Cholesterol also contributes to the formation of deposits on the inner walls of
blood vessels. However, these deposits harden and obstruct the flow of blood.
This condition results in various heart diseases, strokes and high blood
pressure, and a high level of cholesterol can be life-threatening. A number of
vertebrate hormones, which govern a number of physiological functions,
from growth to reproduction, are biosynthesized from cholesterol.
Much research is currently underway to determine whether a correlation
exists between cholesterol levels in the blood and diet. Cholesterol not only
comes from the diet, but is also synthesized in the body from carbohydrates
and proteins as well as fat. Therefore, the elimination of cholesterol rich
foods from the diet does not necessarily lower blood cholesterol levels.
Some studies have found that if certain unsaturated fats and oils are
substituted for saturated fats the blood cholesterol level decreases.
Sex hormones control tissue growth and reproduction. Male sex hormones
are testosterone and 5a-dihydrotestosterone, also known as androgens, which
are secreted by the testes. The primary male hormone, testosterone, is responsible for the development of secondary sex characteristics during puberty. They
also promote muscle growth. The two most important female sex hormones are
oestradiol and oestrone, also known as oestrogens (estrogens). They are
responsible for the development of female secondary sex characteristics.
OH
O
OH
O
H
Testosterone
5α-Dihydrotestosterone
Oestrogen (estrogen) is biosynthesized from testosterone by making the first
ring aromatic, which results in more double bonds, the loss of a methyl
group and formation of an alcohol group. Oestrogen, along with progesterone, regulates changes occurring in the uterus and ovaries known as the
menstrual cycle. Progesterone is a member of the class called progestins. It
is also the precursor of sex hormones and adrenal cortex steroids. Progesterone is an essential component for the maintenance of pregnancy. It also
prevents ovulation during pregnancy. Many of the steroid hormones are
ketones, including testosterone and progesterone. The male and female
hormones have only slight differences in structure, but yet have very
different physiological effects. For example, the only difference between
testosterone and progesterone is the substituent at C-17.
O
H
O
Oestrone (estrone)
358
CH6 NATURAL PRODUCT CHEMISTRY
blood vessels. However, these deposits harden and obstruct the flow of blood.
This condition results in various heart diseases, strokes and high blood
pressure, and a high level of cholesterol can be life-threatening. A number of
vertebrate hormones, which govern a number of physiological functions,
from growth to reproduction, are biosynthesized from cholesterol.
Much research is currently underway to determine whether a correlation
exists between cholesterol levels in the blood and diet. Cholesterol not only
comes from the diet, but is also synthesized in the body from carbohydrates
and proteins as well as fat. Therefore, the elimination of cholesterol rich
foods from the diet does not necessarily lower blood cholesterol levels.
Some studies have found that if certain unsaturated fats and oils are
substituted for saturated fats the blood cholesterol level decreases.
Sex hormones control tissue growth and reproduction. Male sex hormones
are testosterone and 5a-dihydrotestosterone, also known as androgens, which
are secreted by the testes. The primary male hormone, testosterone, is responsible for the development of secondary sex characteristics during puberty. They
also promote muscle growth. The two most important female sex hormones are
oestradiol and oestrone, also known as oestrogens (estrogens). They are
responsible for the development of female secondary sex characteristics.
OH
O
OH
O
H
Testosterone
5α-Dihydrotestosterone
Oestrogen (estrogen) is biosynthesized from testosterone by making the first
ring aromatic, which results in more double bonds, the loss of a methyl
group and formation of an alcohol group. Oestrogen, along with progesterone, regulates changes occurring in the uterus and ovaries known as the
menstrual cycle. Progesterone is a member of the class called progestins. It
is also the precursor of sex hormones and adrenal cortex steroids. Progesterone is an essential component for the maintenance of pregnancy. It also
prevents ovulation during pregnancy. Many of the steroid hormones are
ketones, including testosterone and progesterone. The male and female
hormones have only slight differences in structure, but yet have very
different physiological effects. For example, the only difference between
testosterone and progesterone is the substituent at C-17.
O
H
O
Oestrone (estrone)
358
CH6 NATURAL PRODUCT CHEMISTRY