PLANTS AND ANIMALS PIGMENTS

Plants and animals pigments.

1. PLANTS AND ANIMALS PIGMENTS SNEHA.P.M. 2ND BT PLANTS AND ANIMALS PIGMENTS

2. WHAT IS PIGMENT? A pigment is a substance that appears a certain color because it selectively absorbs wavelength of light . ... Pigments that either fade or else blacken over time or with extended exposure to light are called fugitive pigments .Pigment, any of a group of compounds that are intensely coloured and are used to colour other materials.

3. CLASSIFICATION OF PIGMENTS: The pigments are produced by the living organisms and have a colour, which results from the colour absorption techniques. There are two different types of pigments an are classified base on their sources: ORGANIC PIGMENTS The organic pigments are made from some of the Natural sources.

4. INORGANIC PIGMENTS; The inorganic pigments, also called the synthetic pigments are derived from the coal tars and some of the other form of petrochemicals. In some rare cases, these pigments can also be synthesized by a simpler form of chemical reactions called oxidation.

5. PLANT PIGMENTS: Normal constituents of cells or tissues that impact colour.It has another properties such as energy receptors , carriers of O2, Protects against radiation . Chlorophylls Carotenoids Flavonoids Anthocyanins Tannins Betalains Quinones Xanthones

6. PIGMENTS IN PLANTS: Plants have a unique feature of capturing the light energy and convert it into sugars through the process called photosynthesis . The process begins with the absorption of light energy by some specialized form of organic molecules, called the pigments . The photosynthesis, a biological process requires green coloured pigment called chlorophyll along with other forms of yellow and red coloured pigments. Other essential plant pigments include anthocyanins, betalains, carotenoids, and much more. All these pigments stimulate the process of chemical reactions by reflecting the wavelengths.

7. CHLOROPHYLL: Chlorophyll is one of the primary pigment found within the plant cells of all green plants. The green colouring of the plant leaves and the tender part of the stem is due to the presence of a pigment called chlorophyll . The chlorophyll pigment is the most significant and essential pigments, as it plays a vital role in the biological process of photosynthesis .

8. There are different types of chlorophyll pigments and are classified mainly based on their structure, functions and other features. The different types of chlorophyll pigments are: Chlorophyll a– found in algae, cyanobacteria and in all higher plants. Chlorophyll b– found only in green algae and in higher plants. Chlorophyll c– found in certain photosynthetic Chromista and in some marine algae. Chlorophyll d– found only in red algae. Chlorophyll e– found only in algae. Among all these five types of chlorophyll pigments, chlorophyll a and b are considered as the primary photosynthetic pigments.

9. CAROTENOIDS; Carotenoids are the pigments in the form of orange, red, yellow colours. These compounds are insoluble in water and are attached to the membranes of the cell bodies. These Biomolecules are antioxidants which promote a good eyesight in humans.

10. OCCURENCE OF CAROTENOIDS: Animals cannot synthesize carotenoids so their presence is due to dietary intake. Carotenoids are the most complex class of natural food colourants with around 750 different structures identified. Carotenoids can be divided into carotenes containing only carbon and hydrogen. They are found in the chloroplast and chromoplasts in plants and animals.

11. CHEMICAL STRUCTURE OF CAROTENOIDS: Carotenoids has two structural groups they are hydrocarbon carotenes and oxygenated xanthophyll. This xanthophyll contains hydroxyl,epoxy, aldehyde and ketone groups. The basic carotenoids backbone structure consists of isoprene units linked by covalently in either head-to-tail or tail-to-tail fashion.

12. LYCOPENE: Being a precursor in the biosynthesis of beta-carotene, lycopene can be expected to be found in plants. The best known source of lycopene are Tomatoes, Watermelon, Guava and Pink Grapefruit. In Tomato oleoresin also contains appreciable amounts of beta-carotene,Phytoene and phytofluene.

13. LUTEIN: Lutein is also very common carotenoids. The name is derived from Latin word for Yellow. Lutein is made from Aztee Marigold also contains some Zeaxanthin (Typically less than 10%) Containing only ten conjugated double bonds, lutein is more yellowish green.

14. FLAVONOIDS; Flavonoids are a type of yellow coloured pigments, which are abundantly found in lemons, grapefruit, oranges and in some ark and yellow coloured flowers. This type of pigments is largely found in the plastids and cytoplasm of the plant cell. Flavonoids are the chemicals with the antioxidant properties and help in lowering the cholesterol levels.

15. OCCURENCE OF FLAVONOIDS: Flavonoids or bioflavonoids(From latin word Flavus meaning Yellow, their colour in nature) are a class of plants secondary metabolites. Over 5000 naturally occurring flavonoids have been characterized from various plants. They have been classified according to their chemical structure, and are usually subdivided into the following groups: SUB GROUPS : Anthoxanthins(Flavone and Flavonol). Flavonones Flavonols Anthocyanidinds.

16. STRUCTURE OF FLAVONOIDS: Chemically they have the general structure of a 15carbon skeleton, which consists of two phenyl rings(A and B) and heterocyclic ring (C) . The chemical group in flavonoid is O- heterocyclic compounds.

17. ANTHOCYANINS; Anthocyanins are a type of flavonoid pigments found naturally in all the tissues of the higher group of plants. This pigment functions by providing colour to the stem, leaves, roots, fruits, and flowers. Based on their pH, these type of pigments appears red, blue, purple and other dark colours.

18. OCCURENCE OF ANTHOCYANINS: Anthocyanins occur in all tissues of higher plants, mostly in Flowers and fruits but also in leaves, stems and roots. In these parts they are predominantly found in the outer cell layers such as epidermis and peripheral mesophyll cells and also cell vacuole. No fewer than 109 tons of anthocyanins are produced in nature per year. Not all land plants contain anthocyanins in the caryophyllales(Including cactus,beets and amaranth)they are replaced by Betalains . Anthocyanins and carotenoids contribute distinctive pigmentation to blood oranges.

19. STRUCTURE OF ANTHOCYANINS: The basic structure of anthocyanins is 2-phenylbenzopyrylium of flavyliam salts. They differ in the number of polyhydroxy and polymethoxy derivative of the salt. An anthocyanin pigment composed of an aglycone esterified to one or more sugars with O- heterocyclic compounds . When the sugar moiety of an anthocyanin is hydrolyzed the aglycone,is called ANTHOCYANIDIN .

20. TANNINS: Tannin solutions are acid and have an astringent taste . Tannin is responsible for the astringency, colour, and some of the flavour in tea. Tannins occur normally in the roots, wood, bark, leaves, and fruit of many plants, particularly in the bark of oak species and in sumac and myrobalan .

21. OCCURENCE OF TANNINS: A tannin are special compound,water soluble polyphenolic compounds with molecular weight between 500-3000 . The tannin compounds are widely distributed in many species of plants where they play a role in protection and predation . They are commonly found in both gymnosperm and in angiosperms . The most abundant polyphenols are the condensed tannins and comprising upto 50% of the dry weight of leaves . Tannins are found in leaf,bud,seed,root,stem tissues and vacuoles or surface wax of plants, mostly found in the growth areas of trees. Bark of the oak trees and grape seeds are source of tannins.

22. STRUCTURE OF TANNINS: Tannins (or tannoids) are a class of astringent, polyphenolic biomolecules that bind to and precipitate proteins and various other organic compounds including amino acids and alkaloids. ... Tannins have molecular weights ranging from 500 to over 3,000 (gallic acid esters) and up to 20,000 (proanthocyanidins). There are three major classes of tannins: Hydrolyzable tannins(Gallic acid) Non-hydrolyzable or condensed tannins (Flavone) Phlorotannins (Phloroglucinol).

23. ANATOMY OF A GRAPE:

24. BETALAINS: Betalains are a red and yellow color pigment of indole derivatives. It can be easily found in plants of the Caryophyllales. Betalains are related to anthocyanins and are replacements for anthocyanin pigments. Both (betalains and anthocyanin) are water soluble and are present in vacuoles of plant cells.

25. OCCURENCE OF BETALAINS: The name betalain comes from the Latin name of the common beet (BEETA VULGARIS) from which Betalains was first extracted. Betalains are a class of red and yellow indole derived. These pigments found in the plants of the caryophyllales, where they replace anthocyanin pigments. They are most often noticable in the petals of flowers ,but may colour the fruits, leaves, stems and roots of plants that contain them. Betalains water soluble pigments found in the vacuoles of plants cells.

26. CATEGORIES OF BETALAINS: 1.BETACYANINS: It includes the reddish to violet Betalains pigment. Betacyanins present in plants include betanin,isobetanin,probetanin and neobetanin. 2.BETAXANTHINS: They are Betalain pigment that appear Yellow to Orange. Betaxanthins in plants include Vulgaxanthin,Miraxanthin,Portulaxanthin and Indicaxanthin.

27. STRUCTURE OF BETALAINS: It is now known that Betalains are aromatic indole derivatives synthesized from tyrosine (N-heterocyclic compounds). Each Betalains is a glycoside and consist of a sugar and a coloured portion. For example: Betalains contain nitrogen whereas anthocyanin do not. Source of Betalains are red beet-root,swiss chard, cactus,pear and amaranth.

28. QUINONES: Quinones are a class of natural and synthetic compounds that have several beneficial effects. Quinones are electron carriers playing a role in photosynthesis. As vitamins, they represent a class of molecules preventing and treating several illnesses such as osteoporosis and cardiovascular diseases.

29. OCCURENCE OF QUINONES: They are widely distributed in plants, especially trees which gives colour of wood and bitter in taste. Derivatives of quinones are common constituents of biologically active molecules. Some serve as electron acceptor in electron transport chain such as those in photosynthesis (Plastoquinone,Phyllo quinone) and aerobic respiration (Ubiquinone) . Most quinones are bitter in taste. Their contribution to the colour of plants is minimal. Colour changes occur by the addition of hydroxyl groups.

30. STRUCTURE OF QUINONES: The quinones are a class of organic compounds that are formally "derived from aromatic compounds [such as benzene or naphthalene] by conversion of an even number of –CH= groups into –C(=O)– groups with any necessary rearrangement of double bonds", resulting in "a fully conjugated cyclic dione structure".

31. XANTHONES: Xanthone is an organic compound with the molecular formula C₁₃H₈O₂. In 1939, xanthone was introduced as an insecticide and it currently finds uses as ovicide for codling moth eggs and as a larvicide . Xanthone is also used in the preparation of xanthydrol, which is used in the determination of urea levels in the blood.

32. OCCURENCE OF XANTHONES: These pigments are yellow, phenolic pigments they are confused with Quinones and Flavones because of their structural characteristics. Many xanthones are phytochemicals, found in plants(In the families Bonnetiaceae,Clusiaceae,Podostemaceae). Some xanthones are found in the pericap of the mangosteen fruit (Garcinia Mangostana).

33. STRUCTURE OF XANTHONES: Xanthone is the parent compound of the xanthone class consisting of xanthene bearing a single oxo substituent at position 9. It has a role as an insecticide.

34. ANIMAL PIGMENTS

35. PIGMENTS IN ANIMALS: Pigments present in animals are by nature which makes them colourful in nature.Some animals get their colour through what they eat…… There are various kinds of pigments present in Animals.They are: Carotenoids Carotenoproteins Tetrapyrroles Melanin Chromataphores.

36. CAROTENOIDS IN ANIMALS: Marine animals accumulate carotenoids from foods such as algae and other animals and modify them through metabolic reactions. Many of the carotenoids present in marine animals are metabolites of β-carotene, fucoxanthin, peridinin, diatoxanthin, alloxanthin, and astaxanthin, etc.

37. STRUCTURE OF CAROTENOIDS: The general structure of the carotenoid is a polyene chain consisting of 9-11 double bonds and possibly terminating in rings. ... The length of carotenoids also has a role in plant coloration, as the length of the polyene tail determines which wavelengths of light the plant will absorb.

38. TETRAPYRROLES: Tetrapyrroles are a class of chemical compounds that contain four pyrrole or pyrrole-like rings. The pyrrole/pyrrole derivatives are linked by (=(CH)- or -CH2- units), in either a linear or a cyclic fashion. Pyrroles are a five-atom ring with four carbon atoms and one nitrogen atom. Tetrapyrroles are common cofactors in biochemistry and their biosynthesis and degradation feature prominently in the chemistry of life.

39. STRUCTURE OF TETRAPYRROLES: Linear tetrapyrroles(called bilanes) include: Heme breakdown products(eg.bilirubin,biliverdin). Phycobilins(found in cyanobacteria). Luciferins as found in dinoflagellates and euphausiid shrimps(Krill).

40. MELANIN: Melanin is the main pigment found in mammals. It is responsible for the color of hair and fur. There are different types of melanin (eumelanin and pheomelanin), and they produce a huge color range, from black to sandy to red. A lion's coloring is produced by melanin.

41. PROPERTIES OF MELANIN; Melanins seem to be heterogeneous, with some small regions of order at the nanometer scale. The optical properties we can see depend on the ability of monomers and oligomers (made up of small numbers of monomers) that make up melanin to absorb light, and the ability of melanin particles to reflect and scatter incident light for different wavelengths .

42. FLAVINS: Flavin , also called Lyochrome , any of a group of pale-yellow, greenly fluorescent biological pigments (biochromes) widely distributed in small quantities in plant and animal tissues. Flavins are synthesized only by bacteria, yeasts, and green plants; for this reason, animals are dependent on plant sources for them, including riboflavin (vitamin B2), the most prevalent member of the group.

43. CHROMATOPHORES; Amphibians’ and reptiles’ skin contains three kinds of highly branched color cells called chromatophores . The chromatophores occur in three discrete layers. The top layer is generally made of xanthophores bearing yellow pigments ; the middle layer includes iridophores ; and the bottom layer has melanophores with black or brown melanin.

44. OTHER WAYS THAT ORGANISMS CREATE COLOURS; Fireflies and bacteria emit light in the form of bioluminescence . Luciferins are a class of light-emitting biological substance found in these organisms. Although animals do manufacture their own melanin, they can’t make many other pigments. Plants, however, can produce a range of pigments, so many animals are colored by what they eat .

45. DISEASE CAUSED BY LACK OF PIGMENTS. Four diseases caused by lack of pigmentation. ALBINISM: Inherited disorder by partial loss of Melanin pigment. LAMELLAR ICHTHYOSIS: Fish scale disease,Excess production of Melanin pigment. MELASMA: Dark brown patches of pigment appear on face. LEUCISM: Partial loss of pigmentation in animals.

46. WHITE ANIMALS:(Albinism) White animals are often found in nature and sometimes the cause is albinism . Melanin is the primary pigment that determines the color of a mammal`s skin, fur, and eyes . Albinism occurs in mammals (including humans), fish, birds, reptiles, and amphibians. It is a hereditary condition; the principal gene which results in albinism prevents the body from making the usual amounts of the pigment melanin.

47. LAMELLAR ICHTHYOSIS: Lamellar ichthyosis is a rare genetic condition that affects the skin . Infants affected by lamellar ichthyosis are generally born with a shiny, waxy layer of skin (called a collodian membrane) that is typically shed within the first two weeks of life. The skin beneath the collodian membrane is red and scaly.

48. LEUCISM: Leucism is a term used to describe a wide variety of conditions which result in the partial loss of pigmentation in an animal—which causes white, pale, or patchy coloration of the skin, hair, feathers, scales or cuticles, but not the eyes. It is occasionally spelled leukism.

49. REFERENCE: Book of Natural dyes and pigments.