Browsing by Issue Date, starting with "2021-06-18"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- Laccases: versatile biocatalysts for the synthesis of heterocyclic coresPublication . Sousa, Ana Catarina; Martins, Lígia O.; Robalo, M. PaulaLaccases are multicopper oxidases that have shown a great potential in various biotechnological and green chemistry processes mainly due to their high relative non-specific oxidation of phenols, arylamines and some inorganic metals, and their high redox potentials that can span from 500 to 800 mV vs. SHE. Other advantages of laccases include the use of readily available oxygen as a second substrate, the formation of water as a side-product and no requirement for cofactors. Importantly, addition of low-molecular-weight redox mediators that act as electron shuttles, promoting the oxidation of complex bulky substrates and/or of higher redox potential than the enzymes themselves, can further expand their substrate scope, in the so-called laccase-mediated systems (LMS). Laccase bioprocesses can be designed for efficiency at both acidic and basic conditions since it is known that fungal and bacterial laccases exhibit distinct optimal pH values for the similar phenolic and aromatic amines. This review covers studies on the synthesis of five- and six-membered ring heterocyclic cores, such as benzimidazoles, benzofurans, benzothiazoles, quinazoline and quinazolinone, phenazine, phenoxazine, phenoxazinone and phenothiazine derivatives. The enzymes used and the reaction protocols are briefly outlined, and the mechanistic pathways described.
- Cultivating entrepreneuship in higher education during a crisis condition: crisis related issues discussed in entrepreneurship literaturePublication . João, Isabel; Silva, JoãoThis paper presents a comprehensive state of the art regarding the crisis issues debated within entrepreneurship literature. It is crucial to understand the way that different types of entrepreneurs and entrepreneurial activities and dynamics are affected by the crisis to produce insights to foster entrepreneurship in higher education during crisis conditions. The literature review covers the last twenty years, and the nature of research studies highlights the relevance as seen by the growing number of studies over the last years. A set of criteria were used to classify the selected paper and crisis related issues were discussed within the chosen criteria. The discussion produced insights to cultivate higher education entrepreneurship in times of crises and helped do envisage useful teaching and learning tools to shape an entrepreneurial culture by fostering students' skills in crisis environments. Findings can have direct implications for scholars on entrepreneurship education and contribute to enrich entrepreneurial higher education during adverse conditions.