Biomedical subjects
Publications and source records attributed to Zheng-Zhi Zhang.
Two silver(I) N-heterocyclic carbene-bridged calix[4]arene analogues 4 and 5 were synthesized by a fragment-coupling approach; the preliminary inclusion properties of 5 with [60]fullerene shows that it is a novel efficient [60]fullerene fluorescent sensor.
Two novel extended calix[4]arene analogues by two P-Cu(I)-P bridges have been synthesized. The molecular structures and anion encapsulation ability for ClO4- and BF4- have been studied by X-ray analysis.
The reaction of 9-{[N-n-propyl-N-(diphenylphosphino)amino]methyl}anthracene (1) with Au(SMe2)Cl yields complex 2 with an arm-opening configuration. The latter is treated with AgClO4 to form complex 4 and then respectively reacted with acetonitrile, pyridine, and triphenylphosphine sulfide to afford novel gold(I) eta2-arene complexes 3a-c, which have arm-closing configurations and feeble or weak fluorescence emissions. The observation can be attributed to charge transfer from the anthracene unit to the Au+ ion. When the solution of 3a or 4 in CH2Cl2 was added with 1 equiv of Ph3P, complex 5 with the arm-opening configuration was formed and strong emission was restored.
The cDNA encoding TOM7 (translocase of outer mitochondrial membrane subunit 7) like protein in wheat was cloned through RT-PCR, and its genomic DNA fragment was subsequently cloned. This gene was tentatively designated as TaTOM7. It has no intron in the coding region and its product possesses one hydrophobic trans-membrane domain in the middle, and one hydrophilic domain in the N-terminal and C-terminal domain, respectively. The amino acid composition in the trans-membrane domain of the TaTOM7 subunit is highly conserved among plants, animals and fungi. According to the phylogenetic tree, TOM7-like proteins from different species can be classified into three groups, representing plants, animals and fungi respectively. TaTOM7 is a single- or oligo-copy gene in the wheat genome, displaying different expression levels between Ms2 near-isogenic lines in some tissues, suggesting a role of Ms2 in its expression. TaTOM7 was mapped to chromosome group three of wheat.
The dominant male sterility gene Ms2 in wheat has been widely used in recurrent selection and variety improvement. Identification of genes associated with the male sterility in Ms2-carrying wheat will help us understand how Ms2 functions. Using a pair of isogenic lines of Ms2, subtractive hybridization was conducted with cDNA from bulked spikelets at meiophase of sterile plants as the tester and cDNA from the same tissues of fertile plants as the driver. Two major bands at 270 bp and 450 bp were obtained by suppression PCR (polymerase chain reaction) of the subtractive cDNA. A total of 882 recombinants from PCR product cloning were isolated for reverse Northern analysis. The results demonstrated that up to 90% of the inserts in the library were up-regulated in the sterile spikelets. Twenty-one unique inserts from this library were sequenced. Similarity search showed that eighteen of them were homologous to ESTs (expression sequence tags) derived from spike or anther tissues at meiophase. The chromosome locations of nine of the ESTs were determined using C.S. (Chinese spring) nulli-tetrasomic lines, one of which was assigned to chromosome group 4 that includes chromosome 4D where Ms2 is located. In addition, four additional ESTs could also be assigned to this group according to their homology to BACs (bacterial artificial chromosomes) or PAC (P1 artificial chromosomes) of rice chromosome 3. The expression patterns of eight of the inserts examined displayed increased expression in spikelets and anthers of the sterile plants.
Two novel tweezer-like 25,27-dihydroxy-26,28-bis(phenylthiaethoxy)calix[4]arenes 6 and 7 were synthesized by the reaction of 25,27-dihydroxy-26,28-bis(bromoethoxy)calix[4]arenes 3 and 4 for the evaluation of their ion-selectivity in ion-selective electrodes (ISEs). X-ray structural analysis indicated that calix[4]arene 7 is in an interesting infinite linear aggregate via self-inclusion. For investigation of the influences of substitutes on the behavior of the ISEs, the halogen substituted aryl analogues of 25,27-dihydroxy-26,28-bis(arylthiaethoxy)calix[4]arenes 8-12 were also synthesized and their ISE performances were evaluated under the same conditions. ISEs based on 6-12 as neutral ionophores were prepared, and their selectivity coefficients for Ag+ (log KAg,M(pot)) were investigated against other alkali metal, alkaline-earth metal, lead, ammonium ions and some transition metal ions using the fixed interference method (FIM). These ISEs showed excellent Ag+ selectivity over most of the interfering cations examined, except for Hg2+ having relative smaller interference (log KAg,Hg(pot) < or = 2.1). The 19F NMR spectra of 9 and 9.AgClO4 were recorded for investigation the fluorine environments in the complex. The 19F NMR spectra strongly suggested that the fluorine atoms on ionophore 9 participated in ligation with silver cation.
The P,N,P-tridentate ligand 2,6-bis(diphenylphosphino)pyridine, L, was employed to generate a twelve-membered metallomacrocyclic host species cis-Pt(2)Me(4)(mu-L)(2) that encapsulates Tl(I) and Cu(I) guest ions. The ligand was also used to synthesize another two linear heterotrinuclear complexes, [Me(2)Pt(mu-L)(2)Ag(2)(MeCN)(2)](BF(4))(2).MeCN and [(CO)(3)Fe(mu-L)(2)Ag(2)(Et(2)O)](ClO(4))(2), both containing a metal-metal dative bond (Pt-->Ag and Fe-->Ag, respectively) and stabilized by the d(10)-d(10) argentophilic interaction.
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