Discovering Drugs

• What were drugs traditionally extracted from?

  plants/ microorganisms e.g. mould
• In 1928, Alexander Fleming was growing bacteria for study purposes and after a holiday came back to find mould growing on the culture plates.
• He died but it was demonstrated that penicillin could cure bacterial infections
• Working with Pfizer in the US Florey and Chain made penicillin on an industrial scale supplying WW2
• There was a clear ring in the jelly around some spots of mould so something must have destroyed the bacteria covering the gel.
• Ernst Chain and Howard Florey tried to extract penicillin 10 years after the discovery and succeeded.
• Penicillin was named after the 'penicillium' mould that produced it, which was tried to extract an active juice from for several years before giving up and moving onto other work.
• They gave some to a man dying of a blood infection and he recovered miraculously until the penicillin ran out.
• Future medicine involves the use of new medicines without damaging human cells.
• Most drugs are synthesised by research chemists working in the pharmaceutical industry using chemical banks and computer models, but the starting point could still be a chemical extracted from a plant or microorganism.
• Compounds that show promise as antibiotics are modified to produce more powerful molecules.
• Noni fruit, widely used in traditional medicine in Costa Rica to treat infections and non-communicable diseases, may be the source of new antibiotics.
• Antibiotics from soil:

  • Scientists are collecting samples globally + searching for microorganisms to produce a new antibiotic against antibiotic-resistant bacteria. Only 1% of soil microorganisms can be cultured in the lab.
  • Scientists have developed a special unit that enables them to grow microorganisms in the soil in a controlled way
  • 2015- a new type of antibiotic announced from some soil bacteria. In tests so far the antibiotic has destroyed MRSA and other antibiotic - resistant pathogens.
• Many drugs used today are based on traditional medicines, such as Digitalis/digoxin which is derived from foxgloves and is used to strengthen the heartbeat.
• Digitalis/digoxin is still used but primarily for older people as too much can be poisonous.
• Aspirin, which originates from a compound found in willow tree bark, has anti-inflammatory and pain-relieving properties that were first recorded in 400BC.
• In 1897, Felix Hoffman synthesised acetyl salicylic acid (aspirin), which relieves pain and inflammation better than willow bark but has side effects.
• Aspirin is still used to provide a wide range of health problems.
• Chewing on the glands of a beaver tail brought relief to people before painkillers were available as they contained concentrated pain relieving chemicals from willow bark that was chewed by the beaver.