Plant compounds that are widely used and are associated with plant defence mechanisms.
About 12% of birch pollen allergy sufferers produce IgE antibodies against a 34.2kDa secondary birch pollen allergen Bet v 6 (formerly Bet v 5), which belongs to the group of phenylcoumarin-benzylether-reductase homologues. Bet v 6 is highly IgE cross-reactive with pyr c 5 from pears.
Analogous phenylcoumarin-benzylether reductase homologues are found in apple, strawberry, carrot, zucchini, peach, lychee, orange and others.
The tertiary structure of phenylcoumarin-benzylether reductases is still unknown.