The substances with a chemical moiety are derived from plants known as phytochemicals.The detailed study of these phytochemicals is called as phytochemistry which describes the structures of  large number of  secondary metabolic compounds which are observed in plants. It consists of wide range  of organic substances that are accumulated by plants and which further  deals with the chemical structures, biosynthesis, metabolism, distribution and biological function of the substances.  

Herbal drugs were standardised based on the chemical and biological activity profile is an important prerequisite for acquiring the herbal market. The global market for botanical and plant-derived drugs was valued at $24.4 billion in 2014. This broad  market is expected to reach approx. $25.6 billion in 2015 and nearly $35.4 billion in 2020, with a compound annual growth rate (CAGR) of 6.6% from 2015 to 2020.