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The β-carbon of the acyl group of β-hydroxy-β-methylglutarylhydroxyabscisic acid was shown to possess R-configuration by HPLC analysis of the reduced product. 相似文献
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A. O. Adede 《Ocean Development & International Law》2013,44(1-2):31-64
Abstract The Group of 77 favors the establishment of a strong International Sea‐Bed Authority with powers to regulate and control all the activities of exploration and exploitation of the “common heritage of mankind,”; referred to in the draft articles as “the Area.”; The Authority itself is to be composed of an Assembly as the supreme policy‐making organ in which the Contracting Parties are to be represented on the basis of sovereign equality; a Council as the executive organ implementing the policies emanating from the Assembly, to be composed of at least 36 states elected to ensure representation of clearly defined special interests and the principle of equitable geographical distribution, and to eschew any form of veto mechanism in its decision‐making process; the Enterprise as the operational organ through which the Authority is to undertake direct exploitation of the Area along with the other entities given access to the Area; and a Secretariat as well as certain subsidiary bodies of the Council. The Group of 77 takes the position that the Convention itself and the Basic Conditions governing the entire process of exploration and exploitation of the Area must leave the Authority an appreciable margin of discretion in managing the Area for the benefit of mankind as a whole. Thus, a limited category of judicially reviewable decisions of the Authority is envisaged so long as such review does not challenge the legislative powers and resource policy decisions of the Authority. A Sea‐Bed Tribunal is no longer necessary as an organ of the Authority, since the work of such a Tribunal could be done by the special Sea‐Bed Disputes Chamber of the Proposed Law of the Sea Tribunal dealing with disputes arising under the Convention as a whole. 相似文献
4.
Galina T. Babkina Jiří Jonák Ivan Rychlík 《Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression》1982,698(2):116-127
New types of azidoaryl analogs of GTP: γ-(4-azido)anilide of GTP (I), γ-(N-(4-azidobenzyl)-N-methyl)amide of GTP (II) and of GDP: β-(4-azido)anilide of GDP (III), β-(N-(4-azidobenzyl)-N-methyl)amide of GDP (IV) have been synthesized by treatment of the nucleotide in aqueous solution with N-cyclohexyl-N′-β-(4-methylmorpholinium)- ethylcarbodiimidep-toluene sulfonate and the respective amine. The analog of GTP bearing at the γ-phosphate an alkylating 2-chloroethylamino group: γ-(4-N-(2-chloroethyl)-N-methylaminobenzyl)amide of GTP (V) was prepared by the method described previously for the preparation of the analog of ATP (Knorre, D.G., Kurbatov, V.A. and Samukov, V.V. (1976) FEBS Lett. 70, 105–108). Azidoaryl analogs of GTP and GDP as well as the chloroethylaminoaryl analog of GTP compete with GDP in the formation of the binary complex EF-Tu·GDP with the respective Ki values 3.9·10?7 M (I), 2.9·10?8 M (II), 6.9·10?7 M (III), 5.0·10?7 M (IV) and 3.8·10?8 M (V) relative to GDP. constants of the complexes of the radioactively-labeled GTP analogs I, II and V with elongation factor Tu were calculated to be 8.5·10?6 M, 3.4·10?7 M and 4.6·10?8 M, respectively, or approx. 1740-, 70- and 9-times greater than that of GDP. GTP analogs I, II and V were found to substitute GTP in the stimulation of EF-Tu-dependent binding of aminoacyl-tRNA to the ribosome-mRNA complex. 相似文献
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Are the supportive structures of the tardigrade pharynx homologous throughout the entire group? 总被引:1,自引:0,他引:1
Based on the differences in position, structure and function of the cuticular supportive structures in the pharynx of representatives of two major groups of tardigrades, the Heterotardigrada and Eutardigrada, it is postulated that these structures are not homologous throughout the Tardigrada. Hithero, these structures have been termed placoids in both classes (fused placoids in Heterotardigrada versus macro- and microplacoids in Eutardigrada). It is proposed here that there are two different kinds of fused placoids within the Heterotardigrada and that only one of these is homologous to the macro- and microplacoids of the Eutardigrada. It is furthermore proposed that the plesiomorphic condition for the tardigrade pharynx is without reinforced cuticular supportive structures and not the presence of encrusted fused placoids as found in Heterotardigrada. 相似文献
8.
Andrea Caporale Iwona Woznica Elisabetta Schievano Stefano Mammi Evaristo Peggion 《Amino acids》2010,38(4):1269-1275
A series of PTH hybrids containing a diamine [NH2(CH2)
n
NH2; n = 4, 5, 6] in the C-terminal position was synthesized based on the H-Aib-Val-Aib-Glu-Ile-Gln-Leu-Nle-His-Gln-Har-NH2 (Har = homoarginine) template. The compounds were pharmacologically characterized at PTH1R receptors for agonist activity. 相似文献
9.
Bae JS 《Journal of cellular biochemistry》2011,112(9):2502-2507
It is well known that the expression level of secretory group IIA phospholipase A(2) (sPLA(2)-IIA) is elevated in inflammatory diseases and lipopolysaccharide (LPS) up-regulates the expression of sPLA(2)-IIA in human umbilical vein endothelial cells (HUVECs). Recently, lower concentration thrombin could elicit anti-inflammatory responses in HUVECs. Here, the effects of lower concentration thrombin on the expression of sPLA(2)-IIA in LPS-stimulated HUVECs were investigated. Prior treatment of cells with thrombin (25-75 pM) inhibited LPS-induced sPLA(2)-IIA expression by activating its receptor, protease-activated receptor-1 (PAR-1). And pretreatment of cells with either PI3-kinase inhibitor (LY294002) or cholesterol depleting agent (methyl-β-cyclodextrin, MβCD) abolished the inhibitory activity of thrombin against sPLA(2)-IIA expression. Therefore, these results suggest that PAR-1 activation by lower concentration thrombin inhibited LPS mediated expression of sPLA(2)-IIA by PAR-1 and PI3-kinase-dependent manner in lipid raft on the HUVECs. 相似文献
10.
Yoshimoto Y Jyojima T Arita T Ueda M Imoto M Matsumura S Toshima K 《Bioorganic & medicinal chemistry letters》2002,12(24):3525-3528
Synthetic analogue of the concanamycins, which lacks the hydrogen bond network existing in the concanamycin structure, retains vacuolar-type H+-ATPase (V-ATPase) inhibitory activity and induces apoptosis to cancer cells that overexpressing epidermal growth factor receptors (EGFR). 相似文献
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Q- and C-band polymorphism of heterochromatic regions of chromosomes were studied in a group of patients with Turner's syndrome (30 girls with the karyotype 45, X) and in 105 normal individuals. No significant differences in the frequencies of Q-polymorphic variants for the most part of chromosomes studied (with the exception of chromosome 13 satellites) were obtained between patients with Turner's syndrome and the control. There were no differences in the mean number of Q-variants per individual in both groups investigated. An increase in the frequency of large C-segments of chromosome 9 was detected in patients with Turner's syndrome. An increase in the frequency of individuals carrying a combination of several extreme variants in the individual karyotype was found for patients with Turner's syndrome. The differences revealed are of non-specific character for a given form of developmental pathology. 相似文献
12.
Wolfram Zillig Karl O. Stetter Simon Wunderl Wolfgang Schulz Harro Priess Ingrid Scholz 《Archives of microbiology》1980,125(3):259-269
The similarity of the morphology and of DNA composition, the homology of the component patterns of DNA-dependent RNA polymerases and their immunochemical crossreactivity support the conclusion that several extreme thermoacidophiles are related to each other. We name two new species of the genus Sulfolobus. The first, Sulfolobus solfataricus (DSM 1616 and DSM 1617) has the same GC content in its DNA and the same general properties as S. acidocaldarius, but differs significantly from the latter species in the molecular weights of the 11 components of its RNA polymerase and in the salt requirements of this enzyme. The second, Sulfolobus brierleyi, DSM 1651, differs from S. acidocaldarius in several respects. The cells show much less stability at neutral pH. The GC content is significantly lower. The RNA polymerase lacks two components present in the enzymes from the other species. The residual 9 components show larger size differences from the homologous subunits of the S. acidocaldarius enzyme.Like the enzyme from S. solfataricus, the polymerase from S. brierleyi yields an incomplete immunochemical crossreaction with an antibody against the RNA polymerase from S. acidocaldarius.The isolates DSM 1616 and DSM 1617 of Sulfolobus solfataricus are probably identical with or similar to the Caldariella strains MT 3 and MT 4, isolated by de Rosa et al. (1975).Like all other known archaebacterial RNA polymerases the enzymes from these species are insensitive to rifampicin and streptolydigin.Abbreviations G+C
Guanine + Cytosine
- HPLC
High Performance Liquid Chromatography
- SAB
Similarity coefficient between two different RNAs as defined by Fox et al. (1977)
- SDS
Sodium dodecylsulfate (Sodium laurylsulfate), SSC 0.15 M NaCl, 0.015 M Na Citrate pH 7.4 相似文献
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Natalia Cecilia Moreno L. Stiefkens M. L. Las Pe?as A. Bartoli R. Tortosa G. Bernardello 《Plant Systematics and Evolution》2012,298(8):1503-1514
Fourteen North American members of the “Xanthocephalum group” were studied by classical and molecular cytogenetics. Location and number of rDNA sites were determined by FISH. For the 5S rDNA, a probe was obtained from Prionopsis ciliata. Most species were diploid (2n?=?12), although Isocoma menziesii, Grindelia hirsutula, G. robusta, both varieties of G. stricta, and one population of G. camporum were tetraploid (2n?=?24). Diploid Grindelia and Prionopsis ciliata were 5m?+?1sm, tetraploids 10m?+?2sm, except G. hirsutula (8m?+?4sm), and Isocoma and Olivaea 6m?+?2sm and 3m?+?3sm, respectively. Most species had satellites on the short arms of m pairs: two in tetraploids and P. ciliata and one in diploids. Satellites were associated with two CMA+/DAPI? bands in diploid species and four bands in tetraploids and in P. ciliata. rDNA loci (two in diploids to four in tetraploids) may be indicative of ploidy level. Grindelia tetraploids could have originated recently by autopolyploidy. Chromosome duplication was followed by modifications in the genome structure, resulting in higher heterochromatin amounts not associated with NORs. There is only one 5S site per basic genome in para or pericentromeric regions. Although not always large, chromosome variation has accompanied the evolutionary divergence of the taxa studied. 相似文献
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Max Henry 《Phytochemistry Reviews》2005,4(2-3):89-94
The chemical structure of triterpenoid saponins is quite complicated, especially the glucuronide oleanane-type triterpene
carboxylic acid 3,28-bidesmosides (GOTCAB) saponins. Moreover, triterpenoid saponins are numerous as a result of this complicated
structure. This review tries to explain this diversity in terms of plant classification and phylogeny. The study focuses on
the three main successive steps of the biosynthetic pathway of the triterpenoid saponins: cyclisation, oxidation and glycosylation
showing the relationship between triterpenols and sterols in terms of cell membrane evolution and the importance of which
metabolic intermediates involved as aglycones of the triterpenoid saponins, represented progressively less and less in the
advanced groups of the plant kingdom as they are more and more oxidised. This oxidation seems to reflect a better adaptation
to new environmental conditions of some of these groups. By their enormous chemical diversity, the triterpenoid saponins seem
to be good candidates to study the phylogeny of the flowering plants. A first attempt is given using recent advances in botanical
classification for the orders and families by the Angiosperm Phylogenic Group (APG). This study was simplified in the first
step focusing only on the “gypsogenin group” of the GOTCAB saponins. For example, as a result, these compounds are mainly
concentrated in advanced groups such as Caryophyllideae, primitive Rosideae and Asterideae. 相似文献
15.
The nature of the DR
II pseudogene in a haplo-type of the DRw52 supertypic group was investigated by nucleotide sequence analysis. It revealed several deleterious mutations in the signal sequence and second domain regions in addition to the complete absence of the first domain and adjacent sequences. No expression of DR
II pseudogene mRNA can be detected. The same DR
II pseudogene is probably present in other members of the DRw52 supertypic group. The pattern of mutations in this DR
II pseudogene is different from that observed in the DR
pseudogene of the DRw53 supertypic group, indicating a distinct evolutionary pathway for these two groups of DR haplotypes. 相似文献
16.
Karin Lindström Per-Åke Jovall Sohbat Ghardashkani Bo E. Samuelsson Michael E. Breimer 《Glycoconjugate journal》1996,13(2):307-313
Total neutral glycolipid fractions were isolated from kidney and ureter tissue obtained at autopsy of an individual of the rare blood group A1 Le(a–b+) p. The amount of glycolipids isolated were 3.7 and 2.5 mg g–1 dry tissue weight for the kidney and ureter tissue, which is in the range of reference blood group P kidneys. Part of the kidney glycolipid fraction was subfractionated by HPLC. Glycolipid compounds were structurally characterized by thin-layer chromatography (chemical detection and immunostaining with monoclonal antibodies), proton NMR spectroscopy and mass spectrometry. Globotriaosyl- and globotetraosyl-ceramides, which are the major compounds in kidneys of P individuals, were absent in the p kidney, and a comparatively increased amount of monoglycosyland lactosylceramides was found. A shift to longer fatty acyl chains in the ceramide part of lactosylceramides was noted. Elongated globoseries compounds with five to seven sugar residues, including the blood group A type 4 chain structure, were lacking. A slight increase in neolactotetraosyl- and blood group X pentaglycosyl-ceramides was noticed. The study confirms an enzymatic block in the conversion of lactosylceramide to elongated globoseries compounds in the kidney tissue similar to that of erythrocytes of p individuals.Abbreviations: for blood group glycolipid antigens the short hand designation stands for: blood group — number of sugar residues — type of carbohydrate chain. Thus A-7-4 means a blood group A heptaglycoconjugate on a type 4 chain. The sugar types are abbreviated for mass spectrometry to Hex for hexose, HexNAc forN-acetylhexosamine and dHex for deoxyhexose. HPLC, high-performance liquid chromatography; HPTLC, high performance thin layer chromatography; EI, electron impact ionisation; LSI, liquid secondary ion; MS, mass spectrometry; NMR, nuclear magnetic resonance. 相似文献
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Demographic data of genetic interest were studied in presently living population in comparison with preseding generations of Nganasans. Decrease of sex ratio in the whole population has been revealed along with the reduction of reproductive and, possibly, effective size. The number and variance of livebirths per female were 7.29 and 9.86 respectively. Crow' index of the opportunity for selection (I) and its components (Im and If) were estimated. I was found to be 1.17, whereas Im and If--1.56 and 0.18 respectively. Linear pattern of settling in the past as well as the type of migration between adjoining subpopulations depended on culture and economy of arctic reindeer hunters as well as landscape character. 相似文献
18.
The requirement for the protonated α-amino group for the transport of peptides in Escherichia coli 总被引:1,自引:1,他引:0
J. W. Payne 《The Biochemical journal》1971,123(2):245-253
Many glycine peptides support growth of a glycine auxotroph of Escherichia coli. If the alpha-amino group of these peptides is methylated, the products are still utilized for growth, and also retain comparable ability with the unsubstituted peptides to compete with natural peptides for transport into the cell. In contrast, glycine peptides devoid of an alpha-amino group, or that have the alpha-amino group substituted by one of a number of acyl groups are not utilized, although E. coli possesses intracellular enzymic activity able to release glycine from such compounds; further, these derivatives do not compete with natural peptides for transport into the cell. 相似文献
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Naoto Kojima Masato Abe Yuki Suga Kazufumi Ohtsuki Tetsuaki Tanaka Hiroki Iwasaki Masayuki Yamashita Hideto Miyoshi 《Bioorganic & medicinal chemistry letters》2013,23(5):1217-1219
C34-epi and C34-epi-C35-trifluoro analogues of solamin, a mono-THF annonaceous acetogenin, were synthesized. Their inhibitory activity, along with previously synthesized analogues (C35-fluoro, C35-difluoro, and C35-trifluorosolamins), against bovine mitochondrial NADH–ubiquinone oxidoreductase (complex I) was determined. The present study revealed that the methyl group on the γ-lactone moiety is critical to the potent inhibition of complex I by natural acetogenins. 相似文献
20.
Seth PP Allerson CR Berdeja A Swayze EE 《Bioorganic & medicinal chemistry letters》2011,21(1):588-591
The synthesis and hybridization properties of an α-L-LNA analog where the 2'-oxygen atom is replaced with an exocyclic methylene group is reported. Contrary to the β-D series where the exocyclic methylene group is extremely well tolerated, this group was very poorly tolerated in the α-L-series and lead to duplex destabilization. Modeling studies showed that the exocyclic methylene group results in a steric clash with the nucleobase 3' to the modified residue. Based on this structural model one can anticipate that replacing the 2'-oxygen atom of α-L-LNA with larger groups is likely to be detrimental to duplex stability. The model also provides insights into what type of 2',4'-bridges are most likely to be tolerated in α-L-LNA modified oligonucleotide duplexes. 相似文献