VITAMINS are organicsubstances , essential in the dietin small amounts that are involvedin fundamental functions of thebod...
Vitamin K (intestinal flora micro-Organisms in intestine.Vitamin D is synthesized by irradiation (UV light) of 7-dehydro c...
VITAMINSINTRODUCTIONDefination: A vitamin is an organic compound required as a nutrient in tinyamounts for the maintenance...
• In 1906, the British biochemist Sir. Frederick Hopkins demonstrated thatfoods contain accessory factors in addition to p...
• Cereal and seeds can be important because of its source ofVitamin B. Vitamin B is important because it can prevent berib...
• The value of eating a certain food to maintain health was recognizedlong before vitamins were identified. The ancient Eg...
Fruits and vegetables are often a good source of many vitamins.Since the human body can‘t produce vitamins naturally or no...
• The Japanese navy, he experimented using crews of two battleships; one crew was fed only white rice, while the other was...
• In humans• Vitamins are classified as either water-soluble or fat soluble.• In humans there are 13 vitamins:• 4 fat-solu...
Fat soluble vitamins• Vitamins A, D, K and E are the fat-soluble vitamins.• These vitamins are soluble mainly in lipidsor ...
• Fat soluble vitamins Basic structural moiety.vitamin A DiterpenoidVitamin D Steroidal moeity.Vitamin E Chromane ring sys...
The biological and IUPAC name ofvitamin A is Retinol.• Vitamin is also known asAxerophthol becauseit is used in the treatm...
Animal Foods Plant FoodsCod liver oil Sweet potatoLiver & kidney CarrotsEgg CantaloupeButter SpinachMilk & cheese ApricotF...
Vitamin A• Exits in 3 forms:• all trans-retinol• long chain fatty acyl ester of retinol (mainstorage form)• retinal (the a...
Vitamin AChemical nature and properties﹡natural form : A1 ( retinol )A2 ( 3-dehydro-retinol )﹡active form : retinol 、 reti...
CH3CH3H3CCH3CH2OHCH3VITAMIN A (RETINOL)RDA: 0.7 mgChemistry of vitamin A.•Vitamin A (Retinol) is a cyclic polyene alcohol ...
The Retinoids• 3 forms of vitamin Aimportant for health– Retinal– Retinoic acid– Retinol (key player; canbe converted to o...
Terminal Ends of RetinoidsCH3CH3H3CCH3CH2OHCH3VITAMIN A (RETINOL)β-ionone ring.β-carotine(some)Beta-carotene (most)(retiny...
5 “W”2 “W”, 1”V”(which is abundantly found in carrots)(intestinal mucosa)(2 molecules of vitaminA aldehyde)(VitaminA)(Redu...
Role of Vitamin A in VisionVisual Pigment
The Eye is a camera• Retina is the innermost photosensitive layer of the eyecomposed of nerve cells called rods and cones....
The RetinaCross-section of eyeGanglion cell layerBipolar cell layerReceptor layerPigmentedepitheliumGanglion axonsCross se...
Retina up-closeLight
© Stephen E. Palmer, 2002Conescone-shapedless sensitiveoperate in high lightcolor visionTwo types of light-sensitive recep...
The Visual Cycle(Rods and conesContains opsinWhich is photoSensitive pigment)(vitamin Aaldehyde)Activation of rhodopsin by...
Physiological RoleAs previously mentioned vitamin A is essential to vision. Within the photoreceptor cells of the retina ...
Physiological Role/ Importance of Vitamin AVitamin A is needed for the various functions ofthe body like…..• Vision• Growt...
Uses of Vitamin A.1. Vitamin A is mainly used in the treatment oftreatment of deficiency of Vitamin A.2. It is also used i...
Carotenoids• Additional physiologiceffects beyond vitamin A– Serving as an “antioxidant”• Remove excess “electrons”from ce...
Functions of Vitamin A:Growth and Differentiation of Cells• Retinoic acid is necessary for cellulardifferentiation• Import...
Functions of Vitamin A:Immunity• Deficiency leads to decreased resistanceto infections• Supplementation may decrease sever...
Vitamin A Analogs for Acne• Topical treatment (Retin-A)– Causes irritation, followed by peeling of skin– Antibacterial eff...
Possible Carotenoid Functions• Prevention of cardiovascular disease– Antioxidant capabilities– ≥5 servings/day of fruits a...
Deficiency of Vitamin A• Most susceptiblepopulations:– Preschool childrenwith low F&V intake– Urban poor– Older adults– Al...
• Diseases of deficiency:– Nigh blindness and xerophthalmia (dry eye)– Skin disorders– Lack of growth• Hypervitaminosis:– ...
Upper Level for Vitamin A• 3000 μg retinol• Hypervitaminosis A results from long-term supplement use (2 – 4 x RDA)• Toxici...
Toxicity of Vitamin A–Acute – short-term megadosesymptoms disappear when intake stops• GI effects• Headaches• Blurred visi...
Toxicity of Vitamin A–Chronic – long-term megadose;possible permanent damage• Bone and muscle pain• Loss of appetite• Skin...
Toxicity of Vitamin A• Teratogenic (may occur with as little as 3 xRDA of preformed vitamin A)– Tends to produce physical ...
Health Effects of Vitamin A
Toxicity of Carotenoids• Not likely, as rate of conversion ofcarotenoids to retinoic acid by liver is slowand efficiency o...
Vitamin A analogues:Tretinoin1. Tretinoin is also called retinoicacid or Vitamin A acid.2. Tretinoin is obtained by theoxi...
• Physico-chemical properties:Tretinoin is yellow to light –orange crystalline powder,insoluble in water andslightly solub...
Uses of tretinoin:Tretinoin is used mainly in the treatment of• skin diseases.• Acne vulgaris.• In the treatment of Hyperk...
Isotretinoin(Accutane)• Isotretinoin is a cis-isomer of retinoicacid(tretinoin).• The configuration of double bond at α an...
CH3CH3H3CCH3 CH3COOHISOTRETINOIN (ACCUTANE)Used in the treatment of severe acne
• Physico-chemical properties:It is yellow-orange to orange,crstallinpowder,sparingly soluble in alcohol andinsoluble in w...
Uses of isotretinoin• Isotretinoin is mainly used in the treatmentof Recalcitrant cystic Acne.( acne in whichpredominant l...
Fat soluble vitamins (Vitamin A) Medicinal chemistry- ravisankar - iIntroduction,classification, Differencebetween fat and...
Fat soluble vitamins (Vitamin A) Medicinal chemistry- ravisankar - iIntroduction,classification, Differencebetween fat and...
Fat soluble vitamins (Vitamin A) Medicinal chemistry- ravisankar - iIntroduction,classification, Differencebetween fat and...
Fat soluble vitamins (Vitamin A) Medicinal chemistry- ravisankar - iIntroduction,classification, Differencebetween fat and...
Fat soluble vitamins (Vitamin A) Medicinal chemistry- ravisankar - iIntroduction,classification, Differencebetween fat and...
Fat soluble vitamins (Vitamin A) Medicinal chemistry- ravisankar - iIntroduction,classification, Differencebetween fat and...
Fat soluble vitamins (Vitamin A) Medicinal chemistry- ravisankar - iIntroduction,classification, Differencebetween fat and...
Fat soluble vitamins (Vitamin A) Medicinal chemistry- ravisankar - iIntroduction,classification, Differencebetween fat and...
Fat soluble vitamins (Vitamin A) Medicinal chemistry- ravisankar - iIntroduction,classification, Differencebetween fat and...
Fat soluble vitamins (Vitamin A) Medicinal chemistry- ravisankar - iIntroduction,classification, Differencebetween fat and...
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Fat soluble vitamins (Vitamin A) Medicinal chemistry- ravisankar - iIntroduction,classification, Differencebetween fat and water soluble vitamins,slurces of vitamin A, chemistry of Vitamin A, Physiological Role of Vitamin-A, uses, Tretinoin and Isotretino

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Fat soluble vitamins (Vitamin A) Medicinal chemistry- By ravisankar - iIntroduction,classification, Differencebetween fat and water soluble vitamins,slurces of vitamin A, chemistry of Vitamin A, Physiological Role of Vitamin-A, uses, Tretinoin and Isotretinoin

Fat soluble vitamins (Vitamin A) Medicinal chemistry- ravisankar - iIntroduction,classification, Differencebetween fat and water soluble vitamins,slurces of vitamin A, chemistry of Vitamin A, Physiological Role of Vitamin-A, uses, Tretinoin and Isotretino

  1. 1. VITAMINS are organicsubstances , essential in the dietin small amounts that are involvedin fundamental functions of thebody.Fat soluble vitaminsVitamin - A
  2. 2. Vitamin K (intestinal flora micro-Organisms in intestine.Vitamin D is synthesized by irradiation (UV light) of 7-dehydro cholesterol(ergosterols) in the skin.Biotin is synthesized by bacteria in the large intestine.(or) obtained fromfood.
  3. 3. VITAMINSINTRODUCTIONDefination: A vitamin is an organic compound required as a nutrient in tinyamounts for the maintenance and growth of an living organism.In the early 20th century the discovery of vitamins began.Each and every living animal needs vitamins to grow and be healthy.Since the human body can ‘t produce vitamins naturally or normally produce theamounts needed, food provides the body with them.There are different vitamins found in different foods. These vitamins give vitalnutrients to an animal..Vitamins deficiency may lead to certain specific diseases or symptoms whichcan be cured by the administration of that specific vitamin only.The term vitamin was first discovered by Funk.He coined the term "vitamine," a combination word from vita and amine, meaningamine of life.At the time they were considered to be amines that are vital for the life.How ever it was later found that not all vitamins were “nitrogen” or amines.After researchers began to suspect that not all "vitamines" had an aminecomponent. (particularly vitamin A)In 1920, Drummond proposed that the final "e" be dropped.That’s why in theword Vitamines “e” is removed and called vitamins.
  4. 4. • In 1906, the British biochemist Sir. Frederick Hopkins demonstrated thatfoods contain accessory factors in addition to proteins, carbohydrates, fats,minerals and water.• Funk identified that the antiberiberi substance in unpolished rice wasan amine (a type of Nitrogen-containing compound), so Funkproposed that it be named vitamine, from vital amine. It was laterdiscovered that different vitamins have different chemical properties.This discovery caused vitamine to be turned into vitamin.• 1912 Hopkins and Funk made a hypothesis. The hypothesis stated theabsence of some vitamins could cause diseases such as beriberi and scurvy.Later a letter was assigned to each vitamin.• The letters which were assigned to vitamins in the early years ofvitamin research categorize them according to their functions.• Later the names were given to vitamines based on their order of discovery.• Butter can be important because it is a source of Vitamin A.The pigments that are converted into Vitamin A, are found inmost fruits and vegetables. Vitamin A is important because itcan prevent diseases.
  5. 5. • Cereal and seeds can be important because of its source ofVitamin B. Vitamin B is important because it can prevent beriberi.• Citrus Fruits can be important because of their source of vitamin C.Vitamin C is important for strength and metabolism.• Milk can be important because it is a source of vitamin D. Vitamin D isimportant because it is essential for bone growth.• Plants can be important because of the plant oil which is a sourceof Vitamin E. Vitamin e is important because it is a source ofoxidation in body tissues.• Sub groups of these vitamins weredisignated using subscripts 1,2,3,4,5 etc.• Ex:- VitaminB1,B2,B3,B6,B12; VitaminD2,D3,VitaminK1,K3.
  6. 6. • The value of eating a certain food to maintain health was recognizedlong before vitamins were identified. The ancient Egyptians knew thatfeeding liver to a patient would help cure night blindness, an illnessnow known to be caused by a vitamin A deficiency.The Ancient Egyptians knew that feeding a patient liverwould help cure night blindness.
  7. 7. Fruits and vegetables are often a good source of many vitamins.Since the human body can‘t produce vitamins naturally or normally produce theamounts needed, food provides the body with them. There are different vitaminsfound in different foods. These vitamins give vital nutrients to an animal.
  8. 8. • The Japanese navy, he experimented using crews of two battleships; one crew was fed only white rice, while the other was feda diet of meat, fish, barley, rice, and beans. The group that ateonly white rice documented 161 crew members with beriberiand 25 deaths, while the latter group had only 14 cases ofberiberi and no deaths. This convinced Takaki and theJapanese Navy that diet was the cause of beriberi, butmistakenly believed that sufficient amounts of protein preventedit.• Feeding unpolished rice instead of the polished variety tochickens helped to prevent beriberi in the chickens.• Frederick Hopkins postulated that some foods contained"accessory factors"—in addition to proteins, carbohydrates,fats, that were necessary for the functions of the human body.• Hopkins and Eijkman were awarded the Nobel Prize forPhysiology or Medicine in 1929 for their discovery of severalvitamins.
  9. 9. • In humans• Vitamins are classified as either water-soluble or fat soluble.• In humans there are 13 vitamins:• 4 fat-soluble (A, D, E and K)• 9 water-soluble (8 B vitamins and vitamin C). Water-solublevitamins dissolve easily in water and in general, are readilyexcreted from the body, to the degree that urinary output is astrong predictor of vitamin consumption• Because they are not readily stored, consistent daily intake isimportantMany types of water-soluble vitamins are synthesizedby bacteria.• Fat-soluble vitamins are absorbed through the intestinal tractwith the help of lipids (fats). Because they are more likely toaccumulate in the body, they are more likely to lead tohypervitaminosis than are water-soluble vitamins.• Fat-soluble vitamin regulation is of particular significance incystic fibrosis
  10. 10. Fat soluble vitamins• Vitamins A, D, K and E are the fat-soluble vitamins.• These vitamins are soluble mainly in lipidsor oil and hence called fat soluble vitamins.• excessive use of fat soluble vitamins may lead to theiraccumulation in the body (hypervitaminosis) due todelayed elimination rate. This accumulation of vitaminsresults in toxic effects.• fat soluble vitamin tend to be stored in fatty tissues(adipose tissue) of the body and in the liver.• They are eliminated slowly from the body because oftheir lipophilic character.
  11. 11. • Fat soluble vitamins Basic structural moiety.vitamin A DiterpenoidVitamin D Steroidal moeity.Vitamin E Chromane ring systemwith an isoprenoid sidechain.Vitmin K Napthaquinone derivativeBASIC STRUCTURAL MOIETY OF FAT SOLUBLE VITAMINS
  12. 12. The biological and IUPAC name ofvitamin A is Retinol.• Vitamin is also known asAxerophthol becauseit is used in the treatment ofXerophthalmia(Drying and thickening ofconjunctiva).• The structure of vitamin Aconstitute a β-ionone ring.• Vitamin A contains 5 conjugated doublebonds which are key to some biologicalactions.• Isolated in impure form by McCollum in1915.
  13. 13. Animal Foods Plant FoodsCod liver oil Sweet potatoLiver & kidney CarrotsEgg CantaloupeButter SpinachMilk & cheese ApricotFish & meet PapayaRICH DIETARY SOURCESRICH DIETARY SOURCES
  14. 14. Vitamin A• Exits in 3 forms:• all trans-retinol• long chain fatty acyl ester of retinol (mainstorage form)• retinal (the active form in the retina)• retinoic acid is also considered to bephysiologically active• provitamin A or carotene can beconverted to retinol in vivo
  15. 15. Vitamin AChemical nature and properties﹡natural form : A1 ( retinol )A2 ( 3-dehydro-retinol )﹡active form : retinol 、 retinal 、 retinoic acid﹡pro-vitamin A : β-carotene﹡storage : liver,adipose tissue of the body.
  16. 16. CH3CH3H3CCH3CH2OHCH3VITAMIN A (RETINOL)RDA: 0.7 mgChemistry of vitamin A.•Vitamin A (Retinol) is a cyclic polyene alcohol which resembles thestructure of Diterpenoid.•The structre of vitamin A constiture of a β- ionone ring.• four conjugated double bonds in the side chain of vitaminA.•They are in trans arrangement.•Synthetic retinol is a trans isomer. It exists in 8 stereoisomericforms.•β- ionone ring and conjugated double bonds are essential for thebiological activity of vitaminA.General structure ofβ- ionone ring.CH3CH3H3CCH3CH2OHCH3VITAMIN A (RETINOL)
  17. 17. The Retinoids• 3 forms of vitamin Aimportant for health– Retinal– Retinoic acid– Retinol (key player; canbe converted to otherforms)• β-carotene (acarotenoid or pigment)in yellow/orange foodsis a potent provitamin A
  18. 18. Terminal Ends of RetinoidsCH3CH3H3CCH3CH2OHCH3VITAMIN A (RETINOL)β-ionone ring.β-carotine(some)Beta-carotene (most)(retinylesters)
  19. 19. 5 “W”2 “W”, 1”V”(which is abundantly found in carrots)(intestinal mucosa)(2 molecules of vitaminA aldehyde)(VitaminA)(Reduction)(tretinoin)Conversion of carotenoids to Retinoids
  20. 20. Role of Vitamin A in VisionVisual Pigment
  21. 21. The Eye is a camera• Retina is the innermost photosensitive layer of the eyecomposed of nerve cells called rods and cones.• Rhodopsin(photosensitive pigment) is formed form aprotein called Opsin and cis-isomer of Retinali.e.vitaminA aldehyde.The Role of Vitamin A in vision:
  22. 22. The RetinaCross-section of eyeGanglion cell layerBipolar cell layerReceptor layerPigmentedepitheliumGanglion axonsCross section of retina
  23. 23. Retina up-closeLight
  24. 24. © Stephen E. Palmer, 2002Conescone-shapedless sensitiveoperate in high lightcolor visionTwo types of light-sensitive receptorsconerodRodsrod-shapedhighly sensitiveoperate at nightgray-scale vision photoreception is the function of 2specialized cell types: rods and conesboth types of cells contain a photosensitivecompound called opsinin rod cells opsin is called scotopsinand the receptor is called rhodopsin orVisual purple.
  25. 25. The Visual Cycle(Rods and conesContains opsinWhich is photoSensitive pigment)(vitamin Aaldehyde)Activation of rhodopsin byLight rays leads to genarationOf transmission of impulseThrough the optic nerves.is formed from aProtein pigmentOpsin +11-cisRetinal.+(Retinol is carried from the liver (storage site) to retina by means of carrier proteins calledRetinolbinding proteins(RBP) by forming complex (RBP_retinol complex)this complexDissociates in the retina and gets deposited in the pigmented epithelial cells of the inner
  26. 26. Physiological RoleAs previously mentioned vitamin A is essential to vision. Within the photoreceptor cells of the retina arethe rods, which detect small amounts of light and are specialized for motion detection and vision in dimlight.The cones that are specialized for color vision in bright light .Both rods and cones posses specialized outer segment disks that contain high amounts of rhodopsinand iodopsin respectively.These compounds are often referred to as the "visual pigment"Photoreceptor cells detect light and undergo a series of reactions, which send signals to the brain,where they are deciphered as a particular visual image. A second very important function of vitamin A involves retinoic acid. Acting as a hormone, retinoic acidfirst binds to retinoic acid receptors. The receptors then interact with specific nucleotide sequences ofDNA. The interaction directly affects gene expression and transcription, which in turn control cellulardevelopment and body processes.For example, epithelial cells depend on retinoic acid for structural and functional maintenance. Thisrole of vitamin A is important for growth mechanisms in a manner that is not completely understood. Retinoic acid is especially important in heart, eye, lung and ear development.The development of gap junctions between cells is also affected by retinoic acid.Besides the previously mentioned functions, vitamin A plays a role in numerous other processes.Vitamin A is thought to play a key role in glycoprotein synthesis.. Once formed, glycoproteins are important in multiple cellular processes including: communication,recognition, adhesion, and aggregation. Reproductive processes, bone development, along withmaintenance, and immune system function are dependent upon different isoforms of vitamin A. Retinoids are most commonly used in the treatment of skin diseases. The role the retinoids play inepithelial cell formation is very important in the treatment of skin cancer, acne, and acne-related diseasesVitamin A also has antioxidant properties. However, beta-carotene has been noted as having pro-oxidant properties.Despite these discrepancies vitamin A is known to help repair damaged tissue and therefore may bebeneficial in counter-acting free radical damage.
  27. 27. Physiological Role/ Importance of Vitamin AVitamin A is needed for the various functions ofthe body like…..• Vision• Growth and differentiation of epithelial cells.• Reproduction and embryonic development.• Maintenance of epithelial cells.• Maintence of immune system.• β-carotine acts as an antioxidant and thus decreases the risk ofcancers.• Retinol and retinoic acid are involved in the regulation of the proteinsynthesis,which inturn is involved in cell differentiation and growth.• Maintenance of healthy epithelial tissue because it prevents keratinsynthesis.• Retinyl phosphate is required for the production ofmucopolysaccharides.• Vitamin A is involved in the synthesis of transferrin ( iron transportprotein)
  28. 28. Uses of Vitamin A.1. Vitamin A is mainly used in the treatment oftreatment of deficiency of Vitamin A.2. It is also used in the treatment of …Dermatological disease and lesions.- Xerophthalmia.- Cold,warts,corns and calluses( skin infections- Acne- Hyperkeratosis of arms.
  29. 29. Carotenoids• Additional physiologiceffects beyond vitamin A– Serving as an “antioxidant”• Remove excess “electrons”from cell system• Electrons (free radicals)damage cells and DNA– Can cause mutations– Protecting from cancer(related to antioxidantfunction?)– Protecting from heartdisease?– Supports immune systemfunction
  30. 30. Functions of Vitamin A:Growth and Differentiation of Cells• Retinoic acid is necessary for cellulardifferentiation• Important for embryo development, geneexpression• Retinoic acid influences production,structure, and function of epithelial cellsthat line the outside (skin) and externalpassages (mucus forming cells) within thebody
  31. 31. Functions of Vitamin A:Immunity• Deficiency leads to decreased resistanceto infections• Supplementation may decrease severityof infections in deficient person
  32. 32. Vitamin A Analogs for Acne• Topical treatment (Retin-A)– Causes irritation, followed by peeling of skin– Antibacterial effects• Oral treatment– Regulates development of skin cells– Caution regarding birth defects
  33. 33. Possible Carotenoid Functions• Prevention of cardiovascular disease– Antioxidant capabilities– ≥5 servings/day of fruits and vegetables• Cancer prevention– Antioxidant capabilities– Lung, oral, and prostate cancers– Studies indicate that vitamin A-containing foodsare more protective than supplements• Age-related macular degeneration• Cataracts• In general, foods rich in vitamin A and otherphytochemicals are advised rather thansupplements
  34. 34. Deficiency of Vitamin A• Most susceptiblepopulations:– Preschool childrenwith low F&V intake– Urban poor– Older adults– Alcoholism– Liver disease (limitsstorage)– Fat malabsorption• Consequences:– Night blindness– Decreased mucusproduction– Decreased immunity– Bacterial invasion ofthe eye– Conjunctival xerosis– Bitot’s spots– Xerophthalmia– Irreversible blindness– Follicularhyperkeratosis– Poor growth
  35. 35. • Diseases of deficiency:– Nigh blindness and xerophthalmia (dry eye)– Skin disorders– Lack of growth• Hypervitaminosis:– A serious potential problem (CNS disorders;birth defects)
  36. 36. Upper Level for Vitamin A• 3000 μg retinol• Hypervitaminosis A results from long-term supplement use (2 – 4 x RDA)• Toxicity• Fatal dose (12 g)
  37. 37. Toxicity of Vitamin A–Acute – short-term megadosesymptoms disappear when intake stops• GI effects• Headaches• Blurred vision• Poor muscle coordination
  38. 38. Toxicity of Vitamin A–Chronic – long-term megadose;possible permanent damage• Bone and muscle pain• Loss of appetite• Skin disorders• Headache• Dry skin• Hair loss• Increased liver size• Vomiting
  39. 39. Toxicity of Vitamin A• Teratogenic (may occur with as little as 3 xRDA of preformed vitamin A)– Tends to produce physical defect ondeveloping fetus as a result of excess vitaminA intake– Spontaneous abortion– Birth defects
  40. 40. Health Effects of Vitamin A
  41. 41. Toxicity of Carotenoids• Not likely, as rate of conversion ofcarotenoids to retinoic acid by liver is slowand efficiency of absorption of carotenoidsdecreases as intake increases• Hypercarotenemia– High amounts of carotenoids in the bloodstream– Excessive consumption of carrots/squash/beta-carotene supplements– Skin turns a yellow-orange color
  42. 42. Vitamin A analogues:Tretinoin1. Tretinoin is also called retinoicacid or Vitamin A acid.2. Tretinoin is obtained by theoxidation of retinal(vitamin Aaldehyde).3. Tretinoin was considered to bea form of vitaminA that actsmainly on the skin, hence it isused in the treatment ofdermatological diseases.5. IUPAC name of tretinoin isretinoic acid.(Retinoic acid) (Or) VitaminA acid.CH3CH3H3CCH3CH2OHCH3VITAMIN A (RETINOL)COOHTretinoin (Retinoic acid)
  43. 43. • Physico-chemical properties:Tretinoin is yellow to light –orange crystalline powder,insoluble in water andslightly soluble in alcohol and chloroform.It is unstable to heat,light and air. M.P= 176-181oC.Physiological role/importance of tretinoin:Tretinoin is genarally for maintenance of cell membrane,protein synthesisand formation of skeletal muscle.It is involved in the cell differentiation and cell growth along with Vitamin A.It is involved in the synthesis of transferrin(iron transport protein)Adverse/toxic effects:Hyperpigmentation or Hypopigmentation may occur when exposed to sunlight.(it is temporary effect which may be reversible)When applied to exzematous skin it causes severe irritation.Topical application some times leads to irritation,peeling,crusting,blistering ofskin.
  44. 44. Uses of tretinoin:Tretinoin is used mainly in the treatment of• skin diseases.• Acne vulgaris.• In the treatment of Hyperkeratotic conditions.• Solar and follicular keratosis(red spots with scalysurface)• Lamellar ichthyosis(thickening of skin on plam and soles)• Hyperplastic dermatosis.• It acts as antioxidant and freeradical scavenger,whichprotects the skin form radiation effects.This property isuseful in the treatment of somcancers,carcinogenesis(dueto radiation and carcinogens).
  45. 45. Isotretinoin(Accutane)• Isotretinoin is a cis-isomer of retinoicacid(tretinoin).• The configuration of double bond at α and βcarbon atoms is cis.Mechanism of action:Isotretinoin acts by inhibiting the function ofsabaceous galnds and follicularkeratinization,thus it decreases the productionof sebum,size and differentiation of thesebaceous glands.
  46. 46. CH3CH3H3CCH3 CH3COOHISOTRETINOIN (ACCUTANE)Used in the treatment of severe acne
  47. 47. • Physico-chemical properties:It is yellow-orange to orange,crstallinpowder,sparingly soluble in alcohol andinsoluble in water.Toxic effects:Chronic hypervitaminosisA, facial dermatitis,thinand dry hair,fragile and dryskin,drymouthandeyes,conjunctivitis(inflammation ofconjunctiva),inflammation of chips,inflammationof urethra,peeling of skin onpalms,soles,jointpains and excessive
  48. 48. Uses of isotretinoin• Isotretinoin is mainly used in the treatmentof Recalcitrant cystic Acne.( acne in whichpredominant lesions are cysts and deepseated scars).

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