{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,29]],"date-time":"2026-03-29T11:44:03Z","timestamp":1774784643153,"version":"3.50.1"},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"1","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1980,10,15]]},"abstract":"<jats:p>Substituted muconic acids were prepared from the corresponding catechols by pyrocatechase II from Pseudomonas sp. B13. The stabilities of substituted muconic acids were compared under different pH conditions. 3-Substituted cis, cis-muconic acids cycloisomerized readily in slightly acidic solutions, whereas 2-chloro- and 2-fluoro-cis, cis-muconic acids were stable under these conditions and could be isolated as crystalline compounds. They were isomerized to the cis, trans-form in highly acidic solution (pH 1), particularly when heated to 80 degrees C. Cycloisomerization of 2-chloro-cis, cis-muconic acid in 75% (v\/v) H2SO4 yields 4-carboxymethyl-2-chloro-but-2-en-4-olide (4-chloro-2,5-dihydro-5-oxo-3H-furan-2-ylacetic acid). THe cis, cis-configuration of 2-chloromuconic acid was certified by 1H n.m.r. spectroscopy and by enzymic cycloisomerization. Although the cis, cis-configuration of 2-fluoromuconic acid was confirmed by corresponding spectroscopic data, it was not cycloisomerized by crude extracts or cycloisomerase II preparations from Pseudomonas sp. B13.<\/jats:p>","DOI":"10.1042\/bj1920331","type":"journal-article","created":{"date-parts":[[2015,8,10]],"date-time":"2015-08-10T20:25:40Z","timestamp":1439238340000},"page":"331-337","update-policy":"https:\/\/doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":81,"title":["Chemical structure and biodegradability of halogenated aromatic compounds. Halogenated muconic acids as intermediates"],"prefix":"10.1042","volume":"192","author":[{"given":"E","family":"Schmidt","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"G","family":"Remberg","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"H J","family":"Knackmuss","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"288","container-title":["Biochemical Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/192\/1\/331\/575994\/bj1920331.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/192\/1\/331\/575994\/bj1920331.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,25]],"date-time":"2021-11-25T14:11:13Z","timestamp":1637849473000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/192\/1\/331\/17745\/Chemical-structure-and-biodegradability-of"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1980,10,15]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1980,10,15]]}},"URL":"https:\/\/doi.org\/10.1042\/bj1920331","relation":{},"ISSN":["0264-6021"],"issn-type":[{"value":"0264-6021","type":"print"}],"subject":[],"published":{"date-parts":[[1980,10,15]]}}}