VITAMINS and COENZYMES

VITAMINS and COENZYMES
INGRID ŽITŇANOVÁ
2010/2011

Introduction to Vitamins
VITAL + AMINES = VITAMIN
Organic molecules, essential for the normal
growth and development, required in tiny amounts
Cannot be synthesized by mammalian cells
must be supplied in the diet
Vitamin C – human
Vitamin A - from precursor
Vitamin K, H – gut flora
Vitamin D – skin (UV light)

FUNCTIONS
• Regulate metabolism, help convert lipids and saccharides
into energy
• Hormones (vitamin D)
• Antioxidants (vitamin E)
• Regulators of cell and tissue growth and differentiation
(vitamin A)
• Precursors for enzyme coenzymes (B-complex)

AVITAMINOSIS - chronic or long-term vitamin deficiency
(beri-beri, scurvy, rickets and pellagra)
HYPOVITAMINOSIS - any of several diseases caused by
deficiency of one or more vitamins
HYPERVITAMINOSIS – the condition resulting from the
chronic excessive intake of vitamins (vitamin supplements)
side effects – nausea, diarrhea, vomiting
ANTIVITAMINS – a substance that destroys or inhibits
the metabolic action of a vitamin.

Avitaminoses
Vitamin A deficiency causes xerophthalmia or night blindness
Thiamine (B 1 ) deficiency causes beri-beri
Niacin (B 3 ) deficiency causes pellagra
Vitamin B 12 deficiency leads to megaloblastic anemia
Vitamin C deficiency leads to scurvy
Vitamin D deficiency causes rickets
Vitamin K deficiency causes impaired coagulation
• Rare in developed world - fortification

ANTIVITAMINS
Antivitamins - chemotherapy of several infectious diseases
Classification:
1. Enzymes decomposing vitamins (tiaminase, ascorbase)
2. Compounds forming nonactive complexes with vitamins (avidin)
3. Compounds structurally similar to vitamins (sulphonamides)
H 2 N
C OH
O
H 2 N
S NH 2
Paraaminobenzoic acid (PABA) Sulphonamide O
Sulphonamides – prevent bacterial multiplication, without toxicity to the human tissues
O

GTP
PABA
Sulphon
onamide
– prevents growth and division of MO
interfering with PABA action
FOLIC ACID COENZYME (THF) Purin and
pyrimidin
synthesis
PABA – growth factor for MO
H 2
N
SO 2
H 2
N
COOH
sulphonamide
p-aminobenzoic
acid (PABA)

Water Soluble Vitamins
Fat Soluble Vitamins
Thiamine (B1)
Riboflavin (B2)
Niacin (B3)
Panthotenic acid (B5)
Pyridoxin (B6)
Biotin (B7 ) – vitamin H
Folic acid (B9)
Cobalamin (B12)
Bioflavonoids (P)
Ascorbic acid (vit. C)
Vitamin A - Retinol
Vitamin D - Calciferol
Vitamin E - Tocoferol
Vitamin K – Quinons
Vitamin F

Vitamins soluble in water
directly absorbed from intestine into blood
hypervitaminosis – vitamins excreted from the body
Vitamins soluble in fat
require correct function of the liver and gall bladder
hypervitaminosis – toxic effect

VITAMIN A = R E T I N O L
Its provitamin - β-carotene - (red, orange pigments in plants and fruits)
- Antioxidant
Structure: tetraterpenoid containing β-ionone ring with an unsaturated
side chain
α-, β- a γ- provitamin A

15
2
O 2
15'
β-carotene
β-karotén
Fe 2+ dioxygenáza dioxygenase
1
all-trans retinal izomeráza isomerase
kyselina Retinoicretinová
acid
dehydrogenáza
dehydrogenase
11
11
CH 2 OH
1
1
trans retinol 1 - vitamín A 1
11-cis retinal CHO
Premeny β-karoténu a vitamínu A 1
CHO COOH

All-trans-retinal
11-cis-retinal
Retinol
Kyselina retinová
Retinoic acid

Functions of vitamin A
• Vision – retinal is a structural part of rhodopsin (visual purple) –
light sensitive pigment in retina
• Bone remodeling – function of osteoblasts and osteoclasts depend
on it. Excess – bone loss, hip fracture (increase of osteoclasts – cells,
that break down bones)
• Reproduction – sperm production, menstrual period
• Resistance to infectious disease – deficiency leads to increased
frequency and severity of disease
• Epithelial cell "integrity“ – they require vitamin A for proper
differentiation and maintenance. Lack of vitamin A - the skin becomes
keratinized and scaly, and mucus secretion is suppressed.

R
E
VISION CYCLE
RHODOPSIN
(PIGMENT)
LIGHT
T
I
N
CIS-RETINAL
OPSIN
TRANS-RETINAL-OPSIN
NERVE
IMPULS
A
RETINAL
ISOMERASE
TRANS-RETINAL
DEHYDROGENASE
NADH+H +
NAD +
TRANS -RETINOL
Retinolesters (liver)
transport by blood proteins

HYPOVITAMINOSIS A
Night blindness – mild deficiency of vitamin A – inability to
produce sufficient amount of rhodopsin (lack of retinal)
Large deficiency of vit. A – xeroftalmia – keratinisation of the eye
tissue (today in Africa, Asia)
Dry skin, frequent infections, decreased synthesis of thyroid
hormones

HYPERVITAMINOSIS
β-carotene supplements (high doses)
• Lung cancer / smokers /
• Skin discoloration
Retinal
• Birth defects
• Liver problems
• Reduced bone mineral density that may result in
osteoporosis
• Coarse bone growths
• Hair loss
• Excessive skin dryness/peeling
• Death
Signs of acute toxicity – nausea, vomiting, headache, dizziness, blurred
vision, loss of muscular coordination

SOURCES
β-carotene - carrot, green leafy vegetables – spinach, kale,
sweet potatoes, yellow and orange fruits
Retinal – liver of polar bear, seal, eggs and fatty fish

VITAMINS D - CALCIFEROL
• Increases Ca into bloodstream by promoting absorption of
Calcium and Phosphorus from food in the intestines and
reabsorption of Ca in the kidneys, enabling normal mineralization
of bone
2 types:
D 2 – derived from precursor ergosterol present in plants
D 3 – derived from precursor 7-dehydrocholesterol
present in skin
Structure similar to steroid hormones (cortizol, estradiol, progesteron) - derived
from cholesterol

UV
7-dehydrocholesterol (skin) cholecalciferol
(provitamin) (D3, calciol)
UV
Ergosterol (plants) ergocalciferol (D2, ercalciol)
(provitamin)
Adequate amounts of vitamin D 3 can be made in the skin after only
10 -15 minutes of sun exposure at least 2x per week to the face,
arms, hands, or back without sunscreen

7-dehydrocholesterol Cholekalciferol (D 3 )
Plants
Ergosterol pre-D 2

UV
Kidneys: 25-hydroxylase
Liver: 1-hydroxylase

SKIN
7-dehydrocholesterol
Increased parathyroid hormone

DEFICIENCY
Results from a number of factors:
inadequate intake coupled with inadequate sunlight
exposure
liver or kidney disorders (impair conversion of vitamin
D into active metabolites)
body characteristics (skin color and body fat)

DEFICIENCY
Leads to impaired bone mineralization, and to bone softening diseases including:
• RICKETS - a childhood disease - impeded growth, and
deformity of the long bones
• OSTEOMALACIA - a bone-thinning disorder
occurs exclusively in adults proximal muscle
• OSTEOPOROSIS - reduced bone mineral density and
increased bone fragility

Stunted growth
Large
forehead
Odd curve to spine or
back
Odd-shaped
ribs and
breast bones
Large
abdomen
Wide joints at
elbow and
wrist
Wide
bones
Odd-shaped
legs
Wide ankles

Vitamin D malnutrition may also be linked to an
increased susceptibility to several chronic diseases:
high blood pressure
tuberculosis
cancer
periodontal disease
multiple sclerosis
chronic pain
memory loss
autoimmune diseases including type 1 diabetes

Sources of vitamin D
Fatty
Fish liver oils
Fatty fish species
A whole egg
Beef liver, cooked
UV-irradiated mushrooms (Vitamin D 2 )

Vitamin E – Tocopherols
antisterile vitamin
•
Benefits
• Protects lipids (cell membranes), DNA, proteins from
oxidation – ANTIOXIDANT
Protects food fats from going rancid
• Helps to form red blood cells
• Aids in the absorption of vitamin K

Vitamin E protects cell membrane lipids from oxidation by reacting
with lipid radicals produced in the lipid peroxidation chain reaction
Free radical
Cell
Mitochondria

R
vitamín E
vitamín E
RH
O=C
O-C
HO-C
vitamín E + vitamín C vitamín E + H-C
HO-C-H
O
CH 2 OH
Radical of
radikál
L-ascorbic
acid radical
L-ascorbic kyseliny acid
L-
askorbovej
O=C O=C O=C O=C
O-C
O
O-C
O
HO-C
O
O=C
HO-C HO-C HO-C O=C
+ +
H-C H-C H-C H-C
O
HO-C-H HO-C-H HO-C-H HO-C-H
CH 2 OH
Radical of
radikál
kyseliny L-ascorbic
acid L-
acid radical
CH 2 OH
Radical of
radikál
kyseliny
L-ascorbic
L-ascorbic
L- acid radical
acid
askorbovej
Nonenzymatic scavenging
of free radicals by vitamins
Nonenzyme scavenging of free radicals by vitamins
Neenzýmové vychytávanie radikálov vitamínmi
CH 2 -OH CH 2 -OH
ascorbate
Ascorbic askorbát acid
dehydroascorbate
Dehydroascorbic acid
GS-SG 2 GSH
dehydroaskorbá
Glutathione glutatiónreduktáza
t
reductase
NADPH
pentózafosfátový
Pentose
NADP +
Phosphate
cyklus
cycle

STRUCTURE: tocol, forms 8 basic derivatives
α-tocopherol is a most effective form
R 2
R 3
O
CH 3 CH 3 CH 3
HO
R 1 R 2 R 3
Tocol α -CH 3
-CH 3
-CH 3
CH 3
R 1
Chromanol ring
HO- group - reduction of free radicals
Saturated side chain – penetration in membranes
β -CH 3 -H -CH 3
γ -H -CH 3
-CH 3
δ -H -H -CH 3
R3
R2
O
CH 3
CH 3 CH 3 CH 3
CH 3
HO
tocotrienol
R1

Deficiency
neurological problems, anemia
Natural Sources
green leafy vegetable, vegetable oils, nuts, seeds, spinach,
broccoli, soybean oil

VITAMIN K - QUINONES
Vitamin K1 (phylloquinone) - from plants sources
Vitamin K2 (menaquinone) - made by intestinal bacteria
(production can be disturbed by antibiotics, Crohn disease, gallstones)
Vitamin K3 (menadione, menadiol) - synthetic
German „koagulation“
vitamin K

Overview
• Promotes normal blood clotting (coagulation)
• Bone metabolism
• Vascular health
Biochemistry
coenzyme for a vitamin K-dependent carboxylase –
carboxylation of glutamic acid gammacarboxyglutamic
acid (Gla)– involved in binding Ca 2+
Vitamin K
clotting factor-glutamic acid clot.factor-Gla-Ca 2+
carboxylase
nonactive
CO 2
active

Bone metabolism
• gamma-carboxylation of osteocalcin (bone-related
protein) in the presence of vitamin K
Vascular health
• decreases calcification in the arteries by absorbing the
hardened calcium to lessen risk of heart disease

Deficiency
Rare in healthy adults: 1) vitamin K widespread in foods
2) vitamin K cycle conserves vitamin K
3) large intestine bacteria synthesize vit. K
Adults at risk:
• those taking vitamin K antagonist - anticoagulant drugs
• adults with significant liver damage
• newborn babies – exclusively breast-fed:
1) vitamin K is not easily transported across the placental
barrier
2) the newborn's intestines are not yet colonized with bacteria
that synthesize menaquinones
3) the vitamin K cycle may not be fully functional in newborns

Isoprene units
(K2)

Toxicity
Vitamin K 1 , K 2 – no known toxicity
Vitamin K 3 – interferes with glutathione (antioxidant)
oxidative damage to cell membranes.
- injections – liver toxicity, jaundice, hemolytic
anemia in infants

Warfarin
Bromadiolon
(anticoagulant)
(Anticoagulant)

Natural Sources
green leafy vegetables – alpha-alpha, Brussel sprouts,
spinach, kale, cabbage, avocado, cheddar cheese

VITAMIN F
ESSENTIAL UNSATURATED HIGHER
CARBOXYLIC ACIDS
Structure: unsaturated higher carboxylic acids
• Linoleic acid - 2 double bonds 18:2
• Linolenic acid - 3 double bonds 18:3
• Arachidonic acid??? – 4 double bonds 20:4– synthesized
from linoleic acid in the body
Fatty acids needed for:
normal growth, behavior, healthy cell membranes, well balanced
hormone level, immune system

Linoleic acid
ω-6 fatty acid
Arachidonic
acid
ω-6 fatty acid
Linolenic acid
ω-3 fatty acid

ARACHIDONIC ACID WITH 4 DOUBLE BONDS
cyclooxygenase
lipoxygenase
epoxides
prostaglandins
leukotriens
prostacyclins
tromboxanes
cytochrom P 450
The eicosanoids from AA generally promote inflammation

VITAMIN B 1 – THIAMINE, ANEURINE
(antineuritic factor, antiberiberi factor)
PYRIMIDINE and THIAZOL rings linked through
methylene bridge
Antagonists – Sulfites (food preservatives) – attack at the
methylene bridge

VITAMIN B 1 – THIAMINE, ANEURIN
Natural thiamine phosphate derivatives:
thiamine monophosphate (TMP)
thiamine diphosphate (TDP) (pyrophosphate TPP)
thiamine triphosphate (TTP)
Phosphate derivatives involved in many cellular
processes
COENZYME = thiamine diphosphate – cocarboxylase -
in catabolism of saccharides and aminoacids

Thiamine pyrophosphate
TPP - cofactor for the pyruvate dehydrogenase
- alpha-ketoglutarate dehydrogenase catalyzed reactions
- the transketolase catalyzed reactions of the pentose
phosphate pathway.

TPP
TPP

Deficiency
severely reduced capacity of cells to generate energy
BERI-BERI - affecting the peripheral nervous system
(polyneuritis) and/or the cardiovascular system, with
fatal outcome
Overdose
Hypersensitive reactions resembling anaphylactic shock
Natural Sources
Meat, potatoes, bananas, lentils, beans, yeast
Interactions
Antibiotics - Decrease thiamine level

Overview
Essential to energy generation
Riboflavin - precursor for the coenzymes FAD, FMN – redox
reactions
FLAVIN MONONUCLEOTIDE (FMN)
FLAVIN ADENINE DINUCLEOTIDE (FAD)
The enzymes requiring FMN or FAD as cofactors – flavoproteins
– involved in redox reactions (succinate dehydrogenase and
xanthine oxidase)

VITAMIN B 2 – RIBOFLAVIN
Lactoflavin, ovoflavin, vitamin G
ribitol
Riboflavin powder.
Riboflavin solution
METHYL DERIVATE OF IZOALOXAZINE + RIBITOL

FUNCTION:
• Key role in energy metabolism - required for the metabolism of
lipids, saccharides, and proteins
• It is the central component of the cofactors FAD (flavinadenin
dinucleotide) and FMN (flavinmononucleotide)

Riboflavin
Flavinmononucleotide
(FMN)
Flavinadenine dinucleotide
reduc.
(FADH 2 )

FAD
Nitrogens 1 & 5 transfer hydrogen in FADH 2
Riboflavin
H
H

Deficiency
Fatigue, red, swollen, cracked mouth and tongue, mouth
ulcers, cracks at the corners of the mouth
Riboflavin deficiency is often seen in chronic
alcoholics due to their poor dietetic habits
Overdose
Itching, numbness, a burning sensation
Storage
Riboflavin decomposes when exposed to visible light
This characteristic can lead to riboflavin deficiencies in
newborns treated for hyperbilirubinemia by phototherapy

Food sources
Food
Serving
Riboflavin
(mg)
Fortified cereal 1 cup 0.59 to 2.27
Milk (nonfat) 1 cup (8 ounces) 0.34
Egg (cooked) 1 large 0.27
Almonds 1 ounce 0.23
Spinach (boiled) 1/2 cup 0.21
Salmon (cooked) 3 ounces* 0.12
Cheddar cheese 1 ounce 0.11
Chicken, dark meat
(roasted)
3 ounces 0.16
Beef (cooked) 3 ounces 0.16
Broccoli (boiled) 1/2 cup chopped 0.10
Asparagus (boiled) 6 spears 0.13
Halibut (broiled) 3 ounces 0.08

Vitamin B-3, Niacin, vitamin PP
Nicotinic Acid
Nicotinamide
nicotinic acid + vitamin
Niacin is not a true vitamin in the strictest definition since it
can be derived from tryptophan.

Nicotinamide adenine dinucleotide (NAD + ) and Nicotinadenine
dinucleotide phosphate (NADP + ) - cofactors for numerous
dehydrogenases (lactate and malate dehydrogenases)- acceptor
during alcohol oxidation
H -
NADH
-OH phosphorylated in
NADPated in NADP +
(ATP, ATPase)
NICOTINAMIDE ADENINE DINUCLEOTIDE (NAD+)

alcohol
to be
oxidized
Transfer:
H -
Alcohol dehydrogenase
NADH
Aldehyde
H +
Residue
NAD +
Riboflavin
unit
Coenzyme
Residue +
Reoxidation of NADH
Residue
NAD + Coenzyme
Residue +

Function
• Niacin is a precursor to NADH, NAD + - coenzymes of
oxido-reductases – transfer of hydrogen anion
• Nicotinic acid (but not nicotinamide) - lowers plasma
cholesterol levels (and TAG, LDL, VLDL) and has been
shown to be a useful therapeutic for hypercholesterolemia
• Elevates blood glucose and uric acid production (not
recommended for diabetics or gout)

Deficiency
Dermatitis on the hands and face, weakness
The severe symptoms, depression, dermatitis and
diarrhea, - PELLAGRA (3D disease)
Natural Sources
Beef liver, brewer’s yeast, meat, eggs, grains and
milk

PELLAGRA

Overdose
Niacin flush, liver damage, stomach ulcers, nausea,
diarrhea, weakness

Overview
• Pantothenate is required for synthesis of coenzyme A –
metabolism of saccharides, proteins, lipids.
• Growth factor for MO
• „Anti-stress vitamin“

D-pantoate
ß-alanine
Pantothenic Acid

Fatty acids
Fatty acids
Krebs cycle
Respiratory chain

SOURCES
Whole grains - milling removes much of the pantothenic acid
Vegetables – broccoli, avocados
Meats, rice, alfalfa, peanuts, molasses, yeasts
Deficiency
Excessive fatigue, sleep disturbances.
Deficiency - extremely rare due to its widespread
distribution in whole grain cereals, meat.
Toxicity
Mild intestinal distress and diarrhea at worst

Pyridoxine
(Pyridoxol )
Pyridoxal
Pyridoxamine
Pyridoxal Phosphate
(PDP)
All three compounds are
efficiently converted to the
biologically active form of
vitamin B 6
, PYRIDOXAL
PHOSPHATE (PDP)

Overview
Affects the body’s use of proteins, saccharides
• a coenzyme in all transamination reactions, in some
decarboxylation and
deamination of amino acids
PDP aids in the synthesis of heme
Helps in absorption of vitamin B 12 and formation of
erythrocytes
Role in the conversion of tryptophan to serotonin – help against
mental depression
A role in preventing heart disease – prevents homocysteine build
up (damage to blood vessel linings)

Folic acid
hyperhomocysteinemia – cause of atherosclerosis
Homocystein
Cystein

Vitamin B 6 -magnesium - help attention deficit disorder -
improvements in hyperactivity, and improved school
attention
Vitamin B6 - cure for premenstrual syndrome (PMS)
Deficiency
• Anemia
• Nerve damage (mental confusion, irritability, nervousness)
• Skin problems
• Sores in the mouth
Deficiencies of vitamin B6 are rare

Natural Sources
Potatoes, Salmon, Shrimp,
grains, soya, yeasts,
poultry, fish, eggs, nuts
Interactions
Tobacco/alcohol - Reduces
vitamin absorption rates

VITAMIN H - BIOTIN
FUNCTION
• Cofactor of enzymes that are involved in CARBOXYLATION
reactions (e.g. acetylCoA carboxylase, pyruvate carboxylase)
helps to transfer carbon dioxide CO 2
• Key role in the metabolism of lipids, proteins and carbohydrates
• It activates protein/amino acid metabolism in the hair roots and
fingernail cells - the “beauty vitamin” - often recommended for
strengthening hair and nails.
• Role in DNA replication and transcription arising from its
interaction with nuclear histone proteins

DEFICIENCY
• hair loss,
• depression, halucination,
• muscle pain,
• dermatitis
Synthetized by intestinal bacteria - deficiencies rare

Deficiency Occurs in:
• Alcoholics
• People with inflammatory bowel disease
• Someone who eats large quantities of raw egg whites
• Long-term antibiotic use
• Long-term use of anti-seizure medications
Raw eggs -
avidin from egg whites + biotin = complex
preventing absorption of biotin
deficiency
SOURCES
gut flora, liver, egg yolk, nuts, seeds, soya
vit. H

imidazol
valeric acid
thiophane
STRUCTURE - imidazol and thiophane heterocyclic
ring with valeric acid

COENZYME - BIOCYTIN
Biotin + Lysin-enzyme = Biocytin (biotinyllysin)
ATP
CO 2
carboxybiocytin
• Coenzyme of carboxylases – enzymes transporting CO 2

Biotin
Biocytin
Carboxybiocytin

HN
Biotin
Carboxybiotin
Activation of CO 2 by biotin - formation of carboxybiotin

Vitamin B 9 - Folic Acid
:
Overview
• Nucleotide biosynthesis
• DNA and RNA synthesis and repair
• Cofactor in biological reactions involving folate
• Important during periods of rapid cell division and growth
• Production of red blood cells, prevention of anemia.
Benefits
To carry and transfer various forms of one carbon units
(methyl, methylene, methenyl, formyl or formimino groups)
during biosynthetic reactions (purine nucleotides, dTMP)
Promotes a healthy pregnancy

pterin PABA Glutamic acid
Folic Acid
positions 7 & 8 carry hydrogens in dihydrofolate (DHF)
positions 5-8 carry hydrogens in tetrahydrofolate (THF)
• Active form of folic acid - tetrahydrofolate (THF) – coenzyme F –
formylating coenzyme – transfer of 1-carbon moeities
• PABA (para-aminobenzoic acid)- vitamin character – not
synthetized in the organism

Folic acid
Metotrexate
Aminopterin
(competitive inhibitors)
Dihydrofolate
reductase
THF
DNA
Synthesis

GTP
PABA
Sulphon
onamide
– prevents growth and division of MO
interfering with PABA action
FOLIC ACID COENZYME (THF) Purin and
pyrimidin
synthesis
PABA – growth factor for MO
H 2
N
SO 2
H 2
N
COOH
sulphonamide
p-aminobenzoic
acid (PABA)

Deficiency
Neural tube defects in developing embryos
Megaloblastic anaemia, mood disorders and gastrointestinal
disorders
Overdose
Prostate cancer
latin word folium = leaf
Interactions
Methotrexate - Folic acid efficacy reduced
Natural Sources
Green leafy vegetables, yeasts, animal liver

Spina bifida
malformation of the spine

VITAMIN B 12 - Cyanocobalamin
Function
• Synthesis of DNA and erythrocytes
• Coenzyme during conversion of methylmalonyl to succinyl CoA
• Coenzyme during conversion of homocystein to methionine
• Functioning of brain and nervous system
Benefits
Promotes growth and cell development
Natural Sources
Dairy products, Eggs

Deficiency
Nausea, loss of appetite, sore mouth
Deficiencies - rare
The liver can store up to six years worth of vitamin B12
Pernicious anaemia develops as a result of a lack of intrinsic factor in
the stomach leading to malabsorption of the vitamin.
Interactions
Tobacco/Alcohol - Reduces the absorption of vitamin B12

Cyanocobalamin

B12 Synthesis
(MO)
B12 - protein
hydrolysis
B12 protein
B12-IF
Intrinsic faktor (IF)
(stomach)
Absorption (small intestine)
Transcobalamine II
B12-transcobalamine II
(circulation)

Binding of B12-transcobalamin II to the cell
receptors
Endocytosis of the complex into cells
Degradation of the complex in lysosomes and liberation
of B12
Coenzyme of enzymes in the cell cytoplasm

Overview
Participates in oxidation-reduction reactions
Ascorbic acid
Dehydroascorbic acid

Enzyme block
Gulonic
acid
L-ascorbic acid
L-dehydroascorbic
acid
The vast majority of animals and plants are able to synthesize their
own ascorbic acid (excluding humans, guinea pigs, bats)

FUNCTION
Antioxidant (prooxidant)
Cofactor of enzymes used in the synthesis of collagen
Tyrosine degradation
Adrenalin synthesis
Carnitin synthesis
Bile acids production
Steroidogenesis
Iron absorption
Metabolism of bone minerals

vitamín E
O=C
R
RH
O-C
vitamín E
HO-C
O
vitamín E + vitamín C vitamín E + H-C
HO-C-H
CH 2 OH
radikál
kyseliny
L-ascorbic
L-
askorbovej
acid radical
O=C O=C O=C O=C
O-C O-C HO-C O=C
O
O
O
HO-C HO-C HO-C O=C
+ +
H-C H-C H-C H-C
O
HO-C-H HO-C-H HO-C-H HO-C-H
CH 2 OH
radikál
kyseliny
L-
L-ascorbic
acid radical
CH 2 OH
radikál
kyseliny L-ascorbic
L-
acid radical
askorbovej
CH 2 -OH CH 2 -OH
ascorbate
dehydroascorbate
Nonenzyme scavenging of free radicals by vitamins
Neenzýmové vychytávanie radikálov vitamínmi
askorbát
dehydroaskorbá
glutatiónreduktáza
t
Glutathione
reductase
GS-SG 2 GSH
NADPH
pentózafosfátový
Pentose
NADP +
Phosphate
cyklus
cycle

Deficiency
Muscle weakness, swollen gums, loss of teeth, tiredness
Scurvy - avitaminosis
Liver spots on the skin
Spongy gums
SCURVY

Overdose
Flushed face, headache,
increased urination,
lower abdominal cramps
Natural Sources
Fruits and vegetables

VITAMIN P – BIOFLAVONOIDS
• Found in close association with vitamin C - vitamin C .
• Bioflavonoids help maximize the benefits of vitamin C by
inhibiting its breakdown in the body
• Antioxidants, antivirals, and anti-inflammatories
• Protection against infections
• Decrease the cholesterol level

• Strengthening the walls of the blood vessels (rutin)
• Preventing nosebleeds, miscarriages, postpartum bleeding,
and other types of hemorrhages
• Protection against cancer and heart disease
• Anticoagulant activity (preventing blood clotting)
• Improvement of circulation
• Improvement of liver function
• Improvement of vision and eye diseases
Essencial compounds are rutin, hesperidin, quercetin.
Colour of flavonoids – from yellow to dark violet

Flavonoids
• Pigments for flower coloration producing yellow or red/blue
pigmentation
• They also protect plants from attacks by microbes and insects
• They show anti-allergic, anti-inflammatory, anti-microbial and anticancer
activity.
•The beneficial effects of fruit, vegetables, and tea or even red wine
have been attributed to flavonoid compounds rather than to known
nutrients and vitamins

Sources
Citrus fruits, grapes, black current, blackberries, blueberries,
cherries, apricots, cacao, tea
Absorption of the bioflavonoids can be slow, but small amounts
can be stored in the body

LIPOIC ACID
LIPOIC ACID
Coenzyme – aerobic decarboxylation and transacylation during
photosynthesis
Growth factor of several bacteria and protozoa
Antioxidant – dihydrolipoic acid regenerates glutathione, vitamin
C and E
- acts in hydrophilic and lipophilic environment

Lipoic acid

Chelator
• Lipoic acid – chelates Cu 2+ , Zn 2+ and Pb 2+ , but not Fe 3+ .
• Dihydrolipoic acid – chelates Cu 2+ , Zn 2+ a Pb 2+ and Fe 3+ .
- prooxidant – it can reduce Fe 3+ to Fe 2+
• Lipoic acid administration - mushroom poisoning, heavy metal
intoxication
Sources - kidney, heart, liver, spinach, broccoli, peas, potatoes
Brewer´s yeasts

UBIQUINONE – COENZYME Q
• Present in the respiratory chain of mitochondria and in membranes
of various organels (ER, peroxisomes, lysosomes…)
• It is not a vitamin - all animals, including humans, can synthesize
ubiquinones
• Fat soluble
• Transports electrones
• Antioxidant – due to its ability to transport electrones
• Important for energy production in cells

Coenzyme Q 3
CH 2 =C(CH 3 )CH=CH 2
isoprene (2-methyl-1,3-butadiene )

mitochondria
Vonkajšia
membrána

Oxidized form
Semiradical
Reduced form

• Biosynthesis
1) Synthesis of the benzoquinone structure from either
tyrosine or phenylalanine
2) Synthesis of the isoprene side chain from acetylcoenzyme
A (CoA) via the mevalonate pathway
3) The joining or condensation of these two structures
• Deficiency
Decreased plasma levels of coenzyme Q10 - diabetes,
cancer, and congestive heart failure
• Sources
meat, poultry, fish, nuts,
moderate sources - Fruits, vegetables, eggs, and dairy
products

ADENOSINEPHOSPHATES
Adenine
5´
Triphosphoric acid
Ribose
- donors and acceptors of phosphoric acid in all living systems

adenine
ribose
adenosine

Adenosine-5'-triphosphate (ATP)
• Transports chemical energy within cells for metabolism
• It is an energy source produced during photosynthesis and
cellular respiration
• It is consumed by many enzymes in biosynthetic reactions,
motility, and cell division.
• ATP is made from adenosine diphosphate (ADP) or
adenosine monophosphate (AMP) and its use in metabolism
converts it back into these precursors

• ATP - substrate in signal transduction pathways by
KINASES - phosphorylate proteins and lipids
ADENYLATE CYCLASE - uses ATP to produce the second
messenger molecule cyclic AMP
cAMP
• ATP is also incorporated into nucleic acids
• ATP has several negatively charged groups in neutral solution, it
can chelate metals with very high affinity
• Due to the strength of these interactions, ATP exists in the cell
mostly in a complex with Mg 2+

Adenylate
cyclase
ATP
cAMP