everywhere in modern life. From the colouring of our clothes to the
shapes of our PCs, all are possible due to chemistry. It has played a
major role in pharmaceutical advances, forensic science and modern
agriculture. Diseases and their remedies have also been a part of human
lives. Chemistry plays an important role in understanding diseases and their
remedies, i.e. drugs. The focus of this section is given to the role of
chemistry in modern medicine.
Medicines or drugs that we take for the treatment of various ailments are
chemicals, either organic or inorganic. However, most drugs are organic
molecules. Let us take aspirin as an example. It is probably the most popular
and widely used analgesic drug because of its structural simplicity and low
cost. Aspirin is chemically known as acetyl salicylic acid, an organic
molecule. The precursor of aspirin is salicin, which is found in willow
tree bark. However, aspirin can easily be synthesized from phenol using the
Kolbe reaction (see Section 4.6.10). As we progress through various
chapters of this book, we will come across a series of examples of drugs
and their properties.
O
OH
O
O
Aspirin
Acetyl salicylic acid
O-Glucosyl
OH
Salicin
The precursor of aspirin
N
H
O
OH
Paracetamol
O
O
H
O
H
H
N
H
Morphine
N
S
O
COOH
H
N
H
O
H
O
Penicillin V
In order to have a proper understanding and knowledge of these drugs and
their behaviour, there is no other alternative but to learn chemistry. Everywhere, from discovery to development, from production and storage to
administration, and from desired actions to adverse effects of drugs,
chemistry is involved directly.
In the drug discovery stage, suitable sources are explored. Sources of
drug molecules can be natural, e.g. narcotic analgesic, morphine, from
Papaver somniferum (Poppy plant), synthetic, e.g. a popular analgesic and
antipyretic, paracetamol, or semi-synthetic, e.g. semi-synthetic penicillins.
2
CH1 INTRODUCTION