4 research outputs found
Identification of a Genetic Factor Required for High γ‑Isoform Concentration in Rice Vitamin E
The
γ-isoforms of tocopherols (Tc) and tocotrienols (T3)
possess high biological activities in comparison to the α-isoforms.
The concentrations of Tc and T3 isoforms in rice (Oriza
sativa) was cultivar-dependent. Using chromosome segment
substitution lines (CSSLs) and near isogenic lines (NILs) of indica cultivar “Kasalath” in a japonica cultivar “Koshihikari” genetic
background, the Kasalath genomic segment on chromosome 2 was determined
to be responsible for the high γ-isoform concentration: γ-tocopherol
methyltransferase (<i>γ-TMT</i>) was identified as
a candidate gene. An amino acid substitution in the coding region
and several nucleotide polymorphisms, including an insertion of 10
base pairs in the promoter region, were identified. Gene expression
analysis revealed that low expression levels of the <i>γ-TMT</i> gene in Kasalath were not associated with the γ-isoform concentration.
Genetic variations in the coding region of the <i>γ-TMT</i> gene may play a major role in determining the γ-isoform concentration.
This information could be used to breed rice with a high γ-isoform
content
Total Synthesis and Structural Determination of XR774, a Tyrosine Kinase Inhibitor
Total
synthesis and structural determination of XR774 has been
accomplished. The benzo[<i>j</i>]fluoranthene skeleton has
been constructed by regioselective coupling between tetraline <b>3</b> and tetralone <b>4</b> successively followed by the
sequential transformation including the Birch reduction to prepare
allylic alcohol, simultaneous bromination of vinylic and aromatic
moieties, and the nickel-mediated intramolecular coupling reaction.
The optical resolution of racemic <b>17</b> led to the first
total synthesis of (−)-XR774
Remote Asymmetric Bromination Reaction with Vinylketene Silyl <i>N</i>,<i>O</i>‑Acetal and Its Application to Total Synthesis of Pellasoren A
Stereoselective
bromination of the <i>E</i>,<i>E</i>-vinylketene
silyl <i>N</i>,<i>O</i>-acetal possessing
a chiral auxiliary has been achieved and applied to introduction of
heteroatom at γ-position of α,β-unsaturated imide.
The reactions proceeded in high stereoselectivity. Total synthesis
of pellasoren A, an antitumor propionate from the myxobacteriun <i>Sorangium cellulosum</i>, has been accomplished in short steps
by this methodology and our method of reduced polypropionate synthesis
Total Synthesis and Structural Determination of XR774, a Tyrosine Kinase Inhibitor
Total
synthesis and structural determination of XR774 has been
accomplished. The benzo[<i>j</i>]fluoranthene skeleton has
been constructed by regioselective coupling between tetraline <b>3</b> and tetralone <b>4</b> successively followed by the
sequential transformation including the Birch reduction to prepare
allylic alcohol, simultaneous bromination of vinylic and aromatic
moieties, and the nickel-mediated intramolecular coupling reaction.
The optical resolution of racemic <b>17</b> led to the first
total synthesis of (−)-XR774