From Biosyntheses to Total Syntheses: An Introduction

The primary and secondary metabolisms are traditionally distinguished by their distribution and utility in the living organism network. Both primary and secondary metabolites could be classified as natural products; where as secondary metabolites are usually regarded as the natural products owing to their complexity and diversity arising from a variety of biosynthetic pathways. Natural products are regarded as one of the main sources of medicines. From the traditional medicinal extracts to every single bioactive molecule, the methods of extraction, purification, identification, and biological investigation of natural products have been well established. Precursor-directed biosynthesis (PDB) is considered as the earliest example of combining chemical and biological methods for the generation of complex natural product analogs. Total synthesis plays an essential role on elucidating the structure of natural products. A variety of new reactions, catalysts, and technologies have been developed for total synthesis.