Inhibition of bromophenols against PTP1B and anti-hyperglycemic effect of <Emphasis Type="Italic">Rhodomela confervoides</Emphasis> extract in diabetic rats

Protein tyrosine phosphatase 1B （PTPIB） plays an important role as a negative regulator In insulin signaling pathways. PTPIB is an effective target for the treatment of type 2 diabetes mellitus. Four bromophenol derivatives from red algae Rhodomela confervoides, 2,2＇,3,3＇-tetrabromo-4,4＇,5,5＇-tetrahydroxydiphenyl methane （1）, 3-bormo-4,5-bis（2,3-dibromo-4,5-dihydroxybenzyl） pyrocatechol （2）, bis（2,3-dibromo-4,5-dihydroxybenzyl） ether （3） and 2,2＇,3-tribromo-3＇,4,4＇,5-tetrahydroxy-6＇-ethyloxymethyldiphenylmethane （4） showed significant inhibitory activity against PTPIB （IC50 were 2.4, 1.7, 1.5 and 0.84 μmol/L, respectively） as potential therapeutical agents for the treatment of type 2 diabetes mellitus. The anti-hyperglycemic effects of the ethanol extracts from If. confervoides on streptozotocin-induced diabetes （STZ-diabetes） in male Wistsr rats fed with high fat diet were investigated. The STZ-diabetic rats treated with medium-dose and high-dose alga extracts showed remarkable reductions in fasting blood glucose （FBG） as compared with the STZ-diabetic control. The results indicate that the in vivo anti-hyperglycemic activity of the R. confervoides extracts can be partially attributed to the inhibitory actions against PTPIB of the bromophenol derivatives and that may be of clinical Importance in improving the management of type 2 diabetes mellitus.     

Resonance-enhanced multiphoton ionization spectroscopy on the B′2Σ+ and B2Π states of NS

Resonance-enhanced multiphoton ionization （REMPI） spectra of N^32S and N^34S have been recorded in the range of 35700-40200 cm^-1. The radical was generated by a pulsed dc discharge of a mixture of SF6 and N2 under a supersonic free jet condition. All the 16 observed bands of N^32S radicals have been assigned, among which 12 bands belong to three transition progressions （v′=0-4, 0）, （v′=1-4, 1） and （v′=2-4, 2） from the X^2П ground state to the B′^2∑^＋ upper state and the rest correspond to （9, 0）, （10, 0）, （11, 0） and （12, 0） bands of B^2П-X^2П transition, respectively. Analysis of the rotationally resolved spectra yields exhaustive spectroscopic constants of both the X^2П ground state and the B′^2∑^＋ excited state. The electronic transition bands of the isotopic molecule N^34S have been rotationally analyzed for the first time and the rotational constants of the ground and upper states have been determined simultaneously.     

Cloning and Characterization of the fecC Gene Necessary for Optimal Growth under Iron-Deficiency Conditions in the Cyanobacterium Anabaena sp. PCC 7120

The fecC gene encoding a putative iron (Ⅲ) dicitrate transporte rwas cloned from nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120, and inactivated. The mutant grows normally in medium with NO3^- , NH1^- or without combined nitrogen. But in iron-deficient medium, the mutant grows slowly. Photosynthetic properties were compared between the mutant and the wildtype strain, the content of photosynthetic pigments in the mutant is lower than that of the wild-type. The results of RT-PCR experiments show that the fecC gene is expressed under iron-deficient conditions, but is not expressed under iron-replete conditions. These results revealed that fecC gene product is required for optimal growth under iron-deficient conditions in Anabaena sp. PCC 7120.     

Synthesis and characterization of novel bridged porphyrins

The reaction of 5-(4-hydroxyphenyl)-10,15,20-triphenyl porphyrin with 2,6-dibromomethylpyridine and 4,4‘-dicarboxyl-2,2‘-bipyridine respectively gave 2,6-bis-[5,10,15-triphenyl-20-( 4-phenoxymethyl )-porphyrin-yl]-pyridine(3) and 4, 4‘-di-[5,10,15-triphenyl-20-( p-phenoxycarbonyl)-porphyrin-yl]-2,2‘-bipyridine (4). 5-[4-(4‘- Bromobutoxy) phenyl]-10, 15, 20-triphenyl porphyrin reacted with 2,6-dihydroxymethyl pyridine to give 2,6-bis-[5,10,15-triphenyl- 20-(4-(p-phenoxy)-butoxymethyl)-porphyrin-yl]-pyridine(5). Those new compounds have been identified by ^1H NMR, IR, MS and UV-visible spectra, and elemental analysis.     

The fourier transformations of positive distributions on lorentz groupSO (3, 1)

With the aid of Plancherel-Godement Theorem, we prove that every positive distributionT onSO (3, 1) which is bi-invariant underSO(3) corresponds to a measure μ on ω=∝σC|s(2-s)>=0∝, and μ can be decomposed intoμ=μ ₁+μ ₂, whereμ ₁ is a bounded measure on 0<=s<=2 andμ ₂ is slowly increasing measure on (sχC|Re(s)=1)} Foundation item: Supported by the National Natural Science Foundation of China (19871065) and Hua Cheng Mathematics Science Foundation. Biography: Zhu Li (1976-), male, Graduate student, research interest: partial differential equation     

Synthesis and light-emitting properties of organic electroluminescent compounds and their metal complexes

Several organic electroluminescent (EL) compounds, 2,2‘-(1,4-phenylenedivinylene)bis-3,3-dimethyl-indolenine (1), 2,2‘-(1,4-phenylenedivinylene)bis-benzoxazole (2), 2,2‘-(1,4-phenylenedivinylene)bis-benzothiazole (3), 4,4‘-(1,4-phenylenedivinylene)bis-quinoline (4), 2,2‘-(1,4-phenylene divinylene)bis-quinoline (5), 2,2‘-(1,4-phenylenedivinylene)bis-1,3,3-trimethyl-indolenine dichlo ride (6), 2,2‘-(1,4-phenylene-divinylene)bis-1-hydro-3,3-dimethyl-indolenine dichloride (7), 2,2‘-(1,4-phenylenedivinylene)bis-8-acetoxy-quinoline (8), 2,2‘-(1,4-phenylenedivinylene)bis-8-hydroxyquinoline (9) and metal complexes of 9, Al(PHQ) (10) and Zn(PHQ) (11), have been synthesized and characterized. The crystal structure of 6 was determined. Light emitting properties of the prepared compounds have been investigated. 1 produces an orange-yellow emission (λmax=575nm). The cation, 6, gives a red emission (λmax=607nm), which is shifted 32 nm to the red compared to 1.8 produces a yellow emission (λmax=567nm). The metal complex 10 gives a red emission (λmax=610nm), which is a red shift of 43 nm compared to 8. The change in structure in the prepared compound caused a change in the electron distribution in the compounds, which induces a large wavelength shift of the emitted-light. Thermal analysis showed that the decomposition temperatures of the metal complexes (10, 11) were higher than those for the smaller organic molecular compounds (1-9). Therefore, metal complexes (10, 11) can be used as EL materials over a larger temperature range.     

Nitrogen-fixing inhibition by KCl in a blue-green algaAnabaena cylindrica

Growing in the medium containing 0.10 mol/L KCl for three days, the nitrogen-fixing activity ofAnabaena cylindrica decreased by 95%. Extent of the inhibition was enchanced with increased KCl concentrations. The biggest decrease of nitrogen-fixing activity was between 0.02–0.05 mol/L KCl. The same decline on growth was between 0.05–0.10 mol/L KCl. The longer treating-time was, the lower nitrogen-fixing activity was. A short time of KCl-treatment (for 4 h) resulted in 66.4% decrease of the activity. Under effecting of KCl for three days, the frequency of heterocyst differentiation decreased from 7.2% to 2.1%. Supported by the National Natural Science Foundation of China Yi Ping: born in 1974, Graduate student     

Recent temperature increase recorded in an ice core in the source region of Yangtze River

Interests on climate change in the source region of Yangtze River have been raised since it is a region with the greatest warming over the Tibetan Plateau (TP). A 70-year history of precipitation δ~(18)O has been recovered using an ice core record retrieved in a plat portion of the firn area in the Guoqu Glacier (33°34′37.8″N, 91°10′35.3″E, 5720 m a.s.l.), Mt. Geladaindong (the source region of Yangtze River), in November, 2005. By using a significant positive relationship between ice core δ~(18)O record and summer air temperature (July to September) from the nearby meteorological stations, a history of summer air temperature has been reconstructed for the last 70 years. Summer temperature was relatively low in 1940s and high in 1950s to the middle of 1960s. The lowest temperature occurred in the middle of 1970s. Temperature was low in 1980s and dramatically increased since 1990s, keeping the trend to the begin-ning of the 21st century. The warming rate recorded in the ice core with 0.5℃/10 a since 1970s is much higher that that in the central TP and the Northern Hemisphere (NH), and it becomes 1.1℃/10 a since 1990s which is also higher than these from the central TP and the NH, reflecting an accelerated warm-ing and a more sensitive response to global warming in the high elevation region.     

Characterization of Anabaena cylindrica Solution System Using Synchronous-Scan Fluorescence Spectroscopy

The characterization of the algaeAnabaena cylindrica solution with Fe (III) was investigated using fluorescence emission and synchronous-scan spectroscopy. The ranges of concentrations of algae and Fe (III) in aqueous solutions were 5.0×10⁸ 2.5×10⁸ cell/L and 1060 μmol/L. respectively. The effective characterization method used was synchronous-scan fluorescence spectroscopy (SFS). The wavelength difference (Δλ) of 90 nm, was maintained between excitation wavelength (λen) and emission wavelength (λen). The peak was observed at about (λex) (λem) 326 nm for synchronous scan fluorescence spectroscopy. The fluorescence quenching in system of algae Fe(III)-HA was studied using synchronous-scan spectroscopy for the first time, Fe(III) was clearly the effective quencher. The relationship betweenI I (quenching efficiency) andc (concentration of Fe (III) added) was, a linear correlation for the algae solution with Fe(III). Also, Aldrich humie acid (HA) was found to be an effective quencher. Foundation item: Supported by the National Natural Science Foundation of China (20177017) and the Scientific Research Foundation of Wuhan Environmental Protection Bureau Biography: LIU Xian li(1965), male. Ph.D. Associate professor, research direction: environmental chemistry.     

Preparation of (R)- and (S)-2-Allyl-1, 3, 2-dinaphtho (α, β) [d.f] dioxaborepin and their reactions with aldehydes

(R)- and(S)-2-Allyl-1,3,2-dinaphtho (α,β) [d.f] dioxaborepin ((R)-2 and(S)-2) have been first prepared by the reaction of(R)-(+)- or(S)-(−)-1, 1′-bi-2-naphthol and triallylborane in THF at room temperature, respectively.(S)-2 and(R)-2 are sensitive to moisture and oxygen in air and disproportionate easily to triallylborane and 1,1′-bi-2 naphthyl bis (1,1′-bi-2-naphtholborate) at ambient temperature. However, THF is a stabilizer for them. The reactions of(R)-2 or(S)-2 and some aliphetic or aromatic aldehydes in CH₂Cl₂ at −78°C for several hours afforded β-alkylenyl alcohols in up to 84.8%ee. Among them, optically active 1-(3, 5-dichlorophenyl)-3-butenol and 1-(2-methoxyphenyl)-3-butenol were first prepared Foundation item: Supported by the National Natural Science Foundation of China (29972033) Biography: Liu Dejun (1973), male, Ph. D, research direction: asymmetric synthesis     

Effect of Nano red elemental selenium on GPx activity of broiler chick kidney cells<Emphasis Type="Italic">in vitro</Emphasis>

A new selenium source, Nano red elemental selenium (Nano-Se) was used to study the effect on the GPx activity of broiler chick kidney cells (BCKC)in vitro, Sodium selenite (Na₂SeO₃) and seleno-1-methionine (Se-Met) were used as the controls. The results showed that the effects of three kinds of Se forms on the GPx activity of BCKC were accordant (p>0.05) compared with each other at 0.01. 0.05 and 0.10 μmol/L Se concentrations treatments. In the range of 0.00–0.10 μmol/L Se concentrations, the GPx activity increased with elevation of Se concentrations in medium. For the three kinds of Se forms, the GPx activity reached the climax at 0.10 μmol/L Se concentration. At 0.20 and 0.30 μmol/L Se concentrations, the influnces of three kinds of Se forms were not accordant with one another. For Nano-Se, the GPx activity at 0.20 and 0.30 μmoi/L Se concentrations remained the same as that at 0.10 μmol/L Se concentration treatment. For Se-Met, the GPx activity at 0.20 μmol/L Se concentration treatment remained the same with 0.10 μmol/L treatment; the GPx activity at 0.30 μmol/L Se concentration treatment was declined significantly (p<0.05) compared with 0.10 or 0.20 μmol/L treatment. For Na₂SeO₃, the GPx activity falled gradually with Se concentration increasing from 0.10 μmol/L to 0.30 μmol/L, and at 0.30 μmol/L Se concentration treatment, the GPx activity was less than the original of BCKC. The results implicated, on the GPx activity of BCKCin vitro, the ranking of width range of the most suitable Se concentration for nutrition curve of the three Se formes is Nano-Se>Se-Met>Na₂SeO₃. Foundation item: Supported by the Key Item of the Science and Technology Bureau of Zhejiang Province (021122680) Biography: Xu Bao-hua (1966-), male, Associate professor, Ph. D. research direction: nanobiology and animal nutrition.     

Mouse Karyotype Obtained by Combining DAPI Staining with Image Analysis

In this study, mitotic metaphase chromosomes in mouse were identified by a new chromosome fluorescence banding technique combining DAPI staining with image analysis. Clear 4＇, 6-diamidino-2-phenylindole （DAPI） multiple bands like （J-hands could be produced in mouse. The Meta- Morph software was then used to generate linescans of pixel intensity for the banded chromosomes from short arm to long arm. These linescans were sufficient not only to identify each individual chromosome but also analyze the physical sites of bands in chromosome. Based on the results, the clear and accurate karyotype of mouse metaphase chromosomes was established. The technique is therefore considered to he a new method for cytological studies of mouse.     

Evolutionary mode of metallothioneins inferred from Cd-MT genes of Tetrahymena

FromTetrahymena thermophila (strain BF5), the coding region ofCd-MT gene was cloned and sequenced, and identified as MTTI isoform. A serial duplicate structure is discovered in its amino acid sequence, which separates the coding region into three parts (Part 1: 7–61: Part 2: 64–118; Part 3: 122–162). The alignments among them and comparison with the corresponding parts of MT1 isoform suggest that MT1 and MTT1 isoforms both come from the same ancient gene that is homologous to Part 1, and Cd-MTs ofTetrahymena are aroused by such ancient gene duplication. The prediction of secondary structures and the analysis of the disulfide-bonding state of cysteine show that there are a lot of differences between MT1 and MTT1 isoforms, which maybe relate to their function mechanism. Foundation item: Supported by KSCX of Chinese Academy of Sciences Grant (SW-102) and the Allocation from the Earmaarked Grant for Hong Kong. Biography: WAN Mingliang (1980-). male, Ph. D. candidate, research direction: molecular ecotoxicology of protozoan.     

Site-directed mutagenesis reveals new and essential elements for iron-coordination of the sulfur oxygenase reductase from the acidothermophilic Acidianus tengchongensis

Previous study on refolding of sulfur oxygenase reductase (SOR) inclusion bodies from recombinant Escherichia coli showed that iron was critical to the activity of the SOR from Acidianus ambivalens. In this study, enzymatic assays showed that 2,2′-Dipyridyl, Tiron and 8-hydroxyquinoline, which are specific for chelating ferrous or ferric ions, strongly inhibited the activity of SOR from A. tengchongensis, suggesting that iron atom is essential for SOR activity. Alignment of several functionally identified SORs and SOR-like sequences from genome database revealed a conserved, putative iron binding motif, H⁸⁶-X₃-H⁹⁰-X _n -E¹¹⁴-X _n -E¹²⁹ (numbering according to the Acidianus tengchongensis SOR sequence). Three mutants of SOR were generated by site-directed mutagenesis of H₈₆, H₉₀ and E₁₂₉ into phenylalanine or alanine residue in this study. Circular dichroism spectrum determination indicated that there was no change of the secondary structures of mutant SORs, H⁸⁶F, H⁹⁰F and E¹²⁹A, but all mutants were completely inactive. Through determination of iron contents we found that SOR mutants of H⁸⁶F, H⁹⁰F and E¹²⁹A completely or partially lost iron, while mutants of C³¹S, C¹⁰¹S, and C¹⁰⁴S (generated in a previous study) did not. This result indicated that H⁸⁶, H⁹⁰ and E¹²⁹ but not C³¹, C¹⁰¹, and C¹⁰⁴ were involved in binding to iron atom. Based on this and previous studies, it is proposed that the conserved motifs, C³¹-X _n -C¹⁰¹-X₂-C¹⁰⁴ and H⁸⁶-X₃-H⁹⁰-X₂₃-E¹¹⁴-X₁₄-(E/D)¹²⁹, are respectively for sulfur and molecular oxygen binding and activation. These two conserved motifs are essential elements for the SOR activity. Supported by National Natural Science Foundation of China (Grant Nos. 30670018, 30621005) and State Key Basic Research and Development Program of China (Grant No. 2004CB719602)     

A convenient preparation of enantiopure 1,1′-bi-2-naphtholsvia an inclusion complexation in the solid state

Inclusion reaction of racemic 1,1′-bi-2-naphthol and (S)-proline was examined under the solid state and the solid-liquid conditions. The results indicated that a solid mixture of racemic 1,1′-bi-2-naphthol and (S)-proline in a 1∶1 molar ratio was kept at 50–80 °C for 3–4 h, followed by treatment with benzene to give an insoluble solid and a benzene solution, from which (S)-(−)- and (R)-(+)-1,1′-bi-2-naphthols of a modest level of optical purity were obtained. After “kinetic” crystallization, both essentially enantiopure isomers were provided in 15%–35% overall yields, respectively. Foundation item: Supported by the National Natural Science Foundation of China (29972033) and the Key Science Research Foundation of Hubei Province (891P1305) Biography: Shan Zi-xing (1945-), male, Professor, research direction: asymmetric synthesis.     

Research of Inclusion Complexation of 4,4＇-Thiodiphenol Effected by β-Cyclodextrin in Aqueous Solutions and the Effect on Photodegradation

The inclusion behavior of 4, 4＇ -Thiodiphenol （TDP）, a typical bisphenol and endocrine disruptor, reacts with β-cyclodextrin （β-CD） in aqueous solutions has been investigated by means of UV absorption spectrum and quantum-chemical calculation with Gaussian 98 software. The results show that the inclusion behavior of TDP is quite different in acidic solutions （pH 5.9） from that in alkaline solutions （pH 10.0）. This behavior difference is attributed to the different formula structures in aqueous solutions at acidic and alkaline pH values that are demonstrated by quantum- chemical modeling and calculation. TDP forms a 1 ： 1 fl-CD inclusion complex in aqueous solutions. The equiiibrium constant K was calculated to be 553.49 L/mol at pH 5.9 and 1 318.20 L/mol at pH 10.0 respectively for the inclusion complex reaction by using the modified Benesi-Heldbrand equation. After inclusion TDP＇s structure is changed especially at the inclusion part with the bond order becoming larger, which results in inhibitive photodegradation during direct photooxidation and H2O2 assisted photooxidation.     

Bridging of Calixarenes with N, N＇-Bis（Chloroacetyl） Propylenediamine

A new bridging reagent, N, N‘-bis (chloroacetyl) propylenediamine was used to explore the relativeactivity and bridging pattern of p-ten-bury lcalix [4] arene, p-tert-butylcalix [6] arene and butylcalix [8] arene. It wasfound that the bridging reaction is selectively, at least, preferably at 1, 3-position for p-tert-butylcalix [4] arene and p-tert-butylcalix [6] arene, 1,5-position for p-tert-butylcalix [8] arene. Taking the yield of bridged calixarene as a compar-sion standard, the activity decreases with the increasing of the number of phenolic units in calixarene.     

Comparison of the carbon isotope composition of total organic carbon and long-chain <Emphasis Type="Italic">n</Emphasis>-alkanes from surface soils in eastern China and their significance

Surface soil samples collected over a high spatial resolution in eastern China were analyzed for carbon isotope composition （δ^13C） of total organic carbon （TOC） and higher plant-derived long-chain n-alkanes, with the latter reported as weighted mean values. The two sets of δ^13C values are significantly correlated and show similar trends in spatial variation. The spatial distribution of δ^13C shows less negative values in the mid-latitudes between 31°N and 40°N and more negative ones at higher and lower latitudes. This is consistent with previously reported carbon isotope data from surface soil phytoliths in the same region and suggests that the mid-latitude area provides relatively favorable growing condi- tions for C4 plants. Furthermore, δ^13C values of both TOC and long-chain n-alkanes from 12 surface soil samples collected from a small grassland in north China displayed similar carbon isotope values and the difference between paired δ^13C of a soil samples remains relatively constant. Our data demonstrate that in eastern China, soil δ^13C composition of both TOC and long-chain n-alkanes is effective indicators of C3/C4 ratios of the prevailing vegetation. This work suggests that -22‰ and -32‰ are good es- timated end members for the weighted mean δ^13C values of long-chain n-alkanes （C27, C29 and C31 n-alkanes） from soils under dominant C4 or C3 vegetation, allowing us to reconstruct paleovegetation trends.     

Southern rice black-streaked dwarf virus: A new proposed <Emphasis Type="Italic">Fijivirus</Emphasis> species in the family <Emphasis Type="Italic">Reoviridae</Emphasis>

For the past several years, a novel dwarf disease has been observed on rice （Oryza sativa） in some regions of Guangdong Province and Hainan Province, southern China. Infected plants showed stunting, dark leaf and small enations on stem and leaf back. Typical Fijivirus viroplasma containing crystalline arrayed spherical virons approximately 70--75 nm in diameter and tubular structures were detected in ultrathin sections by an electron microscope in parenchyma phloem cells of the infected plants. The virus was transmitted to rice seedlings by white-backed planthoppers, Sogatella furcifera （Hemiptera： Delphacidae）, collected in the diseased fields. Analysis of dsRNA extracts from infected plants revealed ten linear segments, which were similar to the electrophoretic profile of Rice black-streaked dwarf virus （RBSDV）. RT-PCR with a single primer which matched to a linker sequence ligated to both 3＇ ends of the viral genomic dsRNAs resulted in amplification of genome segments 9 （S9） and 10 （S10） cDNA products. The complete nucleotide sequences of S9 and S10 were obtained from clones of the RT-PCR amplicon exhibited characteristic properties of Fijivirus including low GC content （34.5% and 35.6%）, genus conserved 5＇ and 3＇ termini sequences and similar genome organization. Blast searches indicated that the sequences of S9 and S10 shared 68.8%--74.9% and 67.1% --77.4% nucleotide identities with those of viruses in the Fijivirus group 2, respectively. These values were similar to those among other viruses in the Fijivirus group 2 and considerably lower than those among RBSDV isolates. Phylogenetic trees based on S9 and S10 nucleotide sequences and their putative amino acid sequences showed that this virus represented a separate branch among other Fijiviruses. The virus was also detected by a nested RT-PCR assay in corn （Zea mays）, barnyard grass （Echinochloa crusgalll）, Juncellus serotinus and flaccidgrass （Pennisetum flaccidum） in and/or adjacent to the infected rice fields. I