For billions of years, the phenomena of life and biocatalysis have been intertwined. If in the beginning biocatalysis was fundamental for the origin of life, currently it is very important for the cleaner production of pharmaceuticals and fine chemical intermediates. There is no doubt that drugs have brought great benefits to humanity, but currently, the expectations of modern society are focused on drugs with greater safety, less environmental impact, more sustainable practices, and less energy use. This review intends to show how the challenges for the production of some low molecular weight drugs produced by synthetic routes that involve at least one biotechnological step using microorganisms or enzymes were faced. These biotechnological drug production routes are more sustainable than conventional synthetic routes, as they produce a much smaller amount of waste, use moderate reaction conditions, have lower energy consumption, and have lower metal consumption, in addition to being more selective. Additionally, many natural products have structures too complex to be produced exclusively by chemical routes. The large-scale and economical production of these drugs is of great importance for fighting cancer as well as inflammatory, infectious, autoimmune, metabolic, hormonal, cardiovascular, and neurological diseases, among others.

The death of professor Rolf Huisgen (1920-2020) was announced on March 26th 2020, in the midst of the COVID-19 pandemic. Professor Huisgen was professor emeritus at the University of Munich in Germany, and studied in detail the mechanism of the 1,3-dipolar cycloaddition reaction, significantly expanding its scope. Even though he did not discover this reaction, it was through his studies that it became important in organic synthesis. Indeed, in honor of his work, the reaction became known as Huisgen’s cycloaddition and it has been consolidated as a useful method for the preparation of five-membered heterocyclic compounds. Considering these facts, in this review we provide an overview on the applications of 1,3-dipolar cycloaddition reactions, starting with the seminal examples in the field and further discussing the most recent applications.

ABSTRACT Naphthoquinones are the most commonly occurring type of quinones in nature. They are a diverse family of secondary metabolites that occur naturally in plants, lichens and various microorganisms. This subgroup is constantly being expanded through the discovery of new natural products and by the synthesis of new compounds via innovative techniques. Interest in quinones and the search for new biological activities within the members of this class have intensified in recent years, as evidenced by the evaluation of the potential antimicrobial activities of quinones. Among fungi of medical interest, yeasts of the genus Candida are of extreme importance due to their high frequency of colonization and infection in humans. The objective of this review is to describe the development of naphthoquinones as antifungals for the treatment of Candida species and to note the most promising compounds. By using certain criteria for selection of publications, 68 reports involving both synthetic and natural naphthoquinones are discussed. The activities of a large number of substances were evaluated against Candida albicans as well as against 7 other species of the genus Candida. The results discussed in this review allowed the identification of 30 naphthoquinones with higher antifungal activities than those of the currently used drugs.