This document provides an overview of steroids, including their structure, classification, nomenclature, biosynthesis, and examples of important sex hormones. Steroids contain a cyclopentanoperhydrophenanthrene nucleus and include substances like sterols, bile acids, sex hormones, and cardiac drugs. Key sex hormones discussed include testosterone, oestriol, oestradiol, and progesterone. The document also outlines the biosynthesis pathway from cholesterol to these hormones and provides their IUPAC names and molecular formulas.

1. Contents
1
⚫ Introduction of Steroids
⚫ Nomenclature
⚫ Sex Hormones
⚫ Biosynthesis of sex hormones
⚫ Structure, synthesis of Testosterone, Oestriol, Oestradiol, Diethyl
stilbestrol, Progesterone
⚫ Reference

2. Introduction
⚫ Steroids are a unique class of chemical compounds found widely in
the animal and plant kingdom.
⚫ These are characterized by the presence of 1,2-
cyclopentanoperhydrophenanthrene nucleus in their structure.
⚫ The steroids include a wide variety of naturally occurring synthetic
substances such as sterols, bile acids, sex hormones, adrenal
cortical, various contraceptive drugs, cardiac-active lactones
sapogenins and certain alkaloids and antibiotics.
Steroid backbone
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3. ⚫ The term cholesterol was derived from the Greek words bile (which
means chole) and solid (which means sterols). The modern era of
steroid research began with steroids chemistry in 1900’s. Dr.AO
Windaus worked for 20 years and received the noble prize in 1928
for his research on the constitution of sterols.
⚫ Dr. Heinrich and Wieland engaged in natural products chemistry
including bile acids and were awarded the noble prize in 1928.
⚫ A total of 6 noble prizes were awarded to scientists working in the
area of steroids, among the 6,4 prizes were in steroid chemistry
category. The pioneer, work of the Adolf Winduas and Heinrich
Wieland in the structure elucidation of a number important steroid
led to the many discoveries in the world of steroids.
3

4. ⚫ The two important discoveries mentioned in 1940 and 1950 had a
dramatic effect not only on the steroids. This led to an extensive
research on medicinal chemistry, pharmacology and clinical studies
of steroids against and antagonists.
⚫ The steroids are found as solids and M.P ranges from 100oC to
250oC, insoluble in water, soluble in ethanol, acetone, chloroform,
(Organic Solvents).
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5. Nomenclature
1. Steroids consist of 4 fused rings (A, B, C and D). Chemically these
hydrocarbons. Are cyclopentanoperhydrophenanthrenes. They
contain 5 membered cyclopentane (ring-D) and the 3 rings of
phenanthrene (A, B, C).
2. Earlier the various steroids are generally designated by their
common names such as cholesterol, progesterone, and testosterone.
However these names were discarded due to development in
chemistry and systemic names as per IUPAC nomenclature were
favoured.
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6. 3. Steroids contain 17 carbon atoms and the numbering the remaining
carbons of phenanthrene followed by numbering the remaining
carbons of the cyclopentane ring. Additional carbon atoms on the
steroids including methyl groups attached to C-10 and C-13 and
alkyl substituent’s on C-17 are numbered.
4. If any unsaturation is present in the steroids the ane ending of the
stem is replacing by ene if it contains one double bound, diene if it
contains two double bounds, triene if it contains three double
bounds.
5. If double bound is not between carbons both the carbons are
indicated as same.
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7. 6. If the steroid contain 3-membered ring it is indicated by the prefix
cyclo preceded by the numbers of positions concerned.
7. Any enlargement of steroid ring is indicated by the prefix homo
preceded by small capital indicating the ring affected.
8. Circles were sometimes used to indicate α-hydrogens and dark dots
are used to indicate β-hydrogens.
9.On the basis of following priorities suffix for stem name is selected
carboxylic acid> carbonyl> alcohol> amine> ether.
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8. Sex Hormones
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⚫ Hormones are the organic substances which are secreted by the
endocrine glands.
⚫ They are brought to the different organs of the body by means of
blood stream to produce the various physiological functions.
⚫ The deficiency of hormone leads to particular disease can be cured
by administration of hormone.

9. Classification
⚫ Steroid hormones are divided into two types Sex hormones (male
and female) and adrenal cortical hormones
⚫ Sex hormones are produced in gonads (testes in male and ovaries in
female). Their production is stimulated by pituitary gland.
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10. Biosynthesis of sex hormones
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11. 11

12. 1. Testosterone:
IUPAC: 17-Hydroxy-10,13-dimethyl-1,2,6,7,8,9,11,12,14,15,16,17-
dodecahydrocyclopenta[a] phenanthren-3-one
Molecular Formula: C19H28O2
In 1935 Testosterone was isolated by E. Laqueru et al. from testes.
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13. Properties and Uses:
⚫ Creamy white crystalline powder, insoluble in water and soluble in
alcohol.
⚫ It may be used for treatment of breast carcinoma in postmenopausal
women.
13

14. 2. Oestriol:
IUPAC: 13-methyl-6,7,8,9,11,12,14,15,16,17-decahydrocyclopenta[a]
phenanthrene-3,16,17-triol
Molecular Formula: C18H24O3
It is isolated by Marrian from urine of pregnant women. It is useful
in some cases of oestrogen defiency especially for the relief of
menopausal symptoms. It occurs mainly in placenta and pregnant
women.
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15. 3.Oestradiol:
IUPAC: 13-methyltetracyclo heptadeca-1,3,5-triene-3,17-diol
Molecular Formula: C18H24O2
It exists as two stereoisomeric oestradiols (α and β) between them β-
isomers is more active, α-isomer is less active.
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16. 4. Diethyl stilbestrol:
IUPAC: 4,4'-[1,2-Diethyl-1,2-ethenediyl]bisphenol
Molecular Formula: C18H20O2
16

17. 5. Progesterone:
⚫ Progesterone means favoring pregnancy. These are substances in the
Corpus Luteum. Which convert the oestrogen-primed endometrium
to secretory endometrium and maintain pregnancy
⚫ Progesterone was isolated from the Corpus Luteum, the adrenal
cortex, the placenta and testes.
IUPAC:17-acetyl-10,13-dimethyl-1,2,6,7,8,9,11,12,14,15,16,17-
dodecahydrocyclopenta[a]phenanthren-3-one
Molecular Formula:C21H30O2
17

18. nandralone

19. oestrione

20. silnedafil

21. Tadalafil

22. Reference books
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⚫ Text book of Medicinal chemistry volume-1-3rd edition by
V.Alagarasamy.
⚫ Text book of Medicinal chemistry volume-2-3rd edition by
V.Alagarasamy.
⚫ Medicinal Chemistry- 4th edition by Ashutosh Kar
⚫ Medicinal and Pharmaceutical Chemistry by Harkishan Singh, V.K
Kapoor.
⚫ Wilson and Gisvolid’s Textbook of Organic Medicinal and
Pharmaceutical chemistry-12th edition by John M. Beale, John. H.
Block.