Contact allergy to Australian blackwood (Acacia melanoxylon R.Br.): isolation and identification of new hydroxyflavan sensitizers.
Australian blackwood is known to be an important cause of allergic contact dermatitis in Australia. Previous investigations have shown that 2,6-dimethoxy-1,4-benzoquinone and acamelin are 2 of the responsible, but weak, sensitizers. When these 2 quinones are lacking, which is occasionally found, the wood still possesses allergenic properties. The present re-examination led to the isolation and identification of 4 hydroxyflavans, of which 3 proved to be allergens. Melacacidin, known to be the main constituent of these flavan derivatives in the heartwood, was isolated and its sensitizing capacity in guinea pigs determined. It showed a moderate sensitizing power. Melacacidin occurs abundantly in 125 Australian and 3 African Acacia species.
Hausen
B M
BM
Department of Dermatology, University Hospital Hamburg, FRG.
Bruhn
G
G
Tilsley
D A
DA
D000045:Acacia; D000485:Allergens / Q000009:adverse effects*; D000818:Animals; D001315:Australia; D003877:Dermatitis, Contact / Q000209:etiology*; D009783:Dermatitis, Occupational / Q000209:etiology*; D005419:Flavonoids / Q000302:isolation & purification*; D006168:Guinea Pigs; D006801:Humans; D011809:Quinones / Q000009:adverse effects; D014197:Trees
D000485:Allergens; D005419:Flavonoids; D011809:Quinones; C065727:melacacidin