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OBJECTIVE: To observe the protective effect of wheat-grain moxibustion on cyclophosphamide (CTX)-induced liver injury in mice, and explore its mechanism based on the nuclear factor E2-related factor 2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) signaling pathway. METHODS: Twenty-four male CD-1 (ICR) mice were randomly divided into a blank group, a model group, and a moxibustion group, with 8 mice in each group. The mice in the model group and the moxibustion group were intraperitoneally injected with CTX (80 mg/kg) to induce liver injury. The mice in the moxibustion group were treated with wheat-grain moxibustion at "Guanyuan" (CV 4) and bilateral "Zusanli" (ST 36) and "Sanyinjiao" (SP 6), with each acupoint being treated by 3 cones, approximately 30 seconds per cone, once daily for 7 days. After intervention, the general condition of the mice was observed; the liver mass was measured and the liver index was calculated; HE staining was used to observe the morphology of the liver, and the liver tissue pathological score was assessed; ELISA was used to detect the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), glutamate dehydrogenase (GLDH) and the levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) in the liver; Western blot and real-time fluorescence quantitative PCR were used to detect the protein and mRNA expression of Nrf2, Keap1, and quinione acceptor oxidoreductase 1 (NQO1) in the liver. RESULTS: Compared with the blank group, the mice in the model group showed sluggishness, unsteady gait, and decreased body weight; liver index was increased (P<0.01); liver cells were loosely arranged, with a small number of cell swollen and exhibiting balloon-like changes; liver tissue pathological score was increased (P<0.05); the serum levels of AST, ALT, GLDH, and level of MDA in the liver were increased (P<0.05), and the levels of SOD and GSH-Px in the liver were decreased (P<0.05); protein and mRNA expression of Nrf2 and NQO1 in the liver was decreased (P<0.01), protein and mRNA expression of Keap1 in the liver was increased (P<0.01). Compared with the model group, the mice in the moxibustion group showed improvement in general condition; liver index was decreased (P<0.01); liver cell structure was relatively intact and clear, and liver tissue pathological score was decreased (P<0.05); the serum levels of AST, ALT, GLDH, and level of MDA in the liver were decreased (P<0.05), and the levels of SOD and GSH-Px in the liver were increased (P<0.05, P<0.01); protein and mRNA expression of Nrf2 and NQO1 in the liver was increased (P<0.05), protein and mRNA expression of Keap1 in the liver was decreased (P<0.05). CONCLUSION: The wheat-grain moxibustion may alleviate CTX-induced liver injury by activating the Nrf2-Keap1 signaling pathway and enhancing the expression of antioxidative enzyme system in the body.
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Ciclofosfamida , Proteína 1 Asociada A ECH Tipo Kelch , Hígado , Moxibustión , Factor 2 Relacionado con NF-E2 , Transducción de Señal , Triticum , Animales , Factor 2 Relacionado con NF-E2/metabolismo , Factor 2 Relacionado con NF-E2/genética , Ratones , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Proteína 1 Asociada A ECH Tipo Kelch/genética , Masculino , Transducción de Señal/efectos de los fármacos , Humanos , Ciclofosfamida/efectos adversos , Triticum/química , Hígado/metabolismo , Hígado/efectos de los fármacos , Ratones Endogámicos ICR , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/terapia , Enfermedad Hepática Inducida por Sustancias y Drogas/genética , Antioxidantes/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Péptidos y Proteínas de Señalización Intracelular/genéticaRESUMEN
INTRODUCTION: Specific treatment for diabetic peripheral neuropathy (DPN) is still lacking, and acupuncture may relieve the symptoms. We intend to investigate the efficacy and safety of electro-acupuncture (EA) in alleviating symptoms associated with DPN in diabetes. METHODS AND ANALYSIS: This multicentre, three-armed, participant- and assessor-blind, randomised, sham-controlled trial will recruit 240 eligible participants from four hospitals in China and will randomly assign (1:1:1) them to EA, sham acupuncture (SA) or usual care (UC) group. Participants in the EA and SA groups willl receive either 24-session EA or SA treatment over 8 weeks, followed by an 8-week follow-up period, while participants in the UC group will be followed up for 16 weeks. The primary outcome of this trial is the change in DPN symptoms from baseline to week 8, as rated by using the Total Symptom Score. The scale assesses four symptoms: pain, burning, paraesthesia and numbness, by evaluating the frequency and severity of each. All results will be analysed with the intention-to-treat population. ETHICS AND DISSEMINATION: The protocol has been approved by the Ethics Committee of the Beijing University of Chinese Medicine (Identifier: 2022BZYLL0509). Every participant will be informed of detailed information about the study before signing informed consent. The results of this trial will be published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ChiCTR2200061408.
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Terapia por Acupuntura , Diabetes Mellitus , Neuropatías Diabéticas , Electroacupuntura , Humanos , Neuropatías Diabéticas/terapia , Dolor , China , Beijing , Resultado del Tratamiento , Electroacupuntura/métodos , Ensayos Clínicos Controlados Aleatorios como Asunto , Estudios Multicéntricos como AsuntoRESUMEN
OBJECTIVES: To observe the clinical efficacy of acupotomy combined with metformin hydrochloride tablet for type 2 diabetes mellitus (T2DM) and its effect on serum levels of inflammatory factors. METHODS: A total of 68 patients with T2DM were randomized into an acupotomy group (34 cases, 2 cases dropped out) and a western medication group (34 cases, 2 cases dropped out). Metformin hydrochloride tablet was given orally in the western medication group, 0.5-1 g each time, twice a day, for continuous 8 weeks. On the basis of the treatment in the western medication group, acupotomy was applied at bilateral Geshu (BL 17), Weiwanxiashu (EX-B 3), Ganshu (BL 18) in the acupotomy group, once a week for continuous 8 weeks. Before and after treatment, in the two groups, blood glucose (fasting blood glucose [FBG], 2-hour plasma glucose [2 h PG] and glycosylated hemoglobin [HbA1c]), TCM syndrome score, blood lipids (total cholesterol [TC], triglyceride [TG], low density lipoprotein cholesterol [LDL-C] and high density lipoprotein cholesterol [HDL-C]), insulin (fasting insulin [FINS] and 2-hour insulin [2 h INS]), C-peptide indexes (fasting C-peptide [FC-P] and 2-hour C-peptide [2 h C-P]), dosage of metformin hydrochloride tablet and diabetes specific quality of life (DSQL) score were observed, the serum levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-17 were measured by ELISA. RESULTS: After treatment, the FBG, 2 h PG, HbA1c, TCM syndrome scores, TC, TG, LDL-C, FINS, 2 h INS, FC-P, 2 h C-P, DSQL scores as well as the serum levels of TNF-α, IL-6, IL-17 were decreased compared with those before treatment (P<0.01), HDL-C was increased compared with that before treatment (P<0.01) in the two groups; the dosage of metformin hydrochloride tablet was decreased compared with that before treatment in the acupotomy group (P<0.01). After treatment, in the acupotomy group, the FBG, HbA1c, TCM syndrome score, TC, TG, LDL-C, FINS, 2 h INS, FC-P, 2 h C-P, dosage of metformin hydrochloride tablet, DSQL score as well as the serum level of TNF-α were lower than those in the western medication group (P<0.05). CONCLUSIONS: Acupotomy combined with metformin hydrochloride tablet can improve the blood glucose, clinical symptoms and quality of life in patients with T2DM, its mechanism may be related to the regulation of inflammatory reaction.
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Terapia por Acupuntura , Diabetes Mellitus Tipo 2 , Metformina , Humanos , Glucemia , Péptido C , LDL-Colesterol , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hemoglobina Glucada , Interleucina-17 , Metformina/uso terapéutico , Calidad de Vida , Comprimidos/uso terapéutico , Factor de Necrosis Tumoral alfaRESUMEN
One stimulus-induced two-step photophysical response, especially with tunable switching time, is a great challenge for organic chromophores. Herein, a polymorphic material 2,7-DCF could undergo in situ two sequential dual-channel responses upon dichloromethane fuming. Both the appearance color and the fluorescence change from red to yellow to deep red with high contrast. The first step corresponds to a fast amorphous-to-crystalline transformation, while the second is a slow solid-state cocrystallization process. Based on single crystal structures and theoretical calculations, such distinct color changes are mainly attributed to conformation twisting and the electron coupling with incorporated solvent molecule through C-Hâ â â O interaction. Importantly, the second slow photophysical response could be drastically sped up by seeding strategy, or be totally inhibited. Such characteristics pave a way for the potential applications in dynamic anti-counterfeiting and data encryption. Based on the two-step transformation, polymorph 2,7-DCF-a could achieve a successive four-level response to external stimuli. In contrast, polymorph 2,7-DCF-d exhibits a stepwise hypsochromic fluorescence shift over 100 nm. This study would significantly promote the development of stimuli-sensitive systems from "one stimulus, one-step response" to "one stimulus, two or multi-step response".
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Stimuli-responsive organic materials with controllable luminescence are of enormous importance because of their potential applications in sensing, data security, and display devices. In this study, a multistimuli-responsive squaraine dyad (SQ-d) composed of two rigid squaraine moieties and a flexible ethylene linker was rationally designed and synthesized. SQ-d exhibits polymorphic luminescence, which can be reversibly switched by various external stimuli, including solvent vapor exposure, heat, and shear force. Unexpectedly, the weakly luminescent phase (O1) of SQ-d exhibits concentration-controlled vapochromic behavior. Film O1 can convert to a highly green-emissive phase (G1) under a low concentration of CHCl3 vapor and convert to a highly yellow-emissive phase (Y) under a high concentration of CHCl3 vapor; these originate from two distinct crystallization-induced emission enhancement processes. To the best of our knowledge, this is the first investigation of the effect of vapor concentration on the phase transitions of organic vapochromic luminophores. By analyzing the single-crystal structures and photophysical properties of SQ-d, we concluded that the green and yellow emissions probably originated from a zigzag stacking mode and an H-type π-π stacking mode, respectively. Finally, two prototypes based on SQ-d for applications in information encryption and vapor sensing were successfully demonstrated.
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A multifunctional smart binuclear Zn(ii) complex (1) was synthesized by a simple process. 1 contains unique water pentamers in its crystals and undergoes reversible thermochromism and exciplex emission on and off during the dehydration and rehydration processes. A thermally induced redox reaction occurred in the charge transfer of complex 1 giving rise to a persistent radical species which shows fast response and high selectivity toward gaseous NH3 as a solid-state colorimetric and fluorescent bifunctional sensor.
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Although great progress has been made in hybrid iodocuprates(i) as lighting phosphors, the effects of aromatic and aliphatic structure directing agents (SDAs) on their water stability, structure and photoluminescence (PL) properties are still not clear. Herein, aromatic N-heterocyclic 1,2-di(4-pyridyl)ethylene (dpe), aliphatic N-heterocyclic 1,8-diazabicyclo[5.4.0]undec-7-ene (dbu) and N-aminoethylpiperazine (app) were selected to be SDAs to construct two types of hybrid iodocuprates(i) via a facile in situ approach. Aromatic dpe-derived cations are successfully directed to form (Me2dpe)(CuI3) (1), (Me2dpe)n(Cu4I6)n (2), (Et2dpe)2(Cu6I10) (3), and (H2dpe)n(Cu2I4)n (4). Three of them contain unprecedented inorganic iodocuprate clusters or chains. The aliphatic N-heterocyclic dbu- and app-derivative cations are responsible for the formation of (Hdbu)n(Cu2I3)n (5) and (H3app)2(Cu2I6)·2I·2H2O (6), which contain a (Cu2I3)- chain and a (Cu2I6)4- binuclear cluster, respectively. For the first time, the influence mechanisms of the water stabilities of iodocuprate-based PL materials were disclosed, by analyzing the possible interactions between SDAs and water molecules. 1-2 are PL silent due to their "self-quenching effect". 3, 4 and5 exhibit bright red, orange and yellow solid-state PL emissions at room temperature respectively, originating from the charge transfer between inorganic iodocuprate species and organic N-heterocycles. The co-template approach leads to multiple charge transfers in 6, which features a tunable PL behavior from bluish green to white by varying the excitation light, and has a quantum yield up to 43% (the highest value among hybrid iodocuprates containing (Cu2I6)4- clusters). The comparative study not only helps us to rationally synthesize iodocuprate-based PL materials with enhanced performance, but also provides a new method to obtain wavelength-dependent PL materials.
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OBJECTIVE: To observe the regulatory effects of electroacupuncture with different acupoints combinations on blood lipid and atherosclerosis index (AI) in rats with hyperlipemia, so as to make a preliminary screening for the optimal acupoints combination for hyperlipemia. METHODS: One hundred and five clean-grade SD male rats were randomly divided into 9 groups, including a normal group, a model group, a Quchi group, a Zhongwan group, a Fenglong group, a Quchi+Zhongwan group, a Quchi+Fenglong group, a Zhongwan+Fenglong group and a Quchi+Zhongwan+Fenglong group (three acupoints group), 17 rats in the normal group and 11 rats in the rest groups. The normal group was fed with normal diet, while the rest groups were fed with high-fat diet for 3 weeks to prepare the hyperlipemia model. All the rats were given unlimited water. After the establishment of model, the normal group was fed freely without any treatment; the model group was bundled and immobilized everyday; the rest groups were bundled, immobilized and treated with electroacupuncture at corresponding acupoints with disperse-dense wave, 20 min per time, once a day. After 4 weeks, the blood examples were collected from abdominal aorta to measure the total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL-C) and low-density lipoprotein (LDL-C), and analyzed the AI in each group. RESULTS: After the treatment, TC, TG, HDL-C, LDL-C and AI in each acupuncture group were all lower than those in the model group (P<0.05, P<0.01). Compared with single acupoint group and the Quchi+Zhongwan group, the content of TC in the three acupoints group was lower (P<0.01). The differences of content of TG among each acupuncture group were not significant (all P>0.05). Compared with the rest 6 acupuncture groups, the content of HDL-C and AI in the three acupoints group were significantly different (all P<0.05). The content of LDL-C in the three acupoints group was decreased as compared with the Quchi group and the Zhong-wan group. CONCLUSION: The electroacupuncture at "Quchi" (LI 11), "Zhongwan" (CV 12) and "Fenglong" (ST 40) has more advantages on regulating the content of HDL-C and LDL-C as well as improving AI in hyperlipemia rats, and it has superior effects on blood lipid metabolism.
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Puntos de Acupuntura , Electroacupuntura , Hiperlipidemias/terapia , Lípidos/sangre , Animales , Humanos , Hiperlipidemias/sangre , Masculino , Ratas , Ratas Sprague-DawleyRESUMEN
New anhydrous lanthanide metal-organic frameworks (MOFs) [Pr(tip)1.5]2n (tip-Pr), [Nd(tip)1.5]2n (tip-Nd), [Eu-(tip)1.5]2n (tip-Eu), and [Eu(OH)(mip)]n (mip-Eu) (tip=5-tert-butylisophthalate anion, mip=5-methylisophthalate ion), have been hydrothermally synthesized and structurally characterized by elemental analyses, FT-IR spectroscopy, single-crystal X-ray diffraction, thermal gravimetric analysis/differential thermal analysis (TG/DTA), and X-ray powder diffraction (XRPD) techniques. MOFs tip-Pr, tip-Nd, and tip-Eu are isostructural anhydrous compounds, and exhibit an unprecedented 3D microporous structure with hexagonal channel arrays. The selectively prepared MOF mip-Eu presents an interpenetrated 3D microporous architecture containing the hydroxyl cluster chains. Solid-state photoluminescence properties at room temperature indicate that both tip-Eu and mip-Eu display the characteristic of the Eu3+ ion spectrum dominated by the 5D0-->7F(J) (J=0-4) transition. Compared with mip-Eu, tip-Eu displays the very high solid-state quantum yield (0.62 ± 0.03) and longer lifetime value (0.94 ± 0.01 ms), which is due to the absence of the hydroxyl groups from the solid-state structure of tip-Eu. More importantly, a new method to directly investigate the potential of solid-state lanthanide MOFs for ionic sensing in aqueous solutions has been developed, and successfully applied it to study the potential sensing function of tip-Eu for polyoxometalates (POMs). The possible mechanism for the quenching effect of POMs on the fluorescence of tip-Eu is elucidated by the strongly competitive absorption of the excited light source energy between POMs and tip ligands. The very promise for the highly sensitive sensing for polyoxometalates, together with the characteristic of the reversible fluorescence response, suggest that solid-state tip-Eu can be an excellent candidate for the directly photoluminescent detection of POMs in aqueous solutions.
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Reactions of lithio-o-carborane with isocyanates under various conditions were studied, and the structural features of the resulting carboranylamides are described. The reactions of o-carborane (o-C2B10H12), n-BuLi (two equiv.) and two equiv. of (substituted) phenylisocyanate, pentylisocyanate and p-ethylphenylthioisocyanate in diethyl ether, respectively, led, after workup, to the corresponding mono-substituted carboranylamide 2a-g and carboranylthioamide 5 in low to moderate yields, and only with RNCO (R = Ph, m-MeOC6H4, pentyl) could disubstituted products 3a-c be isolated. The reaction with phenylisocyanate afforded the mono-amide and di-amide products in a ratio of approximately 1 : 2, whereas in the other two reactions the ratios are approximately 4 : 1 and 3 : 2, respectively. In tetrahydrofuran all the reactions attempted with RNCO (R = Ph, p-IC6H4, m-NCC6H4 and pentyl) gave more monoamide products than those in diethyl ether. With phenylisocyanate no diamide product was isolated and with pentylisocyanate the ratio between monoamide and diamide is approximately 3.5 : 1. The new carboranylamides were characterized by means of elemental analyses, IR and NMR spectroscopy and mass spectrometry, as well as single-crystal X-ray diffraction analyses of 2a-f, 3a and 5.
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In attempts to investigate whether the photoluminescence properties of the Zn-based heterometal-organic frameworks (MOFs) could be tuned by doping different Ln(3+) (Ln = Sm, Eu, Tb) and Mn(2+) ions, seven novel 3D homo- and hetero-MOFs with a rich variety of network topologies, namely, [Zn(mip)](n) (Zn-Zn), [Zn(2)Mn(OH)(2)(mip)(2)](n) (Zn-Mn), [Mn(2)Mn(OH)(2)(mip)(2)](n) (Mn-Mn), [ZnSm(OH)(mip)(2)](n) (Zn-Sm), [ZnEu(OH)(mip)(2)](n) (Zn-Eu1), [Zn(5)Eu(OH)(H(2)O)(3)(mip)(6)·(H(2)O)](n) (Zn-Eu2), and [Zn(5)Tb(OH)(H(2)O)(3)(mip)(6)](n) (Zn-Tb), (mip = 5-methylisophthalate dianion), have been synthesized hydrothermally based on a single 5-methylisophthalic acid ligand. All compounds are fully structurally characterized by elemental analysis, FT-IR spectroscopy, TG-DTA analysis, single-crystal X-ray diffraction, and X-ray powder diffraction (XRPD) techniques. The various connectivity modes of the mip linkers generate four types of different structures. Type I (Zn-Zn) is a 3D homo-MOF with helical channels composed of Zn(2)(COO)(4) SBUs (second building units). Type II (Zn-Mn and Mn-Mn) displays a nest-like 3D homo- or hetero-MOF featuring window-shaped helical channels composed of Zn(4)Mn(2)(OH)(4)(COO)(8) or Mn(4)Mn(2)(OH)(4)(COO)(8) SBUs. Type III (Zn-Sm and Zn-Eu1) presents a complicated corbeil-like 3D hetero-MOF with irregular helical channels composed of (SmZnO)(2)(COO)(8) or (EuZnO)(2)(COO)(8) heterometallic SBUs. Type IV (Zn-Eu2 and Zn-Tb) contains a heterometallic SBU Zn(5)Eu(OH)(COO)(12) or Zn(5)Tb(OH)(COO)(12), which results in a 3D hetero-MOF featuring irregular channels impregnated by parts of the free and coordinated water molecules. Photoluminescence properties indicate that all of the compounds exhibit photoluminescence in the solid state at room temperature. Compared with a broad emission band at ca. 475 nm (λ(ex) = 380 nm) for Zn-Zn, compound Zn-Mn exhibits a remarkably intense emission band centered at 737 nm (λ(ex) = 320 nm) due to the characteristic emission of Mn(2+). In addition, the fluorescence intensity of compound Zn-Mn is stronger than that of Mn-Mn as a result of Zn(2+) behaving as an activator for the Mn(2+) emission. Compound Zn-Sm displays a typical Sm(3+) emission spectrum, and the peak at 596 nm is the strongest one (λ(ex) = 310 nm). Both Zn-Eu1 and Zn-Eu2 give the characteristic emission transitions of the Eu(3+) ions (λ(ex) = 310 nm). Thanks to the ambient different crystal-field strengths, crystal field symmetries, and coordinated bonds of the Eu(3+) ions in compounds Zn-Eu1 and Zn-Eu2, the spectrum of the former compound is dominated by the (5)D(0) â (7)F(2) transition (612 nm), while the emission of the (5)D(0) â (7)F(4) transition (699 nm) for the latter one is the most intense. Compound Zn-Tb emits the characteristic Tb(3+) ion spectrum dominated by the (5)D(4) â (7)F(5) (544 nm) transition. Upon addition of the different activated ions, the luminescence lifetimes of the compounds are also changed from the nanosecond (Zn-Zn) to the microsecond (Zn-Mn, Mn-Mn, and Zn-Sm) and millisecond (Zn-Eu1, Zn-Eu2, and Zn-Tb) magnitude orders. The structure and photoluminescent property correlations suggest that the presence of Mn(2+) and Ln(3+) ions can activate the Zn-based hetero-MOFs to emit the tunable photoluminescence.
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In the title compound, C(7)H(7)N(2)O(+)·I(-), the carbonyl C and O atoms of the cation and the iodide ion are situated on mirror planes. The mean plane of the imidazo[1,2-d]pyridinium cation is perpendicular to the mirror plane as a consequence of the disorder of the cation over two opposite orientations of equal occupancy. In the crystal, N-Hâ¯I interactions are present.
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In the title compound, [PtCl(2)(C(18)H(15)P)(2)]·CHCl(3), each Pt(II) centre adopts a nearly square-planar coordination geometry formed by two P atoms [Pt-P = 2.2481â (17) and 2.2658â (19)â Å] and two Cl anions [Pt-Cl = 2.3244â (19) and 2.3548â (17)â Å]. The Cl atoms of the chloro-form solvent mol-ecule are disordered over two orientations in a 0.778â (11):0.222â (11) ratio. The crystal packing is stabilized by weak inter-molecular C-Hâ¯Cl hydrogen bonds, exhib-iting voids with a volume of 215â Å(3).
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An ortho-rhom-bic polymorph of the title compound, [Fe(C(5)H(5))(C(8)H(17)B(10)O)] or C(13)H(22)B(10)FeO, is described here in addition to the known monoclinic polymorph [Crundwell et al. (1999 â¶). Acta Cryst.C55, IUC9900087]. The asymmetric unit contains four independent mol-ecules with C(cage)-C(cage) distances of 1.636â (16)-1.700â (16)â Å, and with the methyl-hydr-oxy groups disordered over two positions in each mol-ecule [occupancy ratios 0.80â (2):0.20â (2), 0.59â (3):0.41â (3), 0.60â (2):0.40â (2) and 0.793â (17):0.207â (17)].
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In the title complex, [Ni(C(7)H(4)O(2)S)(C(26)H(24)P(2))]·CH(3)OH, the nickel(II) centre adopts an approximately square-planar geometry, with the Ni atom coordinating to the S and O atoms of the bidentate thio-salicylate ligand and the two P atoms of the chelating Ph(2)PCH(2)CH(2)PPh(2) ligand. There is hydrogen bonding between the methanol solvent mol-ecule and the carbonyl O atom of the thio-salicylate ligand.
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In the title compound, [Cu(C(12)H(9)N(2)O)(2)], the Cu(II) atom lies on a crystallographic inversion center and has a nearly square-planar geometry. The Cu(II) center coordinates to the phenolic O and azomethine N atoms of the two symmetry-related 2-[(2-pyrid-yl)imino-meth-yl]phenolate ligands. The pyridyl N atoms do not coordinate to the Cu(II) atom but participate in intra-molecular C-Hâ¯N hydrogen bonding. π-π stacking between the benzene rings and between the pyridyl rings [centroid-centroid distances 3.8142â (5) and 3.8142â (5)â Å, respectively] links the mol-ecules into a chain propagating parallel to [100].
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In the title compound, C(7)H(9)N(2)O(4) (+)·I(3) (-)·C(7)H(8)N(2)O(4), the two imidazolium units are hydrogen bonded through the carboxyl groups. The units are further linked via inter-molecular O-Hâ¯O hydrogen bonding, resulting in a one-dimensional ladder-type structure. As a result, the two carb-oxy groups of each imidazolium unit adopt a cis configuration with respect to the imidazolium ring.
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The title compound, C(11)H(10)N(2)O(4)·H(2)O, has a zwitterionic structure, in which the benzimidazole ring system is planar, with a maximum deviation of 0.007â (3)â Å. The carbox-yl/carboxyl-ate groups adopt a trans configuration. In the crystal structure, inter-molecular O-Hâ¯O hydrogen bonds involving the hydr-oxy/oxide O atoms link the mol-ecules into a one-dimensional chain. These chains are further linked by O-Hâ¯O hydrogen bonds involving the water mol-ecules into a two-dimensional network. π-π contacts between the benzimidazole rings [centroid-centroid distance = 3.5716â (4)â Å] lead to the formation of a three-dimensional supra-molecular structure.
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Free radical reactions of Martynoside (MAR), a phenylpropanoid glycoside, with a variety of oxidants were studied in the aqueous solution by laser photolysis and pulse radiolysis techniques. The pKa value of MAR in aqueous solution was measured from the pH dependent changes of the UV absorption at 384 nm with value of pKa = 9.2. The phenoxyl radical of MAR which exhibits maximum absorption at 360 nm was generated by one-electron transfer to N3* or Br2*-. Other important properties of phenoxyl radical such as extinction coefficient, formation and decay rate constants were also determined. The reaction rate constant of O2*- with MAR, k = 8.5 x 10(4) dm3 x mol(-1) x s(-1), was measured by the method of competition kinetics. By measuring time-resolved luminescence emission at 1270 nm, the quenching rate constant of singlet oxygen by MAR was obtained to be 3.3 x 10(6) dm3 x mol(-1) x s(-1). Reduction potential of the MAR couple (MAR*/MAR), determined using rutin as reference compound, gave a value E = 0.66 V vs. NHE. The antioxidative properties of MAR were compared with those of some well-known antioxidants.