1. Advances in medicine and agriculture have
saved vastly more lives than have been lost in all
the wars in history.
— Carl Sagan

3. INTRODUCTION
Medicinal chemistry is the chemistry discipline concerned
with the design, development and synthesis of
pharmaceutical drugs. The discipline combines expertise
from chemistry and pharmacology to identify, develop and
synthesize chemical agents that have a therapeutic use and
to evaluate the properties of existing drugs.
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4. HISTORY OF MEDICINAL CHEMISTRY
The oldest records of the use of therapeutic plants and
minerals are derived from the ancient civilizations of the
Chinese, the Hindus, the Mayans of Central America, and
the Mediterranean peoples of antiquity. The Emperor Shen
Nung (2735 BC) compiled what may be called a
pharmacopeia including ch’ang shang, an antimalarial
alkaloid.
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5. Quinine is an antimalarial alkaloid derived from the bark of
the Cinchona tree. It was used by the Mayans to cure
Malaria.

6. The early explorers found that the South American Indians
also chewed coca leaves (containing cocaine) and used
mushrooms (containing methylated tryptamine) as
hallucinogens. In ancient Greek apothecary shops, herbs
such as opium, squill, and Hyoscyamus, viper toxin, and
metallic drugs such as copper and zinc ores, iron sulfate,
and cadmium oxide could be found. The ipecacuanha root
containing emetine was used in Brazil for the treatment
of dysentery .
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HISTORY OF MEDICINAL CHEMISTRY

7. The ipecacuanha root containing emetine was used in Brazil
for the treatment of dysentery .

8. The 19th Century: Age of Innovation and Chemistry
The 19th century saw a great expansion in the knowledge of
chemistry, which greatly extended the herbal pharmacopeia
that had previously been established. Building on the work of
Antoine Lavoisier, chemists throughout Europe refined and
extended the techniques of chemical analysis. The synthesis
of acetic acid by Adolph Kolbe in 1845 and of methane by
Pierre Berthelot in 1856 set the stage for organic chemistry.
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9. Acetic acid was synthesized by Adolph Kolbe in
1845.

10. Methane was synthesised by Pierre Berthelot in
1856 set the stage for organic chemistry

11. The emphasis was shifted from finding new medicaments
from the vast world of plants to finding the active ingredients
that accounted for their pharmacologic properties. The
isolation of morphine by Friedrich Sertürner in 1803, the
isolation of emetine from ipecacuanha by Pierre-Joseph
Pelletier in 1816, and his purification of caffeine, quinine, and
colchicine in 1820 all contributed to the increased use of
“pure” substances as therapeutic agents.
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The 19th Century: Age of Innovation and Chemistry

12. The 20th Century and the Pharmaceutical Industry
Diseases of protozoal and spirochetal origin responded to
synthetic chemotherapeutic agents. Interest in synthetic
chemicals that could inhibit the rapid reproduction of
pathogenic bacteria and enable the host organism to cope
with invasive bacteria was dramatically increased when the
red dyestuff 2,4-diaminoazobenzene-4′-sulfonamide
(Prontosil) reported by Gerhard Domagk dramatically cured
dangerous systemic gram-positive bacterial infections in
man and animals.
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13. Together with the discovery of penicillin by Alexander
Fleming in 1929 and its subsequent examination by Howard
Florey and Ernst Chain in 1941, led to a water-soluble
powder of much higher antibacterial potency and lower
toxicity than that of previously known synthetic
chemotherapeutic agents. With the discovery of a variety of
highly potent anti-infective agents, a significant change was
introduced into medical practice.
8 The 20th Century and the Pharmaceutical Industry