Answers to the Quickies
369
Answers to 7 Chap. 17
1. The vitamins A, D, E and K are fat-soluble.
They are long-chain hydrocarbons with
mostly terpenoid or steroid structure and
contain hardly any functional groups or
heteroatoms. They are therefore hydrophobic. Vitamins B and C are soluble in water.
The B vitamins are nitrogen-containing
compounds, mostly heterocycles, with several hydrophilic groups (hydroxyl, amino,
carboxy or amide groups). Vitamin C is a
sugar acid consisting of a lactone ring and
four hydrophilic hydroxyl groups.
2. Vitamin A (retinol) is of great importance
for the visual process. Without retinol, the
cornea and conjunctiva of the eyes degenerate, which can lead to night blindness. Skin
diseases can also be cured with retinoids.
3. Beriberi disease is a nervous disease that can
lead to muscle degradation and heart failure.
It is treated with vitamin B 1 , thiamine, a
compound consisting of a pyrimidine ring
linked to a thiazole ring (see . Fig. 17.2).
4. Vitamin B 3 is found in all animal organs
(beef, liver, …). Milk and eggs contain little
vitamin B 3 , but relatively much tryptophan, from which niacin can be formed in
the body. In South America, many people
predominantly eat maize and millet, in
which niacin is bound in a way that humans
cannot utilize.
5. Vitamin B 7 (biotin) was also called vitamin
H because it is responsible for the functions
of the skin (German: Haut). It is found in
plant seeds, vegetables (spinach), nuts, fruits
(bananas, apples), wheat flour and unpeeled
rice.
6. Vitamin B 12 (cobalamin) contains cobalt(III)
as the central atom surrounded by a corrin
ring with four coordinating N atoms. Several substituents are attached to the corrin
ring system, including a nucleotide-bound
dimethylbenzimidazole that coordinates
with one nitrogen atom on cobalt (see
. Fig. 17.9). In cobalamin itself, a cyano
group is additionally bound to the cobalt
atom. In 1955, the biochemist Dorothy C.
Hodgkin (who received the Nobel Prize for
Chemistry in 1955 for her work) succeeded
in determining the final structure by X-ray
structure analysis. A healthy person does
not have to consume cobalamin every day
because it has a storage capacity, especially
in the liver.
7. Deficiency of vitamin C causes scurvy,
which leads to bleeding, tooth loss and
inflammation. Vitamin C is produced
from d-glucose by Reichstein synthesis
in six steps: Catalytic hydrogenation to
d-sorbitol, microbiological dehydrogenation to l-sorbose, double ketalization with
acetone to diacetone l-sorbose, oxidation
to 2-keto l-gulonic acid with simultaneous
removal of the protective groups and finally
acid-catalyzed lactonization to l-ascorbic
acid (see . Fig. 17.10).
8. Rickets cause bone deformation and growth
disorders. It is treated with calciferols (vitamin D), which are particularly abundant in
the liver oils of marine fish.
9. Vitamin E occurs in the variants of α-, β-,
γ- and δ-tocopherols. The most biologically
active molecule is α-tocopherol (see
. Fig. 17.12). Tocopherols are radical scavengers and thus protect the membrane lipids
from oxidative destruction.
10. Vitamin K has a 2-methyl-1,4-naphthoqui -
none backbone with oligoterpene substituents of different lengths on the C2-atom
(see . Fig. 17.13). It activates the coagulation
factors in the blood.
Answers to 7 Chap. 18
1. Fragrances are used as odor components in
cosmetics, perfumes and detergents. Flavors are used as additives e.g. in food, oral
hygiene products or beverages to provide
a specific taste. The same substance may
be used as a fragrance in one case and as a
flavor in another. There is no clear
distinction.
2. Typical essential oils which are used in
perfumes are citrus oils such as lemon, lime,
orange or bergamot and flower oils such as
jasmine, rose, violet or lily. The essential oils
of cloves, aniseed, cinnamon or vanilla are
important in the food industry.
3. Since eugenol is isolated from clove oil and
biotechnologically converted to vanillin, the
term “natural flavor” should be used in the
list of ingredients.
369
Answers to 7 Chap. 17
1. The vitamins A, D, E and K are fat-soluble.
They are long-chain hydrocarbons with
mostly terpenoid or steroid structure and
contain hardly any functional groups or
heteroatoms. They are therefore hydrophobic. Vitamins B and C are soluble in water.
The B vitamins are nitrogen-containing
compounds, mostly heterocycles, with several hydrophilic groups (hydroxyl, amino,
carboxy or amide groups). Vitamin C is a
sugar acid consisting of a lactone ring and
four hydrophilic hydroxyl groups.
2. Vitamin A (retinol) is of great importance
for the visual process. Without retinol, the
cornea and conjunctiva of the eyes degenerate, which can lead to night blindness. Skin
diseases can also be cured with retinoids.
3. Beriberi disease is a nervous disease that can
lead to muscle degradation and heart failure.
It is treated with vitamin B 1 , thiamine, a
compound consisting of a pyrimidine ring
linked to a thiazole ring (see . Fig. 17.2).
4. Vitamin B 3 is found in all animal organs
(beef, liver, …). Milk and eggs contain little
vitamin B 3 , but relatively much tryptophan, from which niacin can be formed in
the body. In South America, many people
predominantly eat maize and millet, in
which niacin is bound in a way that humans
cannot utilize.
5. Vitamin B 7 (biotin) was also called vitamin
H because it is responsible for the functions
of the skin (German: Haut). It is found in
plant seeds, vegetables (spinach), nuts, fruits
(bananas, apples), wheat flour and unpeeled
rice.
6. Vitamin B 12 (cobalamin) contains cobalt(III)
as the central atom surrounded by a corrin
ring with four coordinating N atoms. Several substituents are attached to the corrin
ring system, including a nucleotide-bound
dimethylbenzimidazole that coordinates
with one nitrogen atom on cobalt (see
. Fig. 17.9). In cobalamin itself, a cyano
group is additionally bound to the cobalt
atom. In 1955, the biochemist Dorothy C.
Hodgkin (who received the Nobel Prize for
Chemistry in 1955 for her work) succeeded
in determining the final structure by X-ray
structure analysis. A healthy person does
not have to consume cobalamin every day
because it has a storage capacity, especially
in the liver.
7. Deficiency of vitamin C causes scurvy,
which leads to bleeding, tooth loss and
inflammation. Vitamin C is produced
from d-glucose by Reichstein synthesis
in six steps: Catalytic hydrogenation to
d-sorbitol, microbiological dehydrogenation to l-sorbose, double ketalization with
acetone to diacetone l-sorbose, oxidation
to 2-keto l-gulonic acid with simultaneous
removal of the protective groups and finally
acid-catalyzed lactonization to l-ascorbic
acid (see . Fig. 17.10).
8. Rickets cause bone deformation and growth
disorders. It is treated with calciferols (vitamin D), which are particularly abundant in
the liver oils of marine fish.
9. Vitamin E occurs in the variants of α-, β-,
γ- and δ-tocopherols. The most biologically
active molecule is α-tocopherol (see
. Fig. 17.12). Tocopherols are radical scavengers and thus protect the membrane lipids
from oxidative destruction.
10. Vitamin K has a 2-methyl-1,4-naphthoqui -
none backbone with oligoterpene substituents of different lengths on the C2-atom
(see . Fig. 17.13). It activates the coagulation
factors in the blood.
Answers to 7 Chap. 18
1. Fragrances are used as odor components in
cosmetics, perfumes and detergents. Flavors are used as additives e.g. in food, oral
hygiene products or beverages to provide
a specific taste. The same substance may
be used as a fragrance in one case and as a
flavor in another. There is no clear
distinction.
2. Typical essential oils which are used in
perfumes are citrus oils such as lemon, lime,
orange or bergamot and flower oils such as
jasmine, rose, violet or lily. The essential oils
of cloves, aniseed, cinnamon or vanilla are
important in the food industry.
3. Since eugenol is isolated from clove oil and
biotechnologically converted to vanillin, the
term “natural flavor” should be used in the
list of ingredients.