High-Current Capable and Non-Flammable Protic Organic Electrolyte for Rechargeable Zn Batteries.

Rechargeable Zinc batteries (RZBs) are considered a potent competitor for next-generation electrochemical devices, due to their multiple advantages. Nevertheless, traditional aqueous electrolytes may cause serious hazards to long-term battery cycling through fast capacity fading and poor Coulombic efficiency (CE), which happens due to complex reaction kinetics in aqueous systems. Herein, we proposed the novel adoption of the protic amide solvent, N-methyl formamide (NMF) as a Zinc battery electrolyte, which possesses a high dielectric constant and high flash point to promote fast kinetics and battery safety simultaneously. Dendrite-free and granular Zn deposition in Zn-NMF electrolyte assures ultra-long lifespan of 2000 h at 2.0 mA cm-2 /2.0 mAh cm-2 , high CE of 99.57 %, wide electrochemical window (≈3.43 V vs. Zn2+ /Zn), and outstanding durability up to 10.0 mAh cm-2 . This work sheds light on the efficient performance of the protic non-aqueous electrolyte, which will open new opportunities to promote safe and energy-dense RZBs.

Retention of anions in cobalt hydroxide with Ni substitution to emphasize the role of anions and cations for high current density in oxygen evolution reactions.

Herein, we report the fabrication of remarkably fine nickel-substituted α-Co(OH)2 sheets using an ingenious co-precipitation method at a lower pH value. An α-CoNiOOH sheet retains the parent α-Co(OH)2 structure consisting of both tetrahedral (Td) and octahedral (Oh) sites with the retention of interlayer chloride ions, which is in contrast to the previous reports. The as-synthesized α-CoNiOOH sheet exhibits excellent oxygen evolution reactions (OERs) and produces a current of 10 mA cm-2 at an overpotential of merely 190 mV in an alkaline environment. Moreover, the α-CoNiOOH sheet attains an exceptionally high current density of 100 mA cm-2 at a low overpotential of only 270 mV. Additionally, this electrocatalyst possesses a 33 mV dec-1 Tafel slope with higher values of TOF (11 s-1) and double-layer capacitance (7.76 mF cm-2). This enhancement is attributed partially to the substitution of Ni during the conversion of α-Co(OH)2 to α-CoNiOOH and partially to the exceptionally thin sheets allowing potential octahedral sites for improved oxygen evolution reactions.

Ultrafine α-CoOOH Nanorods Activated with Iron for Exceptional Oxygen Evolution Reaction.

Two-dimensional oxyhydroxide materials are proved to be a potential candidate for oxygen evolution reaction (OER). Robust, efficient, and cost-effective electrocatalysts are critical to overcome the sluggish kinetics and high overpotential of OERs. Herein, a simple co-precipitation method followed by solvothermal treatment is used to synthesize Fe-doped α-CoOOH at higher pH under optimum conditions for OER. The α-Fe0.24Co0.76OOH/NF illustrates superior OER electrocatalytic performance and requires an overpotential of only 280 mV to produce a current density of 50 mA cm-2 with excellent stability. The detailed analysis reveals that the exceptional OER performance originates from thin nanorods and partially due to the replacement of Fe in α-CoOOH. This work illustrates the presence of interlayer chloride ions through energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy.

CaO-Promoted Graphene-Supported Palladium Nanocrystals as a Universal Electrocatalyst for Direct Liquid Fuel Cells.

Here, we present the fabrication of a reduced graphene oxide-supported PdCa (PdCa/rGO) alloyed catalyst via a NaBH4 reduction method for direct alcohol fuel cells in basic medium and direct formic acid fuel cells in acidic medium. Powder X-ray diffraction, energy-dispersive X-ray spectroscopy, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller, inductively coupled plasma mass spectrometry, and Raman spectroscopy are used to characterize the PdCa/rGO catalyst. We proved that the calcium oxide significantly enhances the electrocatalytic methanol, ethanol, and formic acid oxidation over the Pd/rGO surface. The obtained mass activities for PdCa/rGO are 4838.06, 4674.70, and 3906.49 mA mg-1 for formic acid, methanol, and ethanol, respectively. Long-term stability, high activity, and high level of tolerance to CO poisoning of the PdCa/rGO electrocatalyst are attributed to the presence of calcium oxide. These results prove that the PdCa/rGO catalyst has improved electrocatalytic performance for the oxidation of formic acid, methanol, and ethanol with reference to the Pd/rGO.

Synthesis of new boswellic acid derivatives as potential antiproliferative agents.

In the current investigation, a series of heterocyclic derivatives of boswellic acids were prepared along with new monomers of 3-O-acetyl-11-keto-ß-boswellic acid (AKBA, 1) 11-keto-ß-boswellic acid (KBA, 2) and several new bis-AKBA and KBA homodimers and AKBA-KBA heterodimers. The effects of these compounds on the proliferation of different human cancer cell lines, viz., FaDu (pharynx carcinoma), A2780 (ovarian carcinoma), HT29 (colon adenocarcinoma), and A375 (malignant melanoma), have been evaluated. Thus, KBA homodimer 21 effectively inhibited the growth of FaDu, A2780, HT29, and A375 cells with EC50 values below 9 µM. In addition, compounds 7, 8, 11, 12, 15, 16, and 17 also exhibited cytotoxic effects for A2780, HT29, and A375 cancer cells. In particular, the pyrazine analog 8 was highly cytotoxic for A375 cancer cells with an EC50 value of 2.1 µM.

Optimization of Ag2O nanostructures with strontium for biological and therapeutic potential.

Pristine- and strontium-doped Ag2O nanoparticles (NPs) were synthesized utilizing the symbolic co-precipitation method, in which sodium hydroxide was used as a precipitating agent. Various instrumentation methods were employed to get an inside view of the synthesized NPs. Powdered X-ray diffraction (PXRD) analysis revealed the existence of high crystallinity and small-sized NPs (an average diameter range of 35-48 nm). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) displayed spherical and circular disc-shaped morphology of the particles. Energy-dispersive X-ray spectroscopy (EDX) showed the purity of NPs. All the screened metal functionalized Ag2O NPs exhibited excellent cytotoxicity and antibacterial activities, moderate to good antioxidant and antifungal activities in comparison to Ag2O NPs. Furthermore, nanomaterials were evaluated for DNA interaction studies. The results illustrated that by increasing the concentration of dopant, i.e. strontium up to 5%, the binding affinity of the NPs effectively increased, hence causing the structural changes in DNA.

Therapeutic potential of glycyrrhetinic acids: a patent review (2010-2017).

INTRODUCTION: Glycyrrhetinic acids (GAs) viz., 18ß-glycyrrhetinic acid and 18α-glycyrrhetinic acid, are oleanane-type triterpenes having a carboxylic acid group at C-30, and are extracted from the Chines herbal medicine licorice (Glycyrrhiza uralensis). Although the pharmacological properties of GAs have long been known, attention to them has greatly increased in recent times due to their cytotoxic activity. AREAS COVERED: This review represents the patents granted about natural and synthetic glycyrrhetinic acid analogs from January 2010 to December 2017, the advances made by research groups in conjunction with pharmaceutical companies in the discovery of new natural or synthetic glycyrrhetinic acid analogs. EXPERT OPINION: GAs demonstrate excellent cytotoxic, antimicrobial, enzyme inhibitory, antiinflammatory, antioxidant, analgesic, and antiviral effects. It is interesting to note that the C-3(OH) and C30-CO2H functional groups make GAs very attractive lead structures for medicinal scientists since these functionalities allow the generation of further chemical diversity for improved pharmacological effects. Moreover, various GA analogues have been prepared via modification of the C30-CO2H. It is noteworthy that the C-30 amide of GA demonstrated better cytotoxic effects compared to the parent compounds. In addition, GAs have the capability to conjugate with other anticancer drugs or be converted into their halo or amino analogs which is expected to stimulate medicinal chemist to synthesize new lead compounds in cancer drug discovery.

Synthesis of new triterpenic monomers and dimers as potential antiproliferative agents and their molecular docking studies.

In the current investigation, new monomers of myrrhanone B and lupeolic acid were prepared via reaction of triterpenic acids with linkers in the presence of K2CO3. In addition, new bis-myrrhanone B homodimers, myrrhanone B-myrrhanol B heterodimers, and bis-myrrhanone ß-boswellic acids heterodimer were prepared. Evaluation of these compounds on the proliferation of four different human cancer cell lines, viz., FaDu (pharynx carcinoma), A2780 (ovarian carcinoma), HT29 (colon adenocarcinoma) and A375 (malignant melanoma) has been performed. It is worth mentioning that compounds 4, 7, 8, 10, and 11 possess potent antiproliferative effect towards HT29 cancer cells with IC50 values of 8.1 µM, 5.4 µM, 8.8 µM, 6.8 µM, and 8.2 µM, respectively. In addition, these compounds display good to moderate antiproliferative activities towards A2780 and A375 with IC50 values ranging from 10.4 to 24.2 µM. Moreover, the molecular docking studies of most active compounds (4, 7, 8, 10 and 11) with six anti-cancer drug targets DHFR, VEGFR2, HER-2/neu, CDK6, hCA-IX and LOX also carried, in order to know the mode of binding interaction and energy of this class of compounds.

Therapeutic potential of boswellic acids: a patent review (1990-2015).

INTRODUCTION: Boswellic acids (BAs), a group of pentacyclic triterpenoids, have demonstrated very interesting biological properties that resulted in a number of protocols being developed for their synthesis. During the last twenty-five years (1990-2015), numerous BAs have been prepared. Both natural BAs and their synthetic derivatives can be used to treat various cancers as well as inflammatory diseases. Areas covered: This review covers patents on therapeutic activities of natural BAs and their synthetic derivatives published in last twenty-five years (1990-2015). Only BA patents to treat cancer and inflammation are available. A discussion about structure-activity relationships (SAR) of these analogs is also included. Expert opinion: BAs possess excellent anticancer and anti-inflammatory properties. A large number of BAs and their analogues have been prepared through modification at the C3-OH and C24-CO2H functional groups. Most importantly, the C-24 amide and amino derivatives demonstrated increased anticancer and anti-inflammatory activity compared with other BA derivatives. Furthermore, BAs have the potential to form conjugates with other anticancer drugs that will synergistically enhance their anticancer effects; and we believe that in order to get lead compounds, there needs to be a greater focus on the synthesis of halo derivatives of BAs.

Functional metal sulfides and selenides for the removal of hazardous dyes from Water.

Water contamination by organic dyes, is among the most alarming threats to healthy green environment. Complete removal of organic dyes is necessary to make water healthy for drinking, cooking, and for other useful aspects. Recently use of nanotechnology for removing organic dyes, became fruitful because of high surface to volume ratio and adsorption properties. Among these materials, metal chalcogenides emerge as new class of active materials for water purification. In this review article, we gathered information related to sulfide and selenide based nanomaterials which include metal sulfides and selenides, their binary composites, and use of different capping agents and dopants for enhancing photocatalysis. We have discussed in detail, about adsorption power of different dyes, relative percentage degradation, reaction time and concentration.