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Sherwin, Paul Frederick 2014-12-15T23:17:50Z 2014-12-15T23:17:50Z 10000-01-01 1982 1982 The mixed function oxidase (MFO) catalyzed C19 hydroxylations of ent-kaur-16-ene (1) and of ent-kaur-16-en-19-ol (2) precede a complex cascade of enzyme catalyzed reactions leading to the plant growth regulator gibberellic acid. The stereochemistry and deuterium isotope effects (k(,H)/k(,D)) of these two oxidations were studied using stereospecifically labelled derivatives of 1 and 2 and microsomal enzyme extracts of Marah macrocarpus (wild cucumber) as the MFO source. The intramolecular deuterium isotope effect of kaurene hydroxylation was determined to be 3.8 (+OR-) 0.6 by GC-MS analysis of the deuterated 2 produced in incubations of {19-('2)H(,2)}kaurene with M. macrocarpus microsomes. The enzymic oxidation of 2 was found to proceed with stereospecific removal of the pro-R C19 hydrogen with an intermolecular deuterium isotope effect of 1.82 (+OR-) 0.02, through incubations of (19S)- and (19R)-{19-('3)H,('2)H}kaurenol. These were prepared by stereospecific borohydride reductions of {19-('3)H}kaurenal and {19-('2)H}kaurenal. The C19 isotopic configurations were assigned through chemical and NMR spectral correlations with synthetic decalin analogs of 2, for which the stereochemistry was established by a novel method involving stereospecific proton-phosphorus NMR coupling in a phosphorinane derivative. Made available in DSpace on 2014-12-15T23:17:50Z (GMT). No. of bitstreams: 1 8302985.pdf: 8881498 bytes, checksum: 51ded506420432b90e61677dd7c082f8 (MD5) Previous issue date: 1982 Embargo set by: Seth Robbins for item 70372 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 288 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1982. http://hdl.handle.net/2142/70206 (UMI)AAI8302985 Chemistry, Organic Enzymic Oxidations of Ent-Kaurene and Ent-Kaurenol in Gibberellic Acid Biosynthesis: Stereochemistry and Isotope Effects text Chemistry Chemistry University of Illinois at Urbana-Champaign Dissertation Ph.D.