-Capital scales were also administered. Confirmatory factor analysis showed an internal structure made up of four dimensions: Ideas and Opportunities, Personal Resources, Specific Knowledge, and Into Action. The results showed satisfactory evidence of validity based on relationships with Entrepreneurial Intention and Entrepreneurial Self-Capital and good reliability. The questionnaire has good psychometric properties and can be an easy and useful tool for the self-assessment of entrepreneurial competencies within the EntreComp framework.

This research is concerned with the fungicidal properties of the phenolic extract from industrial residues of Aloe vera used for antifungal treatment of various plant pathogens (Fusarium oxysporum f. sp. radicis-lycopersici, Phaeomoniella chlamydospora, Phaeoacremonium aleophilum, and Sporisorium scitamineum). Six phenolic compounds were identified in this extract from A. vera cortex: aloesin, α-barbaloin, chromone X, isoaloeresin D, β- barbaloin and aloeresin E. Phenolic extract was added to PDA medium at 20 concentrations from 0.32% to 10% and the growth of four different plant pathogenic fungi was tested. Fungal inhibition was calculated in order to evaluate the antifungal efficacy of phenolic extract against pathogens. Inhibition of Sporisorium scitamineum hyphal growth was observed after treatment with the phenolic extract at concentrations higher than 2.5% and a fungistatic effect with a 58.2% mycelia growth inhibition was detected at 3% extract concentration. Inhibition of P. chlamydospora and P. aleophilum hyphal growth was observed at concentrations higher than 4% and 3% respectively. A fungistatic effect with a 71.65% and a 19.87% mycelia growth inhibition was detected at 4.5% and 3.5% extract concentration respectively. About F. oxysporum f. sp. radicis-lycopersici, inhibition of hyphal growth was observed at concentrations higher than 2.5% and a fungistatic effect with a 32.07% mycelia growth inhibition was detected at 3% extract concentration. The results indicate that the tested extract possess antifungal activities against these pathogens at various concentration levels and could be used as a potential natural fungicide in order to control fungi pathogens providing a new use for the A. vera industrial residues.

This study investigates the enhanced production of key therapeutic metabolites (ellagic acid, serotonin, and chlorogenic acid) in response to abiotic stress in in vitro cultures of Quercus suber somatic embryos. Findings indicate significant increases in metabolite levels under various stress conditions, highlighting the potential for commercial-scale production of these compounds, known for their antioxidant, anticancer, and anti-COVID-19 properties. Under osmotic/saline stress, ellagic acid production significantly increased, representing an 80% increase compared to control conditions. In embryos exposed to different stressors, serotonin accumulation showed a six-fold increase under osmotic/saline stress. Although the elicitors used did not increase chlorogenic acid levels, exploring alternative stress types may enhance its production. This research paves the way for sustainable, large-scale production of health-beneficial metabolites, addressing global health challenges and promoting resource sustainability.

Re Vol. 24, núm. 4 julio-agosto 2023 ¡No lo tires, aprovéchalo, es bioeconomía! Elena Pérez-Urria Carril orcid.org/0000-0003-4895-5159 Universidad Complutense de Madrid (ucm) Doctora en Ciencias Biológicas por la Universidad Complutense de Madrid (ucm). Doctora en Ciencias Biológicas por la Universidad Complutense de Madrid (ucm) y experta en Desarrollo de la Inteligencia, Capacidad Superior y Neuropsicología […]