The domain of bioactive natural products contains many oligosaccharides and aglycones decorated with various sugars. Glycan moieties influence essential aspects of biology of small molecules, such as mode of action, target recognition, pharmacokinetics, stability, and others. Methods of generation of novel glycosylated natural products are therefore of great value, as they, for example, may help fight human diseases more efficiently or provide healthier diet. This review covers the existing literature published mainly over the last decade that deals with biology-based approaches to novel glycoforms. Both genetic manipulations of biosynthesis of glycoconjugates and chemoenzymatic synthesis of novel "sweet" molecules are reviewed here. Wherever available, relationships between carbohydrate portions of the natural products and their biological activities are highlighted.