Editing Semisynthesis (section)

== Applications ==
[[Plants]], [[animals]], [[fungi]], and [[bacteria]] are all valuable sources of complex [[reactant|precursor molecules]], with [[bioreactors]] representing an intersection of biological and engineered synthesis. In drug discovery, semisynthesis is employed to retain the medicinal properties of a natural compound while modifying other molecular characteristics—such as [[side effect|adverse effects]] or oral [[bioavailability]]—in just a few chemical steps. Semisynthesis contrasts with [[total synthesis]], which constructs the target molecule entirely from inexpensive, low-molecular-weight precursors, often petrochemicals or minerals.<ref name="rsc.org">{{cite web|url=http://prospect.rsc.org/blogs/cw/2013/10/28/trouble-and-strife-total-synthesis/|title=Welcome to Chemistry World|website=Chemistry World}}</ref> While there is no strict boundary between total synthesis and semisynthesis, they differ primarily in the degree of engineered synthesis employed. Complex or fragile functional groups are often more cost-effective to extract directly from an organism than to prepare from simpler precursors, making semisynthesis the preferred approach for complex natural products.