Metabolites of Aspergillus versicolor

dc.contributor.authorChen, Paul Ning-Chuanen
dc.contributor.departmentChemistryen
dc.contributor.departmentChemistryen
dc.date.accessioned2019-01-31T19:03:58Zen
dc.date.available2019-01-31T19:03:58Zen
dc.date.issued1977en
dc.description.abstractSystematic fractionations of crude extracts from various strains of Aspergillus versicolor were carried out by a combination of techniques, including liquid-liquid partition, column chromatography and thin-layer chromatography. As a result of these fractionations a total of eleven metabolites were obtained in pure form. Ten of these were identified as the known compounds, sterigmatocystin, de-0-methylsterigmatocystin, 5-methoxysterigmatocystin, versicolorin A, versicolorin C, aversin, averufin, griseofulvin, dechlorogriseofulvin and 3,8- dihydroxy-6 -methoxy-1-methylxanthone. A new metabolite was isolated and identified as 6,8-di-O-methylnidurufin. Two high-performance liquid chromatography systems were developed for the analysis of these metabolites, using microparticle silica gel and microparticle polar bonded phase columns. Studies were also carried out on the reduction of the hemi-acetal derivatives of sterigmatocystin and versicolorin A. Reduction with a limited amount of sodium borohydride yielded in each case a mixture of two major products. The fully reduced products were identified as diols, while the partially reduced products were found to be new hemiacetals. The structure elucidation of these compounds was carried out with the aid of carbon magnetic resonance spectroscopy and of chemical conversions. A modified pathway for the biosynthesis of versicolorin A from averufin is proposed that incorporates nidurufin as an intermediate.en
dc.description.degreePh. D.en
dc.format.extentxi, 159, [2] leavesen
dc.format.mimetypeapplication/pdfen
dc.identifier.urihttp://hdl.handle.net/10919/87334en
dc.language.isoen_USen
dc.publisherVirginia Polytechnic Institute and State Universityen
dc.relation.isformatofOCLC# 21425685en
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subject.lccLD5655.V856 1977.C47en
dc.subject.lcshAspergillusen
dc.subject.lcshMicrobial metabolitesen
dc.titleMetabolites of Aspergillus versicoloren
dc.typeDissertationen
dc.type.dcmitypeTexten
thesis.degree.disciplineChemistryen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en

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