The knowledge of accurate bond strengths is a fundamental basis for a proper analysis of chemical reaction mechanisms. Quantum chemical calculations at different levels of theory have been used to investigate heterolytic Fe–O and Fe–S bond energies of para‐substituted phenoxydicarbonyl(η5‐cyclopentadienyl) iron [p‐G‐C6H4O(η5‐C5H5)Fe(CO)2, abbreviated as p‐G‐C6H4OFp (1), where G = NO2, CN, COMe, CO2Me, CF3, Br, Cl, F, H, Me, MeO, and NMe2] and para‐substituted benzenethiolatodicarbonyl(η5‐cyclopentadienyl) iron [p‐G‐C6H4S(η5‐C5H5)Fe(CO)2, abbreviated as p‐G‐C6H4SFp (2)] complexes. The results show that BP86 and TPSSTPSS can provide the best price/performance ratio and more accurate predictions in the study of ΔHhet(Fe–O)'s and ΔHhet(Fe–S)'s. The excellent linear free‐energy relations [r = 0.99 (g, 1a), 1.00 (g, 2b)] among the ΔΔHhet (Fe–O)'s and Δpka's of O–H bonds of p‐G‐C6H4OH or ΔΔHhet(Fe‐S)'s and Δpka's of S–H bonds of p‐G‐C6H4SH imply that the governing structural factors for these bond scissions are similar. And the linear correlations [r = −0.99 (g, 1g), −0.98 (g, 2h)] among the ΔΔHhet (Fe‐O)'s or ΔΔHhet(Fe‐S)'s and the substituent σp− constants show that these correlations are in accordance with Hammett linear free‐energy relationships. The polar effects of these substituents and the basis set effects influence the accuracy of ΔHhet(Fe–O)'s or ΔHhet(Fe–S)'s. ΔΔHhet(Fe–O)'s(g) (1) and ΔΔHhet(Fe–S)'s(g)(2) follow the Capto‐dative principle. The substituent effects on the Fe–O bonds are much stronger than those on the less polar Fe–S bonds. Insight from this work may help the design of more effective catalytic processes. Copyright © 2013 John Wiley & Sons, Ltd.

The thermochemistry of organometallic complexes in solution and in the gas phase has been an area of increasing research interest. In this paper, the Fe–O and Fe–S homolytic bond dissociation energies [ΔHhomo(Fe–O)'s and ΔHhomo(Fe–S)'s] of two series of meta‐substituted phenoxydicarbonyl(η5‐cyclopentadienyl) iron [m‐G‐C6H4OFp (1)] and (meta‐substituted benzenethiolato)dicarbonyl(η5‐cyclopentadienyl) iron [m‐G‐C6H4SFp (2)] were studied using Hartree–Fock and density functional theory methods with large basis sets. In this study, Fp is (η5‐C5H5)Fe(CO)2, and G are NO2, CN, COMe, CO2Me, CF3, Br, Cl, F, H, Me, MeO, and NMe2. The results show that Tao–Perdew–Staroverov–Scuseria and Minnesota 2006 functionals can provide the best price/performance ratio and accurate predictions of ΔHhomo(Fe–O)'s and ΔHhomo(Fe–S)'s. The polar effects of the meta substituents show that the dominant role to the magnitudes of ΔΔHhomo(Fe–O)'s or ΔΔHhomo(Fe–S)'s. σα·, σc· values for meta substituents are all related to polar effects. Spin‐delocalization effects of the meta substituents in ΔΔHhomo(Fe–O)'s and ΔΔHhomo(Fe–S)'s are small but not necessarily zero. Molecular effects rather than ΔΔHhomo(Fe–O)'s and ΔΔHhomo(Fe–S)'s are more suitable indexes for the overall substituent effects on ΔHhomo(Fe–O)'s and ΔHhomo(Fe–S)'s. The meta substituent effects of meta‐electron‐withdrawing groups on the Fe–S bonds are much stronger than those on the Fe–O bonds. For meta‐electron‐donating groups, the meta substituent effects have the comparable magnitudes between series 1 and 2. ΔΔHhomo(Fe–O)'s (1) and ΔΔHhomo(Fe–S)'s (2) conform to the captodative principle. Insight from this work may help the design of more effective catalytic processes. Copyright © 2015 John Wiley & Sons, Ltd.

Traditional Chinese medicine (TCM) is one of the oldest East Asian medical systems. The present study adopted a systems biology-based approach to provide new insights relating to the active constituents and molecular mechanisms underlying the effects of dragon's blood (DB) tablets for the treatment of colitis. This study integrated chemical analysis, prediction of absorption, distribution, metabolism, and excretion (ADME), and network pharmacology. Firstly, a rapid, reliable, and accurate ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry method was employed to identify 48 components of DB tablets. In silico prediction of the passive absorption of these compounds, based on Caco-2 cell permeability, and their P450 metabolism enabled the identification of 22 potentially absorbed components and 8 metabolites. Finally, networks were constructed to analyze interactions between these DB components/metabolites absorbed and their putative targets, and between the putative DB targets and known therapeutic targets for colitis. This study provided a great opportunity to deepen the understanding of the complex pharmacological mechanisms underlying the effects of DB in colitis treatment.

Atherosclerosis (AS) is widespread and develops into circulatory system problems. T cells play an essential regulatory role in AS occurrence and development. So far, there is no bibliometric research on T cells and AS. To learn more about T cell and AS development, 4,381 records were retrieved from Web of Science™ Core Collection. Then, these records were scientometrically analyzed using CiteSpace and VOSviewer in terms of spatiotemporal distribution, author distribution, subject categories, topic distribution, references, and keywords. Our analysis provides basic information on research in the field, demonstrates that the field has stabilized over the past decade, and identifies potential partners for interested researchers. Current research hotspots in this field mainly include the inflammatory mechanism, immune mechanism, related diseases, and related cytokines of AS. B cell, mortality, inhibition, and monocyte represent the frontiers of research in this field, undergoing an explosive phase. We hope that this work will provide new ideas for advancing the scientific research and clinical application of T cell and AS.

As one of the most important components of Panax ginseng, ginsenoside Rg1 has certain anti-aging effects, improving the activity of learning and memory. Studies have showed that ginsenoside Rg1 improves the memory impairment associated with Alzheimer's disease (AD). In this study, the effects of ginsenoside Rg1 were investigated through the activity of toll-like receptor (TLR) 3, TLR4 and their signaling transduction pathways in amyloid β peptide 25-35 (Aβ25-35) induced AD cell model. Thus we investigated several critical components of the TLR pathway. The neuroglial cell line NG108-15 was stimulated with or without Aβ25-35, while different concentrations of ginsenoside Rg1 were administered. After 24 h, tumor necrosis factor-α (TNF-α), interferon-β (IFN-β) in cell supernatant and inducible nitric oxide synthase (iNOS) in cell lysate supernatant were measured with enzyme-linked immunosorbent assays (ELISAs). The mRNA and protein expression of TLR3, TLR4, nuclear factor kappa B (NF-κB) and tumor necrosis factor receptor-associated factor-6 (TRAF-6) were detected by real-time PCR and western blot methods, respectively. The experimental results showed that Aβ25-35 OPEN ACCESSMolecules 2014, 19 16926 could markedly raise the level of TNF-α, IFN-β and iNOS, and increase the expressions of mRNA and TLR3, TLR4, NF-κB and TRAF-6 protein in the NG108-15 cells. At the same time, the ginsenoside Rg1 significantly reduced the expressions of proteins and mRNA of TLR3, TLR4, NF-κB and TRAF-6, and down-regulated the levels of TNF-α, IFN-β of cell supernatant and iNOS of cell lysate supernatant in a concentration-dependent manner. In conclusion, ginsenoside Rg1 has good activity for suppressing the signaling transduction pathway of TLR3 and TLR4, and decreasing the inflammation factors induced by Aβ25-35 in NG108-15 cells, and this may be the mechanism of ginsenoside Rg1 action in AD treatment, but more studies are needed to identify its specificity.