Dehydroabietic acid (DHA) (
1) is one of the main compounds in Scots pine wood responsible for aquatic and microbialtoxicity. The degradation of
1 by
Trametes versicolor and
Phlebiopsis gigantea in liquid stationary cultures was followedby HPLC-DAD-ELSD. Both fungi rapidly degraded DHA relative to a control. More breakdown products were observedfor
T. versicolor than for
P. gigantea. After 13 days, four compounds were identified by means of spectroscopic methodsin
P. gigantea cultures: 1
-hydroxy-DHA (
2), 1
,7
-dihydroxy-DHA (
3), 1
,16-dihydroxy-DHA (
5), and tentatively1
-hydroxy-7-oxo-DHA (
4). In
T. versicolor cultures, 1
,16-dihydroxy-DHA (
5), 7
,16-dihydroxy-DHA (
6), 1
,7
,16-trihydroxy-DHA (
7), 1
,16-dihydroxy-7-oxo-DHA (
8), 1
,15-dihydroxy-DHA (
9), and 1
,7
,16-trihydroxy-DHA (
10)were identified after 9 days of incubation. Thus the biotransformation of
1 by the two fungi was different, with only
5being produced by both strains. Compounds
3,
7,
8, and
10 are reported for the first time as natural products.