Haematoxylon campechianum hematoxylin from

Other important natural dyes are obtained from the heartwood of several species of leguminous trees. Logwood Haematoxylon campechianum) is a small, thorny tree native to Central America that is an important source of a dye known as hematoxylin, which has a deep, purple-red color, and can also be manufactured into a persistent black dye. The brazilette H. brasiletto) is a source of a natural red dye as are brazilwood Caesalpina brasiliensis) and sappanwood (C. sappan) of south Asia. 

From the extract of the heartwood of Haematoxylon campechianum L. (Leguminosae), a sweet principle was isolated, namely, (+)-hematoxylin (82) [100]. This compound has been used for a long time as a microscopic staining reagent, but the sweetness of this compound was not recognized previously. Also, in the same study, brazilin, the 4-deoxy derivative of (+)-hematoxylin, and a constituent of Caesalpinia echinata Lam. (Leguminosae), was found not to be sweet [100]. In a follow-up study. 

Brazilin and hematoxylin were first isolated a long time ago from the heart wood of Caesalpinia spp. and Haematoxylon campechianum L. (Leguminosae) respectively. Aqueous plant extracts have been widely used as mordant dyes especially on silk and furs (63). The extract of the Mexican species H. braziletto was found to exhibit antibacterial activity (59). It was assumed that these compounds belong to the class of the neoflavonoids (20, 31). 

Logwood (Haematoxylon campechianum, Leguminosae) of tropical America was exported from about the middle of the 16th century. Subsequently, the wood extracts were also exported. In the latter half of the 19th century, the annual exports of the wood exceeded 100,000 tons. The major component of the extractives, namely hematoxylin, when oxidized, forms the dye hematin, which produces blue to black colors depending on the mordant of iron or copper salts or potassium dichromate. 

Logwood extract—A reddish brown-to-black solid material extracted from the heart-wood of the leguminous tree Haematoxylon campechianum. The active colorant substance is principally hematein. The latent coloring material is the unoxidized or leuco form of hematein called hematoxylin. The leuco form is oxidized by air. 

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See also in sourсe #XX -- [ ]

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