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991.
Conversion of native lignin to a highly phenolic functional polymer and its separation from lignocellulosics 总被引:3,自引:0,他引:3
An original reaction system (the phase separative reaction system) has been designed for derivatizing native lignins to highly phenolic, functional polymers. This system is composed of a phenol derivative and concentrated acid, which are not miscible at room temperature. The key point of the lignin functionalization process, including the phase separative system, is that lignin and carbohdrates, which are totally different in structures and reactivitie, are modified individually in the different phases: lignin is present in the organic phase and carbohydrates in the aqueous phase. Through the process, lignin was modified selectively at Calpha-positions of side chains, the most reactive sites, to give highly phenolic, light-colored, diphenylmethane-type materials which still retained original interunit linkages formed by the dehydrogenative polymerization during the biosynthesis. The carbohydrates were swollen, followed by partial hydrolysis and dissolution in the acid solution, resulting in the perfect decomposition of interpenetrating polymer network structures in the cell wall. Therefore, the functionalization of lignin and the separation of resulting lignin from carbohydrates were quickly achieved at room temperature, independent of wood species. This process would be a powerful tool for estimating strutures and reactivities of lignins as well as the functionalization of lignins, because of the selective structural modifications. (c) 1995 John Wiley & Sons, Inc. 相似文献
992.
Takako Matsubara Yasuo Nakagome Nobuaki Ogasawara Shigehiro Oka Tsunehiro Yokochi 《Human genetics》1982,60(1):78-79
Summary An 11-month-old boy with typical Down's syndrome is presented. His karyotype was 47,XY,+r(21); the erythrocyte superoxide dismutase-1 (SOD-1) activity was elevated. His phenotypically normal mother showed 46,XX,r(21) karyotype and normal SOD-1 activity. Analysis of chromosomal heteromorphism revealed that in addition to the ring, a normal chromosome 21 was transmitted from the mother. 相似文献
993.
Wada Keishiro; Matsubara Hiroshi; Chain Richard K.; Arnon Daniel I. 《Plant & cell physiology》1981,22(2):275-281
Pairs of two molecular species of soluble chloroplast-type ferredoxins(Fd I and Fd II) from Nostoc muscorum and Aphanothece sacrumwere used to examine and compare the abilities of ferredoxinto substitute for spinach ferredoxin in the photoreduction ofNADP+ by spinach chloroplasts or N. muscorum membrane fragmentsand to link the reducing power of illuminated spinach chloroplaststo the Bacillus polymyxa nitrogenase system. Ferredoxins II of Nostoc and Aphanothece showed rather low activitiesin NADP+ photoreduction and nitrogenase system with spinachchloroplasts as the photosensitizer, compared to other ferredoxins.However, there was no difference between two ferredoxins (FdI and Fd II) from Nostoc in NADP+ photoreduction by photosyntheticmembrane fragments prepared from the same organism, N. muscorum. The biological significance of two molecular species of ferredoxinsin one organism could be ascribed to the different contributionof each ferredoxin to certain biological reactions in whichferredoxin functioned as an electron carrier. (Received November 4, 1980; Accepted January 9, 1981) 相似文献
994.
Summary A derivative of plasmid F which is packageable in phage coat was constructed using techniques of in vitro recombination. This plasmid is composed of three DNA fragments generated by restriction enzyme EcoRI: a miniF fragment (fragment f5 of F'lac) which is able to replicate autonomously, a DNA fragment from Staphylococcus Plasmid that carries the -lactamase gene, and a portion of guaA (B) transducing phage DNA carrying cohesive ends (cos site) along with almost all the late genes but devoid of all those genes and sites that are needed for replication, regulation, and recombination. The hybrid plasmid has a molecular weight of 2.7×107 daltons, about 84% size of phage genome, and can be packaged in coat when helper phage replicates in the plasmid-carrier cell. The package plasmid and the helper phage particles are separated by CsCl density gradient centrifugation. The replication characteristics of the recombinant plasmid are all those of F including the copy number, incompatibility, and curing with acidine orange. The packaged plasmid is injected into an F- cell and establishes a plasmid state with normal efficiency. In F+ or Hfr cells, the resident F factor hinders this process. 相似文献
995.
996.
A morphological and biochemical study was performed on thyroid tissue with various thyroid diseases. The thyroid peroxidase (TPO) activity of normal thyroid tissues ranged from 2.6 to 7.0 mGU/mg DNA. The activity was low in adenomas and extremely low in carcinomas, and there was no significant relationship between the histological subclassification of follicular adenomas (simple, colloid, oxyphil) and TPO activity. The activity was various in the cases of chronic thyroiditis, ranging from non-detectable to 9.8 mGU/mg DNA, and the TPO activity showed a close correlation with the degree of lymphoid cell infiltration of the diseases. In the seven cases of Graves' disease, the values were high, though the elevation was not so remarkable in three cases which had already been euthyroid or slightly hypothyroid after long-term treatment. By means of subcellular fractionation, more than 50% of peroxidase activity was shown to be localized in the microsomal pellets, and this result well coincided with the electron microscopic findings of prominent development of rER. 相似文献
997.
Tamizi Sugiyama Eizo Kitamura Shigeru Kubokawa Setsuko Kobayashi Takeshi Hashizume Satoshi Matsubara 《Phytochemistry》1975,14(12):2539-2543
Three 7-acylaminoimidazo[4,5-b]pyridines, namely 7-pentanoylaminoimidazo[4,5-b]pyridine (1), 7-benzoylaminoimidazo[4,5-b]pyridine(2), and 7-(2-furoylamino)imidazo[4,5-b]pyridine(3), six 4-acylaminoimidazo[4,5-c]pyridines, namely 4-propionylaminoimidazo[4,5-c]pyridine(4), 4-butyryl-aminoimidazo[4,5-c]pyridine(5), 4-pentanoylaminoimidazo[4,5-c]pyridine(6) 4-hexanoylaminoimidazo[4,5-c]pyridine(7),4-benzoylaminoimidazo[4,5-c]pyridine(8), and 4-(2-furoylamino)imidazo[4,5-c]-pyridine(9), and seven 7-acylaminoimidazo[4,5-c]pyridines, namely 7-propionylaminoimidazo[4,5-c]-pyridine(10), 7-butyrylaminoimidazo[4,5-c]pyridine(11), 7-pentanoylaminoimidazo[4,5-c]pyridine(12), 7-hexanoylaminoimidazo[4,5-c]pyridine(13), 7-benzoylaminoimidazo[4,5-c]pyridine(14), 7-phenylacetylaminoimidazo[4,5-c]pyridine(15), and 7-(2-furoylamino)imidazo[4,5-c]pyridine(16) were synthesized and tested for their cytokinin activity with the tobacco callus bioassay. 2 showed a cytokinin activity at 1 × 10−8 M and gave a callus yield about 72% of that produced by kinetin at 1 × 10−6 M. 1, 3 and 8 showed the optimum growth responses in the range of 10−7−10−6 M. 4, 5, 7, 9–16 were slightly active. These results support previous reports that a nitrogen atom at the 3-position in the purine ring plays an important role in conferring high cytokinin activity. 相似文献
998.
In previous papers [1–2], it was reported that sphingophosphonolipids obtained from the viscera of Turbo cornutus consisted of two types of ceramide 2-N-methyl-aminoethylphosphonates, CMAEP-I and CMAEP-II.1 These sphingophosphonolipids were found to contain uncommon long chain bases, which were identified as C22-sphingadienine in CMAEP-I and C22-dehydrophytosphingosine in CMAEP-II by gas chromatography-mass spectrometric analysis of their corresponding trimethylsilyl derivatives. However, the double bond positions of these two long chain bases remained to be clarified.In this communication, we wish to report that the structures of these two long chain bases are docosa-4,15-sphingadienine and 4-hydroxy-docosa-15-sphingenine 相似文献
999.
Tsunehiro Mukai Kenichi Matsubara Yasuyuki Takagi 《Molecular & general genetics : MGG》1976,146(3):269-274
Summary Fragments ofEscherichia coli DNA carrying genes for -galactosidase, or for biosynthesis of guanine or biotin were recombined in vitro with dv DNA. The cloned recombinant molecules recovered from transformedE. coli cells consisted of a biologically functional bacterial DNA fragment and, except for dv-bio30-7, two dv monomer units: one of the dv units was used as the insertion site for the bacterial DNA, whereas the other was intact, and seemed to be responsible for the replication of the recombinant plasmid. The process which gives rise to these recombinant molecules at high frequency from mixtures of monomeric dv DNA's and bacterial DNA fragments is discussed. 相似文献
1000.
Structural studies on glycolipid of shellfish. III. Novel glycolipids from Turbo cornutus 总被引:2,自引:0,他引:2
Five kinds of sphingoglycolipids were isolated from Turbo cornutus. Four of them were a series of novel glycolipids consisting only of galactose. The structures of these glycolipids were studied by methylation analysis, periodate oxidation, enzymatic degradation, and proton magnetic resonance spectroscopy. Three glycolipids were characterized as galactosyl(beta 1 leads to 1)ceramide, galactosyl(beta 1 leads to 6)galactosyl(beta 1 leads to 1)ceramide, and galactosyl(beta 1 leads to 6)galactosyl(beta 1 leads to 6)galactosyl(beta 1 leads to 1)ceramide. Data indicating that the 4th glycolipid might be the tetragalactosyl derivative of this series were obtained. The carbohydrate moiety of the 5th glycolipid, in contrast, was composed of fucose, galactose, glucose and N-acetylglycosamine in a molar ratio of 1 : 2 : 1 : 1. 相似文献