Chemical constituents of Morinda citrifolia fruits inhibit copper-induced low-density lipoprotein oxidation   总被引：6，自引：0，他引：6  

Kamiya K  Tanaka Y  Endang H  Umar M  Satake T 《Journal of agricultural and food chemistry》2004,52(19):5843-5848

The oxidative modification of low-density lipoprotein (LDL) plays an important role in the genesis of arteriosclerosis. The present study focused on the effects of the fruits of Morinda citrifolia on preventing arteriosclerosis. The MeOH extract and CHCl(3)-, EtOAc-, n-BuOH-, and H(2)O-soluble phases derived from the fruits of M. citrifolia were evaluated for their inhibitory activity on copper-induced LDL oxidation by the thiobarbituric acid-reactive substances (TBARS) method. The MeOH extract and EtOAc-soluble phase showed 88 and 96% inhibition, respectively. Six lignans were isolated by repeated column chromatography from the EtOAc-soluble phase. These compounds were determined by spectroscopic analysis to be 3,3'-bisdemethylpinoresinol (1), americanol A (2), americanin A (3), americanoic acid A (4), morindolin (5), and isoprincepin (6), of which 4 and 5 are novel compounds. These compounds inhibited copper-induced LDL oxidation in a dose-dependent manner. 1, 2, 5, and 6 exhibited remarkably strong activities, which were the same or better than that of the known antioxidant 2,6-di-tert-butyl-p-cresol. The IC(50) values for 1, 2, 5, and 6 were 1.057, 2.447, 2.020, and 1.362 microM, respectively. The activity of these compounds is mainly due to their number of phenolic hydroxyl groups.  相似文献   

Genetic control of long glume phenotype in tetraploid wheat derived from Triticum petropavlovskyi Udacz. et Migusch.     

N. Watanabe  I. Imamura 《Euphytica》2002,128(2):211-217

The Chinese wheat landrace, Xinjiang rice wheat (T. petropavlovskyi Udacz. et Migusch., 2n = 42), known as ‘Daosuimai’ or rice-head wheat is characterized by long glumes, and was found in the agricultural areas in the west part of Talimu basin, Xinjiang, China in 1948. The gene for long glume from T. petropavlovskyi was introduced into a line of spring durum wheat, LD222. The gene for long glume is located approximately46.8 cm from the cn-A1 locus, which controls the chlorinatrait. Significant deviation from a 3:1 in the F₂ of LDN7D(7A)/ANW5C confirmed that the long glume of T. petropavlovskyi can be controlled by a gene located on chromosome 7A. The gene locates approximately 12.4 ± 0.5 cM from the centromere on the long arm of 7A. It is considered that the gene for long glume from T. petropavlovskyi is an allele on the P ₁ locus, and it should be designated as P _1a. It is suggested that T. petropavlovskyi originated from either the natural hybrid between T. aestivum that has an awn-like appendage on the glume and T. polonicum or a natural point mutation of T. aestivum. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Weathering durability of CCB-impregnated wood for clear varnish coatings     

Mustafa Kemal Yalinkiliç  Rifat Ilhan  Yuji Imamura  Munezoh Takahashi  Zafer Demirci  Ahmet Cihangir Yalmkiliç  Huseyin Peker 《Journal of Wood Science》1999,45(6):502-514

Outdoor performances of a polyurethane varnish and an alkyd-based synthetic varnish coated over chromium-copper-boron (CCB)-impregnated Scots pine (Pinus sylvestris L.) and chestnut (Castanea sativa Mill.) [10 (R) × 100 (T) × 150 (L) mm] were investigated. These varnishes were also applied to the wood surface as sole coatings or impregnated into wood as water-repellent (WR) solutions. Outdoor exposure was performed in the Black Sea region of northern Turkey (41°N, 39.43°E) where humid weather predominates throughout the year and accelerates decomposition of coated wood surfaces. The wood panels were exposed at 45° south on their tangential surfaces. After 9 months of exposure to summer, autumn, and the following winter season, the color and glossiness changes of the exposed surface, adhesion of the coating layer to the wood surface, water absorption through the coating layers, mass loss, and the hardness of the board surface were studied. CCB impregnation greatly stabilized the surface color of varnish-coated panels of both wood species. Gradual decreases of adhesion between varnished layers and preimpregnated surfaces were attributed to probable weakening of interactions at the interface of the treated wood and the film layer. A superficial cleaning process of treated wood is suggested to improve glossiness and adhesion. The coated wood surface became harder with time on outdoor exposure until a maximum hardness occurred followed by softening, whereas the uncoated surface softened steadily. Polyurethane varnish yielded a harder surface than synthetic varnish. Mass losses of wood panels after 9 months of exposure were negligible for all treatments compared with the untreated controls, which were totally discolored and eroded on the surface. It is concluded that long-term exterior wood protection has been achieved by a successful combination of an appropriate preservative treatment followed by a compatible surface-coating process.  相似文献   

Termite feeding preference to four wood species after gamma irradiation     

Noriaki Katsumata  Tsuyoshi Yoshimura  Kunio Tsunoda  Yuji Imamura 《Journal of Wood Science》2007,53(4):361-364

The effect of gamma irradiation at 100 kGy and at lower levels on termite resistance was examined in the laboratory by no-choice and choice feeding termite tests (Coptotermes formosanus Shiraki) using four wood species: sapwood of Cryptomeria japonica D. Don, and heartwoods of Pseudotsuga menziesii (Mirbel) Franco, Larix kaempferi (Lambert) Carriere, and Chamaecyparis obtusa Endl. The wood consumption rates in C. japonica and P. menziesii specimens were likely to increase with increases in gamma-irradiation levels, whereas little effect of gamma irradiation was seen in L. kaempferi and C. obtusa. Similar results were obtained in the two-choice test. The current results indicated that in the two-choice test with C. formosanus, 100-kGy-irradiated C. japonica and P. menziesii, which are not rich in antitermite substances, were eaten more than other wood samples with or without gamma irradiation. However, only C. japonica showed significant difference in termite feeding activity. The mass loss in 100-kGy-irradiated C. japonica was significantly higher in the multichoice test.  相似文献   

Diamond and pore structure observed in wood charcoal     

Kengo Ishimaru  Tomas Vystavel  Paul Bronsveld  Toshimitsu Hata  Yuji Imamura  Jeff De Hosson 《Journal of Wood Science》2001,47(5):414-416

Conclusions Various carbon structures were observed in the wood charcoal sample: the well known pyrolytic graphite layers, onion-like particles, and diamond structure. It is suggested that wood charcoal carbonized at 700°C is a complex of various carbon structures. The pore structure was observed by electron microscopy, and it is supposed that the microstructure and pores are closely related. Further study of the microstructure during the carbonization process of charcoal is necessary to better understand the characteristic functions of wood charcoal for utilizing it as a source of carbon material.A summary of this study was presented at the 51st annual meeting of the Japan Wood Research Society, Tokyo, April 2001, and the 50th annual meeting of the Society of Materials Science, Osaka, May 2001  相似文献   

Effect of aluminum compound addition on graphitization of wood charcoal by direct electric pulse heating method   总被引：1，自引：0，他引：1  

Koei?NishimiyaEmail author  Toshimitsu?Hata  Hikari?Kikuchi  Yuji?Imamura 《Journal of Wood Science》2004,50(2):177-181

The catalytic effect of aluminum on graphitization of wood charcoal was examined. Wood charcoal impregnated with aluminum triisopropoxide to various levels was subjected to direct electric pulse heating. Electric conductivity and heat conductivity of the products showed strong, systematic dependence on the amount of aluminum added. X-ray diffractometry indicated that these effects result from a larger degree of graphitization. Because the amount of aluminum in the final product was negligible, aluminum, before being lost by vaporization, apparently catalyzed graphitization at a lower temperature than is used for conventional treatments.Part of this report was presented at the 17th Annual Meeting of the Association of Wood Processing and Technology, November 1999; the 11th MRS-J Annual Meeting, Kawasaki, December 1999; and the 50th Annual Meeting of the Japan Wood Research Association, April 2000  相似文献   

An application of the alkaline extraction – glucoamylase hydrolysis method to analyze starch and sugar contents of bamboo     

Yoko Okahisa  Tsuyoshi Yoshimura  Yuji Imamura 《Journal of Wood Science》2005,51(5):542-545

The alkaline extraction – glucoamylase hydrolysis (AG) method, which extracts sugars and starch by using sodium hydroxide and hydrolyzes starch by using glucoamylase and α-amylase, was compared with the established ethanol extraction – perchloric acid hydrolysis (EPA) method to analyze the sugar and starch contents of moso bamboo (Phyllostachys pubescens Mazel). The results suggested that the two methods had comparable abilities to extract free sugars from moso bamboo. However, the AG method analyzed starch in moso bamboo more accurately than the EPA method under the proper conditions. When we take into account the better time performance of the AG method versus the EPA method, we can conclude that the AG method is superior to EPA for analyzing the sugar and starch contents of moso bamboo.  相似文献   

Resistance of gamma-irradiated sapwood of <Emphasis Type="Italic">Cryptomeria japonica</Emphasis> to biological attacks     

Noriaki Katsumata  Tsuyoshi Yoshimura  Kunio Tsunoda  Yuji Imamura 《Journal of Wood Science》2007,53(4):320-323

Any means helpful for the promotion of termite feeding activity has potential for use in a matrix in termite bait application. Therefore, energy transfer by gamma irradiation is worthy of consideration for converting wood into termite-accessible material. Wood specimens gamma-irradiated at 100 kGy and at lower levels were tested for their degrees of polymerization (DP) of cellulose and biological resistance. The DP of cellulose adversely decreased with increased doses of gamma irradiation. Termite wood consumption rates, which were determined by laboratory tests using undifferentiated larvae (workers) of Coptotermes formosanus Shiraki, were significantly higher at 100 kGy than at other doses. On the other hand, the decay resistance of gamma-irradiated wood against the fungi Fomitopsis palustris (Berkeley et Curtis) Murrill and Trametes versicolor (L. ex Fr.) Quel did not vary by irradiation dose.  相似文献   

Plate-type waveguides for detecting acoustic emissions generated by termite attacks     

Yoshiyuki Yanase  Yoshihisa Fujii  Shogo Okumura  Yuji Imamura  Tsuyoshi Yoshimura 《Journal of Wood Science》2000,46(3):243-247

To examine the feasibility of using plate-type waveguides for effective detection of acoustic emissions (AEs) from termite attacks in wood, AEs generated by breaking pencil leads or by termite attacks were detected using an AE sensor with a resonant frequency of 140kHz with steel plates of four different sizes and thickness and three AE sensors without them. The larger plates were associated with larger amplitudes of the artificial AEs. The amplitudes of AEs detected by an AE sensor with a steel plate larger than 30×30mm were greater than the average amplitude of the artificial AEs detected by three AE sensors. When detecting AEs generated by the feeding activity of workers,Coptotermes formosanus Shiraki, the cumulative AE events detected by the sensor with a steel plate were much larger than those of the three AE sensors without a plate. Because AE waves are attenuated much less in a steel plate than in wood, it is more effective to attach the AE sensor to wood with a steel plate rather than directly to the wood. These findings suggest that it is feasible to use an AE sensor with a plate-type waveguide for the nondestructive detection of termite attacks in wood.  相似文献   

O,O,S-Trimethyl phosphorothioate effects on immunocompetence     

B.H. Devens  M.H. Grayson  T. Imamura  K.E. Rodgers 《Pesticide biochemistry and physiology》1985,24(2):251-259

O,O,S-Trimethyl phosphorothioate (OOS), a contaminant of technical formulations of some organophosphorus pesticides, was found to be immunotoxic at subtoxic doses in female C57Bl/6 mice. Mice treated orally with acute doses of 10 mg/kg OOS show no overt toxic signs such as weight loss or malaise. In addition, the levels of serum cholinesterase was not decreased. Histopathologic investigation demonstrated no alterations in liver, lung, kidney, heart, skin, brain, spleen, or gut. The LD₅₀ for delayed toxicity was approximately 35 mg/kg. Despite the lack of general toxic changes at doses of 5–10 mg/kg OOS, specific immunotoxic changes were found. The humoral or cell-mediated immune response of splenocytes from mice treated with 10 mg/kg OOS to in vivo immunization was diminished with respect to control animals. Responses were measured in ex vivo assays. Cytotoxic T-lymphocyte (CTL) responses were assessed by alloimmunization with the tumor P815 followed by a ⁵¹Cr release assay done ex vivo with splenic lymphocytes. Humoral responses were assessed by immunization with sheep red blood cells followed by a Jerne plaque assay to determine anti-sheep red blood cell antibody. Both cellular and humoral responses could be stimulated in vitro using cells from OOS-pretreated, primed animals, thus indicating that no permanent cellular elterations had occurred.  相似文献