Study of various aliphatic alcohols as sacrificial agents on photoelectrochemical behavior of nickel-platinum-modified Cr-TiO<Subscript>2</Subscript> nanotubes

Cr-TiO₂ nanotubes (Cr-TNTs) have been synthesized via facile one step anodization, followed by co-deposition by nickel-platinum via electroless deposition method. Field-emission scanning electron microscopy (FE-SEM), x-ray diffraction (XRD), and Raman spectroscopy have then been used to characterize the surface morphology and structure of the synthetic samples. The optical properties of the compounds have been investigated by ultraviolet-visible (UV-Vis) diffuse reflectance spectroscopy. Linear sweep voltammetry (LSV) and chronoamperometry were used to study the photoelectrochemical behavior of the obtained samples. The best electrochemical performer sample (t₂₀) was recognized and evaluated in the presence of various aliphatic alcohols, as sacrificial agents, in photoelectrochemical cells (PEC) water splitting. In terms of sacrificial agent used, photocurrent density production was as follows: methanol > ethanol > glycerol > n-propanol > isopropanol > ethylene glycol. Also methanol concentration was optimized. Thus, both co-deposition of Cr-TNTs and addition of scavengers are promising methods to enhance the performance of catalysts for PEC.     

Raman Microspectroscopic Evidence for the Metabolism of a Tyrosine Kinase Inhibitor,Neratinib, in Cancer Cells

Tyrosine kinase receptors are one of the main targets in cancer therapy. They play an essential role in the modulation of growth factor signaling and thereby inducing cell proliferation and growth. Tyrosine kinase inhibitors such as neratinib bind to EGFR and HER2 receptors and exhibit antitumor activity. However, little is known about their detailed cellular uptake and metabolism. Here, we report for the first time the intracellular spatial distribution and metabolism of neratinib in different cancer cells using label‐free Raman imaging. Two new neratinib metabolites were detected and fluorescence imaging of the same cells indicate that neratinib accumulates in lysosomes. The results also suggest that both EGFR and HER2 follow the classical endosome lysosomal pathway for degradation. A combination of Raman microscopy, DFT calculations, and LC‐MS was used to identify the chemical structure of neratinib metabolites. These results show the potential of Raman microscopy to study drug pharmacokinetics.     

配合物(BenzMeIm)_2[PtCl_4]的合成与表征（英文）

通过离子液体氯化1-苄基-3-甲基咪唑(BenzMeIm-Cl)与PtCl_2的反应,合成了配合物(BenzMeIm)_2[PtCl_4],并用元素分析、红外光谱、紫外-可见光谱、1H NMR、13C NMR和单晶X射线衍射对其进行了表征。单晶X射线分析表明,配合物结构属于P21/c空间群,晶胞参数和结构解析参数为:a=0.981 80(5)nm,b=0.861 47(3)nm,c=0.144 332(7)nm,β=92.480(2)°,V=121.96(1)nm3,R1=0.014 4,w R2=0.038 8。     

Heterobimetallic complexes of palladium(II) bridged by the mixed phosphine–phosphine oxide ligand Ph2PCH2CH2P(O)Ph2

The mixed phosphine–phosphine oxide Ph₂PCH₂CH₂P(O)Ph₂ (dppeO) reacts with either trans-[PdCl₂(PhCN)₂], Na₂[PdCl₄] or trans-[PdCl₂(DMSO)₂] to give trans-[PdCl₂{¹-Ph₂PCH₂CH₂P(O)Ph₂}₂]. Treatment of the latter with the metal chlorides, MCl₂ · nH₂O (M = Mn, Cu, Co, Zn, Hg; n = 4, 2, 6, 1, 0, respectively) or with Me₂SnCl₂ or SnCl₄ · 5H₂O, or with UO₂(NO₃)₂ · 6H₂O or UO₂(OAc)₂ · 2H₂O gives heterobimetallic complexes: trans-[PdCl₂{-Ph₂PCH₂CH₂P(O)Ph₂}₂MX₂] · nH₂O. The cobalt complex (MX₂ = CoCl₂) was unstable in solution (MeOH or EtOH/CHCl₃), and reverts to trans-[PdCl₂{¹-Ph₂PCH₂CH₂P(O)Ph₂}₂] and CoCl₂. trans-[PdCl₂{¹-Ph₂PCH₂CH₂P(O)Ph₂}₂] does not apparently react with either NiCl₂ · 6H₂O or CdCl₂ · 2.5H₂O.     

Synthesis and characterization of mononuclear palladium(II) and platinum(II), dinuclear palladium(I) and platinum(I), and heterobimetallic (Pt-Hg or Pt-Ag) complexes containing 1,1-bis-(diphenylphosphino)ethane as ligand

Summary The complex [Pd(dpmMe)₂]Cl₂ [dpmMe = 1,1-bis-(diphenylphosphino) ethane] was prepared from [PdCl₂-(PhCN)₂], whilst [Pd₂X₂(-dpmMe)₂] complexes were prepared from [PdCl₂PhCN₂] and [Pd(PPh₃)₄] (X = Cl), [PdBr( ³-C₃H₅)]₂ (X = Br), or [Pd₂Cl₂(-dpmMe)₂] (X = I). Reaction of [Pd₂Cl₂(-dpmMe)₂] with MeO₂C-C523-01CCO₂Me(L) gave the A-frame complex [PdCl₂(-L) (-dpmMe)₂]. The complexes [PtCl₂(dpmMe)] and [Pt(dpmMe)₂]Cl₂ were prepared from [PtCl₂(Bu ^t CN)₂]. Treatment of either [PtCl₂(dpmMe)] with PhC523-02CLi or [Pt(dpmMe)₂]Cl₂ with MeONa gave [Pt(Ph₂PCMe· PPh₂)₂]. Reaction of [PtCl₂(Bu ^t CN)₂] with [Pt(PPh₃)₄] and dpmMe gave a mixture of [Pt₂Cl₂(-dpmMe)₂] and [PtCl₂(dpmMe)]. The heterobimetallic complexes [Pt(C523-03CPh)₂ (-dpmMe)₂MX] (MX = HgCl₂ or AgCl) were made from the reaction of [Pt(dpmMe)₂]Cl₂ with Hg(C523-04CPh)₂ or Ag(C523-05CPh), respectively. Reaction of the Pt-Hg complex with Na₂S gave [Pt(C523-06CPh)₂ ( ¹-dpmMe)₂]. Oxidative addition of MeI to [PtMe₂· (dpmMe)] gave two Pt^IV isomers of the formula [PtMe₃I(dpmMe)].     

Significance of β-sheet formation for micellization and surface adsorption of surfactin

It was found that surfactin, an anionic lipopeptide biosurfactant, forms large rod-shaped micelles (micellar weight, 179 000, aggregation number n = 173) having a critical CMC of 9.4 × 10⁻⁶ M and a surface tension at the CMC γ_CMC of 30 mN m⁻¹ in 0.1 M NaHCO₃ (pH 8.7). This excellent surface-active behaviour was attributed to the ease of piling of surfactin molecules organized by β-sheet formation. Surfactin also showed a possible organization between molecules due to β-sheet structure at the air-water interface under forced experimental conditions.     

Modulation of DNAzyme Activity via Butanol Dehydration

Understanding the activity of biomolecules in cosolvent systems is important for catalysis, separation and developing biosensors. The majority of previously studied solvents are either phase separated with water or miscible with water. Butanol was recently used to extract water for the conjugation of DNA to gold nanoparticles. In this work, the effect of butanol on the activity of a few RNA-cleaving DNAzymes was studied. A 130-fold improvement in sensitivity for the Na⁺-specific EtNa DNAzyme was observed, and butanol also improved the activity of another Na⁺-specific DNAzyme, NaA43T by a few folds. However, when divalent metal ions were used for both EtNa and 17E DNAzymes, the activity was inhibited. A main driven force for enhanced DNAzyme activity is the concentration effect due to butanol dehydration. This study provides insights into the interplay between DNA, metal ions and organic solvents, and such an understanding might be useful for developing sensitive biosensors.     

Natural Compound 3β,7β,25-trihydroxycucurbita-5,23(E)-dien-19-al from Momordica charantia Acts as PPARγ Ligand

Momordica charantia is a popular vegetable associated with effective complementary and alternative diabetes management in some parts of the world. However, the molecular mechanism is less commonly investigated. In this study, we investigated the association between a major cucurbitane triterpenoid isolated from M. charantia, 3β,7β,25-trihydroxycucurbita-5,23(E)-dien-19-al (THCB) and peroxisome proliferator activated receptor gamma (PPARγ) activation and its related activities using cell culture and molecular biology techniques. In this study, we report on both M. charantia fruit crude extract and THCB in driving the luciferase activity of Peroxisome Proliferator Response Element, associated with PPARγ activation. Other than that, THCB also induced adipocyte differentiation at far less intensity as compared to the full agonist rosiglitazone. In conjunction, THCB treatment on adipocytes also resulted in upregulation of PPAR gamma target genes expression; AP2, adiponectin, LPL and CD34 at a lower magnitude compared to rosiglitazone’s induction. THCB also induced glucose uptake into muscle cells and the mechanism is via Glut4 translocation to the cell membrane. In conclusion, THCB acts as one of the many components in M. charantia to induce hypoglycaemic effect by acting as PPARγ ligand and inducing glucose uptake activity in the muscles by means of Glut4 translocation.     

Polyaniline decorated graphene oxide on sulfonated poly(ether ether ketone) membrane for direct methanol fuel cells application

In direct methanol fuel cells (DMFC), methanol crossover is a major issue which has reduced the performance of polymer electrolyte membrane (PEM) for energy generation. In this study, graphene oxide (GO) and conductive polyaniline decorated GO (PANI-GO) were used as additives in fabrication of sulfonated poly(ether ether ketone) (SPEEK) nanocomposite PEM membrane to reduce methanol crossover. PANI-GO was synthesized by in situ polymerization method and the formation of PANI coated GO nanostructures was confirmed by surface morphology and crystallinity analysis. The membrane morphology and topography analysis confirmed that GO and PANI-GO were well dispersed on the surface of SPEEK membrane. 0.1 wt% PANI-GO modified SPEEK nanocomposite membrane exhibited the highest water uptake and ion exchange capacity of 40% and 1.74 meq g^?1, respectively. The oxidative stability of the nanocomposite membranes also improved. Lower methanol permeability of 4.33 × 10^?7 cm^?2S^?1 was noticed for 0.1 wt% PANI-GO modified SPEEK membrane. PANI-GO modified SPEEK membrane enhanced the proton conductivity, which was due to the existence of acidic and hydrophilic group present in PANI and GO. PANI-GO modified SPEEK membrane held higher selectivity of 1.94 × 10⁴ S cm^?3 s^?1. Overall, these studies revealed that PANI-GO modified SPEEK membrane is a potential material for DMFC applications.     

Recent advances in oxygen electrocatalysts based on tunable structural polymers

Due to their high energy density, great safety and eco-friendliness, zinc-air batteries (ZABs) attract much attention. During the process of charging and discharging, the two key processes viz. oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) limit their efficiency. In general, the noble metal-based electrocatalysts (ORR: platinum (Pt); OER: iridium (IV) oxide [IrO₂] and ruthenium oxide [RuO₂]) have long been used. Nonetheless, these noble metal electrocatalysts also have their limitations owing to high cost and poor stability. As alternatives, polymers are found to be most promising on account of their tunable structure, uniform network, high surface morphology and strong durability. Polymers are capable catalysts. In this review, recent advances as well as insight into the architecture of covalent organic polymers (COPs), metal coordination polymers (MCPs) and pyrolysis-free polymers (PFPs) are duly outlined.