{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T14:38:24Z","timestamp":1781102304554,"version":"3.54.1"},"reference-count":0,"publisher":"National Academy of Sciences","issue":"8","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[1974,8]]},"abstract":"<jats:p>\n                    A novel ansamycin, rifamycin W, was isolated from a mutant strain of\n                    <jats:italic>Nocardia mediterranei<\/jats:italic>\n                    . The metabolic origin of rifamycin W was studied by\n                    <jats:sup>13<\/jats:sup>\n                    C nuclear magnetic resonance spectroscopy. Examination of the proton-decoupled pulse and Fourier transform\n                    <jats:sup>13<\/jats:sup>\n                    C spectra of rifamycin W biogenetically enriched with [\n                    <jats:italic>1<\/jats:italic>\n                    -\n                    <jats:sup>13<\/jats:sup>\n                    C]-, [\n                    <jats:italic>2<\/jats:italic>\n                    -\n                    <jats:sup>13<\/jats:sup>\n                    C]-, and [\n                    <jats:italic>3<\/jats:italic>\n                    -\n                    <jats:sup>13<\/jats:sup>\n                    C]propionate and with [\n                    <jats:italic>1<\/jats:italic>\n                    -\n                    <jats:sup>13<\/jats:sup>\n                    C]acetate has revealed that the alignment of\n                    <jats:italic>acetate<\/jats:italic>\n                    and\n                    <jats:italic>propionate<\/jats:italic>\n                    units corresponds to that previously proposed for rifamycin S. Washed mycelium from a rifamycin B-producing strain of\n                    <jats:italic>N. mediterranei<\/jats:italic>\n                    transformed rifamycin W into rifamycin B. We suggest that rifamycin W is a normal intermediate in the biosynthesis of the other rifamycins. These results, together with the structural similarity of rifamycin W to the streptovaricins, reinforce our hypothesis that a common progenitor is involved in the biogenesis of all naphthalenic ansamycins.\n                  <\/jats:p>","DOI":"10.1073\/pnas.71.8.3260","type":"journal-article","created":{"date-parts":[[2006,5,31]],"date-time":"2006-05-31T02:59:12Z","timestamp":1149044352000},"page":"3260-3264","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":42,"title":["Ansamycin Biogenesis: Studies on a Novel Rifamycin Isolated from a Mutant Strain of\n                    <i>Nocardia mediterranei<\/i>"],"prefix":"10.1073","volume":"71","author":[{"given":"Richard J.","family":"White","sequence":"first","affiliation":[{"name":"Research Laboratories, Gruppo Lepetit S.p.A., via Durando, 38, 20158 Milano, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Edoardo","family":"Martinelli","sequence":"additional","affiliation":[{"name":"Research Laboratories, Gruppo Lepetit S.p.A., via Durando, 38, 20158 Milano, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Giancarlo","family":"Lancini","sequence":"additional","affiliation":[{"name":"Research Laboratories, Gruppo Lepetit S.p.A., via Durando, 38, 20158 Milano, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[1974,8]]},"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.71.8.3260","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,4,13]],"date-time":"2022-04-13T10:22:37Z","timestamp":1649845357000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.71.8.3260"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1974,8]]},"references-count":0,"journal-issue":{"issue":"8","published-print":{"date-parts":[[1974,8]]}},"alternative-id":["10.1073\/pnas.71.8.3260"],"URL":"https:\/\/doi.org\/10.1073\/pnas.71.8.3260","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[1974,8]]},"assertion":[{"value":"1974-08-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}