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N-substituted iminosugar analogues are potent inhibitors of glucosidases and glycosyltransferases with broad therapeutic applications, such as treatment of diabetes and Gaucher disease, immunosuppressive activities, and antibacterial and antiviral effects against HIV, HPV, hepatitis C, bovine diarrhea (BVDV), Ebola (EBOV) and Marburg viruses (MARV), influenza, Zika, and dengue virus. Based on our previous work on functionalized isomeric 1,5-dideoxy-1,5-imino-D-gulitol (L-gulo-piperidines, with inverted configuration at C-2 and C-5 in respect to glucose or deoxynojirimycin (DNJ)) and 1,6-dideoxy-1,6-imino-D-mannitol (D-manno-azepane derivatives) cores N-linked to different sites of glucopyranose units, we continue our studies on these alternative iminosugars bearing simple N-alkyl chains instead of glucose to understand if these easily accessed scaffolds could preserve the inhibition profile of the corresponding glucose-based N-alkyl derivatives as DNJ cores found in miglustat and miglitol drugs. Thus, a small library of iminosugars (14 compounds) displaying different stereochemistry, ring size, and N-substitutions was successfully synthesized from a common precursor, D-mannitol, by utilizing an SN2 aminocyclization reaction via two isomeric bis-epoxides. The evaluation of the prospective inhibitors on glucosidases revealed that merely D-gluco-piperidine (miglitol, 41a) and L-ido-azepane (41b) DNJ-derivatives bearing the N-hydroxylethyl group showed inhibition towards α-glucosidase with IC50 41 µM and 138 µM, respectively, using DNJ as reference (IC50 134 µM). On the other hand, β-glucosidase inhibition was achieved for glucose-inverted configuration (C-2 and C-5) derivatives, as novel L-gulo-piperidine (27a) and D-manno-azepane (27b), preserving the N-butyl chain, with IC50 109 and 184 µM, respectively, comparable to miglustat with the same N-butyl substituent (40a, IC50 172 µM). Interestingly, the seven-membered ring L-ido-azepane (40b) displayed near twice the activity (IC50 80 µM) of the corresponding D-gluco-piperidine miglustat drug (40a). Furthermore, besides α-glucosidase inhibition, both miglitol (41a) and L-ido-azepane (41b) proved to be the strongest β-glucosidase inhibitors of the series with IC50 of 4 µM.

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Brazil is considered one of the world's leading producers of biofuels given the predominance of ethanol fuel in its energy matrix. However, despite the prominence of Brazil in ethanol production, the vast majority of biodiesel production plants in Brazil use methanol instead of ethanol as the alcohol for transesterification reaction, as is generally the case in the rest of the world. The aim of this paper is therefore to examine the transesterification process in the Brazilian biodiesel production in terms of sustainability. In this regard, it was necessary to evaluate the way in which the industrial process is currently carried out, the role of government incentives or subsidies for the use of ethanol to produce biodiesel, and the investments of companies in technology development for the same purpose. This study presents indications that the development of the biodiesel market in Brazil is still oriented toward a production model which is inconsistent with the environmental and social aspects of sustainability.

The high abundance of carbohydrates in nature and their diverse roles in biological systems validate the increasing interest for their chemical and biological research. Carbohydrates can be found as monomers or oligomers, or as glycoconjugates, which are formed by an oligosaccharide moiety linked to a protein (glycoproteins) or to a lipid moiety (glycolipids). Blood groups determinants (ABH), tumor associated antigens and pathogen binding sites are some of the relevant glycoconjugates found on mammalian cells. It is well known that carbohydrate and glycoconjugate molecules are implicated in many cellular processes, especially in biological recognition events, including cell adhesion, differentiation and growth, signal transduction, protozoa, bacterial and virus infections as well as immune responses. Therefore, the demand for glycans and glycoconjugates for various studies of targets involved in several serious diseases have been continuously growing. In this chapter we will present the design of drugs based on carbohydrate structure for treatment of parasitic diseases (T. cruzi) and virus infections (influenza and HIV). In addition, the development of glycoconjugate antitumour vaccines related to the structure of human mucin-associated glycans will also be discussed.

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