Simplicispira sedimenti sp. nov., isolated from a sediment of drainage ditch in winery.

A Gram-stain-negative, motile (by single polar flagellum) and rod-shaped bacterium, designated W1-6T, was isolated from a sediment of drainage ditch in winery in Guiyang, south-western China. Strain W1-6T showed the highest 16S rRNA gene sequence similarities with the type strain of Acidovorax wautersii (98.1%) and Simplicispira lacusdiani (97.9%). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain W1-6T was placed adjacent to the members of the genus Simplicispira and formed a separat subclade. Cells showed oxidase and catalase negative reactions. The only respiratory quinone detected was ubiquinone-8 (Q-8). Summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), C16:0 and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c) were predominant cellular fatty acids (> 10%) of strain W1-6T. Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and five unidentified phospholipids were found in the polar lipid extraction. The genomic DNA G + C content was 65.6%. Strain W1-6T shared the highest digital DNA-DNA hybridization [dDDH, (27.6%)] and average nucleotide identity [ANI (84.3%)] values with the type strain of S. lacusdiani. The dDDH and ANI values were below the cutoff level (dDDH 70%; ANI 95-96%) for species delineation. The polyphasic characteristics indicated that the strain W1-6T represents a novel species of the genus Simplicispira, for which the name Simplicispira sedimenti sp. nov. is proposed. The type strain is W1-6T (= CGMCC 1.16274T = NBRC 115624T).

Dyella sedimenti sp. nov., Isolated from the Sediment of a Winery.

A Gram-staining negative, aerobic, non-motile and rod-shaped bacterium, designated strain N-S-14T, was isolated from the sediment of a winery in Guiyang, south-western China and subjected to a polyphasic taxonomic characteristics. The cells showed oxidase-negative and catalase-negative reactions. Growth occurred at 5-45 °C (optimum 30 °C), pH 5.0-8.0 (optimum pH 6.0-7.0) and with 0-3% (w/v) NaCl on R2A medium. The major respiratory quinone was ubiquinone-8 (Q-8). The predominant cellular fatty acids (> 10.0%) were identified as iso-C15:0, iso-C17:0 and summed feature 9 (iso-C17:1ω9c or C16:0 10-methyl). The profile of polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unidentified phospholipid, one unidentified aminophospholipid, one unidentified aminolipid and one unidentified lipid. The genomic DNA G + C content was 67.5%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain N-S-14T should be affiliated to the genus Dyella and formed a clade with most closely related Dyella solisilvae DHG54T (98.3%) and Dyella halodurans DHOG02T (97.8%). The digital DNA-DNA hybridization values ranged from 17.7 to 27.1% and the ANI values ranged from 75.2 to 84.0% between strain N-S-14T and other members of the genus Dyella, respectively, and thus the results indicated that strain N-S-14T represented a novel genomic species belonging to the genus Dyella. The polyphasic taxonomic characteristics indicated that the strain N-S-14T represent a novel species of the genus Dyella, for which the name Dyella sedimenti sp. nov. (type strain N-S-14T = CGMCC 1.18717T = KCTC 82384T) is proposed.

Chthonobacter rhizosphaerae sp. nov., a bacterium isolated from rhizosphere soil of Citrus sinenesis.

A Gram-staining negative, facultative anaerobic, motile and short rod-shaped bacterium, designated strain yh7-1T, was isolated from rhizosphere soil of Citrus sinenesis collected from the garden of Citrus sinenesis in Ailao Mountain, south-west China. Cells grew at 15-45 °C, pH 5.0-9.0 and were able to tolerate up to 1% (w/v) NaCl on R2A medium. The respiratory lipoquinone was Q-10 and the major cellular fatty acids contained summed feature 8 (C18:1 ω7c or C18:1 ω6c) and C18:0. Polar lipids in the cellular membrane were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, two unidentified phospholipids and one unidentified aminophospholipid. The genomic DNA G+C content was 69.9 mol%. On basis of 16S rRNA gene sequence analysis, strain yh7-1T showed the highest similarities with Chthonobacter albigriseus KCTC 42450T (97.6%), Mongoliimonas terrestris KCTC 42635T (97.0%) and lower than 97.0% to other species. Phylogenetic trees based on 16S rRNA gene sequences indicated that strain yh7-1T clustered with C. albigriseus KCTC 42450T. The ANI values ranged between 78.1 and 82.7% for C. albigriseus KCTC 42450T, M. terrestris KCTC 42635T and strain yh7-1T, which were lower than the prokaryotic species delineation threshold of 95.0-96.0%. The digital DNA-DNA hybridization values between C. albigriseus KCTC 42450T, M. terrestris KCTC 42635T and strain yh7-1T indicated that the new isolate represents a novel genomic species. According to the phenotypic and genotypic characteristics, strain yh7-1T should belong to the genus Chthonobacter, for which the name Chthonobacter rhizosphaerae sp. nov. (type strain yh7-1T = CGMCC 1.17236T = CCTCC AB 2019258T = KCTC 82185T) is proposed.

MiR-146a functions as a potential tumor suppressor in retinoblastoma by negatively regulate neuro-oncological ventral antigen-1.

MicroRNAs (miRNAs) are dysregulated in many tumors and have been found to play crucial roles in cancer biology. Retinoblastoma is a rare tumor that develops rapidly from a malignant tumor of immature cells in the retina known as photoreceptor progenitors. Our study aimed to explore the role of miR-146a in the pathology of retinoblastoma. Potential target gene of miR-146a was predicted by Targetscan. Reverse transcription quantitative polymerase chain reaction (RT-PCR) showed that miR-146a was downregulated and ventral nerve tumor antigen 1 (Neuro - oncological ventral antigen 1, NOVA1) was upregulated in retinoblastoma. Luciferase assay confirmed that miR-146a directly target NOVA1. MiR-146a knockdown and overexpression experiments were performed and found that miR-146a could regulate the expression of NOVA1. The miR-146a knockdown and overexpression experiments were conducted to investigate the biological function of miR-146a. MiR-146a was found inhibited the viability, proliferation and invasion of retinoblastoma cell by MTT, EdU, and transwell assays. Flow cytometry was performed for the apoptosis analysis and miR-146a increased the apoptosis of retinoblastoma cell was found. Above phenomenon can be rescued by overexpression of NOVA1. In conclusion, these results suggest that miR-146a acts as a tumor suppressor and can act as a potential therapeutic target for retinoblastoma in the future.

[Bioinformatics analysis of safflower WD40 transcription factor family genes].

The WD40 transcription factor family is a gene superfamily widely found in eukaryotes, which is closely related to plant growth and development regulation. It has been reported that the WD40 transcription factor was involved in the synthesis of anthocyanins, which is one of the vital components of safflower flavonoid compounds. In this study, 40 CtWD40 members in the safflower genome were identified though bioinformatics tools and gene expression analysis methods. According to the WD40 protein sequence and phylogenetic characteristics of Arabidopsis and other plants, the safflower CtWD40 family was classified into 7 subfamilies. Conservative motif analysis was used to reveal the specific conserved motifs and gene structures of each subfamily member, and there exist a certain degree of similarities in the conserved motifs and gene structure between the closely related family members. Subsequently, the search for cis-acting elements of gene promoters found CtWD40-specific promoter elements, revealing the metabolic pathways which may involve. Next, enrichment of function analysis was employed to analyze the functional categories and cellular localization of the CtWD40 protein. Furthermore, the interactions between CtWD40 proteins predicted its potential regulatory function. Finally, 19 members of the safflower CtWD40 subfamily were analyzed by qRT-PCR, the result showed the expression patterns of these members were different in diverse tissue and flowering period. This study provides a basis for the functional and expression research of the CtWD40 genes.

[Spatial Distribution and Pollution Assessment of As at a Small Scale in Agricultural Soils of the Karst Region].

The karst landforms in Guizhou are widely distributed, and the problem of soil arsenic (As) pollution is prominent in these areas because of the high environmental background levels. In order to study the distribution characteristics of As contents in agricultural soils with high background values of As, representative As polluted regions (typical karst region, semi-karst region) in southwestern Xingyi City of Guizhou Province were selected as the research objects, and the non-karst region served as the control group. Geostatistical analyses were then combined with GIS data to study the spatial variability and pollution conditions of As in agricultural soils. Furthermore, Moran's I statistic was used to analyze the spatial autocorrelation and directional characteristics of As at a small scale in the soil. The results showed that As contents in soils from different geomorphological regions were ranked as follows:typical karst region > semi-karst region > non-karst region. The arithmetic mean value and geometric mean value of As in agricultural soils in the typical karst region were 47.9 mg·kg-1 and 43.3 mg·kg-1, respectively. Meanwhile, the arithmetic mean value and geometric mean value of As in agricultural soils in the semi-karst region were 36.8 mg·kg-1 and 30.1 mg·kg-1, respectively. The As content in agricultural soils from these two regions was significantly higher than the background values of As in Guizhou. In addition, the standard exceedance rates of As in those two regions were 98.5% and 96.7%, respectively, thus demonstrating a high degree of As accumulation. In contrast, the standard exceedance rate of As in the non-karst region was only 6.7%. Among these three afore-mentioned landform types, the results of independent sample T tests showed that there were no significant differences in the content of As between agricultural soil and (natural) soil (P>0.05). The Moran's I coefficient of the As content in agricultural soil was 0.45, and the Z value was 11.61, thus suggesting that there was a significant positive spatial autocorrelation at the small scale (P<0.05), especially in the northeast-southwest direction, and the structural variation was dominant. The As polluted agricultural soils were generally at the slight pollution and mild pollution levels, which accounted for 27.10% and 29.02% of the samples, respectively. However, some regions were at the level of moderate pollution. The non-polluted samples accounted for 41.94% of the samples.

[Cd Accumulation and Risk Assessment for Arable Soils in the Karst Region of Northern Luodian, Guizhou].

Background levels of cadmium (Cd) in carbonate rock areas of Guizhou Province are high. In order to understand the characteristics of Cd in arable soils in these karst areas, the soils in the northern county of Luodian were selected as the study object. By comparing soils in non-karst areas, the distribution characteristics of soil Cd were studied by combining geostatistical analysis and GIS, and the potential ecological risk index and health risk were used to evaluate the potential level of risk to adults and children. The results show that the arable soil Cd content in this karst area is significantly higher than that in non-karst areas (P<0.05), with a geometric mean of 1.33mg·kg-1 and 0.27 mg·kg-1, respectively. In comparison, the geometric mean of soil Cd content in forested land in the same areas is 1.57mg·kg-1 and 0.22 mg·kg-1, respectively. Based on "soil pollution risk control standards", the Cd content of 90% and 22% of arable soil samples was higher than the risk screening value and the risk control value for karst and non-karst areas, respectively. The areas with medium and high Cd values were mainly distributed in the karst areas, presenting medium to strong ecological risks and extremely strong ecological risks, respectively. In contrast, the areas with the lowest Cd concentrations were distributed in the non-karst areas of Jiaoyan, presenting low potential ecological risk. The health risk assessment showed that the non-carcinogenic risk and carcinogenic risk of the three exposure pathways for adults and children in the karst areas are significantly higher than those in the non-karst areas, but the Cd content in the soil does not present non-carcinogenic and carcinogenic risks to local residents. Overall, the problem of Cd pollution in arable soils in the karst area of northern Luodian, Guizhou, is prominent. Therefore, the study of the risks posed by Cd pollution to the soil-plant-human system should be strengthened, and appropriate measures should be taken to prevent and control Cd pollution in the areas at risk.

[Cloning and expression analysis of CtbHLH transcription factor gene from Carthamus tinctorius and construction of plant expression vector].

To clone bHLH( basic helix-loop-helix) gene from Carthamus tinctorius,analyze the expression level in different plant tissues and construct the plant expression vector. The bHLH1 gene was cloned by RT-PCR techniques,and the protein characteristics were analyzed by bioinformatics,and phylogenetic tree was constructed. The expression of bHLH1 gene in different tissues and the roots after inoculated by Fusarium oxysporum were analyzed using real time-PCR,and the plant expression vector p BASTA-bHLH1 was constructed. The obtained ORF sequence of bHLH1 gene was 897 bp,encoded a protein of 298 amino acids. Sequence alignment and phylogenetic tree analyses showed that C. tinctorius bHLH1 had a certain homology with other species of amino acids,and was the most similar to the amino acid sequence of tobacco. Real-time PCR results showed significant differences,CtbHLH1 gene in red flower petals in different tissues and different flowering period had remarkable difference in expression level,its high amount expressed in petals,flowers third day after blossom expressed the highest quantity,at the end of the flowering the expression quantity is low. In addition,it is expressed in the root,and the expression in the stem and leaves is extremely low. The bHLH1 gene of C. tinctorius is successfully cloned,and the expression is analyzed. The plant expression vector p BASTA-bHLH is constructed.

Comprehensive Genomic Analysis and Expression Profiling of Diacylglycerol Kinase (DGK) Gene Family in Soybean (Glycine max) under Abiotic Stresses.

Diacylglycerol kinase (DGK) is an enzyme that plays a pivotal role in abiotic and biotic stress responses in plants by transforming the diacylglycerol into phosphatidic acid. However, there is no report on the characterization of soybean DGK genes in spite of the availability of the soybean genome sequence. In this study, we performed genome-wide analysis and expression profiling of the DGK gene family in the soybean genome. We identified 12 DGK genes (namely GmDGK1-12) which all contained conserved catalytic domains with protein lengths and molecular weights ranging from 436 to 727 amino acids (aa) and 48.62 to 80.93 kDa, respectively. Phylogenetic analyses grouped GmDGK genes into three clusters-cluster I, cluster II, and cluster III-which had three, four, and five genes, respectively. The qRT-PCR analysis revealed significant GmDGK gene expression levels in both leaves and roots coping with polyethylene glycol (PEG), salt, alkali, and salt/alkali treatments. This work provides the first characterization of the DGK gene family in soybean and suggests their importance in soybean response to abiotic stress. These results can serve as a guide for future studies on the understanding and functional characterization of this gene family.

Sphingomonas tabacisoli sp. nov., a member of the genus Sphingomonas, isolated from rhizosphere soil of Nicotiana tabacum L.

A Gram-staining-negative, aerobic, motile and rod-shaped bacterium, designated strain X1-8T, was isolated from rhizosphere soil of Nicotiana tabacum L. collected from the tobacco produce base located in Kunming, south-west PR China. Cells showed oxidase-negative and catalase-positive reactions and were motile by means of peritrichous flagella. Growth occurred at 25-40 °C and pH 6.0-8.0 with optimal growth at 30-35 °C, pH 7.0. The major respiratory lipoquinone was Q-10. C16 : 0 and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) were identified as major cellular fatty acids. The profile of polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, sphingoglycolipid, phosphatidylcholine and one unidentified glycolipid. The major polyamine was sym-homospermidine. The genomic DNA G+C content was 66.5 mol%. The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that X1-8T should be affiliated to the genus Sphingomonasand formed a clade with most closely related species Sphingomonas changbaiensisNBRC 104936T. The results of 16S rRNA gene sequences similarity analysis indicated that X1-8T had the highest similarity with S. changbaiensisNBRC 104936T (98.4 %) and lower than 96.0 % with other species of the genus Sphingomonas. DNA-DNA hybridization data indicated that X1-8T represented a novel genomic species of the genus Sphingomonas. The characteristics determined in the polyphasic taxonomic study indicated that X1-8T represents a novel species of the genus Sphingomonas, for which the name Sphingomonas tabacisoli sp. nov. (type strain X1-8T=KCTC 62032T=CGMCC 1.16275T) is proposed.

PF-06409577 activates AMPK signaling to protect retinal pigment epithelium cells from UV radiation.

Ultra-violet (UV) radiation (UVR) to human retinas induces oxidative injury to the resident retinal pigment epithelium (RPE) cells. PF-06409577 a novel, potent and direct AMP-activated protein kinase (AMPK) activator. In ARPE-19 cells and primary murine RPE cells, PF-06409577 significantly inhibited UVR-induced viability reduction, cell death and apoptosis. PF-06409577 activated AMPK signaling in RPE cells by increasing AMPKα1-acetyl-CoA carboxylase phosphorylation and AMPK activity. AMPK inhibition, by AMPKα1-shRNA, -CRISPR/Cas9 knockout or -T172A dominant negative mutation, almost abolished PF-06409577-induced RPE cytoprotection against UVR. PF-06409577 enhanced nicotinamide adenine dinucleotide phosphate (NADPH) activity and expression levels of Nrf2-dependent genes in RPE cells. Furthermore, UVR-induced reactive oxygen species (ROS) production, lipid peroxidation and DNA damage were largely inhibited by the AMPK activator. In summary, PF-06409577 inhibits UVR-induced oxidative stress and RPE cell death by activating AMPK signaling.

Long Noncoding RNA-Sox2OT Knockdown Alleviates Diabetes Mellitus-Induced Retinal Ganglion Cell (RGC) injury.

Retinal ganglion cell (RGC) injury is one of the important pathological features of diabetes-induced retinal neurodegeneration. Increasing attention has been paid to find strategies for protecting against RGC injury. Long noncoding RNAs (lncRNAs) have emerged as the key regulators of many cell functions. Here, we show that Sox2OT expression is significantly down-regulated in the retinas of STZ-induced diabetic mice and in the RGCs upon high glucose or oxidative stress. SOX2OT knockdown protects RGCs against high glucose-induced injury in vitro. Moreover, Sox2OT knockdown plays a neuroprotective role in diabetes-related retinal neurodegeneration in vivo. Sox2OT knockdown could regulate oxidative stress response in RGCs and diabetic mouse retinas. Sox2OT knockdown plays an anti-oxidative role via regulating NRF2/HO-1 signaling activity. Taken together, Sox2OT knockdown may be a therapeutic strategy for the prevention and treatment of diabetes-induced retinal neurodegeneration.

Lignans Extracted from Eucommia Ulmoides Oliv. Protects Against AGEs-Induced Retinal Endothelial Cell Injury.

BACKGROUND/AIMS: Advanced glycation end products (AGEs) could elicit oxidative stress, trigger and aggravate endothelium damage in several ischemic retinopathies including diabetic retinopathy (DR). The leaves of Eucommia ulmoides O., also referred to as Tu-chung or Du-zhong, have been used for the treatment of hypertension and diabetes, showing great antioxidant activity and anti-glycation activity. Lignans is one of the main bioactive components of Eucommia ulmoides. This study mainly investigated the effect of lignans treatment on AGEs-induced endothelium damage. METHODS: MTT assay, Hoechst staining, and calcein-AM/ propidium iodide (PI) staining was conducted to determine the effect of lignans treatment on endothelial cell function in vitro. Retinal trypsin digestion, Evans blue assay, isolectin staining, and western blots were conducted to determine the effect of lignans treatment on retinal microvascular function in vivo. Western blot, protein immunoprecipitation (IP), MTT assays, and enzyme activity assay was conducted to detect the effect of ligans treatment on oxidative stress response. RESULTS: Lignans protected retinal endothelial cell against AGEs-induced injury in vitro and diabetes-induced vascular dysfunction in vivo. Lignans treatment could regulate oxidative stress response in retinal endothelial cell line, retina, and liver. Moreover, we showed that NRF2/HO-1 signaling was critical for lignans-mediated oxidative stress regulation. CONCLUSION: Lignans treatment could protect against endothelial dysfunction in vivo and in vitro via regulating Nrf2/HO-1 signaling. Lignans might be developed as a promising drug for the treatment of diabetes-induced microvascular dysfunction.

High-performance fluorescence sensing of lanthanum ions (La(3+)) by a polydentate pyridyl-based quinoxaline derivative.

A polydentate pyridyl derivative, 2,3,6,7,10,11-hexa(2-pyridyl)-dipyrazino [2,3-f:2',3'-h]quinoxaline (HPDQ), exhibits a high-performance fluorescence response to La(3+) with an ∼65 nm redshifted emission wavelength and 38 fold enhanced intensity, in contrast to its weakened emission for other lanthanide ions. The final La(3+) coordination complex in solution has a stoichiometric ratio of 1 : 3 of ligand-to-metal, as testified by the Job's plot and single crystal structure analyses. The red shift of the luminescence emission as well as UV-vis absorption was rationalized in terms of the change of the electron structure as indicated by nuclear magnetic titration, electrochemical experiment and density functional theoretical calculation, while the significant enhancement of emission was attributed to the enhanced π conjugated extent of HPDQ caused by La(3+) coordination.

The AaDREB1 Transcription Factor from the Cold-Tolerant Plant Adonis amurensis Enhances Abiotic Stress Tolerance in Transgenic Plant.

Dehydration-responsive element binding (DREB) transcription factors (TFs) play important roles in the regulation of plant resistance to environmental stresses and can specifically bind to dehydration-responsive element/C-repeat element (DRE/CRT) proteins (G/ACCGAC) and activate expression of many stress-inducible genes. Here, we cloned and characterized a novel gene (AaDREB1) encoding the DREB1 transcription factor from the cold-tolerant plant Adonis amurensis. Quantitative real-time (qRT)-PCR results indicated that AaDREB1 expression was induced by salt, drought, cold stress, and abscisic acid application. A yeast one-hybrid assay demonstrated that AaDREB1 encodes a transcription activator and specifically binds to DRE/CRT. Furthermore, transgenic Arabidopsis and rice harboring AaDREB1 showed enhanced tolerance to salt, drought, and low temperature. These results indicated that AaDREB1 might be useful in genetic engineering to improve plant stress tolerance.

A new benzofuran derivative from Nicotiana tabacum.

A new benzofuran derivative, methyl 3-acetyl-7-hydroxy-6-methoxy-2-methylbenzofuran-4-carboxylate (1), and a known compound pyrrolezanthine (2), were isolated from leaves of Nicotiana tabacum. Compound 1 was elucidated by means of spectroscopic methods, as well as X-ray diffraction. Both compounds 1 and 2 exhibited moderate inhibitory activities on human cancer cell lines.

The complete mitochondrial genome of Diqing wild boar (Sus verrucosus breed Diqing wild boar).

In the present study, the complete mitochondrial genome sequence of the diqing wild boar (Sus verrucosus breed diqing wild boar) was reported for the first time. The total length of the mitogenome was 16,506 bp. It contained the typical structure, including two ribosomal RNA genes, 13 protein-coding genes, 22 transfer RNA genes and one non-coding control region (D-loop region) as that of most other wild boars. The overall composition of the mitogenome was estimated to be 34.9% for A, 26.1% for T, 26.0% for C and 13.0% for G showing an A-T (61.0%)-rich feature. The mitochondrial genome analyzed here will provide new genetic resource to uncover wild boars' genetic diversity.

[Full-length cDNA cloning of flavonol synthase genes of Carthamus tinctorius and construction plant expression vector].

Flavonol synthase (FLS) is one of the key enzymes in flavonoids metabolic pathways. In this study, middle sequence was obtained from Carthamus tinctorius transcriptome sequencing results. Full-length cDNAs of FLS was cloned from petals of C. tinctorius to FLS by using RT-PCR and RACE technology. Its full-length cDNA was 1,201 bp, with an open reading frame of 1,101 bp and 336 encoded amino acids. The phylogenetic analysis showed that, FLS gene encoded amino acids in C. tinctorius were highly homologous with amino acids in congeneric Compositae species, especially Rudbeckia laciniata. The pBASTA-FLS plant expression vector was successfully built by the molecular biology method, which lays a foundation for further studying biology functions of the gene and biosynthesis mechanism of flavonoids.

Ratiometric fluorescence detection of fluoride ion by indole-based receptor.

A novel artificial receptor 1 containing the indolocarbazole-NH moieties as the recognition sites exhibited high selectivity and sensitivity toward F(-) over other typical anionic species in DMSO solution. Upon addition of F(-) into the solution, receptor 1 showed a remarkable ratiometric shift of the fluorescence maximum from 535 to 590 nm, and also a prominent color change from light yellow to orange, which was observable by the naked eye. The recognition properties of receptor 1 were investigated by (1)H NMR, UV-vis, and fluorescence titration experiments, with the results suggesting a two-step strategy of binding with F(-). In addition, the theoretical calculations were carried out to reveal the role of intramolecular charge transfer in the ratiometric fluorescence recognition process.

A polypyridyl-pyrene based off-on Cd²âº fluorescent sensor for aqueous phase analysis and living cell imaging.

By retaining the quadrapyridyl receptor of polypyridylhexaazatriphenylene (a Cd(2+) sensor reported by us) and extending its chromophoric group with pyrene, a chemical sensor (1) was designed and synthesized in this work. This sensor exhibit selective off-on fluorescence response to Cd(2+) over other metal ions, and the detection limit is as low as 0.02 µM. The Cd(2+) sensing of 1 has high water toleration and can be carried out in the media with the water content up to 70%. Additionally, 1 was successfully applied to the in vivo imaging of intracellular Cd(2+) in living HaLa cells, and showed low cytotoxicity and cell membrane permeability in these experiments. These results suggest that 1 has potential application in the Cd(2+) analysis of environmental and biological samples.