Preface

The chapters of this volume comprise synthetic approaches demonstrating the potential of carbohydrates to access a diversity of biologically active structures and also their importance for the generation of new lead molecules and for the understanding of biological processes at the molecular level.

Ana Gómez, Cristóbal López and their co-worker demonstrate the usefulness of pyranose glycals for the creation of a diversity of structures, namely to access tetrahydroquinolines, aminocyclopentenones, bicyclononenes bearing endocyclic oxygen and nitrogen atoms, pyranose-fused heterocycles and butyrolactones, chromans, anthracycline mimics, chiral biphenyls, among many others, showing the importance of carbohydrate chemistry for innovation in organic chemistry. Glycals as substrates for radical addition and cycloaddition reactions and their application as activated olefins in multicomponent reactions is well documented, with examples given with Povarov reaction and Mannich–Ritter transformations.

Deoxy glycosides are widely found in nature and exhibit diverse bioactive activities, being important synthetic targets. Carmen Galan and co-worker highlight in this chapter the most recent synthetic efforts in the area over the last 3 years.

Mycothiol is a low-molecular weight thiol produced by Mycobacterium tuberculosis, the causative pathogen of the disease tuberculosis, with a role in the detoxification mechanism implicated in the development of drug resistance. Inhibitors of MSH biosynthesis may therefore contribute for development of more efficacious treatments against tuberculosis. Gammon and co-worker, in this chapter, summarize the recent progress in the synthesis of mycothiol and analogues, including precursors and metabolites as potential “small molecule” targets and promising lead compounds for the treatment of tuberculosis.

Murphy's review covers recent developments and applications of Lewis acid promoted anomerisation. An overview on anomerisation reactions described prior to 2010 and recent developments in the area are critically revised, covering the identification of Lewis acid promoters/catalysts of anomerisation such as iodine derivatives, Bi(iii) triflates and gold catalysed reactions. Cross-over experiments, DFT based searching of transition states, trapping of intermediates and structure–reactivity studies employed to study the reaction mechanism and evidence for pathways involving both endocyclic cleavage and exocyclic cleavage have been reviewed. Applications e.g. to stereoselective synthesis of (neo)glycolipids with potential immunostimulatory properties are given, demonstrating the usefulness of the area for chemistry and biology.

Nifantiev and co-workers have surveyed syntheses of glyco structures related to reserve polysaccharides, molecules of recognition and immunogenic glycoconjugates that possess one or more alpha-glucose residues, paying particular attention to the most relevant and modern methods for alpha-selectivity control. An overview on recognition molecule roles and their synthetic approaches is given, including those involved in post-translational modification of proteins and immunogens, focusing also on the immunostimulatory activity of amphiphilic glycoconjugates and giving insights into innate immunity. Focusing on the most prominent and recent achievements, this chapter demonstrates the importance of bridging carbohydrate chemistry and glycobiology for this area of interdisciplinary research.

The work reported in the last 5 years on synthetic approaches toward mimics of oligosaccharides aiming to design antagonists of medically relevant lectins is covered in the chapter authored by Anna Bernardi. It focuses on multivalent sugar-processing enzyme inhibitors, synthesis of oligosaccharide and glycoconjugate mimics with unnatural glycosidic bonds/linkers and the use of second site interactions in monosaccharide anchored lectin antagonists.

Oscar Francesconi and Cristina Nativi describe the design of effective synthetic receptors for molecular recognition of carbohydrates, covering systematic studies related to the understanding of the key structural and functional features that are effective for carbohydrate recognition.

The importance of carbohydrate–carbohydrate interaction in biological processes is highlighted in Zhang and co-workers' chapter. It covers the work reported so far on these interactions involved in cell adhesion and proliferation processes, including Lewis^x–Lewis^x interactions.

This volume comprises contributions covering carbohydrate chemistry and glycobiology, and demonstrates glycoscientists’ trends toward interdisciplinary research. It is not only required for the discovery of new lead molecules but also for the generation of new approaches for the cure of devastating diseases that threaten our society nowadays. Carbohydrates are the tool for the discovery of many of mechanisms involved and required interventions.

We are sure that readers will enjoy this volume and we really hope that these book chapters will contribute to generate new ideas and new findings.

Amelia P. Rauter

Thisbe K. Lindhorst

Yves Queneau