Kaempferol glycosides in the flowers of carnation and their contribution to the creamy white flower color

Three flavonol glycosides were isolated from the flowers of carnation cultivars 'White Wink' and 'Honey Moon'. They were identified from their UV, MS, 1H and 13C NMR spectra as kaempferol 3-O-neohesperidoside, kaempferol 3-O-sophoroside and kaempferol 3-O-glucosyl-(1 --> 2)-[rhamnosyl-(1 --> 6)-glucoside]. Referring to previous reports, flavonols occurring in carnation flowers are characterized as kaempferol 3-O-glucosides with additional sugars binding at the 2 and/or 6-positions of the glucose. The kaempferol glycoside contents of a nearly pure white flower and some creamy white flower lines were compared. Although the major glycoside was different in each line, the total kaempferol contents of the creamy white lines were from 5.9 to 20.9 times higher than the pure white line. Thus, in carnations, kaempferol glycosides surely contribute to the creamy tone of white flowers.     

Potent 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity of novel antioxidants, double-stranded tyrosine residues conjugating pyrocatechol

New potent antioxidants conjugating the catechol (=pyrocatechol; pyrCat) group to two N-termini of modified double-stranded tyrosine residues were synthesized and showed radical scavenging activity with 2,2-diphenyl-1-picrylhydrazyl radical (DPPH radical, DPPH˙) as a free radical model, second-order rate constants for the DPPH˙ scavenging reaction, and the results from electron spin resonance (ESR) studies. It was found that the tyrosine (Tyr) residue and pyrCat containing new antioxidants developed in the study have about 3-20 times more potent antioxidative activity than Trolox, pyrCat, and L-ascorbic acid (VC). In order to elucidate the relationship between antioxidant activity and the molecular orbital states, and to design potent antioxidants we present an interesting approach using an absolute hardness (η)-absolute electronegativity (χ) diagram based on chemical hardness. It was shown that quantum chemicals were required to develop potent antioxidants.     

Peierls mechanism of the metal-insulator transition in ferromagnetic hollandite K2Cr8O16

Synchrotron x-ray diffraction experiment shows that the metal-insulator transition occurring in a ferromagnetic state of a hollandite K(2)Cr(8)O(16) is accompanied by a structural distortion from the tetragonal I4/m to monoclinic P112(1)/a phase with a √2×√2×1 supercell. Detailed electronic structure calculations demonstrate that the metal-insulator transition is caused by a Peierls instability in the quasi-one-dimensional column structure made of four coupled Cr-O chains running in the c direction, leading to the formation of tetramers of Cr ions below the transition temperature. This provides a rare example of the Peierls transition of fully spin-polarized electron systems.     

Time periodic solutions to the Navier–Stokes equations in the rotational framework

We consider the Navier–Stokes equations in the rotational framework with the time periodic external force. We give sufficient conditions on the size of the external forces for the existence of time periodic solutions in terms of the Coriolis parameter. It follows from our conditions that the unique existence of time periodic solutions is guaranteed for large external forces provided the speed of rotation is sufficiently fast.     

9,9′‐spirobifluorene‐containing polycarbonates: Transparent polymers with high refractive index and low birefringence

Syntheses of 2,2′‐bisalcoholic group‐substituted 9,9′‐spirobifluorene monomers 2 were performed by the reaction of 2,2′‐dihydroxy‐9,9′‐spirobifluorene 2a with haloalcohols. Polycarbonates consisting of 9,9′‐spirobifluorene skeleton in the main chain (PC 4 ) were synthesized by the polycondensation of 2,2′‐bisalcoholic monomers 2 and triphosgene or diphenyl carbonate. PC 4 showed good thermal stability: the 5% weight loss temperature was over 330 °C under both nitrogen and air atmospheres. The glass transition temperature was in a range of 16–269 °C estimated by differential scanning calorimetry, depending on the flexibility of the alkylene or oxyethylene chains of 2 . PC 4 showed high solubility toward ordinary organic solvents such as CHCl₃, benzene, and THF, making possible the preparation of the flexible thin films. Very high refractive index in a range of 1.62–1.66 at 589 nm was observed although PC 4 consists only of C, H, and O atoms, whereas very low degree of birefringence was confirmed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3658–3667, 2010     

Direct evidence for degradation of esperamicin A1 with thiol confirmed by fast-atom bombardment mass spectrometry.

A degradation of esperamicin A1, which is a potent antitumor antibiotic having DNA-cleaving activity, was studied by fast-atom bombardment (FAB) mass spectrometry. It was proved that the degradation easily occurs via the thiol group(s) in the matrix solution and not by a FAB-induced reaction. It was concluded that from the FAB mass spectra of all non-volatile compounds, the molecular weight should be determined by using at least two chemically different matrices.     

Crosstalk Suppression in Header Recognition Unit Using Time-Space Conversion

We demonstrate a suppression effect of a crosstalk among a target and similar header signals using the header recognition filter designed by a design technique of the multiple-object discriminant filter.     

Design and Evaluation of Computer Generated Hologram with Binary Subwavelength Structure Designed by Deterministic Process

A binary subwavelength structure for multilevel phase modulation can be designed by our previously proposed deterministic design method without iterative optimization method. To use our design technique in various applications of a computer generated hologram (CGH) like an array illuminator, beam-shaping, signal processing, and so on, an image quality of a reconstructed image from a CGH has become much more important. In this paper, we verify the image quality of a reconstructed image from a CGH designed by our method in terms of the modulation transfer function (MTF) and the spatial resolution. Simulation results show that our technique can theoretically achieve a MTF of more than 99% over a wide range and a spatial resolution of less than 9.66μm.