An Overview on the Biosynthetic Pathways and Medicinal Values of Secondary Metabolites

Nature is a treasure hunt of novel molecules which are extensively used by humans for their medicinal values for millennia. Herbal medicines have emerged as life savers all over the world due to their multifunctional and diverse array of activities on the human body. Plants supply numerous bioactive molecules which are capable of treating disease conditions. Plants produce varieties of phytochemicals which are commonly recognized as primary and secondary metabolites. Secondary metabolites are inimitable resources for exploitation for pharmaceuticals, food additives e.t.c. They are often involved in the control of abiotic or biotic stress. They play distinctive roles in the defense mechanism of plants, act as insect repellant, regulate signaling pathways, and also exhibit varied range of pharmacological actions such as antibacterial, antioxidant, anticancer anti-diabetic and others. Secondary metabolites are derived from one or mixed pathways that give rise to formation of various compounds i.e., alkaloids, volatile oils, tannins, glycosides and resins etc. which have great importance in modern medicine. Isopentenyl diphosphate and Shikimic acid pathway serve as primary precursors for the synthesis some of types of secondary metabolites. The present review deals with the brief introduction, significance of secondary metabolites in the plants, biosynthetic pathways, and therapeutic importance of some commonly known secondary metabolites.