**1. Introduction**

Glycoconjugates are a class of sugars, or glycans, that are bonded covalently to various chemical species, such as proteins, peptides, lipids, and other compounds. The production of glycoconjugates occurs through the process of glycosylation [1]. Glycoconjugates, which include glycoproteins, glycopeptides, peptidoglycans, glycolipids, glycosides, and lipopolysaccharides, among other groups, are very important biological compounds. They take part in cell-cell interactions, matrix interactions, cell-cell interactions, and detoxification activities [2].

In general, the carbohydrate part(s) of a glycoconjugate play a vital role in its function; noteworthy examples of this are blood proteins and neural cell adhesion molecule, where minute differences in the carbohydrate structure influence cell attachment (or not) or lifetime in circulation.

Despite having a portion of carbohydrates, the significant biological species DNA, RNA, ATP, cAMP, cGMP, NADH, and coenzyme A are not typically regarded as glycoconjugates. Covalently joining polysaccharides antigens with protein scaffolds results in glycoconjugates, which are intended to produce a sustained immunological response in the body [3]. Glycoconjugate-based immunisation successfully produced long-lasting immunological memory against carbohydrate antigens. Since their introduction in the 1990s, glycoconjugate vaccines have demonstrated efficacy against meningococcus and influenza. GlycoRNAs were discovered for the in 2021.

The entire biological study of carbohydrates is known as glycobiology [4, 5]. It is frequently necessary to attach carbohydrates to surfaces, tag them with fluorophores, or transform them into natural or artificial glycoconjugates, like glycopeptides or glycolipids, in order to comprehend the role and behaviour of complex carbohydrates. These glycoconjugates must be created using simple and reliable chemical techniques in order to support glycobiology and its "omics," glycomics. An overview of the quickly developing area of chemical reactions that specifically transform unguarded carbohydrates into glycoconjugates via the anomeric position is provided in this article. O-, N-, S-, and C-glycosides are included in the discussion as well as other anomeric bond types of the newly generated glycoconjugates [6–8].

The biosynthetic enzymes called glycosidases and glycosyltransferases catalyse the hydrolysis of interglycosidic connections and the biosynthesis of interglycosyltransferases. The variety of naturally occurring glycosyltransferases and glycosidases, each of which has a distinct substrate preference, reflects the diversity of natural glycans. Natural glycans are frequently found in varied forms and frequently formed in minuscule quantities, making it difficult to isolate and characterise them from natural sources. As a result, synthetic glycans are crucial to glycobiology, and glycan production methods have advanced significantly. Glycosyltransferases and glycosidases are advantageous biocatalysts for the synthesis of glycans because they are very effective under controlled conditions. In this chapter, we go over basic ideas in glycobiology and combine them with recent developments in comprehending the main functions of the glycome in health and illness. Glycans are saccharides or sugar chains that can be free or attached to proteins or lipids to form simple or complex glycoconjugates. We review how glycosylation patterns are altered in a variety of human diseases, including congenital disorders of glycosylation (CDGs) as well as autoimmune, infectious, and chronic inflammatory diseases.

Key points of Glycosylation [9, 10]:


*Synthesis of Glycoconjugates in Potentiating Pharmacological and Pharmaceutical Activity DOI: http://dx.doi.org/10.5772/intechopen.109703*

for the development of metastatic characteristics, the inhibition of apoptosis, and chemotherapy resistance.


There are five types of glycans produced [11, 12]:

