Definition:
Semisynthesis starts by extracting a substrate from natural sources such as plants, animals, fungi and bacteria, which is then synthetically modified.
In order to modulate molecular properties (e.g. drug-like properties), the natural product substrate is often chemically modified by semisynthesis. The use of artemisinic acid produced by an engineered microbe to produce the antimalarial drug artemisinin is a good example of the semisynthetic process. However, due to the low levels at which these products accumulate in plants, access to and isolation of natural products is limited.
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