Hc. Beck, BIOSYNTHETIC-PATHWAY FOR HALOGENATED METHOXYBENZALDEHYDES IN THE WHITE-ROT FUNGUS BJERKANDERA-ADUSTA, FEMS microbiology letters, 149(2), 1997, pp. 233-238
Through experiments with fluoro-labelled phenylalanine, tyrosine and b
enzaldehyde, the biochemical pathway leading to the chlorinated methox
ybenzaldehydes in the white rot fungus Bjerkandera adusta has now been
verified. Cultures of this organism supplied with fluoro-labelled phe
nylalanine, tyrosine or benzaldehyde showed a bioconversion of these c
ompounds into fluoro-4-methoxybenzaldehyde, fluoro-3-chloro-4-methoxyb
enzaldehyde and fluoro-3,5-dichloro-4-methoxybenzaldehyde In addition
fluoro-phenylalanine also yielded fluorobenzaldehyde. FIuorodichlorina
ted compounds were only detected in cultures supplied with ortho subst
ituted fluoro-phenylalanine demonstrating a meta specific halogenation
mechanism. These results are the first to give direct;evidence of the
involvement of both tyrosine and phenylalanine in the biosynthetic pa
thway of chloromethoxy substituted benzaldehydes in B. adusta and sugg
est a pathway for the biosynthesis of 3-chloro-4-methoxybenzaldehyde a
nd 3,5-dichloro-4-methoxybenzaldehyde that proceeds either via phenyla
lanine through benzaldehyde and 4-methoxybenzaldehyde or via tyrosine
through 4-methoxybenzaldehyde.