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In‐Planta Expression: Searching for the Genuine Chromophores of Cryptochrome‐3 from Arabidopsis thaliana 下载免费PDF全文
Wolfgang Gärtner 《Photochemistry and photobiology》2017,93(1):382-384
Göbel et al. present in this issue an exemplary study of identification of chromophores from Arabidopsis thaliana cryptochrome‐3. Usually taken for granted, proteins and cofactors, respective chromophores, from heterologous expression are considered identical to material isolated from their genuine host. Cryptochromes carry two chromophores, an antenna cofactor and a functional flavin chromophore, both noncovalently embedded into the protein. In particular the antenna chromophore is loosely bound and often lost during protein purification. The authors identify from plant‐extracted Cry3 unambiguously N5,N10‐methenyltetrahydrofolate as antenna chromophore and flavin adenine dinucleotide as the functional chromophore. 相似文献
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盐酸- N1,NN', N'1-二甲双胍(HDMBG∙HCl)是临床广泛应用的降血糖药物,用于非胰岛素依赖型糖尿病的治疗。本文合成了三氯三(N5-苯甲酰-N1', N'1-二甲双胍)合钕 (Nd(BDMBG)3Cl3)和一氯二(N5-邻羧基苯甲酰- N1,NN', N'1-二甲双胍)合钕(Nd(CDMBG)2Cl)两种固态配合物,并通过元素分析、ICP、IR、UV、荧光光谱等表征了它们的化学组成和结构。糖尿病小鼠模型和ESR谱测定结果显示,几种化合物的降血糖作用及对人工脂质体膜超氧自由基的清除率呈现如下顺序:Nd(SDMBG)3 [)三(N5-水杨酰-N1,N1-二甲双胍)合钕] >Nd(CDMBG)2Cl » HDMBG·HCl > Nd(BDMBG)3Cl3,表明芳酰基邻位取代基的不同对配合物的降血糖作用和对O2-的清除作用具有重要影响。 相似文献
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Lionel Salmon Pierre Thury Michel Ephritikhine 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(6):m246-m248
The title complex, bis(acetylacetonato‐κ2O,O′)[N,N′‐bis(3‐hydroxy‐2‐oxidobenzaldimino)‐2‐methyl‐1,2‐propanediamine‐κ4N,O,O′,N′]uranium(IV) tetrahydrofuran solvate, [U(C18H18N2O4)(C5H7O2)2]·C4H8O, is a rare example of a uranium(IV) complex with a compartmental Schiff base. The U atom is located in the N2O2 inner site of the hexadentate N,N′‐bis(3‐hydroxy‐2‐oxidobenzaldimino)‐2‐methyl‐1,2‐propanediamine group and is bound also to the two O atoms of both acetylacetonate moieties, which results in a dodecahedral coordination environment. Centrosymmetric dimers are formed through intermolecular hydrogen bonds that link the terminal uncoordinated hydroxy groups to one another and to the O atoms of the acetylacetonate ligands. 相似文献
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Low-temperature heat capacities of 2-chloro-N,N-dimethylnicotinamide were precisely measured with a high-precision automated adiabatic calorimeter over the temperature range from 82 K to 380 K. The compound was observed to melt at (342.15±0.04) K. The molar enthalpy AfusionHm, and entropy of fusion, △fusionSm, as well as the chemical purity of the compound were determined to be (21387±7) J·mol^-1, (62.51±0.01) J·mol^-1·K^-1, (0.9946±0.0005) mass fraction, respectively. The extrapolated melting temperature for the pure compound obtained from fractional melting experiments was (342.25±0.024) K. The thermodynamic function data relative to the reference temperature 298.15 K were calculated based on the heat capacity measurements in the temperature range from 82 to 325 K. The thermal behavior of the compound was also investigated by different scanning calorimetry. 相似文献
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《Magnetic resonance in chemistry : MRC》2003,41(9):709-713
The 15N‐labelled iron dinitrogen complexes trans‐[FeH(N2)(PP)2]+[BPh4]? (PP = dppe, depe, dmpe) and cis‐[FeH(N2)(PP3)]+[BPh4]? were prepared in situ by exchange of unlabelled coordinated dinitrogen with 15N2. 15N NMR chemical shifts and coupling constants are reported. The 15N spectra exhibit separate signals for the metal‐bound and terminal nitrogen atoms of the coordinated N2. The 15N resonances display 15N, 15N coupling as well as 31P, 15N coupling and long‐range 15N, 1H coupling when there is a metal‐bound hydrido ligand. Exchange between free and coordinated dinitrogen was monitored by magnetization transfer between 15N‐labelled sites using an inversion–transfer–recovery experiment. Exchange between the metal‐bound and terminal nitrogen atoms of coordinated N2 was also monitored by magnetization transfer and this could proceed by N2 dissociation or by an intramolecular process. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
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Bing Zhang Hui‐Zhong Kou Yi He Hong‐Gen Wang Ai‐Li Cui 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(7):m341-m342
A new polymeric copper complex, viz.catena‐poly[[[μ‐N,N′‐bis(3‐aminopropyl)oxamidato‐κ6N,N′,O:N′′,N′′′,O′]dicopper(II)]‐di‐μ‐dicyanamido‐1:1′κ2N1:N5;2:2′κ2N1:N5], [Cu2(C8H16N4O2)(C2N3)2]n or [Cu(oxpn)0.5{N(CN)2}]n [where H2oxpn is N,N′‐bis(3‐aminopropyl)oxamide], has been synthesized by the reaction of Cu(oxpn), [Cu(ClO4)2]·6H2O and NaN3. In the crystal structure, the Cu atom is five‐coordinate and has a square‐pyrimidal (SP) configuration. In the polymer, dicyanamide (dca−) groups link CuII cations in a μ‐1,5‐bridging mode, generating novel ladders in which each step is composed of dimeric [Cu2(oxpn)]2+ cations. Abundant hydrogen bonds connect the polymer ladders into a two‐dimensional network structure. 相似文献
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A series of six N,N‐di‐substituted acylthiourea ArC(O)NHC(S)NRR′ ligands (denoted as HLn) [Ar = 1‐Naph: NRR′ = NPh2, HL1 ( 1 ); N(iPr)Ph, HL2 ( 2 ). Ar = Mes: NRR′ = NPh2, HL4 ( 3 ); N(iPr)Ph, HL5 ( 4 ); NEt2, HL6 ( 5 ). Ar = Ph: NRR′ = N(iPr)Ph, HL8 ( 6 )] were synthesized and characterized. These ligands were deprotonated to form CuII complexes through metathesis or combined redox reaction with copper halides. The structures of the complexes were investigated with single‐crystal X‐ray diffraction. The reaction of the 1‐naphthalene derivative HL1 ( 1 ) with CuBr in the presence of sodium acetate produced cis‐CuL12 ( 7 ), where the deprotonated ligand is bound to the CuII atom in a bidentate‐(O, S) coordination mode. Similarly treatment of HL2 ( 2 ) with NaOAc and CuCl resulted in the formation of the cis‐arranged product [cis‐CuL22 ( 8 )]. The reaction of mesityl derivative HL4 ( 3 ) and CuBr with and without the addition of NaOAc gave the cis‐CuL42 ( 9 ) and cis‐(HL4)2CuBr ( 10 ), respectively. In contrast, reaction of HL5 ( 4 ) and CuI in the presence of NaOAc resulted in trans‐CuL52 ( 11 ). Alternatively trans‐CuL62 ( 12 ) was obtained by the reaction of diethyl‐substituted HL6 ( 5 ) with CuCl2 in the absence of a base. 相似文献
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Xin Qiang Wang Wen Tao Yu Dong Xu Meng Kai Lu Duo Rong Yuan Guang Tian Lu 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(6):m341-m343
The title complex, {[CdHg(SCN)4(C4H9NO)2]2}n, contains two crystallographically independent CdII centres and two HgII centres. Each CdII atom is bound to four N atoms belonging to SCN groups and to two O atoms from N,N‐dimethylacetamide (DMA) ligands in an octahedral geometry. Each HgII centre is tetrahedrally coordinated by four SCN S atoms. 相似文献
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Jaromír Marek Pavel Kopel Zdenk Trvní
ek 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(12):m558-m560
In the crystal structure of the title compound, [N,N′‐bis(3‐aminopropyl)ethylenediamine‐κ4N,N′,N′′,N′′′][1,3,5‐triazine‐2,4,6(1H,3H,5H)‐trithionato(2−)‐κ2N,S]zinc(II) ethanol solvate, [Zn(C8H22N4)2(C3HN3S3)]·C2H6O, the ZnII atom is octahedrally coordinated by four N atoms [Zn—N = 2.104 (2)–2.203 (2) Å] of a tetradentate N‐donor N,N′‐bis(3‐aminopropyl)ethylenediamine (bapen) ligand and by two S and N atoms [Zn—S = 2.5700 (7) Å and Zn—N = 2.313 (2) Å] of a trithiocyanurate(2−) (ttcH2−) dianion bonded as a bidentate ligand in a cis configuration. The crystal structure of the compound is stabilized by a network of hydrogen bonds. 相似文献
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Florian J. Pucher Alexey Marchuk Dr. Peter J. Schmidt Detlef Wiechert Prof. Dr. Wolfgang Schnick 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(17):6443-6448
Nitridophosphates MP2N4:Eu2+ (M=Ca, Sr, Ba) and BaSr2P6N12:Eu2+ have been synthesized at elevated pressures and 1100–1300 °C starting from the corresponding azides and P3N5 with EuCl2 as dopant. Addition of NH4Cl as mineralizer allowed for the growth of single crystals. This led to the successful structure elucidation of a highly condensed nitridophosphate from single‐crystal X‐ray diffraction data (CaP2N4:Eu2+ (P63, no. 173), a=16.847(2), c=7.8592(16) Å, V=1931.7(6) Å3, Z=24, 2033 observed reflections, 176 refined parameters, wR2=0.096). Upon excitation by UV light, luminescence due to parity‐allowed 4f6(7F)5d1→4f7(8S7/2) transition was observed in the orange (CaP2N4:Eu2+, λmax=575 nm), green (SrP2N4:Eu2+, λmax=529 nm), and blue regions of the visible spectrum (BaSr2P6N12:Eu2+ and BaP2N4:Eu2+, λmax=450 and 460 nm, respectively). Thus, the emission wavelength decreases with increasing ionic radius of the alkaline‐earth ions. The corresponding full width at half maximum values (2240–2460 cm?1) are comparable to those of other known Eu2+‐doped (oxo)nitrides emitting in the same region of the visible spectrum. Following recently described quaternary Ba3P5N10Br:Eu2+, this investigation represents the first report on the luminescence of Eu2+‐doped ternary nitridophosphates. Similarly to nitridosilicates and related oxonitrides, Eu2+‐doped nitridophosphates may have the potential to be further developed into efficient light‐emitting diode phosphors. 相似文献
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Wolfgang Bauer Birgit Weber 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(6):m237-m239
The reaction of [FeL(MeOH)2] {where L is the tetradentate N2O2‐coordinating Schiff base‐like ligand (E,E)‐diethyl 2,2′‐[1,2‐phenylenebis(nitrilomethylidyne)]bis(3‐oxobutanoate)(2−) and MeOH is methanol} with 3‐aminopyridine (3‐apy) in methanol results in the formation of the octahedral complex (3‐aminopyridine‐κN1){(E,E)‐diethyl 2,2′‐[1,2‐phenylenebis(nitrilomethylidyne)]bis(3‐oxobutanoato)(2−)‐κ4O3,N,N′,O3′}(methanol‐κO)iron(II), [Fe(C20H22N2O6)(C5H6N2)(CH4O)] or [FeL(3‐apy)(MeOH)], in which the FeII ion is centered in an N3O3 coordination environment with two different axial ligands. This is the first example of an octahedral complex of this multidentate ligand type with two different axial ligands, and the title compound can be considered as a precursor for a new class of complexes with potential spin‐crossover behavior. An infinite two‐dimensional hydrogen‐bond network is formed, involving the amine NH group, the methanol OH group and the carbonyl O atoms of the equatorial ligand. T‐dependent susceptibility measurements revealed that the complex remains in the high‐spin state over the entire temperature range investigated. 相似文献
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Reactions of aquapentachloroplatinic acid, (H3O)[PtCl5(H2O)]·2(18C6)·6H2O ( 1 ) (18C6 = 18‐crown‐6), and H2[PtCl6]·6H2O ( 2 ) with heterocyclic N, N donors (2, 2′‐bipyridine, bpy; 4, 4′‐di‐tert‐butyl‐2, 2′‐bipyridine, tBu2bpy; 1, 10‐phenanthroline, phen; 4, 7‐diphenyl‐1, 10‐phenanthroline, Ph2phen; 2, 2′‐bipyrimidine, bpym) afforded with ligand substitution platinum(IV) complexes [PtCl4(N∩N)] (N∩N = bpy, 3a ; tBu2bpy, 3b ; Ph2phen, 5 ; bpym, 7 ) and/or with protonation of N, N donor yielding (R2phenH)2[PtCl6] (R = H, 4a ; Ph, 4b ) and (bpymH)+ ( 8 ). With UV irradiation Ph2phen and bpym reacted with reduction yielding platinum(II) complexes [PtCl2(N∩N)] (N∩N = Ph2phen, 6 ; bpym, 9 ). Identities of all complexes were established by microanalysis as well as by NMR (1H, 13C, 195Pt) and IR spectroscopic investigations. Molecular structures of [PtCl4(bpym)]·MeOH ( 7 ) and [PtCl2(Ph2phen)] ( 6 ) were determined by X‐ray diffraction analyses. Differences in reactivity of bpy/bpym and phen ligands are discussed in terms of calculated structures of complexes [PtCl5(N∩N)]— with monodentately bound N, N ligands (N∩N = bpy, 10a ; phen, 10b ; bpym, 10c ). 相似文献
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The coordination chemistry of platinum(II) with a series of thiosemicarbazones {R(H)C2=N3‐N2(H)‐C1(=S)‐N1H2, R = 2‐hydroxyphenyl, H2stsc; pyrrole, H2ptsc; phenyl, Hbtsc} is described. Reactions of trans‐PtCl2(PPh3)2 precursor with H2stsc (or H2ptsc) in 1 : 1 molar ratio in the presence of Et3N base yielded complexes, [Pt(η3‐ O, N3, S‐stsc)(PPh3)] ( 1 ) and [Pt(η3‐ N4, N3, S‐ptsc)(PPh3)] ( 2 ), respectively. Further, trans‐PtCl2(PPh3)2 and Hbtsc in 1 : 2 (M : L) molar ratio yielded a different compound, [Pt(η2‐ N3, S‐btsc)(η1‐S‐btsc)(PPh3)] ( 3 ). Complex 1 involved deprotonation of hydrazinic (‐N2H‐) and hydroxyl (‐OH) groups, and stsc2? is coordinating via O, N3, S donor atoms, while complex 2 involved deprotonation of hydrazinic (‐N2H‐) and ‐N4H groups and ptsc2? is probably coordinating via N4, N3, S donor atoms. Reaction of PdCl2(PPh3)2 with Hbtsc‐Me {C6H5(CH3)C2=N3‐N2(H)‐C1(=S)‐N1H2} yielded a cyclometallated complex [Pd(η3‐C, N3, S‐btsc‐Me)(PPh3)] ( 4 ). These complexes have been characterized with the help of analytical data, spectroscopic techniques {IR, NMR (1H, 31P), U.V} and single crystal X‐ray crystallography ( 1 , 3 and 4 ). The effects of substituents at C2 carbon of thiosemicarbazones on their dentacy and cyclometallation are emphasized. 相似文献
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Yoo Seok Lee Adrian Ruff Rong Cai Koun Lim Wolfgang Schuhmann Shelley D. Minteer 《Angewandte Chemie (International ed. in English)》2020,59(38):16511-16516
We report an organic redox‐polymer‐based electroenzymatic nitrogen fixation system using a metal‐free redox polymer, namely neutral‐red‐modified poly(glycidyl methacrylate‐co‐methylmethacrylate‐co‐poly(ethyleneglycol)methacrylate) with a low redox potential of ?0.58 V vs. SCE. The stable and efficient electric wiring of nitrogenase within the redox polymer matrix enables mediated bioelectrocatalysis of N3?, NO2? and N2 to NH3 catalyzed by the MoFe protein via the polymer‐bound redox moieties distributed in the polymer matrix in the absence of the Fe protein. Bulk bioelectrosynthetic experiments produced 209±30 nmol NH3 nmol MoFe?1 h?1 from N2 reduction. 15N2 labeling experiments and NMR analysis were performed to confirm biosynthetic N2 reduction to NH3. 相似文献
16.
Li‐Ping Lu Hong‐Mei Zhang Si‐Si Feng Miao‐Li Zhu 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(10):o740-o743
The crystal structures of N,N‐dimethylbiguanidium oxalate monohydrate, C4H13N52+·C2O42−·H2O, (I), and N,N‐dimethylbiguanidium sulfate monohydrate, C4H13N52+·SO42−·H2O, (II), show that both compounds contain the same N,N‐dimethylbiguanidium dication. In (I), two independent oxalate ions lie about inversion centres. Strong double hydrogen bonds, with D⋯A distances of 2.658 (2) and 2.830 (3) Å in (I), and 2.722 (3) and 2.815 (3) Å in (II), are present between N atoms of the N,N‐dimethylbiguanidium moieties and either the carboxylate group of the oxalate anion or the sulfate anion. 相似文献
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A group of 2‐(N,N‐diethylamino)‐4‐aminoquinazoline derivatives have been synthesized in the reaction of N1,N1‐diethyl‐N2‐arylchlorocarboxyamidines with cyanamide in the presence of T1Cl4 as a catalyst. Such quinazolines decompose into the corresponding quinazolones in dilute aqueous HC1 solutions at higher temperature. Hydrolysis rates of 2‐(N,N‐diethylamino)‐4‐aminoquinazoline and 2‐(N,N‐diethylamino)‐4‐(N,N‐dimethylamino)‐quinazoline have been determined to observe the influence of substituents at the 4‐amino group upon the hydrolysis. pKa values have been also determined for these compounds and analyzed in conjunction with the Hammett σ constants. 相似文献
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《Magnetic resonance in chemistry : MRC》2003,41(2):102-106
Unsymmetrical, dialkyl‐substituted N,N‐dialkyl‐N′‐acyl(aroyl)thioureas show E,Z configurational isomerism at room temperature in solution, which is also expressed in the existence of cis‐[Pt(ZZ‐L‐S,O)2], cis‐[Pt(EZ‐L‐S,O)2] and cis‐[Pt(EE‐L‐S,O)2] complexes derived from these ligands. These configurational isomers were assigned by means of a double magnetization transfer 1H/13C/195Pt correlation NMR experiment, despite the fact that the long‐range 5J(195Pt, 1H) and 4J(195Pt, 13C) scalar couplings are not directly observable in their 1H and 13C spectra at high field. Depending on the ligand structure, the relative amounts of cis‐[Pt(ZZ‐L‐S,O)2], cis‐[Pt(EZ‐L‐S,O)2] and cis‐[Pt(EE‐L‐S,O)2] complexes are in the ranges 40–42% ZZ, 46–47% ZE and 12–13% EE. The cis‐bis[N‐methyl‐N‐(tert‐butyl)‐N′‐(2,2‐dimethylpropanoyl)thioureato]platinum(II) complex is found to occur exclusively as the ZZ isomer. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
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Yi‐Ping Guo Dong‐Ying Li Guo‐Ting Li 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(10):m284-m286
In the title compound, {[NiCl2(C19H17N5O2)2]·4C3H7NO}n, the NiII atom is located on an inversion centre and is in a six‐coordinated octahedral geometry, formed by four pyridine N atoms from four N2,N6‐bis[(pyridin‐3‐yl)methyl]pyridine‐2,6‐dicarboxamide (BPDA) ligands occupying the equatorial plane and two chloride anions at the axial sites. The bidentate bridging BPDA ligands link the NiII atoms into a two‐dimensional corrugated grid‐like flexible layer with a (4,4)‐connected topology, which consists of left‐ and right‐handed helical chains sharing the common NiII atoms. Investigation of the thermal stability shows that the network is stable up to 573 K. 相似文献
20.
Jianjiang Lu Almaz S. Jalilov Jay K. Kochi 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(5):o226-o228
Crystallization of N,N′‐dimethylpyrazinediium bis(tetrafluoroborate), C6H10N22+·2BF4−, (I), and N,N′‐diethylpyrazinediium bis(tetrafluoroborate), C8H14N22+·2BF4−, (II), from dried acetonitrile under argon protection has permitted their single‐crystal studies. In both crystal structures, the pyrazinediium dications are located about an inversion center (located at the ring center) and each pyrazinediium aromatic ring is π‐bonded to two centrosymmetrically related BF4− anions. Strong anion–π interactions, as well as weak C—H...F hydrogen bonds, between BF4− and pyrazinediium ions are present in both salts. 相似文献