Rosewood

Trade name for various precious wood species of trees of the genus Dalbergien (Dalbergia) from the subfamily of the papilionaceous plants. Rosewood species:

• Rio Rosewood (also Brazilian Rosewood or Dalbergia nigra). In use for high-quality furniture; also as raw material for musical instruments (!).
• East Indian Rosewood (Dalbergia latifolia) is sold under the name Sonokeling.
• Sheesham (Dalbergia sissoo) is currently cultivated in plantations mainly in Pakistan.
• Honduras rosewood "(Dalbergia stevensonii)" is native to Central America.

Wood species of the genus Dalbergia have long been known for their sensitizing (contact allergic) properties. Since many trade names have only the character of a fantasy name, a botanical determination of the wood species is essential. Sensitization is mainly caused by wood dusts in the wood-processing industry, less frequently however also by intensive skin contact with the wood species concerned (e.g. costume jewelry, musical instruments, wooden shoes). Type IV sensitization is basically caused by the ingredients of the heartwood. These are alkaloids, glycosides, saponins, flavonoids and phenol derivatives. Also benzoquinone, naphthoquinone, furanoquinone, phenanthrenequinone. The following substances have been identified as contact allergens:

• Obtusachinone (test concentration: 1%)
• 4-methoxy dalbergion (test concentration: 1%)
• 4-Hydroxy-4-methoxydalbergion (test concentration: 1%)
• 4,4-dimethyloxyalbergion (test concentration: 1%)

Ethanol extracts of the respective wood can also be prepared and, depending on the type of wood, 1%-10% dilutions can be tested.

1. Viardot-Helmer A et al (2008) Late type sensitization against East Indian rosewood. Dermatologist 59: 465-466