Chemistry in nature
How can substances be extracted from plants and other organisms?
One of the difficulties in isolating substances from plants and other organisms is that they contain a large number of substances. There are a great number of precursors – intermediate stages – as well as many so called primary metabolites e.g., amino acids, sugar, hormones, i.e., substances that are necessary for the plant. The medically active substances, however, often belong to the so called secondary metabolites. These are substances that might not be essential for the survival of the plant, but that increase their competitiveness in evolutionary terms. One explanation for the presence of medically active substances in plants and other organisms is that they function as a chemical defence for the plant against plant-eaters and infections.
To isolate a chemical substance from a plant, or some other organism, several different methods can be used. Depending on the chemical characteristics of the substance, they behave in different ways in these methods.
- Element analysis
- Ultraviolet spectroscopy
- Infrared spectroscopy
- Mass spectrometry
- Nuclear magnetic resonance spectroscopy
- Reference comparisons