Current Trends in Biotechnology and Pharmacy Vol. 9 (3) 293-304 July 2015, ISSN 0973-8916 (Print), 2230-7303 (Online) 294 Abstract Secondary metabolites (SM) are compounds that are not necessary for a cell (organism) to live, but play a role in the interaction of the cell (organism) with its environment. These compounds are often involved in plants protection against biotic or abiotic stresses. Secondary metabolites are from different metabolites families that can be highly inducible in response to stresses. Primary metabolites perform essential metabolic roles by participating in nutrition and reproduction. A few SMs are used as especially chemical such as drugs, flavours, fragrances, insecticides, and dyes and thus have a great economic value. These new technologies will serve to extend and enhance the continued usefulness of the higher plants as renewal sources of chemicals, especially medicinal compounds. A continuation and intensification efforts in this field is expected to lead to successful biotechnological production of specific, valuable and as yet unknown plant chemicals. Keywords: Secondary metabolites, drugs, flavours, fragrances, biotechnology Introduction Plants possess capacity to synthesize different organic molecules called secondary metabolites. Unique carbon skeleton structures are basic properties of plant secondary metabolites. Secondary metabolites are not necessary for a cell (organism) to live, but play a role in the interaction of the cell (organism) with its surroundings, ensuring the continued existence of the organism in its ecosystems. Formation of SMs is generally organ, tissue and cell specific and these are low molecular weight compounds. These compounds often differ between individuals from the same population of plants in respect of their amount and types. They protect plants against stresses, both biotic (bacteria, fungi, nematodes, insects or grazing by animals) and abiotic (higher temperature and moisture, shading, injury or presence of heavy metals). SMs are used as especially chemical such as drugs, flavours, fragrances, insecticides, and dyes by human because of a great economic value. In plants, SMs can be separated into three groups (Terpenoids, Polyketides and Phenypropanoids) based on their biosynthesis origin (1). Alkaloids are additional class of SMs, which are nitrogenous organic molecules biosynthesized mainly from amino-acids, e.g., tryptophan, tyrosine, phenylalanine, lysine and arginine using many unique enzymes (2). Many of the most important therapeutic agents are alkaloids. The sites of biosynthesis are compartmentalised at cellular or sub-cellular level. However SMs can be transported long distances and accumulate from their location of synthesis. Primary Vs Secondary Metabolites : Primary metabolites are found in all plants and execute vital metabolic responsibilities, by participating in Secondary Metabolites of Plants and their Role: Overview Saurabh Pagare 1* , Manila Bhatia 1 , Niraj Tripathi 2 , Sonal Pagare 3 and Y.K. Bansal 1 1 Department of Biological Science, Rani Durgavati Vishwavidyalaya, Jabalpur (M.P.)-482001, India 2 Directorate of Weed Science Research, Jabalpur (M.P.)-482004, India 3 NTPC Hospital,Korba (C.G.)-495450, India *For Correspondence - saurabhhind@gmail.com Secondary Metabolites of Plants and their Role