Semisynthesis

This efficiency drives the preference for natural sources in the preparation of certain compounds, especially when synthesizing them from simpler molecules would be cost-prohibitive.

Plants, animals, fungi, and bacteria are all valuable sources of complex 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 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.

[4][5] Other notable examples include the early commercial production of the anti-cancer agent paclitaxel from 10-deacetylbaccatin, isolated from Taxus baccata (European yew),[1] the semisynthesis of LSD from ergotamine (derived from fungal cultures of ergot),[citation needed] and the preparation of the antimalarial drug artemether from the naturally occurring compound artemisinin.