Biosynthesis of a syringyl 8-O-4′ neolignan in Eucommia ulmoides: formation of syringylglycerol-8-O-4′-(sinapyl alcohol) ether from sinapyl alcohol     

Nattaya Lourith  Takeshi Katayama  Kimiko Ishikawa  Toshisada Suzuki 《Journal of Wood Science》2005,51(4):379-386

To investigate the biosynthesis and stereochemistry of syringylglycerol-8-O-4′-(sinapyl alcohol) ether (SGSE), a syringyl 8-O-4′ neolignan, feeding experiments and enzyme assays using Eucommia ulmoides were carried out. Diastereoselective formation of erythro-SGSE was found. When [8-¹⁴C]sinapyl alcohol was administered to excised shoots of E. ulmoides, ¹⁴C was incorporated into free SGSE and SGSE glucosides. In stems, incorporation into (+)-erythro-[¹⁴C]SGSE (0.037%) with 9.1% enantiomeric excess (% e.e.) was found; incorporation into the threo isomer was not detectable. Erythro-[¹⁴C]SGSE glucosides (0.047%) dominated over threo forms (0.007%) with 74.0% diastereomeric excess (% d.e.); both diastereomers were levorotatory with 32.0% e.e. and 18.3% e.e., respectively. In leaves, higher incorporation into (−)-erythro-[¹⁴C]SGSE (0.500%, 15.9% e.e.) than into the threo isomer (0.206%, 7.4% e.e.) was observed (41.6% d.e.). (−)-Erythro-[¹⁴C]SGSE glucosides (1.692%, 25.0% e.e.) were produced at higher rates than threo isomers (0.177%, 16.4% e.e.) with 81.0% d.e. In incubations of a mixture of [8-¹⁴C]sinapyl and [8-¹⁴C]coniferyl alcohols with an insoluble enzyme preparation from stems of E. ulmoides, erythro-SGSE was preferentially produced. The highest % d.e. (82.8) was observed at 60 min with the (+)-erythro isomer (21.4% e.e.) and the (−)-threo form (4.3% e.e.).Part of this report was presented at the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, April 2002, and the 47th Lignin Symposium, Fukuoka, October 2002  相似文献   

Formation of optically active neolignans from achiral coniferyl alcohol by cell-free extracts of Eucommia ulmoides     

Takeshi Katayama  Yuki Kado 《Journal of Wood Science》1998,44(3):244-246

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Stereochemistry and biosynthesis of 8-O-4′ neolignans in Eucommia ulmoides: diastereoselective formation of guaiacylglycerol-8-O-4′-(sinapyl alcohol) ether     

Nattaya Lourith  Takeshi Katayama  Toshisada Suzuki 《Journal of Wood Science》2005,51(4):370-378

Stereochemistry and biosynthesis of guaiacylglycerol-8-O-4′-(sinapyl alcohol) ether (GGSE), an 8-O-4′ neolignan, which consists of coniferyl and sinapyl alcohol moieties, in Eucommia ulmoides were investigated. Four 8-O-4′ neolignans, GGSE, syringylglycerol-8-O-4′-(coniferyl alcohol) ether (SGCE), guaiacylglycerol-8-O-4′-(coniferyl alcohol) ether (GGCE), and syringylglycerol-8-O-4′-(sinapyl alcohol) ether (SGSE), were synthesized. Their erythro and threo diastereomers were separated through acetonide derivatives, intermediates of the synthesis, and identified by means of nuclear magnetic resonance (NMR) spectroscopy. All of the erythro-acetonide derivatives have larger coupling constants (ca 9 Hz) for the C₇-H resonances than those of the threo ones (1.5–2 Hz). In the case of the four 8-O-4′ neolignans, the C₇-H coupling constants of the threo-isomers are not smaller than those of the erythro ones. GGSE isolated previously from this plant was identified as the erythro isomer by comparison of the ¹³C-NMR data with synthetic erythro-GGSE and threo-GGSE and the other 8-O-4′ neolignans mentioned as above. Administration of a mixture of [8-¹⁴C]coniferyl alcohol and [8-¹⁴C]sinapyl alcohol to excised shoots of E. ulmoides was carried out and the incorporation of ¹⁴C into erythro-[¹⁴C]GGSE was found to be higher than that in threo-[¹⁴C]GGSE. The occurrence of diastereoselective formation of erythro-GGSE by cross coupling of coniferyl and sinapyl alcohols is suggested.Part of this paper was presented at the 47th Lignin Symposium, Fukuoka, October 2002 and the 53rd Annual Meeting of the Japan Wood Research Society, Fukuoka, April 2003  相似文献   

Absolute configuration of arylglycerol-β-aryl ethers obtained by asymmetric reduction of the correspondingα-ketonic compound with intactFusarium solani cells     

Takeshi Katayama  Jyoji Tsutsui  Kazuo Tsueda  Takao Miki  Yasuhiro Yamada  Murao Sogo 《Journal of Wood Science》2000,46(6):458-465

When (±)--oxo-guaiacylglycerol--(vanillic acid) ether (1) is degraded byFusarium solani M-13-1, the-ketone is initially reduced to giveerythro andthreo guaiacylglycerol--(vanillic acid) ethers (2), arylglycerol--aryl ethers, both of which are enantiomerically pure. The absolute configuration in each2 was determined by Mosher's method; the products were converted to,-di-(R)--methoxy--trifluoromethylphenylacetates (MTPA esters) (3) oferythro (-)- andthreo (+)-veratrylglycerol--(methyl vanillate) ethers (3), whose¹H nuclear magnetic resonance (NMR) spectra were examined and compared with those of four di-(R)-MTPA ester (3) diastereomers from chemically synthesizederythro (±)-3 andthreo (±)-3. To assign the- and-MTPA-OCH₃ peaks, the¹H NMR scans of several compounds that have substructures of 3 and their 3,4,5-trimethoxyphenyl analogues were examined. When a racemic alcohol reacts with (R)-MTPA to give a pair of (R)-MTPA ester diastereomers, the value was defined as the absolute value of the difference in the¹H chemical shifts of the peak between the diastereomers. It was found that the values of-MTPA-OCH₃ were larger than those of-MTPA-OCH₃ owing to a shielding effect of the veratryl ring located on the-MTPA-OCH₃, and that the-MTPA-OCH₃ peaks in the 3,4,5-trimethoxyphenyl compounds shifted downfield relative to those in the veratryl compounds. On the basis of the¹h NMR data of (R)-MTPA esters, the absolute configuration of the four chemically prepared diastereomers (3) were determined. The catabolicerythro 3 [fromerythro (-)-3] andthreo 3 [fromthreo (+)-3] were identical to (R, S, R)-erythro 3 and (R, S, S)- threo 3, respectively. An hydrogen species in the fungal reduction would attack the-ketone fromre-face of both (R)-1 and (S)-1, givingerythro (S, R)-2 andthreo (S, S)-2, respectively.Part of this paper was presented at the 33rd Lignin Symposium, Tsukuba, November 1988  相似文献   

Novel galactolipids from the leaves of Ipomoea batatas L.: characterization by liquid chromatography coupled with electrospray ionization-quadrupole time-of-flight tandem mass spectrometry     

Napolitano A  Carbone V  Saggese P  Takagaki K  Pizza C 《Journal of agricultural and food chemistry》2007,55(25):10289-10297

Sixteen novel and ten known galactolipids have been isolated and characterized from the leaves of Ipomoea batatas L. (sweet potato) using an analytical method based on high-performance liquid chromatography coupled with electrospray ionization-quadrupole time-of-flight tandem mass spectrometry. Using this technique, the structures and regiochemistries of the fatty acyl groups and the positions of the double bonds on the acyl chains were determined. Sugar moieties were identified by analysis of one- and two-dimensional nuclear magnetic resonance spectra. The positions of the double bonds of polyunsaturated fatty acids were confirmed, and in some cases their geometries determined, by gas chromatography-mass spectrometry. This is the first report of galactolipids in the leaves of sweet potato.  相似文献   

Influence of phosphate-buffered sucrose solution on early graft function in feline renal autotransplantation     

Masaaki Katayama  Yasuhiko Okamura  Shunsuke Shimamura  Rieko Katayama  Hiroaki Kamishina  Yuji Uzuka 《Research in veterinary science》2014

Graft perfusion with cold heparinized saline has known to induce ischemia and reperfusion injury in feline kidney transplantation. In this study, the effects of phosphate-buffered sucrose solution and heparinized saline solution on early kidney graft function were compared in feline kidney autotransplantation. Perfusion of grafts with or without hypothermic storage with chilled phosphate-buffered sucrose solution prevented ischemia and reperfusion injury despite a very short ischemic time. The results of our study suggest that phosphate-buffered sucrose perfusion and storage solution should be effective to reduce ischemia and reperfusion injury despite a very short ischemic time in feline kidney transplantation.  相似文献   

Changes in estrogen receptor expression in the chick thymus during late embryonic development     

Masafumi Katayama  Tomokazu Fukuda  Toshimitsu Hatabu  Kiyoaki Narabara  Asaki Abe  Yasuhiro Kondo 《Animal Science Journal》2014,85(3):277-285

In chickens, although estrogen receptors (ER) are reported to be associated with the immunological processes, detailed information about the differences in ER expression in the tissues related to the development of lymphocytes is not fully known, especially during the developmental stage. To learn more about this immunological relationship, we used semi‐quantitative polymerase chain reaction method to detect the ER expression levels in the thymus tissues of chicks during the developmental stage. Furthermore, ER‐expressing cells were detected by immunohistochemistry. The results of this study show that the expression level of ER increased on embryonic day 16 and decreased on day 20. Furthermore, ER expression was significantly higher in male than in female chickens at day 16. The increased expression on day 16 and decreased level on day 20 were also reproduced in the incidence of immunoreactive cells, although there was a 1‐day delay in the elevated incidence of the cells. This study revealed the changes in ER expression and the incidence of ER‐positive cells in the thymus of chickens during the developmental stage.  相似文献   

Presumptive acute lung injury following multiple surgeries in a cat     

Masaaki Katayama  Yasuhiko Okamura  Rieko Katayama  Jun Sasaki  Shunsuke Shimamura  Yuji Uzuka  Hiroaki Kamishina  Yoshinori Nezu 《The Canadian veterinary journal. La revue veterinaire canadienne》2013,54(4):381-386

A 12-year-old, 3.5-kg spayed female domestic shorthair cat had a tracheal mass identified as malignant B-cell lymphoma. The cat had tracheal resection and subsequently developed laryngeal paralysis. Due to multiple episodes of respiratory distress the cat subsequently had tracheal surgeries. Finally, the cat had a sudden onset of severe respiratory distress and collapsed. Computed tomography imaging and arterial blood gas analysis supported a diagnosis of acute lung injury.  相似文献   

Stability and emulsion-forming ability of water-soluble fish myofibrillar protein prepared by conjugation with alginate oligosaccharide     

Sato R  Katayama S  Sawabe T  Saeki H 《Journal of agricultural and food chemistry》2003,51(15):4376-4381

Carp myofibrillar protein (Mf) was conjugated with alginate oligosaccharide (AO) through the Maillard reaction under low relative humidity, and the functional properties of the Mf-AO conjugate were investigated under different NaCl concentrations and pH levels. Mf became highly solubilized at lower NaCl concentrations by conjugation with AO, with a slight loss of available lysine. The thermal stability of Mf was effectively improved by conjugation with AO. Heat treatment at 80 degrees C for 2 h had no effect on the solubility of the Mf-AO conjugate attached to 227 microg/mg of AO regardless of the NaCl concentration and pH. Furthermore, the Mf-AO conjugate showed excellent emulsion-forming ability regardless of NaCl concentration. The improved functionalities of Mf by conjugation with AO remained even at a nearly isoelectric point. These results indicate that conjugation with AO through the Maillard reaction is an effective way to prepare high-functional food material from fish muscle protein.  相似文献   

Oxygen isotopic compositions of asteroidal materials returned from Itokawa by the Hayabusa mission     

Yurimoto H  Abe K  Abe M  Ebihara M  Fujimura A  Hashiguchi M  Hashizume K  Ireland TR  Itoh S  Katayama J  Kato C  Kawaguchi J  Kawasaki N  Kitajima F  Kobayashi S  Meike T  Mukai T  Nagao K  Nakamura T  Naraoka H  Noguchi T  Okazaki R  Park C  Sakamoto N  Seto Y  Takei M  Tsuchiyama A  Uesugi M  Wakaki S  Yada T  Yamamoto K  Yoshikawa M  Zolensky ME 《Science (New York, N.Y.)》2011,333(6046):1116-1119

Meteorite studies suggest that each solar system object has a unique oxygen isotopic composition. Chondrites, the most primitive of meteorites, have been believed to be derived from asteroids, but oxygen isotopic compositions of asteroids themselves have not been established. We measured, using secondary ion mass spectrometry, oxygen isotopic compositions of rock particles from asteroid 25143 Itokawa returned by the Hayabusa spacecraft. Compositions of the particles are depleted in (16)O relative to terrestrial materials and indicate that Itokawa, an S-type asteroid, is one of the sources of the LL or L group of equilibrated ordinary chondrites. This is a direct oxygen-isotope link between chondrites and their parent asteroid.  相似文献