Vitamins_2011.pdf

8/14/2019 Vitamins_2011.pdf

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VITAMINS and COENZYMES

INGRID ITANOV2010/2011


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Introduction to Vitamins

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 K, H gut floraVitamin A - from precursor Vitamin D skin (UV light)

Introduction to Vitamins

VITAL + AMINES = VITAMIN


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FUNCTIONS

Regulate metabolism, help convert lipids and saccharidesinto energy

Hormones (vitamin D)

Antioxidants (vitamin E)

Regulators of cell and tissue growth and differentiation(vitamin A)

Precursors for enzyme coenzymes (B-complex)


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AVITAMINOSIS - chronic or long-term vitamin deficiency(beri-beri, scurvy, rickets and pellagra)

HYPOVITAMINOSIS - any of several diseases caused bydeficiency 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.


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Avitaminoses

Vitamin A deficiency causes xerophthalmia or night blindnessThiamine (B1) deficiency causes beri-beri

Niacin (B3) deficiency causes pellagra

Vitamin B12 deficiency leads to megaloblastic anemia

Vitamin C deficiency leads to scurvy

Vitamin D deficiency causes ricketsVitamin K deficiency causes impaired coagulation

Rare in developed world - fortification


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ANTIVITAMINSANTIVITAMINS

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)

H2N C

O

OH

Paraaminobenzoic acid (PABA)

H2N S

O

NH2

O

Sulphonamide

Sulphonamides prevent bacterial multiplication, without toxicity to the human tissues


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FOLIC ACID COENZYME (THF)FOLIC ACID COENZYME (THF) PurinPurin andandpyrimidinpyrimidinsynthesissynthesis

SulphSulphononamideamide preventsprevents growthgrowth andand divisiondivision ofofMOMOinterferinginterfering withwith PABAPABA actionaction

HH22NN HH22NNSOSO22 COOHCOOH

sulphosulphonnamideamide pp--aminobenzoicaminobenzoic acidacid ((PABA)PABA)

GTPGTP

PABAPABA

PABAPABA growthgrowth factorfactor forfor MOMO


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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


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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


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VITAMIN A = R E T I N O L

Its provitamin --carotene - (red, orange pigments in plants and fruits)

- Antioxidant

Structure: tetraterpenoid containing-ionone ring with an unsaturated

side chain

-, - a - provitamin A


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dioxygenza

CHO COOH

all-transretinal izomerza kyselina retinov

dehydrogenza

CH2OH

transretinol1- vitamn A1

Premeny -karotnu a vitamnu A1

15'

1

1111

1

1

CHO

Fe2+

O2

11-cisretinal

-karotn

15

-carotene

dioxygenase

Retinoic acidisomerasedehydrogenase

2


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All-trans-retinal 11-cis-retinal

Retinol Kyselina retinovRetinoic acid


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RHODOPSIN(PIGMENT)

LIGHT

CIS-RETINAL TRANS-RETINAL-OPSIN

NERVEIMPULS

TRANS-RETINAL

NADH+H+

DEHYDROGENASE

NAD+

TRANS -RETINOL

OPSIN

RETINALISOMERASE

R

E

T

I

N

A

Retinolesters (liver)

transport by blood proteins

VISION CYCLE


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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


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HYPERVITAMINOSIS

-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, blurredvision, loss of muscular coordination


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SOURCES

-carotene - carrot, green leafy vegetables spinach, kale,

sweet potatoes, yellow and orange fruits

Retinal liver of polar bear, seal, eggs and fatty fish


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VITAMINS D - CALCIFEROL

Increases Ca into bloodstream by promoting absorption ofCalcium and Phosphorus from food in the intestines and

reabsorption of Ca in the kidneys, enabling normal mineralization

of bone

2 types:

D2 derived from precursor ergosterol present in plants

D3 derived from precursor 7-dehydrocholesterol

present in skin

Structure similar to steroid hormones (cortizol, estradiol, progesteron) - derivedfrom cholesterol


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UV

7-dehydrocholesterol (skin) cholecalciferol(provitamin) (D3, calciol)

UV

Ergosterol (plants) ergocalciferol (D2, ercalciol)

(provitamin)

Adequate amounts of vitamin D3 can be made in the skin after only10 -15 minutes of sun exposure at least 2x per week to the face,arms, hands, or back without sunscreen


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7-dehydrocholesterol Cholekalciferol (D3)

Plants

Ergosterol pre-D2


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UV

Kidneys: 25-hydroxylase

Liver: 1-hydroxylase


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Increased parathyroid hormone

SKIN

7-dehydrocholesterol


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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)


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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


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Odd curve to spine or

back

Stunted growth

Wide joints at

elbow and

wrist

Odd-shaped

legs

Wide ankles

Wide

bones

Large

abdomen

Odd-shaped

ribs andbreast bones

Largeforehead


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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


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Sources of vitamin D

Fish liver oils

Fatty fish species A whole egg

Beef liver, cooked

UV-irradiated mushrooms (Vitamin D2)

Fatty


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Benefits

Protects lipids (cell membranes), DNA, proteins fromoxidation ANTIOXIDANTProtects food fats from going rancid

Helps to form red blood cells

Aids in the absorption of vitamin K

Vitamin E Tocopherols

antisterile vitamin


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Free radical

Cell

Mitochondria

Vitamin E protects cell membrane lipids from oxidation by reacting

with lipid radicals produced in the lipid peroxidation chain reaction


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Nonenzymatic scavenging

of free radicals by vitamins

Radical of

L-ascorbicacid

Radical of

L-ascorbic

acid

ascorbate dehydroascorbate

Radical of

L-ascorbic acid

O=C

O-C

HO-C

vitamn E vitamn C H-C

HO-C-H

O=C O=C O=C O=C

O-C O-C HO-C O=C

HO-C HO-C HO-C O=C

H-C H-C H-C H-C

HO-C-H HO-C-H HO-C-H HO-C-H

CH2-OH CH2-OH

+

O

R

O

RH

CH2OH

radikl

kyseliny

L-

O

CH2OH

radikl

kyselinyL-

O

CH2OH

radikl

kyseliny

L-

+ +

askorbt dehydroaskorb

GS-SG 2 GSH

glutatin-

reduktza

NADPHNADP

+

pentza-fosftov

vitamn E

vitamn E +

vitamn E

O

L-ascorbic

acid radical

L-ascorbic

acid radical

L-ascorbic

acid radical

Ascorbic acid Dehydroascorbic acid

PentosePhosphate

Glutathionereductase


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OCH3

CH3 CH3 CH3R3

R2

HO

R1

O

HO

CH3

CH3CH3 CH3 CH3

R1 R2 R3

Tocol -CH3 -CH3 -CH3

-CH3 -H -CH3 -H -CH3 -CH3

-H -H -CH3

tocotrienol

STRUCTURE: tocol, forms 8 basic derivatives-tocopherol is a most effective form

Chromanol ring

HO- group - reduction of free radicals

Saturated side chain penetration in membranes

R1

R2

R3

Deficiency


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Deficiencyneurological problems, anemia

Natural Sources

green leafy vegetable, vegetable oils, nuts, seeds, spinach,broccoli, soybean oil

VITAMIN K QUINONES


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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

VITAMIN K - QUINONES


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Overview

Promotes normal blood clotting (coagulation) Bone metabolism

Vascular health

Biochemistrycoenzyme for a vitamin K-dependent carboxylase

carboxylation of glutamic acid gamma-

carboxyglutamic acid (Gla) involved in binding Ca2+

nonactive active

clotting factor-glutamic acid clot.factor-Gla-Ca2+

CO2

Vitamin K

carboxylase


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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


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Rare in healthy adults: 1) vitamin K widespread in foods2) 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

barrier2) 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

Deficiency


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Vitamin K1, K

2 no known toxicity

Vitamin K3 interferes with glutathione (antioxidant)

oxidative damage to cell membranes.

- injections liver toxicity, jaundice, hemolytic

anemia in infants

Toxicity


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Bromadiolon

(Anticoagulant)

Warfarin

(anticoagulant)


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Natural Sources

green leafy vegetables alpha-alpha, Brussel sprouts,

spinach, kale, cabbage, avocado, cheddar cheese


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VITAMIN F

ESSENTIAL UNSATURATED HIGHERCARBOXYLIC 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 synthesizedfrom linoleic acid in the body

Fatty acids needed for:

normal growth, behavior, healthy cell membranes, well balanced

hormone level, immune system


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Linoleic acid

-6 fatty acid

Linolenic acid

-3 fatty acid

Arachidonicacid

-6 fatty acid

ARACHIDONIC ACID WITH 4 DOUBLE BONDS


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ARACHIDONIC ACID WITH 4 DOUBLE BONDS

cyclooxygenase

prostaglandins

prostacyclins

tromboxanes

lipoxygenase

epoxides

leukotriens

cytochrom P450

The eicosanoids from AA generally promote inflammation

VITAMIN B1 THIAMINE, ANEURINE


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1 ,(antineuritic factor, antiberiberi factor)

PYRIMIDINE and THIAZOL rings linked throughmethylene bridge

Antagonists Sulfites (food preservatives) attack at the

methylene bridge

VITAMIN B THIAMINE ANEURIN


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VITAMIN B1 THIAMINE, ANEURIN

Natural thiamine phosphate derivatives:thiamine monophosphate (TMP)

thiamine diphosphate (TDP) (pyrophosphate TPP)

thiamine triphosphate (TTP)

Phosphate derivatives involved in many cellular

processesCOENZYME = thiamine diphosphate cocarboxylase -

in catabolism of saccharides and aminoacids


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Thiamine pyrophosphate

TPP - cofactor for the pyruvate dehydrogenase

- alpha-ketoglutarate dehydrogenase catalyzed reactions

- the transketolase catalyzed reactions of the pentose

phosphate pathway.


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TPP

TPP

Deficiency


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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

Natural SourcesMeat, potatoes, bananas, lentils, beans, yeast

InteractionsAntibiotics - Decrease thiamine level

Overdose

Hypersensitive reactions resembling anaphylactic shock


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Overview

Essential to energy generation

Riboflavin - precursor for the coenzymes FAD, FMN redoxreactions

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 B2 RIBOFLAVIN


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METHYL DERIVATE OF IZOALOXAZINE + RIBITOL

Lactoflavin, ovoflavin, vitamin G

Riboflavin powder.

Riboflavin solution

ribitol

C O


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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)


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Riboflavin

Flavinmononucleotide

(FMN)

Flavinadenine dinucleotide

reduc.

(FADH2)

FAD


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FAD

Nitrogens 1 & 5 transfer hydrogen in FADH2

Riboflavin

H

H


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DeficiencyFatigue, 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

OverdoseItching, numbness, a burning sensation

StorageRiboflavin decomposes when exposed to visible light

This characteristic can lead to riboflavin deficiencies in

newborns treated for hyperbilirubinemia by phototherapy

Food sourcesRiboflavin


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Food ServingRiboflavin

(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 0.16Broccoli (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


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, ,

NicotinamideNicotinic Acid

Niacin is not a true vitamin in the strictest definition since it

can be derived from tryptophan.

nicotinic acid + vitamin

Nicotinamide adenine dinucleotide (NAD+) and Nicotinadeninedinucleotide phosphate (NADP+) - cofactors for numerous


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dinucleotide phosphate (NADP ) - cofactors for numerous

dehydrogenases (lactate and malate dehydrogenases)- acceptorduring alcohol oxidation

NICOTINAMIDE ADENINE DINUCLEOTIDE (NAD+)

H-

NADH

-OH phosphorylated inNADPated in NADP+

(ATP, ATPase)

alcoholto be


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oxidized

Transfer:H-

Alcohol dehydrogenase

Aldehyde

ResidueNAD+

ResidueNAD+

CoenzymeResidue+

CoenzymeResidue+

Riboflavinunit

H+

NADH

Reoxidation of NADH

Function


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Function

Niacin is a precursor to NADH, NAD+ - coenzymes ofoxido-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


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Dermatitis on the hands and face, weakness

The severe symptoms, depression, dermatitis and

diarrhea, - PELLAGRA (3D disease)

Natural Sources

Beef liver, brewers yeast, meat, eggs, grains and

milk


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PELLAGRA


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Overdose

Niacin flush, liver damage, stomach ulcers, nausea,

diarrhea, weakness


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Overview

Pantothenate is required for synthesis of coenzyme A

metabolism of saccharides, proteins, lipids.

Growth factor for MO

Anti-stress vitamin

-alanineD-pantoate


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Pantothenic Acid


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Fatty acids Fatty acids

Respiratory chain

Krebs cycle


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SOURCES

Whole grains - milling removes much of the pantothenic acid

Vegetables broccoli, avocados

Meats, rice, alfalfa, peanuts, molasses, yeastsDeficiency

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


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Pyridoxine(Pyridoxol ) Pyridoxal Pyridoxamine

Pyridoxal Phosphate(PDP)

All three compounds are

efficiently converted to thebiologically active form of

vitamin B6, PYRIDOXAL

PHOSPHATE (PDP)

Overview


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Affects the bodys use of proteins, saccharides

a coenzyme in all transamination reactions, in somedecarboxylation and

deamination of amino acids

PDP aids in the synthesis of heme

Helps in absorption of vitamin B12 and formation oferythrocytes

Role in the conversion of tryptophan to serotonin help againstmental depression

A role in preventing heart disease prevents homocysteine build

up (damage to blood vessel linings)


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hyperhomocysteinemia cause of atherosclerosis

Folic acid

Homocystein Cystein


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Vitamin B6-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


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Natural SourcesPotatoes, Salmon, Shrimp,

grains, soya, yeasts,

poultry, fish, eggs, nuts

InteractionsTobacco/alcohol - Reduces

vitamin absorption rates

VITAMIN H - BIOTIN


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FUNCTION Cofactor of enzymes that are involved in CARBOXYLATION

reactions (e.g. acetylCoA carboxylase, pyruvate carboxylase)

helps to transfer carbon dioxide CO2

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 forstrengthening hair and nails.

Role in DNA replication and transcription arising from its

interaction with nuclear histone proteins

DEFICIENCY


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hair loss,

depression, halucination,

muscle pain,

dermatitis

Synthetized by intestinal bacteria - deficiencies rare


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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 -

preventing absorption of biotin vit. H

deficiency

avidin from egg whites + biotin = complex

SOURCES

gut flora, liver, egg yolk, nuts, seeds, soya

imidazol valeric acid


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STRUCTURE - imidazol and thiophane heterocyclic

ring with valeric acid

thiophane

COENZYME - BIOCYTIN


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Biotin + Lysin-enzyme = Biocytin (biotinyllysin)

carboxybiocytin

CO2

Coenzyme ofcarboxylases enzymes transporting CO2

ATP

BiotinBiocytin


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Carboxybiocytin


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HN

Activation of CO2 by biotin - formation of carboxybiotin

CarboxybiotinBiotin

Vitamin B9 - Folic Acid


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:

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 ofone carbon units(methyl, methylene, methenyl, formyl or formimino groups)

during biosynthetic reactions (purine nucleotides, dTMP)

Promotes a healthy pregnancy


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pterin PABA Glutamic acid


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Folic Acidpositions 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

M


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Dihydrofolatereductase

THF

DNASynthesis

Metotrexate

Aminopterin

(competitive inhibitors)


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FOLIC ACID COENZYME (THF)FOLIC ACID COENZYME (THF) PurinPurin andand

pyrimidinpyrimidinsynthesissynthesis

SulphSulphononamideamide preventsprevents growthgrowth andand divisiondivision ofofMOMOinterferinginterfering withwith PABAPABA actionaction

HH22NN HH22NNSOSO22 COOHCOOH

sulphosulphonnamideamide pp--aminobenzoicaminobenzoic acidacid ((PABA)PABA)

GTPGTP

PABAPABA

PABAPABA growthgrowth factorfactor forfor MOMO


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Deficiency

Neural tube defects in developing embryosMegaloblastic anaemia, mood disorders and gastrointestinaldisorders

OverdoseProstate cancer

InteractionsMethotrexate - Folic acid efficacy reduced

Natural Sources

Green leafy vegetables, yeasts, animal liver

latin wordfolium = leaf

Spina bifida


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malformation of the spine

VITAMIN B12 - Cyanocobalamin


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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


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DeficiencyNausea, 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 inthe stomach leading to malabsorption of the vitamin.

InteractionsTobacco/Alcohol - Reduces the absorption of vitamin B12


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Cyanocobalamin

B12 - protein

B12 t i

B12 Synthesis

(MO) hydrolysis


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B12 protein

Intrinsic faktor (IF)(stomach)

B12-IF

Absorption (small intestine)

B12-transcobalamine II

(circulation)

Transcobalamine II

Binding of B12-transcobalamin II to the cell

receptors


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receptors

Endocytosis of the complex into cells

Degradation of the complex in lysosomes and liberation

of B12

Coenzyme of enzymes in the cell cytoplasm


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Overview

Participates in oxidation-reduction reactions

Ascorbic acid Dehydroascorbic acid


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Gulonic

acid

L-ascorbic acidL-dehydroascorbic

acid

Enzyme block

The vast majority of animals and plants are able to synthesize their

own ascorbic acid (excluding humans, guinea pigs, bats)

FUNCTION


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Antioxidant (prooxidant)

Cofactor of enzymes used in the synthesis of collagenTyrosine degradation

Adrenalin synthesis

Carnitin synthesis

Bile acids production

Steroidogenesis

Iron absorption

Metabolism of bone minerals

FUNCTION

O=C

O-C

HO-C

vitamn E vitamn C H-C+

R

O

RH

radiklkyseliny

vitamn E

vitamn E +

vitamn E

L ascorbic


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HO-C-H

O=C O=C O=C O=C

O-C O-C HO-C O=C

HO-C HO-C HO-C O=C

H-C H-C H-C H-C

HO-C-H HO-C-H HO-C-H HO-C-H

CH2-OH CH2-OH

O

CH2OH

kyseliny

L-

O

CH2OH

radikl

kyseliny

L-

O

CH2OH

radikl

kyseliny

L-

+ +

askorbt dehydroaskorb

GS-SG 2 GSH

glutatin-

reduktza

NADPH NADP+pentza-

fosftov

O

L-ascorbic

acid radical

L-ascorbic

acid radical

L-ascorbic

acid radical

ascorbate dehydroascorbate

Pentose

Phosphate

Glutathione

reductase

Deficiency

Muscle weakness, swollen gums, loss of teeth, tiredness

Scurvy - avitaminosis


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SCURVY

y

Liver spots on the skin Spongy gums


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OverdoseFlushed face, headache,

increased urination,

lower abdominal cramps

Natural Sources

Fruits and vegetables

VITAMIN P BIOFLAVONOIDS


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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,


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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


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Flavonoids

Pigments for flower coloration producing yellow or red/bluepigmentation

They also protect plants from attacks by microbes and insects

They show anti-allergic, anti-inflammatory, anti-microbial and anti-

cancer 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


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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


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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


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Chelator

Lipoic acid chelates Cu2+, Zn2+ and Pb2+, but not Fe3+.

Dihydrolipoic acid chelates Cu2+, Zn2+ a Pb2+ and Fe3+.


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- prooxidant it can reduce Fe3+ to Fe 2+

Lipoic acid administration - mushroom poisoning, heavy metal

intoxication

Sources - kidney, heart, liver, spinach, broccoli, peas, potatoes

Brewers yeasts

UBIQUINONE COENZYME Q


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Q 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 Q3


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CH2=C(CH3)CH=CH2isoprene (2-methyl-1,3-butadiene )


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mitochondriaVonkajia

membrna


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Reduced form

Oxidized formSemiradical

Biosynthesis1) Synthesis of the benzoquinone structure from either

tyrosine or phenylalanine

2) Synthesis of the isoprene side chain from acetyl-


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coenzyme A (CoA) via the mevalonate pathway

3) The joining or condensation of these two structures

DeficiencyDecreased plasma levels of coenzyme Q10 - diabetes,

cancer, and congestive heart failure

Sourcesmeat, poultry, fish, nuts,

moderate sources - Fruits, vegetables, eggs, and dairy

products

ADENOSINEPHOSPHATES

Adenine


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Ribose

Triphosphoric acid

- donors and acceptors of phosphoric acid in all living systems

5

adenine


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ribose

adenosine

Adenosine-5'-triphosphate (ATP)


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Transports chemical energy within cells for metabolism

It is an energy source produced during photosynthesis andcellular respiration

It is consumed by many enzymes in biosynthetic reactions,motility, and cell division.

ATP is made from adenosine diphosphate (ADP) oradenosine monophosphate (AMP) and its use in metabolismconverts it back into these precursors

ATP - substrate in signal transduction pathways byKINASES - phosphorylate proteins and lipids

ADENYLATE CYCLASE - uses ATP to produce the second

messenger molecule cyclic AMP

cAMP


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ATP is also incorporated into nucleic acids

ATP has several negatively charged groups in neutral solution, itcan chelate metals with very high affinity

Due to the strength of these interactions, ATP exists in the cell

mostly in a complex with Mg2+

Adenylate

cyclase


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ATP

cAMP

Documents

Vitamins_2011.pdf