Nature provides huge range of colour possibilities

The chemistry of natural dyes will be focused on comprehensively, and alphabetically, in two parts – the first being this article and the second an article to be published in the July edition of Personal Care Asia Pacific.

 Alkanin or Anchusin

Alkanna tinctoria, Alkanet In addition to the common name, it is called Orchanet and Spanish Bugloss and by the apothecaries it was known as enchusa. It has blue or reddish-purple flowers. Currently, alkanna root has no recognised medical uses except for its older use as an astringent. It is used as a cosmetic dye. The esteric pigments displayed excellent antibiotic and wound-healing properties in a clinical study on 72 patients with ulcus cruris (indolent leg ulcers). Alkanet root contains a red colouring matter known as anchusin (alkannin or alkanet-red). Alkanet is an ancient dyestuff known throughout Europe.

Annatto Annatto or norbixin is extracted from the Bixa orellana or lipstick tree, and gives a yellow to deep orange colour. The plant has entered into commercial cultivation for the production of this dye which is used mainly in the food industry and for colouring dairy products such as butter and cheese, margarine, edible oils, etc.
Bixa orellana, Annatto Annatto is a red to orange natural (golden yellow) pigment derived from the seed of the tropical bush Bixa orellana. The major colour present is cis-bixin, the monomethyl ester of the diapocarotenoic acid norbixin, which is found as a resinous coating surrounding the seed itself. Also present, as minor constituents, are trans-bixin and cisnorbixin. The annatto bush is native to Central and South America where its seeds are used as a spice in traditional cooking. It has been reported that the dye is also used in Brazil in pottery and as an insect-repellent, and in the Philippines in furniture and shoe polishes, nail varnish, brass lacquer, hair oil, etc. It is further stated that Jamaica and South India have been major producers of the top quality product. From other countries the dye has lacked the bright colour required. In South America the shrub is cultivated around villages, where it is native to and widespread throughout the neotropics. It is called kiswe or kyswi by the Waimiri Atroari. A red dye is obtained from the aril of the seed that is sometimes used for body painting. It is called urucum in the local vernacular. Another chemical found in the plant that is responsible for some of the colour is bixin. Bixin is one of the more stable natural yellow colours. However, it loses much of its tinctorial power gradually on storage, the process being accelerated by light and heat. Hence for manufacturing purposes fresh seeds are preferred. The tinctorial strength of bixin is comparable to that of ?-carotene. However, bixin is the more stable.

Anthocyanins [Category]

Anthocyanins are natural red, blue or violet plant pigments present in the cell sap of many flowers, fruits and vegetables. Anthocyanins are contained in cherries, plums, blackberries, black carrot, blueberries, cranberries, grapes, elderberry, mulberry, purple corn, rosehips, red cabbage, redcurrant, and red radish. They have the general structure shown in Figure 4. Cyanidin is found specifically in Purple corn. They are used as pH indicators and are heat, oxygen and enzyme labile, but the stability is a major limitation for use. Red cabbage “juice” has been used in barbecue sauce and for colouring pink lemonade.

Anthraquinones [Category]

Rubia tinctorum, roots of Madder Madder is native to the Mediterranean and the Near East and was once widely grown as a dye plant and was used in central Europe since around the 9th Century. The common name Madder comes from the Anglo-Saxon name maedere for the plant. The generic name, Rubia means red and the plant has been used as a source of a permanent red dye. The two to three year old rootstock of the plants is used medicinally, and it remains red when dried. The constituents include anthraquinone glycosides which are two red chemical entities derived from the roots and tubers, and which are known as alizarin and purpurin. The isolation requires the prior hydrolysis of the glucoside precursor in the roots (Alizarin red from Rubia tinctorum occurs in nature as the glycoside and is called ruberythrinic or ruberythric acid and is its 6-O-?-D-xylopyranosyl-?-D-glucopyranoside). The Indian madder mainly yields purpurin (see Figure 5). In the care of the skin it is considered an astringent, tonic, vulnerary and antiseptic. Madder is also used to cleanse open wounds and can remove skin blemishes if bruised leaves are applied externally. Externally, a decoction of madder can be used for skin problems, especially tubercular conditions of the skin and mucous tissue. The decoction can also be used as a bath additive. Galium mollugo, White Bedstraw The native Indians used Bedstraw roots (Galium mollugo) to obtain a red colour and the root of this plant is an important source of the dye alizarin. Galium odoratum, Sweet Woodruff Sweet Woodruff is similar to White Bedstraw and its roots can be used to produce a red/pink dye. It is the same family as Madder.

Apigenin

Matricaria recutita, German Chamomile This flavonoid, which occurs widely in plants gives a dull, golden yellow and is usually obtained from German Chamomile or Matricaria recutita. Apigenin and lutolin were more active than the other flavonoids tested. The spasomolytic activity of chamomile has been attributed to apigenin, apingenin-7-0-glucoside and (-) - bisabolol, which have activity similar to papaverine. Apigenin and lutolin were more active than the other flavonoids tested.
Calendula officinalis, Marigold It is also found in Marigold (Calendula officinalis), where it was shown, using the mouse ear test, that the flavonoids – and not the essential oil – were responsible for the activity and, of these, apigenin was more active than indomethacin in the test.
Artemisia inculta, Artemisia Artemisia (Artemisia inculta) also contains apigenin and in a recent study was demonstrated to have anti-inflammatory activity.
Cuminum cyminum, Cumin Cuminum cyminum or Cumin also contains apigenin and luteolin and their derivatives in addition to plants like Carrot (Daucus carota), Agrimony (Agrimonia eupatoria), Arnica (Arnica montana), Purple Coneflower (Echinacea purpurea) and Eyebright (Euphrasia officinalis) – all of which have demonstrated antiinflammatory activity when used under the right conditions. Yellow apigenin is also found in Parsley (Petroselinum crispum) and Celery (Apium graveolens).

Arbutin
Shepherdia canadensis, Canada Buffaloberry The Canada Buffaloberry (Shepherdia canadensis), also known as Canada Buffaloberry, Soopolallie, Soapberry or Foamberry, is one of a small number of shrubs of the genus Shepherdia bearing edible red berries. One recognised form, however, bears yellow fruits. The fruit produces a red dye, and it contains ericolin glucoside, and chimaphilin which is a yellow naphthoquinone.

Astacin
 Astacin is found in the shells of crabs and lobsters Homarus, algae, sponges and fish. Is practically insoluble in water.

Astaxanthin

Astaxanthin, a carotenoid, is classified as a xanthophyll (having yellow leaves).

 Azulene

Sadly, this wonderful blue (blue-black) no longer seems to be available commercially. Azulene is a prime component of the essential oil of chamomile flowers, Matricaria recutita L. and related plant species. Products containing azulene generally also contain the other characteristic components of chamomile’s essential oil. Azulene extracts are used in skin creams for reducing skin puffiness and wrinkles and are also known for their anti-irritant and vulnerary properties. It has never been clear whether the material was extracted from one of the chamomiles or from Myoporum crassifolium Forst or Vanillosmopsis erythropappa Schultz-Bip in which this material is also found. Maybe the source has become too scarce for there to be a reliable commercial supply.

Betalains and Betacyanins [Category]

Betanin Dried beet juice contains 0.2%-1.0% betanin and is most stable between pH 4.0-5.0. It is heat, oxygen and light labile. Beets give rust/red or pink colours, but fade with time. This colour occurs in the fruits of Phytolacca americana (Phytolaccaceae) and in Portulaca grandiflora (Portulacaceae). It is a purple pigment. Other places where it may be found are Carpobrotus acinaciformis, Drosanthemum floribundum, Mesembryanthemum spp., Opuntia bergeriana and other Opuntia spp. (Cactaceae).

Brazilein, Brazilin

 Caesalpinia echinata, Brazilwood The heartwood of American Brazilwood, Caesalpinia echinata, contains a water-soluble compound called Brazilin, which on oxidation transforms to a red dyestuff called Brazilein. As a mordanted dye the colours can range from purple to bright red depending on the chemicals used. In an acidic solution Brazilin will appear yellow, but in an alkaline preparation it will appear red. Brazilin is closely related to the blue-black dye haematoxylin, having one less hydroxyl group.

Canthaxanthin

This is a carotenoid that naturally occurs in fungi but is more usually produced by “nature identical” synthesis. It is also a component of Spirulina-Dunaliella algae. The colour can be yellow to an almost orange red. Canthaxanthin is a natural orange xanthophyll (E161a) isolated from some mushrooms, crustacea, fish and also flamingo feathers. It is used to enhance the colour of fish flesh, particularly trout and salmon. There is some evidence that prolonged ingestion of canthaxanthin in large amounts may cause spotting of the retina.

Capsanthin and Capsorubin

 Capsanthin and the related capsorubin are most commonly found in paprika or Capsicum annuum. It is rich in carotenoid pigments, including capsanthin, capsorubrin, carotene, luteine, zeaxanthin, and cucurbitaxanthin. As well as being a dyestuff, it is also used in cosmetics in ointments, oils and emulsions for its stimulating effect and as a sports massage.
Capsicum annuum, Capsicum It is also called Cayenne pepper, African Pepper, Chillies, Bird Pepper. It contains 0.1% capsaicin, capsacutin, capsico (a volatile alkaloid) together with fixed oils. Capsicum in the form of an alcoholic tincture is sometimes incorporated into hair lotions as a stimulant, particularly in preparations designed for alopecia. The pigments present in paprika are a mixture of carotenoids, in which capsanthin and capsorubin dominate. These are oilsoluble, are stable to heat and pH variation but may deteriorate in light. It is employed in preparations to prevent chilblains and is the purest and most certain stimulant in materia medica. It produces natural warmth and equalises the circulation. It is an important herbal remedy. It is used externally as a counterirritant, rubefacient and antiseptic. It is recommended for use in neuralgia, rheumatic pains, unbroken chilblains and is also used in cases of lumbago. Capsicum is especially useful for providing counter-irritation when applied to skin overlying an inflamed or irritated joint. Combined with myrrh it makes a good antiseptic wash.

Caramel

 Caramel colouring is produced by heat treatment of carbohydrates such as glucose syrup and sucrose, in the presence of ammonia, ammonium sulphate, sulphur dioxide or sodium hydroxide. The types of caramel colour available include plain (spirit) caramel (prepared by controlled heat treatment of carbohydrates with or without an acid or base), caustic sulphite caramel (produced by heat treatment of carbohydrates with sulphur containing compounds), ammonia caramel (heat treatment in the presence of ammonia) and sulphite ammonia caramel. Caramelised sugar or burnt sugar is formed by heating sugars without a catalyst.

 Carminic acid

Coccus cacti, Cochineal This extract is associated with the protein material of the cochineal beetle and gives red, yellow and orange colours depending on the products and pH. Coccus cacti or scale insects are insects that live and feed on the prickly pear cactus (Opuntia megacantha) of Mexico and Central America. They increase rapidly in size and lose their original shape until they appear as protuberances of the plant. The dried pulverised bodies of these insects yield the red dyestuff cochineal, which the Aztec Indians used as body paint and for dyeing their fabrics a brilliant crimson. They also used cochineal for medicinal purposes. It has been used as a pigment and as a colouring agent in cosmetics, paints and beverages, but it is expensive as it takes 70,000 insects to make one pound of dye. The homoeopathic tincture is prepared from the dried bodies of the female insects, which are larger than the male and have no wings. It is one of the main whooping cough remedies. In both India and Australia attempts have been made to take advantage of this for the production of cochineal, for purposes such as dyeing soldiers’ uniforms red. But chaos resulted. Either the insects fed so heartily that they wiped out the cacti; or the cacti multiplied so excessively that they became a real plague. This can be purified to yield carminic acid or reacted with alumina to produce the aluminium lake of carminic acid which is referred to as carmine. Carminic acid is a polyhydroxyanthraquinone acid or a red glucosidal hydroxyanthrapurin. It is water soluble, and acid stable yielding orange to red shades depending on the pH. Its aluminium lake, carmine, is soluble in alkaline media and is very stable in relation to heat, light and oxygen. In alkaline conditions carmine provides a blue-red shade which becomes progressively less blue as the pH is decreased. Under acidic conditions below pH 3 carmine becomes insoluble.

Carotenes [Category]

Carotenes are fat soluble and often synthetically produced natural pigments. The colours range from yellow to red. The pigment is sensitive to oxidation because of the conjugated double bonds and the molecule may be isomerised if involved in heat processing. There are a number of related chemicals:
w ?-Carotene (0.6 ?g = 1IU)
w ?-Apo-8’-Carotenal (0.83 ?g = 1IU)
w Canthaxanthin (No vitamin A activity)
w Bixin (Annatto extract) (No vitamin A activity)
w Lycopene (No vitamin A activity)

This is a group of yellow/orange colours extracted from such diverse sources as algae, carrots and palm oil. It is also available as a “nature identical” product. Crystalline ?-carotene is sensitive to air and light. Vegetable fat and oil solutions and suspensions are quite stable in products. The carotenoids – apart from the chlorophylls – are the largest group of oil soluble pigments found in nature. They consist of molecules with long chains made up of carbon, hydrogen and mostly oxygen (?-carotene consists of only carbon and hydrogen). One of the carotenoid’s characteristics is that the colour varies (according to the type of carotenoid) from yellow to red-orange. Carotenoids, like chlorophylls, exist in green plants. They are responsible for the yellow colour of flowers and the pigments of many fruits and vegetables such as carrots, paprika and tomato. The first discovery of the colour in carrots was the reason for the generic name of carotenoids. It is converted by mammals into vitamin A and as a result is called provitamin A. ?-carotene is one of the major yellow colours used in the food industry and the largest use is by the dairy industry (for butter, cheese and ice cream). The use of ?-carotene has almost entirely replaced E102 Tartrazine yellow, which for various reasons has received a bad press in recent years. ?-carotene is one of the popular free radical scavengers and antioxidants.

Carthamin

Carthamus tinctoria, Safflor Carthamin is found in the flowers of Carthamus tinctoria or Safflor (Bastard Saffron), Dyer’s Saffron, American Saffron, Fake Saffron, or Flores Carthami. It yields a pigment carthamin, which is a yelloworange colour. On closer examination it is shown to contain two colouring matters, one yellow the other red. Safflower (Carthamus tinctorius L.) was formerly used as a red dyestuff for textiles and is also currently used as a colorant by the food industry in small amounts. The florets contain three major pigments, all of which are present as chalcone glucosides: the scarlet red carthamin is water insoluble but the “safflor yellow” A and B or safflomin(e) A and B are both insoluble in water. The seeds yield an oil which is used in India for burning and for culinary use. The flowers are used for their laxative and diaphoretic properties, and also used for children’s complaints of measles, fevers and eruptive skin conditions. Apart from the seeds for oil and the flowers for dyeing, the Egyptians found the flower pleasing to the eye and included it in garlands placed on mummies. Remains of safflower were found in the tomb of Tutankhamun. The safflower florets are gathered just before they die off, and are used for dyeing wool, silk and leather. The flowers give a yellow dye, and the Chinese used an alkaline solution to produce the bright reds and purples for their silks. Also produced is a pink dye that was used by the Indians to dye their official red tape used on legal documents. Mixed with talc it was employed as rouge by actors. It was also the principal ingredient in Macassar Oil, the hair oil so very popular with the Victorian gentlemen. Certain oil paints are based on carthamin. Another little known fact is that it was used to impart a pink-red colour to the ribbon used to bind legal documents (and is still used to this day). Hence the expression “tied up in red tape”

Chimaphilin

 Chimaphilin is a yellow naphthoquinone found in Shepherdia canadensis (see arbutin) [Syn: Hippophae canadensis]. The fruit juice has been drunk in the treatment of digestive disorders and has also been applied externally in the treatment of acne and boils. The alternative name for the plant “soopolallie” is from the Chinook language for soap (soop) and berry (olallie) and the froth from the berries (which contain a natural saponin) or a jelly of the fruit, have been eaten as an insect repellent as it was said that mosquitoes were far less likely to bite a person who had eaten them.

Chlorophyll

Extracted from grass and alfalfa, this is present in all green plants and has always been a part of man’s diet. It gives moss green colour. It is naturally oil soluble, and is also found in green vegetables such as spinach or Spinacia oleracea and the common stinging nettle or Urtica dioica.

Copper chlorophyll

Derived from plants (as above) but gives a brighter more intense green colour due to the replacement of the naturally occurring magnesium in the chlorophyll by copper. It is naturally oil soluble. This is produced as the copper chlorophyll but a saponification process renders this form water soluble. The colour is a bright green to green/blue.

Chrysophanic acid

Chrysophanic acid was discovered by Schrader, in 1819, in Parmelia parietina, Linné, a common wall lichen. It was purified in 1843 by Rochleder and Heldt, who gave it the name chrysophanic acid, from its yellow colour and later Schlossberger and Dopping decided the colouring matter obtained from rhubarb was identical. This colouring matter had been known under the names of rheine, rheumine, rhabarberic acid, rhubarb yellow, etc. Chrysophanic acid is chiefly obtained from a vegetable powder, called Goa or Poh di Bahia, which is the product of some unknown Brazilian plant probably Andira araroba (Leguminosae) and also known as Araroba. The powder contains 70% to 80% of acid. Chrysophanic acid has been chiefly employed as a local application for certain cutaneous conditions, e.g. eczema, various herpes conditions, psoriasis, acne and rosacea, etc.
Rheum rhaponticum, Rhubarb Rhubarb roots makes yellow, orange or red shades and were sometimes used for dyeing hair. Rhubarb root has chrysophanic acid, a yellow dye, which will bind to keratin. Chrysophanic acid, as such, does not perhaps exist to any large extent in rhubarb, but is formed by the splitting up of chrysophane.

Citranaxanthin

This is a carotenoid pigment. There are natural sources of citranaxanthin, but it is generally prepared synthetically. It is used as an animal feed additive to impart a yellow colour to chicken fat and egg yolks.

??-Citraurin

?-citraurin from Citrus sinensis (Sweet Orange, Navel Orange) is a carotenoid pigment found in orange peel.

Crocetin

 Crocus sativus, Crocus It is also known CI Natural Yellow 6; CI 75100; Croci Stigma; Crocus; Safran. The dried stigmas and tops of the styles of the Crocus sativus contain crocines, crocetins and picrocrocine. They are delicate colours and should be protected from light. Saffron is used as a food and cosmetic dye and flavouring agent. In some circles it is considered to be a food. It was once widely used for colouring medicines. There have been early reports of poisoning with saffron. This may be because of confusion with Autumn Crocus (Colchicum autumnale). For years English saffron was the most highly esteemed (grown in Saffron Walden from about 1350), and most expensive, in Europe. Today, however, the best saffron comes from the barren plain of La Mancha in Spain. One kilogramme of plant yields about 460,000 stigmas. The colour is due to a pigment called crocin, so strong that 1 part crocin in a 100,000 parts of water is a deep golden colour. The flavour comes from a related compound called picrocrocin. Saffron also seems to contain a substance that helps blood to clot. It is as a water-soluble dye that saffron probably found most use. The colour is deep and rich, and most familiar today in the saffron robes of Buddhist monks. Folkloric uses of saffron have included its use as a sedative, expectorant, aphrodisiac and diaphoretic. Anecdotal reports from the tropical regions of Asia describe the use of a paste composed of sandalwood and saffron as a soothing balm for dry skin. The stigmas of Crocus sativus are rich in riboflavin, a yellow pigment and vitamins. In addition, saffron contains crocin, the major source of yellow-red pigment. An hypothetical protocrocin of the fresh plant is decomposed on drying into one molecule of crocin (a coloured glycoside) and two molecules of picrocrocin (a colourless bitter glycoside). Crocin is a mixture of glycosides: crocetin, a dicarboxylic terpene lipid, and alpha-crocin, a digentiobiose ester of crocetin. In addition, cis- and trans-crocetin dimethylesters have been identified. Similar compounds have been isolated from other members of the family. A compound named gardenidin, obtained from gardenias, has been shown to be identical with crocetin.

Crocin

Crocin extract is the trade term for the yellow, water-soluble food colourant obtained from cape jasmine (Gardenia jasminoides L.) and from red stigmas of saffron (Crocus sativus L.). However, the extracts are not used interchangeably in all applications since saffron is valued as much for its aroma and flavour as for its colouring properties. It is an expensive spice which may prohibit its commercial use as a natural colorant. Gardenia jasminoides, Gardenia A bright yellow colour that has been in use for over a thousand years. Extracted from the fruit of Gardenia jasminoides. Gardenia florida [possibly a synonym for G. jasminoides] also contains crocin and is prescribed as an antipyretic, haemostatic, and antiphlogistic, and in cases of jaundice. A paste of the herb with flour and wine is used as a poultice on twists, sprains, strains, bruises, and abscesses. It is very effective in cases of injury to tendons, ligaments, joints and muscles. Chinese medicine considers it to have antiinflammatory, antipyretic, astringent, and haemostatic functions as well as use in the treatment of mastitis. The main component of its yellow pigment is crocin, which is now generally used as a natural yellow pigment. It is also used for irritation, sore and swollen eyes and abscesses. Fructus gardeeniae is widely used in Chinese medicine. The fruits of Gardenia jasminoides also contain ursolic acid which possesses hypothermic, sedative and anticonvulsant characteristics. The attributes of this plant may, therefore, be in part due to the ursolic acid present. Gardenia Blue is derived from Gardenia jasminoides Ellis. Crocus sativus, Crocus The characteristic yellow-orange colour of saffron (Crocus sativus L.) comes from water-soluble pigment, the carotenoid crocin. Saffron carotenoids with ethanolextractable mostly contain safranal as an antibacterial, and were used in Persian traditional medicine to treat some skin disorders. The extracted carotenoids from saffron as an antioxidant prevent many common diseases by taming harmful molecules known as free radicals. Crocin is 8,8’-Diapo-?,?-carotenedioic acid bis (6-O-?-D-glucopyranosyl-?-Dglucopyranosyl) ester; ?-crocin; digentiobiose ester of crocetin. It is also the colouring principal of saffron and also occurs in crocus.

Cryptoxanthin

Cryptoxanthin is a xanthophyll (E161a) and is found naturally in members of the potato and tomato family, as well as in egg yolks and butter. It provides a natural yellow colour but is not available for commercial colouring use. Cryptoxanthin is also found in corn and strawberries

Curcumin

Curcumin provides a water soluble orange-yellow colour. It is a natural extract obtained by solvent extraction from the dried rhizomes of turmeric (used in Indian cuisine as a flavouring agent). Curcumin may be used to compensate for fading of natural colouring in pre-packed foods. It was recognised as an anticarcinogenic agent during laboratory tests. This is the pigment of the spice turmeric and will give a range of colour from yellow to a deep orange. This has been in use as a food ingredient for over 2,000 years. It also contains a closely related chemical called desmethoxycurcumin, where one of the methoxy groups is replaced with a hydrogen atom. Curcuma longa, Turmeric The rhizome of Curcuma longa has been used as a medicine, spice and colouring agent for thousands of years. Turmeric was listed in an Assyrian herbal reference work dating from about 600 BC and was also mentioned by Dioscorides. It has many medicinal properties including those of being an antioxidant and an anti-inflammatory. The anti-inflammatory activity of curcumin was first reported in 1971. In an extension of this work, it was reported that oral doses of curcumin possess significant anti-inflammatory action in both acute and chronic animal models. Curcumin was as potent as cortisone in the acute test (carrageenan oedema), but only about half as potent as phenylbutazone in chronic tests. The Negritoes of the Philippines utilise the fresh rhizome to treat recent wounds, bumps, bruises and leech bites. Mixed with gingelly oil (a localy produced oil), it is applied to the body to prevent further skin eruptions. Turmeric paste mixed with a little lime and saltpetre and applied hot is a popular application for sprains and bruises among other Filipino blacks. In smallpox and chickenpox, the Negritoes make a thin paste of turmeric powder and apply it to the entire body in order to prevent pock marks from occurring by facilitating the scabbing process. It is also used for ringworm. The blacks of Trinidad in the West Indies use turmeric rhizome poultices to reduce the swellings of sprains and pulled tendons, while the rhizome juice and oil is used for its antiseptic properties on various skin affections – i.e. razor bumps, herpes lesions and venereal sores. Among the dark races of India, turmeric has been used since time immemorial to treat skin problems. Both the Ayurvedic and the Unani practitioners have used a paste of powdered turmeric or its fresh juice made into a paste or a decoction of the whole plant as a local application in the treatment of leprosy and cobra bites. It is especially useful for indolent ulcers on the surface of the skin and gangrene in the flesh. A paste made from the powdered rhizomes along with caustic lime forms a soothing remedy for inflamed joints. Turmeric is also as an external application of “rouge” and is used by some women in India to suppress the unwelcome growth of facial hairs and upper lip moustaches. In Northern India the rhizome is used by many natives for treating cuts, burns and scalds. The natives of Samoa use the powdered rhizome to sprinkle on newborn infants to help heal a recently cut umbilical cord, to prevent nappy rash from occurring, and to keep the skin continually soft and resilient. The powder is also used as a paste or poultice to treat skin ulcers and to help heal extensive skin eruptions. In parts of Africa, turmeric has been successfully tested for healing rashes due to allergies and psoriasis inflammation and itching accompanying arthritis.

Datiscetin

This flavonoid has a yellow colour and is found in Bastard Hemp (Datisca cannabina).

 Delphinidin

 Delphinidin is an anthocyanidin that gives colours from red wine to brown

. Deoxyisosantalin, Deoxysantalin

The heartwood (camwood) and roots of Baphia nitida yield a red dye called Deoxyisosantalin that was used until recently to dye raffia and cotton textiles. The powdered heartwood is a used as a red body paint and the paste is used as a cosmetic for the skin. As a body paint it is considered to have magic powers. The leaves or leaf juice are applied against parasitic skin diseases. The leaves and bark are considered haemostatic and anti-inflammatory, and are used for healing sores and wounds. The powdered heartwood is made into an ointment with shea butter which is applied against stiff and swollen joints, sprains and rheumatic complaints.

Flavoxanthin

Flavoxanthin is a xanthophyll, providing a natural yellow colour. Xanthophylls are mixtures of hydroxy derivatives of alpha-, beta- and gamma-carotenes, their natural epoxides and fatty acid esters.

Fumigatin

Fumigatin is isolated from Aspergillus fumigatus (a brown fungal toxin with antibiotic properties).

Fustin

Fustin is closely related to morin and these two flavones are found in the wood from Chlorophora tinctoria and Morinda citrifolia (Indian Mulberry) whose pigments are mixtures of yellow to orange flavones similar in structure to fustin and morin. It is called maclurin which has long been used as a yellowish-brown or khaki dye.

Genistein

Genistein is one of several known isoflavones. Isoflavones, such as genistein and daidzein, are found in a number of plants, with soybeans and soy products like tofu. Genistein functions as an antioxidant and many isoflavones have been shown to interact with oestrogen receptors and cause an effect in the body similar to those caused by the hormone oestrogen. It is a protein tyrosinase kinase inhibitor. Both the oestrogenic effect and the inhibition of kinases positively influence skin collagen content which is good for anti-ageing products. In adipose tissue it produces a lipolytic activity and is so useful in the treatment of cellulite. Genista tinctoria, Dyer’s Greenweed Genistein is a yellow dye contained as the glucoside genistin in Dyer’s Greenweed, Genista tinctoria. An infusion is used against rheumatism, arthritis, dropsy and chronic skin disorders. In the past the flowers were used for dyeing fabrics.

Gentisin

Gentisin is a yellow flavone found in the roots of Genista tinctoria, Dyer’s Greenweed.

Acknowledgement I would like to thank Union Swiss in South Africa for its valued sponsorship of the oil soluble colour research.

Reference 1 International Journal of Cosmetic Science 24, 5, 287-302, (2002). Natural ingredients for colouring and styling.