Biosynthetic Gene Cluster for the Cladoniamides, Bis-Indoles with a Rearranged Scaffold

The cladoniamides are bis-indole alkaloids isolated from Streptomyces uncialis, a lichen-associated actinomycete strain. The cladoniamides have an unusual, indenotryptoline structure rarely observed among bis-indole alkaloids. I report here the isolation, sequencing, and annotation of the cladoniamide biosynthetic gene cluster and compare it to the recently published gene cluster for BE-54017, a closely related indenotryptoline natural product. The cladoniamide gene cluster differs from the BE-54017 gene cluster in gene organization and in the absence of one N-methyltransferase gene but otherwise contains close homologs to all genes in the BE-54017 cluster. Both gene clusters encode enzymes needed for the construction of an indolocarbazole core, as well as flavin-dependent enzymes putatively involved in generating the indenotryptoline scaffold from an indolocarbazole. These two bis-indolic gene clusters exemplify the diversity of biosynthetic routes that begin from the oxidative dimerization of two molecules of l-tryptophan, highlight enzymes for further study, and provide new opportunities for combinatorial engineering

Studies in Asymmetric Catalysis: Lewis Base catalyzed/Lewis Acid Mediated Aldol Reactions of Ketone- and Amide Derived Nucleophiles

373 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007.Additionally, the use of the silicon tetrachloride---chiral phosphoramide system has proven a competent catalyst for highly selective vinylogous aldol reactions between dienolates derived from a variety of alpha,beta-unsaturated carbonyl compounds to aldehydes. These reactions provided high levels of gamma-site selectivity for a variety of substitution patterns on the dienyl unit. Both ketone- and morpholine amide-derived dienol ethers afforded excellent enantio- and diastereoselectivity in the addition to conjugated aldehydes. Although ketone-derived dienolate did not react with aliphatic aldehydes, amide-derived dienolates were found to undergo addition at reasonable rates affording high yields of vinylogous aldol product. The enantioselectivity achieved with the morpholine derived-dienolate in the addition to aliphatic aldehydes was the highest afforded to date with the silicon tetrachloride---chiral phosphoramide system. Furthermore, the ability to cleanly convert the morpholine amide to a methyl ketone was demonstrated.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Evaluation of Revalor®-G as an Initial Implant for Yearling Steers

Three hundred thirty-six English crossbred steers (715 lb) were used to compare effects of reimplanting with Revalor®-S (administered on day 66) after three different initial implants (administered on day zero), to single implantation with Revalor-S (administered on day zero or day 66). Over the entire study, implanted steers gained faster and more efficiently than non-implanted control steers. Steers implanted initially with Revalor-G or Synovex-S gained faster than steers implanted only once. Of the three reimplant treatments, only those initially implanted with Revalor-G had improved feed efficiency compared with single-implanted steers on a live basis. Compared to non-implanted controls, marbling score was reduced only when Synovex-S or Ralgro was used as initial implants

Studies in Asymmetric Catalysis: Lewis Base catalyzed/Lewis Acid Mediated Aldol Reactions of Ketone- and Amide Derived Nucleophiles

373 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007.Additionally, the use of the silicon tetrachloride---chiral phosphoramide system has proven a competent catalyst for highly selective vinylogous aldol reactions between dienolates derived from a variety of alpha,beta-unsaturated carbonyl compounds to aldehydes. These reactions provided high levels of gamma-site selectivity for a variety of substitution patterns on the dienyl unit. Both ketone- and morpholine amide-derived dienol ethers afforded excellent enantio- and diastereoselectivity in the addition to conjugated aldehydes. Although ketone-derived dienolate did not react with aliphatic aldehydes, amide-derived dienolates were found to undergo addition at reasonable rates affording high yields of vinylogous aldol product. The enantioselectivity achieved with the morpholine derived-dienolate in the addition to aliphatic aldehydes was the highest afforded to date with the silicon tetrachloride---chiral phosphoramide system. Furthermore, the ability to cleanly convert the morpholine amide to a methyl ketone was demonstrated.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD