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排序方式: 共有550条查询结果,搜索用时 78 毫秒
91.
92.
Tsuboi M Etoh H Kato K Nakatugawa H Kato H Maejima Y Matsumoto G Mori H Hosokawa M Miyashita K Tokuda H Suzuki N Maoka T 《Journal of agricultural and food chemistry》2011,59(19):10572-10578
The in vitro reactivity of capsanthin (1) and fucoxanthin (2) with peroxynitrite was investigated, and the reaction products produced by scavenging with peroxynitrite were analyzed. (14'Z)-Nitrocapsanthin (3) and 12-nitrocapsanthin (4) were isolated from the products of the reaction of capsanthin with peroxynitrite. Similarly, (14Z)-15-nitrofucoxanthin (5), (11Z)-11-nitrofucoxanthin (6), and (14Z,9'Z)-15-nitrofucoxanthin (7) were obtained from the reaction of peroxynitrite reaction with fucoxanthin. Capsanthin and fucoxanthin inhibited the nitration of tyrosine by peroxynitrite. Furthermore, nitrocapsanthins (3 and 4) and nitrofucoxanthins (5 and 6) exhibited an inhibitory effect on Epstein-Barr virus early antigen activation in Raji cells and an antiproliferative effect on human pancreatic carcinoma. Moreover, nitrocapsanthins (3 and 4) inhibited carcinogensis of mouse skin tumors initiated by 7,12-dimethylbenz[a]anthracene (DMBN). 相似文献
93.
We examined arsenic (As) accumulation and speciation in the major cultivars currently grown in Japan, because differences in grain As levels among cultivars may influence dietary As exposure in Japanese people. Ten major cultivars (Oryza sativa L.) were grown under flooded conditions in a paddy field with a background level of As (low-As soil) or in pots filled with soil containing a high level of As (high-As soil). In the low-As soil, the total grain As ranged from 0.11 to 0.17?mg?kg?1, with a mean concentration of 0.14?mg?kg?1, and inorganic As was the major species in all cultivars. There were few genotypic differences in the levels of either total As or inorganic As in the grain. In the high-As soil, total grain As increased to a mean level of 2.4?mg?kg?1 in the 10 cultivars, with markedly increased levels of dimethylarsinic acid. The genotypic variations among cultivars in the levels of both total As and dimethylarsinic acid were statistically significant. However, the genotypic variability of inorganic As levels was quite small, and these levels remained low (at about 0.2?mg?kg?1) even when total As levels increased markedly. These results suggest that differences in grain As levels among Japanese cultivars may not influence dietary As exposure, because there is little genotypic difference in the accumulation of inorganic As, which is considered more toxic than organic As to humans. We discuss the possible mechanism of As accumulation in Japanese paddy rice, in the context of the accumulation of As species in the developing grain and in other plant tissues. 相似文献
94.
The possibility of in vitro binding between proteins of rice shoots and germanium (Ge) was investigated. The proteins in mixtures of aqueous extracts of rice shoots and radioactive germanium (68GeO2) were fractionated. The binding of radioactivity to the proteins was observed even after 5 successive fractionation steps from the original mixtures. At the final fractionation step using polyacrylamide gel electrophoresis, a constant proportionality between protein concentration and associated radioactivity was found in most samples although not all. These results indicate that the binding of 88Ge to proteins is not due to the simple adsorption by proteins. 相似文献
95.
Aluminum (Al) occurs abundantly in soil and solubilized aluminum ions in acid soil inhibit plant growth, in particular, root growth. Although several toxic effects of Al on plant growth have been reported, the mechanism of Al toxicity remains to be clarified. 相似文献
96.
Application of the amount of oxygen consumption to the investigation of the oxidation mechanism of lignin during oxygen-alkali treatment 总被引:1,自引:1,他引:0
Aiko Imai Iori Tomoda Tomoya Yokoyama Yuji Matsumoto Gyosuke Meshitsuka Guolin Tong 《Journal of Wood Science》2008,54(1):62-67
The dioxygen consumption by kraft lignin and several lignin model compounds during oxygen-alkali treatments were directly
analyzed using a dioxygen fl owmeter. The average dioxygen consumption by 200 g of kraft lignin was about 3 moles. Because
this value was as much as those obtained for monomeric phenolic lignin model compounds, guaiacol and vanillyl alcohol, it
was postulated that not only phenolic but also nonphenolic moieties in kraft lignin are extensively oxidized. The dioxygen
consumption by 0.5 moles (one equivalent of aromatic units) of a dimeric lignin model compound, guaiacylglycerol-β-guaiacyl
ether (GG), was also similar to that for 1 mole of guaiacol and vanillyl alcohol, regardless of the type of the aromatic moiety,
which supports the above postulation. The most plausible mechanism for the oxidation of nonphenolic moieties is the oxidation
of side chains of residual β-O-4 substructures by active oxygen species. By this mechanism, nonphenolic moieties in kraft lignin and GG are converted into
corresponding phenolic moieties, and the oxidation by dioxygen progresses.
Part of this article was presented at the 13th International Symposium on Wood, Fiber, and Pulping Chemistry (13th ISWFPC),
Auckland, New Zealand, May 2005 相似文献
97.
The effects of canopy and shrub layer coverage on the frequency of oviposition by a papilionid butterfly, Luehdorfia japonica, were investigated. Density of larval host plant tended to be higher where shrub layer was thinner, and the frequency of
oviposition was correlated with host plant abundance. On the other hand, host plant abundance and the frequency of oviposition
were not correlated with canopy layer coverage. Eggs were mainly found at or near the forest edge irrespective of host plant
abundance. 相似文献
98.
Hisayuki Arakawa Yohei Ohi Akira Matsumoto Kenji Takio Takumi Kimoto Katsutoshi Kawabe 《Fisheries Science》2012,78(5):1083-1090
The populations of red alga Gelidium elegans along the coast of Miyakejima Island were severely damaged by a volcanic eruption in 2000. The effect of this volcanic eruption has been long lasting, and populations of this red alga still have not recovered. We investigated the effect of seabed sediment particles derived from volcanic ash on the substrate adhesion of G.?elegans spores. The analysis provides evidence that increasing amounts of sediment particles result in lower adhesion rates of G.?elegans spores, and that smaller sediment particles have a greater influence on adhesion. The amount of seabed sediment particles around Miyakejima Island was 9.3?C1815.4?mg/cm2. This amount has changed greatly from year to year. The adhesion rate of G.?elegans spores in water around Miyakejima Island was 0?% at all points in 2008 and 2010, but it was estimated as 6.3?C38.6?% in 2009. These results suggest that there is significant inhibition of algal spore adhesion by seabed sediment particles derived from volcanic ash around Miyakejima Island. 相似文献
99.
100.