摘要：
Achieving fast transmembrane transmission of molecules in organisms is a challenging problem. Inspired by the transport of Dopmine (DA) in organisms, the DA transporter (DAT) binds to DA in a way that has a ring recognition (the recognition group is the tryptophan group). Herein, D-Tryptophan-pillar[5]arene (D-Trp-P5) functionalized conical nanochannel is constructed to achieve fast transmission of DA. The D-Trp-P5 functionalized nanochannel enables specific wettability recognition of DA molecules and has great cycle stability. With the controlling of voltage to wettability, the transport flux of DA is up to 499.73 nmol cm(-2) h(-1) at -6 V, 16.88 times higher than that under positive voltages. In response to these results, a high-throughput DA transport device based on controlled electricity-wettability is provided.
作者机构：
[Tang, Yuchen; Gao, Tingjuan; Zheng, Xingxing] Cent China Normal Univ, Coll Chem, China Key Lab Pesticide & Chem Biol, Minist Educ, Wuhan 430079, Peoples R China.
通讯机构：
[Tang, YC; Gao, TJ ] C;Cent China Normal Univ, Coll Chem, China Key Lab Pesticide & Chem Biol, Minist Educ, Wuhan 430079, Peoples R China.
摘要：
High-throughput assays play an important role in the fields of drug discovery, genetic analysis, and clinical diagnostics. Although super-capacity coding strategies may facilitate labeling and detecting large numbers of targets in a single assay, practically, the constructed large-capacity codes have to be decoded with complicated procedures or are lack of survivability under the required reaction conditions. This challenge results in either inaccurate or insufficient decoding outputs. Here, we identified chemical-resistant Raman compounds to build a combinatorial coding system for the high-throughput screening of cell-targeting ligands from a focused 8-mer cyclic peptide library. The accurate in situ decoding results proved the signal, synthetic, and functional orthogonality for this Raman coding strategy. The orthogonal Raman codes allowed for a rapid identification of 63 positive hits at one time, evidencing a high-throughput-out capability in the screening process. We anticipate this orthogonal Raman coding strategy being generalized to enable efficient high-throughput-out screening of more useful ligands for cell targeting and drug discovery.
期刊：
JOURNAL OF ORGANIC CHEMISTRY,2023年88(11):7463-7468 ISSN：0022-3263
通讯作者：
Ke Gao
作者机构：
[Gao, Ke; Sun, Yulin] Cent China Normal Univ, CCNU uOttawa Joint Res Ctr, Key Lab Pesticide & Chem Biol, Minist Educ,Coll Chem, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Ke Gao] C;CCNU-uOttawa Joint Research Centre, Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, 152 Luoyu Road, Wuhan, Hubei 430079, P. R. China
摘要：
An inexpensive and efficient aminoguanidine-catalyzed reductive cyclization of o-phenylenediamines with CO2 in the presence of triethoxysilane is described. Various functionalized benzimidazoles, benzoxazole, and benzothiazole were synthesized in high yields. Mechanistic studies indicate that formic acid as a cocatalyst promotes the cyclization reaction.
作者机构：
[Gao, Ke; Zhang, He; Zhang, Yanmeng] Cent China Normal Univ, Coll Chem, CCNU uOttawa Joint Res Ctr, Key Lab Pesticides & Chem Biol,Minist Educ, 152 Luoyu Rd, Wuhan, Hubei, Peoples R China.
通讯机构：
[Ke Gao] C;CCNU-uOttawa Joint Research Centre, Key Laboratory of Pesticides & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, 152 Luoyu Road, Wuhan, Hubei, P.R. China
摘要：
The selective reductive N-methylation and N,N-dimethylation of primary amines using CO2 are some of the most significant challenges faced by organic chemists. Herein, we report the highly selective N,N′-diisopropylcarbodiimide-catalyzed methylation of primary amines using 1 atm CO2 under metal-free conditions. Borane–piperazine and borane–trimethylamine complexes were used as reducing agents for the N-methylation and N,N-dimethylation of various aromatic primary amines, respectively, in the presence of CO2. Mechanistic studies suggest that the selectivity of methylation is controlled by the steric effects of amines and boranes.
通讯机构：
[Lingling Feng] K;Key Laboratory of Pesticide & Chemical Biology (CCNU), Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, China
摘要：
The frequency and intensity of harmful cyanobacterial blooms (HCBs) are increasing all over the world, their prevention and control have become a great challenge. In this paper, a series of 1,3,4-thiadiazole thioacetamides (T series) were designed and synthesized as potential algaecides. Among them, the compound T3 showed its best algacidal activity against Synechocystis sp. PCC 6803 (PCC 6803, EC50 = 1.51 mu M) and Microcystis aeruginosa FACHB 905 (FACHB905, EC50 = 4.88 mu M), which was more effective than the lead compound L1 (PCC6803, EC50 = 7.7 mu M; FACHB905, EC50 = 8.8 mu M) and the commercially available herbicide prometryn (PCC6803, EC50 = 4.64 mu M;FACHB905, EC50 = 6.52 mu M). Meanwhile, T3 showed a lower inhibitory activity (EC50 = 12.76 mu M) than prometryn (EC50 = 7.98 mu M) to Chlorella FACHB1227, indicating that T3 had selective inhibition to prokaryotic algae (PCC6803, FACHB905) and eukaryotic algae (FACHB1227). Furthermore, the algacidal and anti-algae activities of T3 were significantly better than those of prometryn, while the toxicity of zebrafish and human cells was less than prometryn. Electron microscope, physiological, biochemical and metabonomic anal-ysis showed that T3 interfered with light absorption and light conversion during photosynthesis by significantly reducing chlorophyll content, thus inhibited metabolic pathways such as the Calvin cycle and TCA cycle, and eventually led to the cell rupture of cyanobacteria. These results afforded further development of effective and safe algaecides.
作者机构：
[Cheng, Ying; Xiao, Wen-Jing; Chen, Jia-Rong; Shi, De-Qing; Li, Tian-Tian; Chen, JR] Cent China Normal Univ, Coll Chem, Engn Res Ctr Photoenergy Utilizat Pollut Control &, 152 Luoyu Rd, Wuhan 430079, Hubei, Peoples R China.;[Xiao, Wen-Jing] Shanghai Inst Organ Chem, State Key Lab Organometall Chem, 345 Lingling Rd, Shanghai 200032, Peoples R China.
通讯机构：
[Shi, DQ; Chen, JR ] C;Cent China Normal Univ, Coll Chem, Engn Res Ctr Photoenergy Utilizat Pollut Control &, 152 Luoyu Rd, Wuhan 430079, Hubei, Peoples R China.
摘要：
Radical Cross‐CouplingA copper‐catalyzed enantioselective three‐component radical relay 1,2‐alkylesterification of 1,3‐dienes using cycloalkyl hydroperoxides and carboxylic acids was reported. This protocol features broad substrate scope and good functional group tolerance with respect to each component, providing practical access to a variety of distally keto‐functionalized chiral allylic esters with high enantioselectivity under mild and redox‐neutral conditions. Abstract Transition‐metal‐catalyzed radical relay cross‐coupling reactions of 1,3‐dienes have recently emerged as one of the most powerful methods for construction of structurally diverse allylic compound in a single chemical step. However, there still has been limited success in expanding substrate scope of radical precursors and coupling partners, as well as exploring catalytic asymmetric variants. Herein, we report a copper‐catalyzed enantioselective three‐component 1,2‐alkylesterification of 1,3‐dienes using cycloalkyl hydroperoxides as the carbonyl‐containing alkyl radical sources and carboxylic acids as O‐nucleophiles under mild and redox‐neutral conditions. This protocol features broad substrate scope and good functional group tolerance with respect to each component, providing practical access to a variety of distally keto‐functionalized allylic esters with high enantioselectivity. Mechanistic studies suggest the involvement of a sequential radical relay and C−O cross‐coupling in this three‐component radical reaction.
期刊：
Journal of Materials Science,2023年58(31):12764-12774 ISSN：0022-2461
通讯作者：
Cao, Y;Chen, DD
作者机构：
[Cao, Y; Asibaike, Laizaiti; Mukerabigwi, Jean Felix; Wu, Xuelin; Cao, Yu; Qu, Jiaying; Sun, Yuyang; Huang, Xueying] Cent China Normal Univ, Coll Chem, Key Lab Pesticide & Chem Biol, Minist Educ, Wuhan 430079, Peoples R China.;[Chen, Didi; Qu, Jiaying] Hubei Univ Educ, Hubei Key Lab Purificat & Applicat Plant Anticanc, Wuhan 430205, Peoples R China.;[Mukerabigwi, Jean Felix] Univ Rwanda, Coll Sci & Technol, Dept Chem, POB 3900, Kigali, Rwanda.
通讯机构：
[Cao, Y ] C;[Chen, DD ] H;Cent China Normal Univ, Coll Chem, Key Lab Pesticide & Chem Biol, Minist Educ, Wuhan 430079, Peoples R China.;Hubei Univ Educ, Hubei Key Lab Purificat & Applicat Plant Anticanc, Wuhan 430205, Peoples R China.
摘要：
Due to its small particle size, high specific surface area, functional capability and long-term stable fluorescence, nanodiamond (ND) has been widely used in biomedical applications including fluorescent probes, drug delivery and biological imaging. Nevertheless, the metabolism of ND and its derivatives is not yet well understood for diverse biomedical applications. In this study, to evaluate the cytotoxicity and biodistribution of the ND derivative, pure ND was functionalized with ethylenediamine (EDA) as a linker (ND-EDA) and then covalently labeled with an organic fluorescent dye called calcein. The modified ND is referred to as ND-EDA-calcein. Even at the maximum dose of 0.1 mg & BULL;mL(-1), the in vitro results for ND-EDA-calcein against HepG2 and LO2 cell lines showed negligible cytotoxicity, which was in line with the in vivo observations. In addition, it was found that following an intraperitoneal injection, ND-EDA-calcein could be accumulated mostly in the liver and kidney of the mice but not in the spleen. It is interesting to note that after 5 days following intraperitoneal injection, mice can totally metabolize the elimination of ND-EDA-calcein outside of their bodies. Therefore, our findings suggested that NDs can be considered for various nanomedicine applications including drug delivery and biomarkers.
作者机构：
[Zhu, Xinrui; Jia, Shuwen; Li, Dongfeng; Li, DF] Cent China Normal Univ, Coll Chem, Key Lab Pesticide & Chem Biol, Minist Educ, Wuhan 430079, Peoples R China.
通讯机构：
[Li, DF ] C;Cent China Normal Univ, Coll Chem, Key Lab Pesticide & Chem Biol, Minist Educ, Wuhan 430079, Peoples R China.
摘要：
A key challenge in the design of magnetic molecules with intramolecular charge transfer behavior is to obtain reversible magnetic bistability triggered by external stimuli. Here, we show that two dinuclear metal complexes, [(bbp)Fe(CN)3Mn(Py5Me2)]center dot 2.5CH3OH (4) and [(bbp)Fe(CN)3Ni(Py5Me2)]center dot 2.5CH3OH (5) (Py5Me2 = 2,6-bis(1,1-di(pyridine-2-yl)ethyl)pyridine, H2bbp = 2,6-bis(benzimidazole-2-yl)pyridine), were self-assembly synthesized by (Bu4N)2[(bbp)FeIII(CN)3] and [Mn(Py5Me2)(OH2)](ClO4)2 or [Ni(Py5Me2)(OH2)](ClO4)2, respectively. Complexes 4 and 5 exhibited intramolecular metal-to-metal charge transfer with the addition of acids or bases in solution by UV-visible spectrophotometric measurements and electrochemistry studies, and concomitant switching of the {FeIII(mu-CN)MnII/NiII} state to the {FeII(mu-CN)MnIII/NiIII} state. The possibility of external stimulus induced intra-molecular metal-to-metal charge transfer by protonation in [(bbp)Fe(CN)3Mn(Py5Me2)]center dot 2.5CH3OH and [(bbp)Fe(CN)3Ni(Py5Me2)]center dot 2.5CH3OH molecules was investigated.
通讯机构：
[Wu, DY ] X;Xiamen Univ, State Key Lab Phys Chem Solid Surface, Collaborat Innovat Ctr Chem Energy Mat, Xiamen 361005, Peoples R China.;Xiamen Univ, Coll Chem & Chem Engn, Dept Chem, Xiamen 361005, Peoples R China.
摘要：
Stereoelectronic effects in single-molecule junctions have been widely utilized to achieve a molecular switch, but high-efficiency and reproducible switching remain challenging. Here, we demonstrate that there are three stable intramolecular conformations in the 9,10-diphenyl-9,10-methanoanthracen-11-one (DPMAO) systems due to steric effect. Interestingly, different electronic coupling approaches including weak coupling (through-space), decoupling, and strong coupling (through-bond) between two terminal benzene rings are accomplished in the three stable conformations, respectively. Theoretical calculations show that the molecular conductance of three stable conformations differs by more than 1 order of magnitude. Furthermore, the populations of the three stable conformations are highly dependent on the solvent effect and the external electric field. Therefore, an excellent molecular switch can be achieved using the DPMAO molecule junctions and external stimuli. Our findings reveal that modulating intramolecular electronic coupling approaches may be a useful manner to enable molecular switches with high switching ratios. This opens up a new route for building high-efficiency molecular switches in single-molecular junctions.
摘要：
The comprehensive understanding of contaminant interfacial behavior strongly depends on the in situ characterization technique, which is still a great challenge. In this study, we constructed a device integrated with open-circuit potentialand attenuated total reflectance Fourier transform infrared (OCP-ATR-FTIR) spectroscopy to simultaneously monitor the electrochemical and infrared spectral information on the interfacial reaction for the process analysis, taking the competitive adsorption of hexavalent chromium (Cr(VI)) and oxalate on hematite nanocubes (HNC) as an example. The synchronous OCP and infrared results revealed that Cr(VI) interacted with HNC via bidentate binuclear inner-sphere coordination, accompanied by electron transfer from HNC to Cr(VI), while oxalate was adsorbed on HNC through bidentate mononuclear side-on inner-sphere coordination with electron transfer from HNC to oxalate, and also outer-sphere coordination with negative charge accumulation. When oxalate was added to HNC with preadsorbed Cr(VI), oxalate would occupy the inner-sphere adsorption sites and thus cause the detaching of preadsorbed Cr(VI) from HNC. This study provides a promising in situ characterization technique for real-time interfacial reaction monitoring and also sheds light on the competitive adsorption mechanism of oxalate and Cr(VI) on the mineral surface.
摘要：
Catalytic oxidation technology is currently considered as a feasible approach to degrade and mineralize volatile organic compounds (VOCs). However, it is still challenging to realize efficient removal of VOCs through catalytic oxidation at room temperature. In our study, a novel flow-through electrocatalytic reactor was designed, composed of porous solid-electrolyte, gas-permeable titanium sub-oxides/titanium-foam (TiSO/Ti-foam) as anode and platinum coated titanium foam (Pt/Ti-foam) as cathode. This device could oxidize nearly 100% of benzene (10 ppm) to carbon dioxide at a current density of 1.2 mA/cm2 under room temperature. More importantly, the device maintained excellent stability over 1000 h. Mechanism of benzene mineralization was discussed. Hydroxyl radicals generated on the TiSO/Ti-foam anode played a crucial role in the oxidation of benzene. This study provides a promising prototype of the electrochemical air purifier, and may find its application in domestic and industrial air pollution control.
作者机构：
[Qin, Ying; Zhu, Chengzhou; Liu, Mingwang; Li, Jinli; Tan, Rong; Gu, Wenling; Wang, Hengjia] Cent China Normal Univ, Coll Chem, Int Joint Res Ctr Intelligent Biosensing Technol, Key Lab Pesticide & Chem Biol,Minist Educ, Wuhan 430079, Peoples R China.;[Hu, Liuyong] Wuhan Inst Technol, Hubei Engn Technol Res Ctr Optoelect & New Energy, Hubei Key Lab Plasma Chem & Adv Mat, Wuhan 430205, Peoples R China.;[Li, Jinli] Jingchu Univ Technol, Sch Elect & Informat Engn, Jingmen 448000, Peoples R China.
通讯机构：
[Liuyong Hu] H;[Wenling Gu; Chengzhou Zhu] K;Hubei Key Laboratory of Plasma Chemistry and Advanced Materials, Hubei Engineering Technology Research Center of Optoelectronic and New Energy Materials, Wuhan Institute of Technology, Wuhan 430205, PR China<&wdkj&>Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, PR China
作者：
Li Li;Xiaoxie Ma;Yusong Peng;Jun Yin;Nida El Islem Guissi;...
期刊：
ACS Applied Bio Materials,2023年6(4):1639-1649 ISSN：2576-6422
通讯作者：
Jun Yin<&wdkj&>Nida El Islem Guissi<&wdkj&>Yiqing Wang
作者机构：
[Li Li; Yusong Peng; Nida El Islem Guissi; Yiqing Wang] Department of Biomedical Engineering, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210023, People’s Republic of China;[Xiaoxie Ma; Jun Yin] Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, People’s Republic of China
通讯机构：
[Jun Yin] K;[Nida El Islem Guissi; Yiqing Wang] D;Department of Biomedical Engineering, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210023, People’s Republic of China<&wdkj&>Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, People’s Republic of China
摘要：
Fluorescent probes with fluorescence emission in the NIR-II window have been widely studied due to increased imaging depth. However, the currently reported NIR-II fluorescent probes present some disadvantages, such as complicated synthesis routes and low fluorescence quantum yields (QYs). The shielding strategy has been used in the development of NIR-II probes to improve their QYs. So far, this strategy has only been used for the symmetric NIR-II probes, especially those based on the benzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole) (BBTD) skeleton. This work reports the synthesis of a series of asymmetric NIR-II probes based on shielding strategies accompanied by simple synthetic routes, high synthetic yields (above 90%), high QYs, and large Stoke shifts. Furthermore, the use of d-α-tocopheryl polyethylene glycol succinate (TPGS) as a surfactant for an NIR-II fluorescence probe (NT-4) improved its water solubility. In vivo studies showed that TPGS-NT-4 NPs with a high QY (3.46%) achieve high-resolution angiography and efficient local photothermal therapy, while displaying good biocompatibility. Hence, we combined angiography and local photothermal therapy to improve the tumor uptake of nanophotothermal agents while reducing their damage to normal tissues.
通讯机构：
[Ye, F ; Bao, F] C;[Wu, CG ] M;Cent China Normal Univ, CCNU uOttawa Joint Res Ctr, Key Lab Pesticide & Chem Biol, Minist Educ,Coll Chem, Wuhan 430079, Hubei, Peoples R China.;Minist Educ, Key Lab Xinan Med, Hefei 230038, Anhui, Peoples R China.;Wuhan Inst Photochem & Technol, Wuhan 430082, Hubei, Peoples R China.
摘要：
We report here a general alkylation reaction of terminal alkenes with nucleophilic cobaloxime complex catalysis under visible light irradiation. A broad range of vinyl arenes and heteroarenes, as well as a diverse set of alkyl(pseudo)halides or strained rings as alkyl electrophiles, can efficiently undergo the transformation up to the gram scale. Mechanistic study reveals the radical nature of the reaction and corroborates our design involving alkylcobaloxime as the key intermediate.
通讯机构：
[Cuiju Zhu; Mingqiang Qiu] A;Authors to whom correspondence should be addressed.<&wdkj&>Key Laboratory of Pesticides & Chemical Biology Ministry of Education, College of Chemistry, Central China Normal University, 152 Luoyu Road, Wuhan 430079, China
摘要：
Organic electrochemistry has attracted tremendous interest within the novel sustainable methodologies that have not only reduced the undesired byproducts, but also utilized cleaner and renewable energy sources. Particularly, oxidative electrochemistry has gained major attention. On the contrary, reductive electrolysis remains an underexplored research direction. In this context, we discuss advances in transition-metal-free cathodically generated radicals for selective organic transformations since 2016. We highlight the electroreductive reaction of alkyl radicals, aryl radicals, acyl radicals, silyl radicals, fluorosulfonyl radicals and trifluoromethoxyl radicals.
作者机构：
[Zhang Bingwen; Yang Wenchao] Cent China Normal Univ, Natl Key Lab Green Pesticide, Key Lab Pesticide Chem Biol, Minist Educ, Wuhan 430079, Peoples R China.;[Wang Xiaofeng] Univ Chinese Acad Sci, Hangzhou Inst Adv Study, Sch Chem & Mat Sci, Hangzhou 310024, Peoples R China.;[Wang Xiaofeng; Xue Yanqing; Lin Yuqi; Liu Wen; Wang Jing] Chinese Acad Sci, Shanghai Inst Organ Chem, State Key Lab Bioorgan & Nat Prod Chem, Shanghai 200032, Peoples R China.
通讯机构：
[Wang, XF; Liu, W ] C;[Wang, XF ] U;Univ Chinese Acad Sci, Hangzhou Inst Adv Study, Sch Chem & Mat Sci, Hangzhou 310024, Peoples R China.;Chinese Acad Sci, Shanghai Inst Organ Chem, State Key Lab Bioorgan & Nat Prod Chem, Shanghai 200032, Peoples R China.
摘要：
The immune checkpoint blockade (ICB) antibody immunotherapy has demonstrated clinical benefits for multiple cancers. However, the efficacy of immunotherapy in tumors is suppressed by deficient tumor immunogenicity and immunosuppressive tumor microenvironments. Pyroptosis, a form of programmed cell death, can release tumor antigens, activate effective tumor immunogenicity, and improve the efficiency of ICB, but efficient pyroptosis for tumor treatment is currently limited. Herein, we show a mild hyperthermia-enhanced pyroptosis-mediated immunotherapy based on hollow carbon nanozyme, which can specifically amplify oxidative stress-triggered pyroptosis and synchronously magnify pyroptosis-mediated anticancer responses in the tumor microenvironment. The hollow carbon sphere modified with iron and copper atoms (HCS-FeCu) with multiple enzyme-mimicking activities has been engineered to induce cell pyroptosis via the radical oxygen species (ROS)-Tom20-Bax-Caspase 3-gasdermin E (GSDME) signaling pathway under light activation. Both in vitro and in vivo antineoplastic results confirm the superiority of HCS-FeCu nanozyme-induced pyroptosis. Moreover, the mild photothermal-activated pyroptosis combining anti-PD-1 can enhance antitumor immunotherapy. Theoretical calculations further indicate that the mild photothermal stimulation generates high-energy electrons and enhances the interaction between the HCS-FeCu surface and adsorbed oxygen, facilitating molecular oxygen activation, which improves the ROS production efficiency. This work presents an approach that effectively transforms immunologically "cold" tumors into "hot" ones, with significant implications for clinical immunotherapy.
通讯机构：
[Yin, B ] N;[Li, DF ] C;Cent China Normal Univ, Coll Chem, Key Lab Pesticide & Chem Biol, Minist Educ, Wuhan 430079, Peoples R China.;Northwest Univ, Coll Chem & Mat Sci, Lab Theoret Mol Magnetism LTMM, Xian 710127, Peoples R China.
摘要：
An air-stable Dy-III complexwith a hexagonalbipyramid D (6h) symmetry derived of a neutralhexaaza macrocyclic Schiff base ligand shows zero-field single-moleculemagnet behavior with an open magnetic hysteresis loop up to 13 K andthe effective barrier of 584 K. Thedesign and synthesis of air-stable single-molecule magnets(SMMs) with large effective barriers of magnetic reversal and remarkablyslow relaxation times are challenging. The design and synthesis ofair-stable complexes with large effective magnetic reversal barriersand remarkably slow relaxation times are challenging in the fieldof SMMs. Herein, we present an air-stable hexagonal bipyramid [Dy-III(bpyN4)(Ph3SiO)(2)](BPh4)(1) (bpyN4 = neutral hexaaza macrocyclic Schiff baseligand derived of 6,6 & PRIME;-diformyl-2,2 & PRIME;-bipyridyl and triethylenetetramine).The magnetic data demonstrate that the complex shows zero-field SMMbehavior with magnetic hysteresis loops up to 13 K and an effectivebarrier of 584 K for 1. The experimental effective barrieris close to the energy of the first excited Kramers doublet (E (KD1)) obtained from ab initio calculations.
摘要：
Removing microcystins (MCs) safely and effectively has become an urgent global problem because of their extremely hazardous to the environment and public health. Microcystinases derived from indigenous microorganisms have received widespread attention due to their specific MC biodegradation function. However, linearized MCs are also very toxic and need to be removed from the water environment. How MlrC binds to linearized MCs and how it catalyzes the degradation process based on the actual three-dimensional structure have not been determined. In this study, the binding mode of MlrC with linearized MCs was explored using a combination of molecular docking and site-directed mutagenesis methods. A series of key substrate binding residues, including E70, W59, F67, F96, S392 and so on, were identified. Sodium dodecane sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was used to analyze samples of these variants. The activity of MlrC variants were measured using high performance liquid chromatography (HPLC). We used fluorescence spectroscopy experiments to research the relationship between MlrC enzyme (E), zinc ion (M), and substrate (S). The results showed that MlrC enzyme, zinc ion and substrate formed E-M-S intermediates during the catalytic process. The substrate-binding cavity was made up of N and C-terminal domains and the substrate-binding site mainly included N41, E70, D341, S392, Q468, S485, R492, W59, F67, and F96. The E70 residue involved in both substrate catalysis and substrate binding. In conclusion, a possible catalytic mechanism of the MlrC enzyme was further proposed based on the experimental results and a literature survey. These findings provided new insights into the molecular mechanisms of the MlrC enzyme to degrade linearized MCs, and laid a theoretical foundation for further biodegradation studies of MCs.
摘要：
A new fluorescent imaging probe indocyanine green-VC (ICG-VC) in the second near-infrared window (NIR-II) was fabricated based on the urokinase-type plasminogen activator receptor (uPAR) targeted polypeptide VC (VSNKYFSNIHWGC). The relative quantum yield (phi(F))was 0.34 %. The tail of its fluorescence emission wavelength exceeded 1000 nm with excellent photostability. In vitro cell analysis, MTT results indicated the high biocompatibility of ICG-VC with U87MG cells. ICG-VC showed good photothermal conversion behavior and photothermal stability.In vivo NIR-II fluorescence imaging, ICG-VC exhibited high spatiotemporal resolution in the lymphatic vessels with a high resolution of 717 mu m and signal-to-noise ratio of 4.36, and displayed an excellent U87MG tumor uptake within 4 h, which reached the maximum at 8 h with a signal-to-noise ratio of 5.32.
