Rubia is a genus of flowering plants in the family Rubiaceae. It contains around 80 species of perennial scrambling or climbing herbs and subshrubs native to the Old World. The genus and its best-known species are commonly known as madder, e.g. Rubia tinctorum, Rubia peregrina, and Rubia cordifolia.
Alizarin is an organic compound with formula C
14H
8O
4 that has been used throughout history as a prominent red dye, principally for dyeing textile fabrics. Historically it was derived from the roots of plants of the madder genus. In 1869, it became the first natural dye to be produced synthetically.
Carl Gräbe was a German industrial and academic chemist from Frankfurt am Main who held professorships in his field at Leipzig, Königsberg, and Geneva. He is known for the first synthesis of the economically important dye, alizarin, with Liebermann, and for contributing to the fundamental nomenclature of organic chemistry.
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". The archetypical member of the class is 1,4-benzoquinone or cyclohexadienedione, often called simply "quinone". Other important examples are 1,2-benzoquinone (ortho-quinone), 1,4-naphthoquinone and 9,10-anthraquinone.
A lake pigment is a pigment made by precipitating a dye with an inert binder, or "mordant", usually a metallic salt. Unlike vermilion, ultramarine, and other pigments made from ground minerals, lake pigments are organic. Manufacturers and suppliers to artists and industry frequently omit the lake designation in the name. Many lake pigments are fugitive because the dyes involved are not lightfast. Red lakes were particularly important in Renaissance and Baroque paintings; they were often used as translucent glazes to portray the colors of rich fabrics and draperies.
A glucoside is a glycoside that is derived from glucose. Glucosides are common in plants, but rare in animals. Glucose is produced when a glucoside is hydrolysed by purely chemical means, or decomposed by fermentation or enzymes.
Henry Edward Schunck, also known as Edward von Schunck, was a British chemist who did much work with dyes.
Rose madder is a red paint made from the pigment madder lake, a traditional lake pigment extracted from the common madder plant Rubia tinctorum.
Pierre Jean Robiquet was a French chemist. He laid founding work in identifying amino acids, the fundamental building blocks of proteins. He did this through recognizing the first of them, asparagine, in 1806, in the industry's adoption of industrial dyes, with the identification of alizarin in 1826, and in the emergence of modern medications, through the identification of codeine in 1832, a opiate alkaloid substance of widespread use with analgesic and antidiarrheal properties.
Rubia cordifolia, often known as common madder or Indian madder, is a species of flowering plant in the coffee family, Rubiaceae. It has been cultivated for a red pigment derived from roots.
Carl Theodore Liebermann was a German chemist and student of Adolf von Baeyer.
A trihydroxyanthraquinone or trihydroxyanthracenedione is any of several isomeric organic compounds with formula C
14H
8O
5, formally derived from anthraquinone by replacing three hydrogen atoms by hydroxyl groups. They include several historically important dyes. The isomers may differ in the parent anthraquinone isomer and/or of the three hydroxyl groups.
1,3-Dihydroxyanthraquinone, also called purpuroxanthin or xanthopurpurin, is an organic compound with formula C
14H
8O
4 that occurs in the plant Rubia cordifolia. It is one of ten dihydroxyanthraquinone isomers. Its molecular structure can be viewed as being derived from anthraquinone by replacement of two hydrogen atoms (H) by hydroxyl groups (-OH).
1,4-Dihydroxyanthraquinone, also called quinizarin or Solvent Orange 86, is an organic compound derived from anthroquinone. Quinizarin is an orange or red-brown crystalline powder. It is formally derived from anthraquinone by replacement of two hydrogen atoms by hydroxyl (OH) groups. It is one of ten dihydroxyanthraquinone isomers and occurs in small amounts in the root of the madder plant, Rubia tinctorum.
Rubia tinctorum, the rose madder or common madder or dyer's madder, is a herbaceous perennial plant species belonging to the family Rubiaceae. The plant's roots yield a red dye that was widely used for thousands of years for dyeing cloth.
Anthraquinone dyes are an abundant group of dyes comprising a anthraquinone unit as the shared structural element. Anthraquinone itself is colourless, but red to blue dyes are obtained by introducing electron donor groups such as hydroxy or amino groups in the 1-, 4-, 5- or 8-position. Anthraquinone dyestuffs are structurally related to indigo dyestuffs and are classified together with these in the group of carbonyl dyes.
Dyeing is the craft of imparting colors to textiles in loose fiber, yarn, cloth or garment form by treatment with a dye. Archaeologists have found evidence of textile dyeing with natural dyes dating back to the Neolithic period. In China, dyeing with plants, barks and insects has been traced back more than 5,000 years. Natural insect dyes such as Tyrian purple and kermes and plant-based dyes such as woad, indigo and madder were important elements of the economies of Asia and Europe until the discovery of man-made synthetic dyes in the mid-19th century. Synthetic dyes quickly superseded natural dyes for the large-scale commercial textile production enabled by the industrial revolution, but natural dyes remained in use by traditional cultures around the world.
Alizarin Red S is a water-soluble sodium salt of Alizarin sulfonic acid with a chemical formula of C
14H
7NaO
7S. Alizarin Red S was discovered by Graebe and Libermann in 1871. In the field of histology alizarin Red S is used to stain calcium deposits in tissues, and in geology to stain and differentiate carbonate minerals.
A colorant is any substance that changes the spectral transmittance or reflectance of a material. Synthetic colorants are those created in a laboratory or industrial setting. The production and improvement of colorants was a driver of the early synthetic chemical industry, in fact many of today's largest chemical producers started as dye-works in the late 19th or early 20th centuries, including Bayer AG(1863). Synthetics are extremely attractive for industrial and aesthetic purposes as they have they often achieve higher intensity and color fastness than comparable natural pigments and dyes used since ancient times. Market viable large scale production of dyes occurred nearly simultaneously in the early major producing countries Britain (1857), France (1858), Germany (1858), and Switzerland (1859), and expansion of associated chemical industries followed. The mid-nineteenth century through WWII saw an incredible expansion of the variety and scale of manufacture of synthetic colorants. Synthetic colorants quickly became ubiquitous in everyday life, from clothing to food. This stems from the invention of industrial research and development laboratories in the 1870s, and the new awareness of empirical chemical formulas as targets for synthesis by academic chemists. The dye industry became one of the first instances where directed scientific research lead to new products, and the first where this occurred regularly.
This article explains the history of the color red.
