title: Degradation of dioxins by cyclic ether degrading fungus, Cordyceps sinensis.
abstract: Use of the cyclic ether degrading fungus, Cordyceps sinensis strain A to degrade dibenzo-p-dioxin (DD), 2,3,7-trichlorodibenzo-p-dioxin (2,3,7-triCDD) and octachlorodibenzo-p-dioxin (octaCDD) has revealed a new degradation pathway for dioxins. Catechols and other possible degradation products were synthesized to facilitate the identification, detection and quantification of these products, and phenylboronate was used for the derivatization and analysis of dihydroxylated degradation products. Degradation of DD yielded catechol, which was further metabolized to cis,cis-muconate. 2,3,7-triCDD yielded mono- and dichloro-catechol as well as catechol itself; and the cis,cis-muconates were also detected. octaCDD gave mono- to trichloro-catechol as well as catechol, and the cis,cis-muconates were also found. For all tested dioxin samples dechlorination resulted in replacement of chlorine with hydrogen, and no hydroxylation was observed. It appeared that dechlorination may occur in the degradation of octaCDD to catechols and possibly in the subsequent degradation of chlorinated catechols and/or chlorinated cis,cis-muconates to further breakdown products.
authors.affiliation: Endocrine Disrupters and Dioxins Research Project, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan. nakamiya.kunichika@nies.go.jp
authors.forename: Kunichika
authors.initials: K
authors.lastname: Nakamiya
authors.forename: Shyunji
authors.initials: S
authors.lastname: Hashimoto
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Ito
authors.forename: John S
authors.initials: JS
authors.lastname: Edmonds
authors.forename: Akio
authors.initials: A
authors.lastname: Yasuhara
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Morita
mesh_terms: D002396:Catechols; D032661:Cordyceps / Q000254:growth & development / Q000378:metabolism*; D004147:Dioxins / Q000378:metabolism*; D004988:Ethers, Cyclic / Q000378:metabolism; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism
chemical_list: D002396:Catechols; D004147:Dioxins; D004988:Ethers, Cyclic; D000072317:Polychlorinated Dibenzodioxins; C034221:catechol