Chemical defences in plantsSpec 5.10B
Some plants produce chemicals that defend them against attack. Some of these chemicals kill or slow the growth of microorganisms. Others are poisons that make the plant harmful or unpleasant for pests to eat.
Some of these plant chemicals can be used by humans to treat disease or relieve symptoms. Common examples are:
- willow bark contains a chemical that the painkiller aspirin was developed from
- foxgloves contain digitalis, a chemical used to treat some heart conditions
- the bark of the cinchona tree contains quinine, which was used to treat malaria
This is also why plant extracts are tested for antimicrobial properties, as in the core practical later in this topic.