Atropine is a tropane alkaloid plant natural product. It is used medically as an anti-arrhythmic drug, broncodilator, pupil dilator, and muscarinic antagonist (PubChem, 2011).
Pseudomonas sp. AT3 can grow on atropine as its sole carbon and nitrogen source. The initial step in the degradation is hydrolysis of the atropine ester bond to form tropine and tropate. Tropine is converted to nortropine, which is degraded through oxidative cleavage of the bridging N-C bonds to 6-hydroxycyclohepta-1,4-dione. This is oxidized to cyclohepta-1,3,5-trione. This latter compound is hydrolytically cleaved to 4,6-dioxoheptanoate, which is hydrolyzed to succinate and acetone (Bartholomew et al., 1996). Tropate is oxidized to phenylacetate through phenylmalonate semialdehyde (proposed) and phenylacetaldehyde (Long et al., 1997). Pseudomonas putida L can convert tropate to phenylacetate, possibly by the same mechanism (Stevens and Rörsch, 1971).
The following is a text-format atropine pathway map. An organism which can initiate the pathway is given, but other organisms may also carry out later steps. Follow the links for more information on compounds or reactions. This map is also available in graphic (10k) format.
Atropine Pseudomonas sp. AT3 | | | tropinesterase | | v Tropine + Tropate ---------------------+ | | | | | tropine | tropate | dehydrogenase | dehydrogenase | | v v Nortropine [Phenylmalonate] | [semialdehyde] | | v A | | | | | v v 6-Hydroxycyclo- Phenylacetaldehyde hepta-1,4-dione | | | | 6-hydroxycyclo- | phenylacetaldehyde | hepta-1,4-dione | dehydrogenase | dehydrogenase | v v Cyclohepta-1,3,5-trione Phenylacetate | | | | | cyclohepta-1,3,5-trione | | hydrolase v | to the v Phenylacetate 4,6-Dioxoheptanoate Pathway | | | 4,6-dioxoheptanoate | hydrolase | v Succinate + Acetone | | | | | | v v Intermediary Intermediary Metabolism Metabolism (KEGG) (KEGG)
Page Author(s): Lynda Ellis
April 17, 2013 Contact Us
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