Synthesis of Methyl-branched 2,3,4,5-Tetrahydroxycyclohexanone Derivatives via 6-Deoxyhex-5-enopyranosides

Seven novel methyl-branched 2,3,4,5-tetrahydroxycyclohexanone derivatives were prepared in good yields by Ferrier reaction via corresponding key intermediates: 6-deoxyhex-5-enopyranosides

Unleashing floret fertility in wheat through the mutation of a homeobox gene

Floret fertility is a key determinant of the number of grains per inflorescence in cereals. During the evolution of wheat (Triticum sp.), floret fertility has increased, such that current bread wheat (Triticum aestivum) cultivars set three to five grains per spikelet. However, little is known regarding the genetic basis of floret fertility. The locus Grain Number Increase 1 (GNI1) is shown here to be an important contributor to floret fertility. GNI1 evolved in the Triticeae through gene duplication. The gene, which encodes a homeodomain leucine zipper class I (HD-Zip I) transcription factor, was expressed most abundantly in the most apical floret primordia and in parts of the rachilla, suggesting that it acts to inhibit rachilla growth and development. The level of GNI1 expression has decreased over the course of wheat evolution under domestication, leading to the production of spikes bearing more fertile florets and setting more grains per spikelet. Genetic analysis has revealed that the reduced-function allele GNI-A1 contributes to the increased number of fertile florets per spikelet. The RNAi-based knockdown of GNI1 led to an increase in the number of both fertile florets and grains in hexaploid wheat. Mutants carrying an impaired GNI-A1 allele out-yielded WT allele carriers under field conditions. The data show that gene duplication generated evolutionary novelty affecting floret fertility while mutations favoring increased grain production have been under selection during wheat evolution under domestication

Environmental and vegetational changes recorded in sedimentary leaf wax n-alkanes across the Cretaceous-Paleogene boundary at Loma Capiro, Central Cuba

金沢大学理工研究域自然システム学系The stable carbon isotopic compositions (δ13C) and chain-length distribution [ACL and n-C31/(n-C29+n-C31)] of sedimentary leaf wax n-alkanes were investigated across the Cretaceous-Paleogene (K-Pg) boundary at Loma Capiro, Central Cuba, to reconstruct paleoenvironmental changes that are recorded in terrestrial higher plants. The stratigraphic profiles of the n-alkane δ13C values show a negative excursion in the lowermost Paleocene, although its magnitude is much smaller (~0.3‰) than the global signals (1.5 to 2.0‰) in the surface ocean-atmospheric carbon reservoir. Relations between the n-alkane δ13C values and the C31/(C29+C31) ratios exhibit two different trends, suggesting that our δ13C records are likely affected by two types of paleoenvironmental factors in addition to the δ13C variations in the exogenous carbon reservoir. Rare occurrence of terrigenous organic matter that is usually transported by rivers suggests that the n-alkanes at Loma Capiro are likely to have been transported by trade winds, which recorded paleoenvironmental conditions of the northwestern part of the African continent. The n-alkane δ13C values show a parallel decrease with the ACL and C31/(C29+C31) values in the first 37,000yr following the K-Pg boundary. Such decreases are consistent with plant physiological responses to reduced net evaporation, suggesting a possible influence of the impact-induced warm-humid condition in the early Paleocene. In contrast, the n-alkane δ13C values are negatively correlated with the C31/(C29+C31) ratios from 40,000 to 67,000yr after the K-Pg boundary. This time period matches well with that required for the recovery of terrestrial floras from the K-Pg mass extinction to those with diversity equivalent to the late Cretaceous, suggesting that the n-alkane signals are also likely affected by the plant diversification process after the mass extinction. © 2010 Elsevier B.V

Stereoselectivities in Catalytic Hydrogenation of Several Branched-Chain 6-Deoxyhex-5-enopyranosides. A Synthesis of Branched-Chain Methyl 6-Deoxy-β-L-hexopyranoside

Hydrogenation of several 2-C, 3-C, and 4-C-methyl-branched 6-deoxyhex-5-enopyranosides in the presence of palladium–carbon in ethanol showed stereoselective formation of the corresponding 6-deoxy-β-L-hexopyranosides

分枝5,6-へキソーセン類のFerrier反応による分枝サイクリトール合成の立体化学

講演番号：3 IL 3

分枝5，6‐ヘキソーセン類を経由した天然物の合成研究

講演番号：1 C5 1

Die Nuernberger Tuchmacher, Weber, Faerber und Bereiter vom 14. bis 17. Jahrhundert

Bayereuth, Univ., Diss., 1991Available from Bibliothek des Instituts fuer Weltwirtschaft, ZBW, Duesternbrook Weg 120, D-24105 Kiel A 203386 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman