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1.
Summary The secretory pathway of the complex-type glycoprotein specific to the subcommissural organ (SCO) was examined using the monoclonal antibody (Mab) C 1B 8A 8. Immunoreactive material was revealed in various compartments of the secretory ependymocyte, i.e., the endoplasmic reticulum, the Golgi area and the secretory vacuoles. In addition, immunoreactive material was also observed in the ventricular cavity. Evidence of a release both at the apical lining and at the basal process of the SCO ependymocytes suggests that the same protein could be secreted into the cerebrospinal fluid and the perivascular spaces. After immunoaffinity chromatography of soluble extracts of the SCO on Mab C 1B 8A 8 immunoadsorbent columns, three glycopeptides were identified on Western blots; they were concanavalin A (Con A)-positive (88, 54 and 34 kDa) and wheat-germ agglutinin (WGA)-positive (54 and 34 kDa). The Con A-positive glycopeptide (88 kDa) is probably related to the high-mannose-type glycoprotein, the precursor form of the secreted compound, whereas the 54 kDa-glycopeptide that is both Con A- and WGA-positive could represent an intermediate form. The 34 kDa-glycopeptide that is strongly WGA-positive could be related to the monomeric form of the secreted compound. These three glycopeptides were not revealed in eluted fractions of soluble extracts of the ependyma that served as control. 相似文献
2.
Abstract To elucidate the effect of guanine lesion produced by the oxidative damage on DNA, 1 nanosecond molecular dynamics simulations of native and oxidized DNA were performed. The target DNA molecules are dodecamer duplex d(CGCGAATTCGCG)2 and its derivative duplex d(C 1G 2C 3(8-oxoG) 4A 5A 6T 7T 8C 9G 10C 11G 12)·d(C 13G 14C 15G 16A 17A 18T 19T 20C21 G22C 23G 24), which has one oxidized guanine, 7, 8-dihydro-8-oxoguanine (8-oxoG), at the fourth position. The local structural change due to the lesion of 8-oxoG and the global dynamic structure of the 8-oxoG DNA were studied. It was found that the 8-oxoG DNA remained structurally stable during the simulation due to newly produced hydrogen bonds around the (8-oxoG) 4 residue. However, there were distinguishable differences in structural parameters and dynamic property in the 8-oxoG DNA. The conformation around the (8- oxoG) 4 residue departed from the usual conformation of native DNA and took an unique conformation of ?-ζ in B II conformation and χ in high anti orientation at the (8-oxoG) 4 residue, and adopted a very low helical twist angle at the C 3:G 22—(8-oxoG) 4:C 21 step. Further analysis by principal component analysis indicated that the formation of the hydrogen bonds around the (8-oxoG) 4 residue plays a role as a trigger for the conformational transition of the 8-oxoG DNA in the conformational space. 相似文献
3.
Abstract— Proteins of the brain extracts of 85 individual pigeons ( Columba livia) were mapped by two-dimensional gel electrophoresis. The method is a modification of O'Farrell 'S technique and separates proteins first by charge and then by molecular weight. There were three proteins, A, B and D which had each a variant form. The positions of these six proteins on the gel corresponded to the following pH values and molecular weight values: protein A 1, 6.4/43,000; A 2, 6.6/43,000; B 1, 5.7/41,000; B 2, 5.8/40,000; D 1, 6.2/22,000; D 2, 6.2/21,000. The variants are genetically determined, since protein A, B and D each occurred in three phenotypes (A 1, A 1A 2 and A 2; B 1, B 1B 2 and B 2; D 1, D 1D 2 and D 2) corresponding to the three possible genotypes. From the observed frequencies of the phenotypes the following allele frequencies were calculated: allele A 1, 72%; A 2, 28%; B 1, 15%; B 2, 85%; D 1, 74%; D 2, 26%. A fourth protein named C occurred in four different forms (C 1, 7.2/37,000; C 2, 7.2/36,000; C 3, 7.1/37,000; C 4, 7.1/36,000) and six phenotypes (C 1, C 1C 2, C 2, C 1C 3, C 2C 3 and C 4C 3). This polymorphism is also interpreted as being genetically determined. The four alleles coding for the four protein C forms had the following frequencies: allele C 1, 62%; C 2, 27%; C 3, 10.5%; C 4, 0.5%. 相似文献
5.
In order to identify a high-affinity, selective antagonist for the A 2B subtype adenosine receptor, more than 40 1,8-disubstituted-3-(3-methoxypropyl) xanthines were prepared and evaluated for their binding affinity at recombinant human adenosine receptors, mainly of the A 2A and A 2B subtypes. Some of the 1-ethyl-3-(3-methoxypropyl)-8-aryl substituted derivatives 15(a– m) showed moderate-to-high affinity at human A 2B receptors, with compound 15d showing A 2B selectivity over the other A receptors assayed (A 1, A 2A, A 3) of 34-fold or over. 相似文献
6.
SCO (synthesis of cytochrome c oxidase) proteins are involved in the assembly of the respiratory chain enzyme cytochrome c oxidase acting to assist in the assembly of the Cu A center contained within subunit II of the oxidase complex. The Cu A center receives electrons from the reductive substrate ferrocytochrome c, and passes them on to the cytochrome a center. Cytochrome a feeds electrons to the oxygen reaction site composed of cytochrome a3 and Cu B. Cu A consists of two copper ions positioned within bonding distance and ligated by two histidine side chains, one methionine, a backbone carbonyl and two bridging cysteine residues. The complex structure and redox capacity of Cu A present a potential assembly challenge. SCO proteins are members of the thioredoxin family which led to the early suggestion of a disulfide exchange function for SCO in Cu A assembly, whereas the copper binding capacity of the Bacillus subtilis version of SCO (i.e., BsSCO) suggests a direct role for SCO proteins in copper transfer. We have characterized redox and copper exchange properties of apo- and metalated-BsSCO. The release of copper (II) from its complex with BsSCO is best achieved by reducing it to Cu(I). We propose a mechanism involving both disulfide and copper exchange between BsSCO and the apo-Cu A site. This article is part of a Special Issue entitled: Biogenesis/Assembly of Respiratory Enzyme Complexes. 相似文献
7.
Homozygous typing cells from 13 normal HLA-A1, B8, Dw3, DR3 and five normal HLA-A26, Bw38, Dw10, DR4 individuals were typed for the following markers: HLA-SB, MB, MT; complement proteins BF, C2, C4A, C4B; and GLO. Ninety-one percent of A1, B8, Dw3, DR3 homozygous individuals (HI) tested were homozygous for BF
*
S, C2
*
C, C4A
*
QO, and C4B
*1 ( SCO1 complotype), which indicates that the SCO1 complotype is in linkage disequilibrium with the A1, B8, DR3 haplotype in randomly selected normal populations. Sixty-seven percent of HLA-A1, B8, Dw3, DR3, SCO1 positive HI also expressed SB1; since the frequency of SB 1 in random Caucasian populations is 11.2%, this finding indicates that SB1 is in linkage disequilibrium with the A1, B8, DR3, SCO1 extended haplotype. All HI with the A26, Bw38, Dw10, DR4 haplotype were homozygous for both SC21 and SB4, suggesting that SC21 and SB4 should be included in the A26, Bw38, Dw10, DR4 extended haplotype. On the other hand, neither of the GLO markers were found in association with either haplotype. The results of this study indicate that HLA-SB is included in some extended haplotypes and may be important in these markers for diseases such as insulin-dependent diabetes mellitus. This study also demonstrated an apparent influence of HLA-SB on primary mixed lymphocyte culture (MLC) responses. The mean relative response of primary MLCs between individuals matched for HLA-A, B, D, DR, MB and MT but not SB was 40% of that for the MLCs with mismatched HLA-D, significantly higher than the MLCs matched for all HLA and complotypes. 相似文献
8.
The synthesis of a series of 9-ethyladenine derivatives bearing alkynyl chains in 2- or 8-position was undertaken, based on the observation that replacement of the sugar moiety in adenosine derivatives with alkyl groups led to adenosine receptor antagonists. All the synthesized compounds were tested for their affinity at human and rat A 1, A 2A, and A 3 adenosine receptors in binding assays; the activity at the human A 2B receptor was determined in adenylyl cyclase experiments. Biological data showed that the 2-alkynyl derivatives possess good affinity and are slightly selective for the human A 2A receptor. The same compounds tested on the rat A 1 and A 2A subtypes showed in general lower affinity for both receptors. On the other hand, the affinity of the 8-alkynyl derivatives at the human A 1, A 2A, and A 2B receptors proved to be lower than that of the corresponding 2-alkynyl derivatives. On the contrary, the affinity of the same compounds for the human A 3 receptor was improved, resulting in A 3 selectivity. As in the case of the 2-alkynyl-substituted compounds, the 8-alkynyl derivatives showed decreased affinity for rat receptors. However, it is worthwhile to note that the 8-phenylethynyl-9-ethyladenine was the most active compound of the two series ( Ki in the nanomolar range) at both the human and rat A 3 subtype. Docking experiments of the 2- and 8-phenylethynyl-9-ethyladenines, at a rhodopsin-based homology model, gave a rational explanation of the preference of the human A 3 receptor for the 8-substituted compound. 相似文献
9.
Phytostabilization strategies may be suitable to reduce the dispersion of uranium (U) and the overall environmental risks
of U-contaminated soils. The role of Glomus intraradices, an arbuscular mycorrhizal (AM) fungus, in such phytostabilization of U was investigated with a compartmented plant cultivation
system facilitating the specific measurement of U uptake by roots, AM roots and extraradical hyphae of AM fungi and the measurement
of U partitioning between root and shoot. A soil-filled plastic pot constituted the main root compartment (C A) which contained a plastic vial filled with U-contaminated soil amended with 0, 50 or 200 mg KH 2PO 4−P kg –1soil (C B). The vial was sealed by coarse or fine nylon mesh, permitting the penetration of both roots and hyphae or of just hyphae.
Medicago truncatula plants grown in C A were inoculated with G. intraradices or remained uninoculated . Dry weight of shoots and roots in C A was significantly increased by G. intraradices, but was unaffected by mesh size or by P application in C B. The P amendments decreased root colonization in C B, and increased P content and dry weight of those roots. Glomus intraradices increased root U concentration and content in C A, but decreased shoot U concentrations. Root U concentrations and contents were significantly higher when only hyphae could
access U inside C B than when roots could also directly access this U pool. The proportion of plant U content partitioned to shoots was decreased
by root exclusion from C B and by mycorrhizas (M) in the order: no M, roots in C B > no M, no roots in C B > M, roots in C B > M, no roots in C B. Such mycorrhiza-induced retention of U in plant roots may contribute to the phytostabilization of U contaminated environments. 相似文献
10.
Summary We compared the homologous amino acid sequences of hevein and each of the four domains (A, B, C, and D) of wheat germ agglutinin and used them to construct a pseudophylogenetic tree relating these sequences to a hypothetical common ancestor sequence. In the crystal structure of the wheat germ agglutinin dimer, six pseudo-twofold rotational symmetry axes have previously been located in addition to the true twofold axis. Four of these relate two nonidentical domains to each other in each of the four possible pairs constituting the sugar-binding sites (A 1D 2, A 2D 1, B 1C 2, and B 2C 1). The remaining two relate contiguous unique pairs of sugar-binding sites to each other (A 1D 2 to B 1C 2, and A 2D 1 to B 2C 1). These latter two sets of pairs are related to each other by the true twofold axis. Side chains that mediate sugar binding in the interfaces of each of the four pairs were found to be largely conserved. The sequence homology, taken together with these pseudo-symmetry elements in the dimer structure, suggests a pathway for the evolution of the four-domain molecule from a single-domain dimer that can be correlated with simultaneous development of the saccharide-binding sites. 相似文献
11.
From ezomycin complex produced by a strain of Streptomyces were isolated four components named ezomycins A 1 (C 26H 40N 8O 16S), A 2 (C 19H 28N 6O 13), B 1 (C 26H 39N 7O 17S) and B 2 (C 19H 27N 5O 14) which are new pyrimidine nucleosides. Ezomycins A 1 and B 1 containing l-cystathionine were found to be responsible for specific antimicrobial activity of the complex against Sclerotinia and Botrytis species. 相似文献
12.
Coinhibitory PD-1/PD-L1 (B7-H1) interactions provide critical signals for the regulation of autoreactive T-cell responses. We established mouse models, expressing the costimulator molecule B7.1 (CD80) on pancreatic beta cells (RIP-B7.1 tg mice) or are deficient in coinhibitory PD-L1 or PD-1 molecules (PD-L1 −/− and PD-1 −/− mice), to study induction of preproinsulin (ppins)-specific CD8 T-cell responses and experimental autoimmune diabetes (EAD) by DNA-based immunization. RIP-B7.1 tg mice allowed us to identify two CD8 T-cell specificities: pCI/ppins DNA exclusively induced K b/A 12–21-specific CD8 T-cells and EAD, whereas pCI/ppinsΔA 12–21 DNA (encoding ppins without the COOH-terminal A 12–21 epitope) elicited K b/B 22–29-specific CD8 T-cells and EAD. Specific expression/processing of mutant ppinsΔA 12–21 (but not ppins) in non-beta cells, targeted by intramuscular DNA-injection, thus facilitated induction of K b/B 22–29-specific CD8 T-cells. The A 12–21 epitope binds K b molecules with a very low avidity as compared with B 22–29. Interestingly, immunization of coinhibition-deficient PD-L1 −/− or PD-1 −/− mice with pCI/ppins induced K b/A 12–21-monospecific CD8 T-cells and EAD but injections with pCI/ppinsΔA 12–21 did neither recruit K b/B 22–29-specific CD8 T-cells into the pancreatic target tissue nor induce EAD. PpinsΔA 12–21/(K b/B 22–29)-mediated EAD was efficiently restored in RIP-B7.1 +/PD-L1 −/− mice, differing from PD-L1 −/− mice only in the tg B7.1 expression in beta cells. Alternatively, an ongoing beta cell destruction and tissue inflammation, initiated by ppins/(K b/A 12–21)-specific CD8 T-cells in pCI/ppins+pCI/ppinsΔA 12–21 co-immunized PD-L1 −/− mice, facilitated the expansion of ppinsΔA 12–21/(K b/B 22–29)-specific CD8 T-cells. CD8 T-cells specific for the high-affinity K b/B 22–29- (but not the low-affinity K b/A 12–21)-epitope thus require stimulatory ´help from beta cells or inflamed islets to expand in PD-L1-deficient mice. The new PD-1/PD-L1 diabetes models may be valuable tools to study under well controlled experimental conditions distinct hierarchies of autoreactive CD8 T-cell responses, which trigger the initial steps of beta cell destruction or emerge during the pathogenic progression of EAD. 相似文献
13.
Fragile sites are points of preferential breakage that may be involved in chromosome rearrangements. Induction of common fragile sites (c-fra) and spontaneous breakage were analyzed in two New World Monkeys species: Saimiri boliviensis (SBO) and Alouatta caraya (ACA). Spontaneous chromosome aberrations were analyzed on untreated lymphocyte cultures with Brögger''s formula (1977). SBO presented a low level of spontaneous breakage, while higher frequencies were detected in ACA in which bands 1q23; 2q13 and 11q19 were significantly affected ( p < 0.01). The populational distribution of c-fra was analyzed by the Chi 2 test in FUdR plus caffeine treated cultures. A total of 21 c-fra was identified in SBO and 24 in ACA. Fragile sites A 1q33, B 1p21, B 4p14, C 3q23 and C 5q22 were identified in all analyzed SBO specimens. The most frequent c-fra identified in ACA specimens were 1q23, 1q31, 1q33, 2q22, 8q14, 12q31, 13q22, 14q15 and Xq22. Fragile sites A 1q31, A 1q33, B 1q14, B 3q13, B 4q21 and Xq22 identified in SBO and 1q31, 1q33, 2q22, 4q21, 6q13, 13q22 and Xq22 from ACA were the most conserved sites. A low coincidence between the location of c-fra and that of heterochromatin and breakpoints involved in euchromatic rearrangements known for these genera, was established. 相似文献
14.
快速、定量、精确地估算区域森林生物量一直是森林生态功能评价以及碳储量研究的重要问题。该研究基于机载激光雷达(LiDAR)点云与Landsat 8 OLI多光谱数据, 借助江苏省常熟市虞山地区55块调查样地数据, 首先提取并分析了87个特征变量(53个OLI特征变量, 34个LiDAR特征变量)与森林地上、地下生物量的Pearson’s相关系数以进行变量优选, 然后利用多元逐步回归法建立森林生物量估算模型(OLI生物量估算模型和LiDAR生物量估算模型), 并与基于两种数据建立的综合生物量估算模型的结果进行比较, 讨论预测结果及其精确性。结果表明: 3种模型(OLI模型、LiDAR模型和综合模型)在所有样地无区分分析时, 地上和地下生物量的估算精度均达到0.4以上, 基于不同森林类型(针叶林、阔叶林、混交林)分析时地上和地下生物量的估算精度均有明显提高, 达到0.67及以上。利用分森林类型模型估算生物量, 综合生物量估算模型精度(地上生物量: R 2为0.88; 地下生物量: R 2为0.92)优于OLI生物量估算模型(地上生物量: R 2为0.73; 地下生物量: R 2为0.81)和LiDAR生物量估算模型(地上生物量: R 2为0.86; 地下生物量: R 2为0.83)。 相似文献
15.
Zusammenfassung Die im Jahre 1951 zunächst allgemein gegen die Rassen A und D nachgewiesene Mehltauresistenz von 8 röntgeninduzierten Wintergerstenmutanten ist differenziert und erweitert worden. Mut. 501 ist gegen 10 von 14 untersuchten Rassen der Rassengruppen A, D, B und C resistent ( A
1, A
2, A
3, A
4, D
1, D
3, B
2, B
3, C
2, C
3) und gegen vier anfällig ( B
5, B
6, C
4, C
5). Die übrigen 7 Mutanten 511, 512, 513, 514, 515, 520 und 525a zeigen übereinstimmendes Resistenzverhalten: Von den 16 untersuchten Rassen der Rassengruppen A, D, B, C sind die Mutanten gegen acht resistent ( A
2, A
5, D
1, B
2, B
3, B
7, C
2, C
4) und für die anderen acht anfällig ( A
1, A
3, A
4, D
3, B
5, B
6, C
3, C
5). Die Mutanten stellen durch diese ihnen eigentümliche, bisher nicht bekannte Kombination der Resistenz gegen verschiedene Rassen von Erysiphe graminis hordei wertvolle Differentialwirte dar.Die Genetik der Mehltauresistenz ist bei den acht Mutanten für die Rasse A
2 untersucht worden. Zwei unabhängige Gene sind nachgewiesen: eines bedingt die Resistenz von Mut. 501 ( Obsistens) und ein zweites diejenige der übrigen sieben Mutanten 511, 512, 513, 514, 515, 520, 525a ( Resistens). Diese sieben Mutanten sind also bzgl. der Mehltauresistenz genetisch identisch, während Mut. 501 heterogen ist. Vererbt wird die Mehltauresistenz bei allen acht Mutanten monogen und vollständig bzw. unvollständig dominant. Lediglich Mut. 520 scheint sich labil zu verhalten. alle Mutanten zeigen zusätzliche Merkmalsänderungen. 相似文献
16.
Near-infrared reflectance spectroscopy (NIRS) has been used extensively in the forage industry for rapid measurement of forage constituents and could be useful for determining quality of biomass feedstocks at the point of delivery. In previous work, we developed an assay that partitions feedstock carbohydrates based on their availability to be converted to fermentable sugars, including non-structural carbohydrates ( C N), biochemically available carbohydrates ( C B) with an associated first-order availability rate constant ( k B), and unavailable carbohydrates ( C U ). Additional quality parameters measured included neutral detergent lignin (NDL), total available carbohydrates ( C A), and total carbohydrates ( C T). We evaluated the variability of biomass quality parameters in a set of corn stover samples and developed calibration equations for determining parameter values using NIRS. Fifty-two corn stover samples harvested in Iowa and Wisconsin in 2005 and 2006 were analyzed using a high-throughput assay for determining feedstock quality for biochemical conversion. Non-structural carbohydrates ranged from 84 to 155?g?kg ?1 dry matter (DM); C B ranged from 354 to 557?g?kg ?1 DM; k B ranged from 0.199 to 0.330?h ?1; C A ranged from 463 to 699?g?kg ?1 DM, and NDL ranged from 32 to 74?g?kg ?1 DM. Significant differences ( P?<?0.0001) among samples were observed for all parameters, except k B. Near-infrared reflectance spectroscopy calibration equations were developed for C N, C B, C A, C U , C T, and NDL. It was not possible to generate a meaningful calibration equation for k B. There is significant variability within the corn stover population for several key quality-related carbohydrate and lignin constituents which can be predicted reliably using NIRS. 相似文献
17.
GLC-MS analysis of methylated bhilawanol from S. anacardium nuts and its oxidation product, the methyl ester of an aromatic carboxylic acid, conclusively proved that it contains more than seven closely related compounds. Two of them are major components which were isolated and shown to be 1-pentadec-Δ 5′-enyl-2,3-dimethoxybenzene (I) and 1-pent biflavanoids A, B and C have been also isolated from defatted nuts of S. anacardium. The first of these has been characterized as its methyl ethers. A1 and A2, for which biflavanone structures (VI) and (VII) are suggested on the basis of chemical and spectral evidence. The biflavanones B and C have been also characterized as their methyl ethers. Suggested structures are O-methyl derivatives of a IB-3′, IIA-8-binaringenin (XIV) for the former and IB-3′, IIA-8-biliquiritigenin (XV) for the latter. 相似文献
18.
Panels of monoclonal antibodies to three vasoactive peptide-producing enzymes: tissue kallikrein, tonin and arginine esterase A were developed, characterized and used as probes for identification of tissue-specific expression. In addition, immunoblot analyses were performed, using monospecific monoclonal antibodies which did not show cross-reactivity to related-purified enzymes in enzyme-linked immunosorbant assay (ELISA), and radioimmunoassay. We obtained the following results. In rat submandibular gland extract, the expression of 38 kDa kallikrein, 32 kDa tonin, and 18 kDa heavy chain of esterase A was identified by monoclonal antibodies to kallikrein (V 4D 11), tonin (1F 11), and esterase A (5A 10, 6C 11, and 4B 12), respectively. In the prostate gland, a 32 kDa kallikrein-like protein was identified by monoclonal antibodies to esterase A (5A 10, 6C 11 and 4B 12) and by antibodies recognizing both tonin and esterase A (5A 5), but not by antibody to kallikrein (V 4D 11) or to tonin (1F 11, 1G 6) in Western blot analysis. The esterase A-like enzyme in the prostate gland was found within the cytoplasm of ductal epithelial cells by using monoclonal anti-esterase A antibody (5A 10) but not by employing anti-tonin antibody (1F 11). These results indicate that tissue kallikrein, tonin, and esterase A are all expressed in the submandibular gland, while only esterase A or an esterase A-like enzyme is expressed in the prostate gland. The specific monoclonal antibodies can be used as probes for the identification and expression of the kallikrein gene-family enzymes. 相似文献
19.
Nitrogen uptake by plants is a key step for efficient nitrogen use, which affects plant growth and yield. Arabidopsis thaliana gene NRT1.1 was identified as a transporter related to nitrate (NO3−) signaling and uptake. In rice, three orthologs of NRT1.1, named OsNRT1.1A, OsNRT1.1B, and OsNRT1.1C, have been identified. This study evaluated the potential of OsNRT1.1A, OsNRT1.1B, and OsNRT1.1C in NO3− signaling and uptake through overexpression in the Arabidopsis chl1-5 mutant. The expression of OsNRT1.1A, OsNRT1.1B, and OsNRT1.1C was evaluated in the roots and shoots of rice cultivated with NO3− or NH4+. OsNRT1.1A was expressed in the roots and shoots cultivated with NO3− and NH4+. OsNRT1.1B was expressed predominantly in roots of rice cultivated with NO3−, while the expression of OsNRT1.1C was low in roots and shoots. Arabidopsis chl1-5 plants were transformed by the floral dip method using Agrobacterium tumefaciens to overexpress OsNRT1.1A and the alternative splicing product named OsNRT1.1As, OsNRT1.1B, and OsNRT1.1C. The chlorate test showed the ability of OsNRT1.1A, OsNRT1.1B or OsNRT1.1C to take up chlorate, as evidenced by the decrease in fresh weight. The OsNRT1.1B lineages presented higher toxicity to chlorate. Gene expression analyses showed that the insertion of OsNRT1.1A and OsNRT1.1B into Arabidopsis chl1-5 induced the expression of NRT2.1 and NAR2.1. OsNRT1.1As overexpression did not significantly affect the expression of NRT2.1 and NAR2.1. The results show the differential ability of NRT1.1 orthologs in rice to take up chlorate and signal the expression of other nitrate transporters, which may affect the efficiency of nitrogen utilization and its uptake. 相似文献
20.
Syntheses, electrolytic behaviour and antifungal activities of Zn(II) complexes of isomers of 3,10-C-meso-3,5,7,7,10,12,14,14-octamethyl-1,4,8,11-tetraazacyclotetradecane (L). Crystal and molecular structure of [ZnLB(NO3)]NO3 (LB = a,e,a,e-L)
The isomeric cyclam ligands Me 8[14]anes, designated by L A, L B and L C, produce, on reaction with zinc(II)nitrate, zinc(II)sulphate or zinc(II)chloride corresponding complexes, i.e. dinitrato/mononitrato-nitrate complexes [ZnL(NO 3) 2]/[ZnL(NO 3)](NO 3) (L = L A, L B or L C, where the indices A, B and C refer to differing orientations of the four methyl groups on secondary carbons of Me 8[14]ane) , the diaqua-sulphates [ZnL(H 2O) 2]SO 4 (L = L A, L B or L C), and the diaqua dichloride and dichlorido complexes [ZnL(H 2O) 2]Cl 2 (L = L A or L C) or [ZnL BCl 2], respectively. The complexes have been characterised on the basis of elemental analyses, IR, UV-Vis, 1H and 13C NMR spectroscopies, magnetic and conductance data. The structure of [ZnL B(NO 3)](NO 3) has been determined by X-ray crystallography. The zinc centre is coordinated to a N 4O donor set in a square-pyramidal geometry. The complexes show differing electrolytic behaviour in different solvents. In chloroform, the complexes are non-electrolytes, indicating that both anions are coordinated to Zn 2+. Antifungal activity of the ligands and complexes against the phytopathogenic fungi Alternaria alternata and Colletotrichum corcolei have been investigated, and positive results were noted. 相似文献
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