Stereoselective biosynthesis of chloroarylpropane diols by the basidiomycete Bjerkandera adusta.
Previously we have shown that 1-arylpropane-1,2-diols are catabolic products of L-phenylalanine during idiophasic metabolism of B. adusta that are stereoselectively biosynthesized from a C(7)-unit (ring+benzylic carbon) and a C(2)-unit as predominantly erythro 1R, 2S enantiomers.In order to probe the mechanism of 1-arylpropane-1,2-diol formation, the products of the incubation of isotopically labelled aromatic aldehydes as substrates with Bjerkandera adusta (DAOM 215869) have been characterized. The aromatic aldehydes were benzaldehyde (ring D(5)) and 4-methoxy- and 4-hydroxybenzaldehydes (ring 13C(6)). These aldehydes were all stereoselectively incorporated into the corresponding 1-arylpropane-1,2-diols, including the chloro analogues, as well as into the corresponding alpha-ketols (phenyl acetyl carbinols (PAC's) and 2-hydroxy propiophenones (2-HPP's)) the presumed precursors of the diols. Benzoic acid (ring D(5)) was likewise incorporated into the diols, chlorodiols and alpha-ketols. These results lead us to conclude that the aromatic aldehydes benzaldehyde, 4-hydroxybenzaldehyde and 4-methoxybenzaldehyde are likely C(7)-unit precursors in the carboligation reaction(s) that leads to 1-arylpropane-1,2-diol biosynthesis. The metabolic role of the diols remains to be elucidated but they may be important intermediates in CAM (chlorinated anisyl metabolite) aldehyde-alcohol cycling and also act as substrates for the chlorination/hydroxylation enzymes yet to be identified in white rot fungi.
Silk
P J
PJ
Department of Chemical and Biotechnical Services, Research and Productivity Council, 921 College Hill Road, Fredericton, New Brunswick, Canada E3B 6Z9. psilk@rpc.unb.ca
Macaulay
J B
JB
D000107:Acetylation; D000438:Alcohols / Q000737:chemistry / Q000378:metabolism*; D001487:Basidiomycota / Q000378:metabolism*; D001547:Benzaldehydes / Q000737:chemistry / Q000378:metabolism; D002247:Carbon Isotopes; D003903:Deuterium; D006841:Hydrocarbons, Aromatic / Q000737:chemistry / Q000378:metabolism*; D006843:Hydrocarbons, Chlorinated / Q000378:metabolism*; D007651:Keto Acids / Q000737:chemistry / Q000378:metabolism; D011407:Propane / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization; D013237:Stereoisomerism
D000438:Alcohols; D001547:Benzaldehydes; D002247:Carbon Isotopes; D006841:Hydrocarbons, Aromatic; D006843:Hydrocarbons, Chlorinated; D007651:Keto Acids; D003903:Deuterium; D011407:Propane