Isolation, Identification and Characterization of Glycosides

Nature has bestowed our universe with a vast wealth of restorative and curative plants. In the 21st century, medicinal plants' therapeutic effects have been considered a promising future drug/medicine for managing health care. The phytochemicals in herbs are the active ingredients that possess therapeutic activity and are considered medicine or drug. The ever increasing demand for phytochemicals from plant origin, either as pure compounds or as standardized extracts, provided unlimited opportunities for new drug leads. Seeking therapeutic drugs from natural products is of particular interest throughout the world. Plants synthesize secondary metabolites, which include alkaloids, flavonoids, saponins, terpenoids, glycosides, tannins and volatile oils. One of the important phytochemicals to be discussed in this chapter is glycosides. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycosides. These can be activated by enzymatic or acid hydrolysis leading to one or more sugar moieties along with non-sugar moieties. The former is called glycone, and the latter is aglycone or genin. Based on sugar moiety linkage, they are classified as C-glycosides, O-glycosides, S-glycosides and N-glycosides. Due to the complexity of plant chemical constituents, pure phytochemicals must be obtained using proper extraction and isolation techniques. This chapter focuses on the analytical methodologies, which include the extraction, isolation, identification and characterization of glycosides from medicinal plants.