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1.
Using synthesized 8-hydroxy-2'-deoxyguanosine 3'-monophosphate as a marker, the 32P-postlabeling method was adapted with minimum modifications for the analysis of 8-hydroxy-2'-deoxyguanosine (8-OH-dG) content in deoxyribonucleic acid (DNA). This method allows the analysis of one 8-OH-dG per 10(4) DNA nucleotides with only 10 pmoles of nucleotides required. The amounts of 8-OH-dG in DNA detected by the postlabeling method correlated well with the electrochemical detection method but were consistently lower. 相似文献
2.
Characterization of the non-stoichiometric and isomorphic hydration and solvation in FK041 clathrate
Hisashi Mimura Satoshi Kitamura Teruyuki Kitagawa Shigetaka Kohda 《Colloids and surfaces. B, Biointerfaces》2002,26(4):397-406
FK041 crystallizes as a non-stoichiometric hydrate or as solvated hydrates which were characterized as isomorphic clathrates by powder X-ray diffractometry. Moisture and organic solvent vapor sorption studies, differential scanning calorimetry and thermogravimetric analysis revealed that FK041 monohydrate forms a physically stable host crystal, which has lattice channels for guest water and/or organic solvent molecules. The hydration state varies non-stoichiometrically between dihydrate and tetrahydrate depending on the relative humidity and the mol content of the co-existing organic solvent, that is 2-propanol, ethanol, or acetone. These organic solvents are thought to replace a part of originally present water with a mol ratio of 1:3. 2-Propanol exhibited the most stable solvation, indicating that the size and shape of 2-propanol are the most preferable to the lattice channels. 相似文献
3.
Molluscicidal triterpenoidal saponin from Lysimachia sikokiana 总被引:2,自引:0,他引:2
The main molluscicidal activity of the methanol extract of Lysimachia sikokiana is due to several triterpenic saponins called sakuraso-saponins. The most active component was isolated from the aerial parts and elucidated as 3-O-beta-xylopyranosyl-(1----2)-beta-glucopyranosyl-(1----4)- [beta-glucopyranosyl-(1----2)]-alpha-arabinopyranosyl protoprimulagenin A, named lysikoianoside 1, on the basis of 1H- and 13C-nuclear magnetic resonance spectral data and methylation analysis results. 相似文献
4.
T Oh-Hara Y Ikeda H Sakagami K Konno T Kaiya K Kohda Y Kawazoe 《Chemical & pharmaceutical bulletin》1990,38(1):282-284
We have found that water-soluble extracts of lignified natural products are strong potentiaters of hemolytic plaque-forming cell production in mice. Apparently, the active components involved belong to a lignin family. Consequently, study of medicinal potential, especially immunopotentiating capacity, of lignified materials is important. 相似文献
5.
T Mimura H Nakajima K Tsujikawa M Haruyama B G Lee Y Kohama I Kohda M Iwai 《Chemical & pharmaceutical bulletin》1989,37(7):1946-1947
Bis[2-(E-2-alkenoylamino)ethyl] disulfides (compds. I), synthesized from cystamine and 2-trans fatty acids, inhibited collagen-induced rat and rabbit platelet aggregation. The most potent compound was bis[2-(E-2-hexenoylamino)ethyl] disulfide (compd. I-1), and this compound suppressed thromboxane B2 formation from arachidonic acid in rat platelets. The results suggested that compd. I-1 has an inhibitory effect on cyclooxygenase. 相似文献
6.
Wide distribution of relaxation times is taken into consideration in determination of the activation energy of the molecular motion associated with the motional narrowings of line widths of magnetic resonance spectra. The molecular motion of rotational vibration around the chain axis of polyethylene in urea-polyethylene inclusion complex is examined. Relaxation spectra can be obtained from the data of the motional narrowings of EPR and NMR by assuming the activation energy as a parameter. Also, the representative relaxation times corresponding to EPR and NMR observations can be estimated. These relaxation times give us an activation energy since EPR and NMR observations correspond to different time constants of observations. The activation energy estimated from the data of the representative correlation times is identical with the activation energy obtained as a parameter in determination of the identical relaxation spectrum from the data of motional narrowings of EPR and NMR observations. 相似文献
7.
M. Takai S. Nagatomo H. Kohda C. Yada H. Sandaiji F. Takeya 《Applied Physics A: Materials Science & Processing》1994,58(4):359-363
A laser-induced thermochemical reaction has been used to etch single crystalline magnetic ferrite for industrial application to recording-head processing. Scanning focused Ar-ion laser irradiation to ferrite in flowing aqueous solutions of KOH or H3PO4 resulted in etch rates of 350–400 m/s with aspect ratios of up to 40. Metal-In-Gap (MIG) head structures with Sendust (FeAlSi) have been successfully fabricated using laser chemical processing. The MIG head fabricated by laser chemical processing showed better performance than that by conventional mechanical machining.Presented at LASERION '93, June 21–23, 1993 München (Germany) 相似文献
8.
Shoji Asano Keiji Itano Kohfuku Kohda Yuriko Yamagata 《Journal of heterocyclic chemistry》1996,33(4):1115-1121
Reaction of 9-substituted (methyl or benzyl) 1-aminoadenines 1 with hydrazine afforded 9-substituted 6-hydrazinopurines 2 and 1-substituted 5-ammo-4-(4-amino-1,2,4-triazol-3-yl)imidazole ( 4 ). The product ratio of 2 to 4 rose with increasing amounts of methanol used as the solvent. When the same reaction was carried out using 1,9-dimethyladenine instead of 1 , compounds 2 and 4 were also obtained with N6,9-dimethyladenine. A possible mechanism for formation of 2 and 4 is discussed. 相似文献
9.
Nishikimi A Uruno T Duan X Cao Q Okamura Y Saitoh T Saito N Sakaoka S Du Y Suenaga A Kukimoto-Niino M Miyano K Gotoh K Okabe T Sanematsu F Tanaka Y Sumimoto H Honma T Yokoyama S Nagano T Kohda D Kanai M Fukui Y 《Chemistry & biology》2012,19(4):488-497
Highlights? CPYPP binds to DOCK2 DHR-2 domain and inhibits its catalytic activity ? CPYPP inhibits DOCK2-mediated Rac activation in cells ? The structural features of CPYPP required for its inhibitory effect were revealed ? CPYPP inhibits lymphocyte migration and activation in vitro and in vivo 相似文献
10.
Sako M Kihara T Tanisaki M Maki Y Miyamae A Azuma T Kohda S Masugi T 《The Journal of organic chemistry》2002,67(3):668-673
The UV irradiation of pyrrolnitrin (1a), which is an antibiotic clinically useful against dermatophytosis and possesses a unique 2-(pyrrol-3-yl)nitrobenzene moiety in the molecule, in an anhydrous aprotic solvent resulted in the exclusive formation of transient 7,4'-dichlorospiro[1,3-dihydrobenzo(c)isoxazole-3,3'-pyrrolin-2'-one] (2a) via the intramolecular oxidation of the juxtaposed pyrrole ring by the triplet-excited nitro group. The irradiation in an aqueous aprotic solvent, however, allowed the concurrent occurrence of intramolecular cyclization by the singlet-excited nitro group in 1a and the hydroxylation at the 2-position of the pyrrole ring by water to afford 3,7-dichloro-8-hydroxy-8,8a-dihydropyrrolo[2,3-b]indol-2-one (3a), accompanied by the formation of 2a. Elongation of the irradiation time in these photoreactions caused a rapid consumption of the products, 2a and 3a, to give undetermined polar polymeric products. The present results indicate that the photodegradation of 1a is significantly influenced by the presence of water in the reaction media and by the nature of its excited state. Thus, the loss of the antifungal activities by the photosensitive antibiotic 1a was chemically proved. 相似文献