GC-MS Analysis of Low-polar Components and Antioxidant Activities of Vernonia divergens

[Objective]This study aimed to analyze the low-polar components and antioxidant activities of Vernonia divergens.[Method]After extraction,the relative contents of various components were calculated with peak area normalization method.In addition,V.divergens were extracted with n-hexane,ethyl acetate and n-butanol,respectively;DPPH scavenging capacity and reducing capacity of these three extracts were analyzed and compared with that of vitamin C.[Result]A total of 29 compounds were identified that accounted for 88.30%of the total amount of low-polar chemical components.The results indicated that n-butanol extract exhibited higher DPPH scavenging capacity and reducing capacity than ethyl acetate extract and n-hexane extract.[Conclusion]This study provided a theoretical basis for the development and utilization of V.divergens.

Odorants could elicit repair processes in melanized neuronal and skin cells

The expression of ectopic olfactory receptors （ORs） in melanized cells, such as the human brain nigrostri- atal dopaminergic neurons and skin melanocytes, is here pointed out. ORs are recognized to regulate skin melanogenesis, whereas OR expression in the dopaminergic neurons, characterized by accumulation of pigment neuromelanin, is downregulated in Parkinson＇s disease. Furthermore, the correlation between the pigmentation process and the dopamine pathway through ct-synuclein expression is also highlighted. Purposely, these ORs are suggested as therapeutic target for neurodegenerative diseases related to the pig- mentation disorders. Based on this evidence, a possible way of turning odorants into drugs, acting on three specific olfactory receptors, OR51E2, OR2AT4 and VN1R1, is thus introduced. Various odorous molecules are shown to interact with these ORs and their therapeutic potential against melanogenic and neurodegen- erative dysfunctions, including melanoma and Parkinson＇s disease, is suggested. Finally, a direct functional link between olfactory and endocrine systems in human brain through VNIR1 is proposed, helping to counteract female susceptibility to Parkinson＇s disease in quiescent life.

Ternary-phase layered cathodes toward ultra-stable and highrate sodium ion storage

With the shortage of lithium resources,sodiumion batteries(SIBs)are considered one of the most promising candidates for lithium-ion batteries.P2-type and O3-type layered oxides are one of the few cathodes that can access high energy density.However,they usually exhibit structural change,capacity decay,and slow Na ion kinetic.Herein,we present layered ternary-phase cathodes with P2,P3 and O3 phases by a lattice doping strategy,which is demonstrated by X-ray diffraction(XRD)refinement.Combining the characteristics of P2,P3 and O3 phases,the layered composites show performance improvement during long-term battery cycling.In particular,Na_(0.7)Li_(0.1)Co_(0.3-)Fe_(0.3)Mn_(0.3)O_(2)(NLCFM)delivers a reversible capacity of120.1 mAh·g^(-1)at 0.1C(1.0C=175 mA·g^(-1))with a superior capacity retention of 72.5%after 1000 cycles at10.0C.This work offers insights into the development of advanced cathode materials for SIBs.

The CARSO (Computer Aided Response Surface Optimization) Procedure in Optimization Studies

The paper illustrates innovative ways of using the CARSO (Computer Aided Response Surface Optimization) procedure for response surfaces analyses derived by DCM4 experimental designs in multivariate spaces. Within this method, we show a new feature for optimization studies: the results of comparing their quadratic and linear models for discussing the best way to compute the most reliable predictions of future compounds.

Heptanuclear brucite disk with cyanide bridges in a cocrystal and tracking its pyrolysis to an efficient oxygen evolution electrode

The development of efficient oxygen evolution reaction(OER)catalysts is still lacking in exploration of the mechanism of controlled pyrolysis of precursors among new material platforms.Here,a novel Co-based coordination molecular cluster has been first introduced as precursor to obtain metallic cobalt core shelled by N-doped carbon(Co@NC)structure which operates as an oxygen evolution electrode.Specifically,a new cocrystal compound,[Co7II(l3-CN)6(mmimp)6][CoIICl3N(CN)2]á3CH3OH(Co7+1,mmimp=2-methoxy-6-((methylimino)-methyl)phenol),was isolated consisting of Brucite disks of cobalt where the usual bridging l3-OH is replaced by l3-CN produced by the in-situ decomposition of dicyanamide(NC-N-CNà).The cobalt atoms are bonded through the nitrogen atom of the cyanide.Remarkably,time dependent thermogravimetric-mass spectrometry(TG-MS)analysis was utilized to track its pyrolysis process.It allowed us to propose a possible formation process of the Co@NC structure from Co7+1.Interestingly,an extremely superior OER electrode is optimized for Co@NC-600 having the lowest overpotential of257 m V at 10 m A/cm2in 1 mol/L KOH solution.The present study pins down the importance of clusters of transition metals on realizing distinct nanostructures operating as highly efficient OER electrocatalyst.

Neutralising effects of small molecule toxin inhibitors on nanofractionated coagulopathic Crotalinae snake venoms

Repurposing small molecule drugs and drug candidates is considered as a promising approach to revolutionise the treatment of snakebite envenoming.In this study,we investigated the inhibiting effects of the small molecules varespladib(nonspecific phospholipase A2 inhibitor),marimastat(broad spectrum matrix metalloprotease inhibitor)and dimercaprol(metal ion chelator)against coagulopathic toxins found in Crotalinae(pit vipers)snake venoms.Venoms from Bothrops asper,Bothrops jararaca,Calloselasma rhodostoma and Deinagkistrodon acutus were separated by liquid chromatography,followed by nanofractionation and mass spectrometry identification undertaken in parallel.Nanofractions of the venom toxins were then subjected to a high-throughput coagulation assay in the presence of different concentrations of the small molecules under study.Anticoagulant venom toxins were mostly identified as phospholipases A2,while procoagulant venom activities were mainly associated with snake venom metalloproteinases and snake venom serine proteases.Varespladib was found to effectively inhibit most anticoagulant venom effects,and also showed some inhibition against procoagulant toxins.Contrastingly,marimastat and dimercaprol were both effective inhibitors of procoagulant venom activities but showed little inhibitory capability against anticoagulant toxins.The information obtained from this study aids our understanding of the mechanisms of action of toxin inhibitor drug candidates,and highlights their potential as future snakebite treatments.

Exploring the Pyrolysis Mechanism towards OER Performance Optimization of Salophen-ligated Binuclear Cobalt Complex

Exploring pyrolysis process is an efficient way to study the relationship between molecular level of the precursor structure and electrocatalytic functional materials in practice.Here,the unique semi-enclosed sector structure of Salophen ligands with highly symmetric N,N,0,0 mode was introduced to construct binuclear Co complex[Co2(salophen)(CI)2(C2H3N)](compound 1),which provides pre-liminary theoretical basis for the efficient coreshell structure electrocatalysts obtained by pyrolysis regulation.Moreover,we adopted TG-MS to real-time track the pyrolysis process from precursors of binuclear Co complexes with Salophen ligand to efficient catalytic materials with core-shell nano structures.As expected,the 1-600 sample achieves ultra-low overpote ntial of 256 mV at 10 mA·cm^(-2) and high catalytic stability within 10 h in 1 mol/L KOH solution.This work highlights salophen-ligated complex as excellent precursor material system for the an alysis of pyrolysis evoluti on process,and provides an opport unity for targeted preparati on of efficie nt oxy-gen evoluti on reacti on(OER)nano catalysts.

A Push–Pull Mechanism Helps Design Highly Competent G-Quadruplex-DNA Catalysts

Massive efforts are currently being invested to improve the performance,versatility,and scope of applications of nucleic acid catalysts.G-quadruplex(G4)/hemin DNAzymes are of particular interest owing to their structural programmability and chemical robustness.However,optimized catalytic efficiency is still bottleneck and the activation mechanism is unclear.Herein,we have designed a series of parallel G4s with different proximal cytosine(dC)derivatives to fine-tune the hemin-binding pocket for G4-DNAzymes.