Metabolic pathways of quinoline, indole and their methylated analogs by Desulfobacterium indolicum (DSM 3383) |
| |
Authors: | S S Johansen D Licht E Arvin H Mosbæk A B Hansen |
| |
Institution: | (1) Department of Environmental Science and Engineering, Technical University of Denmark, Building 115, DK-2800 Lyngby, Denmark, DK;(2) Department of Environmental Chemistry, National Environmental Research Institute, Frederiksborgvej 399, DK-4000 Roskilde, Denmark, DK |
| |
Abstract: | The transformation of quinoline, isoquinoline and 3-, 4-, 6- and 8-methylquinoline by Desulfobacterium indolicum was compared with that of the N-containing analogues indole and 1-, 2-, 3- and 7-methylindole. The metabolites were identified
using high-performance liquid chromatography with UV detection, thin-layer chromatography, combined gas chromatography/mass
spectrometry and proton NMR spectroscopy. All degraded compounds were initially hydroxylated at position 2 by D. indolicum. A new degradation product of quinoline was observed in the second transformation step, where 3,4-dihydro-2-quinolinone accumulated.
This ring-reduced compound was further transformed into unidentified products. The transformation pathway of indole was characterized
by well-known steps through oxindole, isatin, and anthranilic acid. No further transformation of the hydroxylated methyl analogues:
3- and 7-methyloxindole and 3- and 4-methyl-2-quinolinone, was observed within 162 days of incubation. These degradation products
accumulated in stoichiometric amounts, while 6- and 8-methyl-2-quinolinone were further degraded to 6- and 8-methyl-3,4-dihydro-2-quinolinone
in stoichiometric amounts. Isoquinoline, 2-methylquinoline and 1- and 2-methylindole were not degraded by D. indolicum. These observations indicate that a methyl group at or close to position 2 results in blockage of the microbial attack, and
that transformation of hydroxyquinolines methylated at the heterocyclic ring also was blocked or sterically inhibited. An
incomplete transformation of some methylated compounds was observed, e.g. for 3- and 6-methylquinoline and 3- and 7-methylindole,
with residual concentrations of 0.5–4 mg/l in relation to initial concentrations of 10–15 mg/l.
Received: 23 July 1996 / Received revision: 4 October 1996 / Accepted: 25 October 1996 |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|