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71.
Yukio Fujiwara Yukie Uehara Masafumi Okawa Masateru Ono Toshihiro Nohara 《Tetrahedron》2004,60(22):4915-4920
Major novel steroidal alkaloid glycosides, named esculeoside A (1) and esculeoside B (2), have been isolated from the pink color-type and the red color-type, respectively, of the ripe tomato fruits of Lycopersicon esculentum MILL. for the first time. The structures of 1 and 2 have been characterized as 3-O-β-lycotetraosyl (5S,22S,23S,25S)-23-acetoxy-3β,27-dihydroxyspirosolane 27-O-β-d-glucopyranoside and 3-O-β-lycotetraosyl (5S,22S,23R,25S)-22,26-epimino-16β,23-epoxy-3β,23,27-trihydroxycholestane 27-O-β-d-glucopyranoside, respectively. 相似文献
72.
73.
From the whole plants and the roots of Gueldenstaedtia multiflora, which has been used in traditional Chinese medicine, five new oleanane glycosides and one lupane glycoside were isolated together with eight known oleanane glycosides and a medicarpin derivative. These structures were determined based on MS and 2D-NMR spectra. 相似文献
74.
Sadakiyo M Okawa H Shigematsu A Ohba M Yamada T Kitagawa H 《Journal of the American Chemical Society》2012,134(12):5472-5475
We controlled the hydrophilicity of metal-organic frameworks (MOFs) to achieve high proton conductivity and high adsorption of water under low humidity conditions, by employing novel class of MOFs, {NR(3)(CH(2)COOH)}[MCr(ox)(3)]·nH(2)O (abbreviated as R-MCr, where R = Me (methyl), Et (ethyl), or Bu (n-butyl), and M = Mn or Fe): Me-FeCr, Et-MnCr, Bu-MnCr, and Bu-FeCr. The cationic components have a carboxyl group that functions as the proton carrier. The hydrophilicity of the cationic ions was tuned by the NR(3) residue to decrease with increasing bulkiness of the residue: {NMe(3)(CH(2)COOH)}(+) > {NEt(3)(CH(2)COOH)}(+) > {NBu(3)(CH(2)COOH)}(+). The proton conduction of the MOFs increased with increasing hydrophilicity of the cationic ions. The most hydrophilic sample, Me-FeCr, adsorbed a large number of water molecules and showed a high proton conductivity of ~10(-4) S cm(-1), even at a low humidity of 65% relative humidity (RH), at ambient temperature. Notably, this is the highest conductivity among the previously reported proton-conducting MOFs that operate under low RH conditions. 相似文献
75.
M Ono Y Takaki M Takatsuji K Akiyama M Okawa J Kinjo H Miyashita H Yoshimitsu T Nohara 《Chemical & pharmaceutical bulletin》2012,60(8):1083-1087
Three new resin glycosides, quamoclins V (1), VI (2), and VII (3) and a new tetrahydropyran derivative, quamopyran (4), were isolated from the seeds of Quamoclit pennata BOJER (Convolvulaceae). The chemical structures of these compounds were determined primarily on the basis of spectroscopic data. The carboxyl group of the aglycone, 11S-convolvulinolic acid, of 1 and 2 was linked intermoleculary with a hydroxy group of the sugar moiety to form a macrocyclic ester structure, as in already known jalapins, and 3 was an acylated glycosidic acid methyl ester. All of the sugar moieties of 1-3 were acylated by one 2S-methylbutyric acid. Compound 4 was a diketone having a tetrahydropyran ring. 相似文献
76.
77.
78.
Ono M Oishi K Abe H Masuoka C Okawa M Ikeda T Nohara T 《Chemical & pharmaceutical bulletin》2006,54(10):1421-1424
Two new iridoid glucosides, verbenabraside A (1) and verbenabraside B (2), were isolated from the aerial parts of Verbena brasiliensis VELL., along with six known iridoid glucosides, gelsemiol 3-O-beta-D-glucoside (3), verbraside (4), 9-hydroxysemperoside (5), griselinoside (6), aralidioside (7), and 6alpha-hydroxyforsythide dimethyl ester (8), three known phenylethanoid glycosides, 2-phenylethyl O-beta-D-xylopyranosyl-(1-->2)-beta-D-glucopyranoside (9), acteoside (10), and leucosceptoside A (11), two known lignan glucosides, dihydroxymethyl-bis(3,5-dimethoxy-4-hydroxyphenyl) tetrahydrofuran-9 (or 9')-O-beta-glucopyranoside (12) and (+)-lyoniresinol 3alpha-O-beta-D-glucopyranoside (13), a known methyl salicylate glucoside, methyl 2-O-beta-D-glucopyranosylbenzoate (14), and two known sterols, beta-sitosterol 3-O-beta-D-glucopyranoside (15) and beta-sitosterol (16). Their chemical structures were determined on the basis of spectroscopic data. Compound 1 exhibited stronger scavenging effect on the stable free radical 1,1-diphenyl-2-picrylhydrazyl than that of alpha-tocopherol. 相似文献
79.
Shuping Wang Nanae Shibahara Daishi Kuramashi Shinpei Okawa Naoto Kakuta Eiji Okada Atsushi Maki Yukio Yamada 《Optical Review》2010,17(4):410-420
In order to investigate the effects of anatomical variation in human heads on the optical mapping of brain activity, we perform
simulations of optical mapping by solving the photon diffusion equation for layered-models simulating human heads using the
finite element method (FEM). Particularly, the effects of the spatial variations in the thicknesses of the skull and cerebrospinal
fluid (CSF) layers on mapping images are investigated. Mapping images of single active regions in the gray matter layer are
affected by the spatial variations in the skull and CSF layer thicknesses, although the effects are smaller than those of
the positions of the active region relative to the data points. The increase in the skull thickness decreases the sensitivity
of the images to active regions, while the increase in the CSF layer thickness increases the sensitivity in general. The images
of multiple active regions are also influenced by their positions relative to the data points and by their depths from the
skin surface. 相似文献
80.
T. Ikuno T. Sainsbury D. Okawa J.M.J. Fréchet A. Zettl 《Solid State Communications》2007,142(11):643-646
The surface of boron nitride nanotubes (BNNTs) has been functionalized with amine groups via ammonia plasma irradiation. The functionalized tubes were characterized by Fourier transform infrared spectroscopy and electron energy loss spectroscopy. Amine-functionalized BNNTs were found to be highly dispersible in chloroform, and are predicted to form the basis of a new class of chemically reactive nanostructures. 相似文献