Silver(I) Bromide Phosphines Induce Mitochondrial-Mediated Apoptosis in Malignant Human Colorectal Cells.

Due to its emerging resistance to current therapies, colon cancer remains one of the most difficult types of cancer to treat. Silver, a non-invasive metal, is well-known for its antimicrobial and anti-cancer properties. Two novel silver(I) phosphine complexes, [silver(I) diphenyl-2-pyridylphosphine]Br (1) and [silver(I) is 4-(dimethylamino)phenyldiphenylphosphine]Br (2), were synthesized and characterized by elemental analysis, infrared spectroscopy, and nuclear magnetic resonance (1H, 13C, 31P). To assess the complexes' potentials as antiproliferative agents, experiments were conducted on human colorectal cancer cells (HT-29) in vitro. The evaluation involved the analysis of morphological changes, the performance of an alamarBlue® proliferation assay, and the undertaking of flow cytometric analyses to detect mitochondrial alterations. Complex 1 displayed superior selectivity and significant inhibitory effects on malignant HT-29 cells while exhibiting minimal toxicity towards two non-malignant HEK-293 and MRHF cells. Moreover, after 24 h of treatment, complex 1 (IC50, 7.49 µM) demonstrated higher efficacy in inhibiting cell proliferation compared with complex 2 (IC50, 21.75 µM) and CDDP (IC50, 200.96 µM). Flow cytometric studies indicated that complex 1 induced regulated cell death, likely through mitochondrial-mediated apoptosis. Treatment with complex 1 induced morphological changes indicative of apoptosis, which includes membrane blebbing, PS externalization, increased levels of reactive oxygen species (ROS) and mitochondrial membrane depolarization (ΔΨm). These observations suggest that complex 1 targets the mitochondria and holds promise as a novel metal-based anti-cancer therapeutic for the selective treatment of colorectal cancer.

Bis[(4-methyl-phen-yl)di-phenyl-phosphine-κP](nitrito-κ2 O,O')silver(I).

The title AgI complex, [Ag(NO2)(C19H17P)2], reveals a distorted pseudo-trigonal-planar shape around the AgI atom geometry resulting from the coordination of two phosphine ligands, as well as a nitrito-O,O' ligand coordinating to the silver(I) atom through the oxygen atoms; in this description, the two oxygen atoms are assumed to occupy one position, forming an acute O-Ag-O angle of 51.44 (9)°. The plane resulting from the NO2 coordination to Ag is nearly perpendicular to the plane from the coordination of the phosphine-P atoms to Ag [dihedral angle = 86.43 (9)°].

catena-Poly[[(benzyl-diphenyl-phosphine-κP)silver(I)]-µ-nitrato-κ2 O:O'-[(benzyl-diphenyl-phosphine-κP)silver(I)]-µ-nitrato-κ4 O,O':O',O''].

The structure of the title complex, [Ag2(NO3)2(C19H17P)2] n , reveals a chain emanating from the coordination of one phosphine ligand to each silver(I) cation, as well as the bis-monodentate coordination of a bridging nitrato ligand (per Ag atom) and the bis-bidentate coordination of another bridging nitrato ligand (per Ag atom). The distorted four-coordinate Ag atoms are characterized by bonding angles that notably deviate from the ideal tetra-hedral shape.

3D food printing improves color profile and structural properties of the derived novel whole-grain sourdough and malt biscuits.

Presentation of foods is essential to promote the acceptance of diversified and novel products. This study examined the color profile, browning index (BI), and structural properties of 3D-printed and traditional biscuits from whole-grain (WG) sourdough and germinated flours. The processed flours and composite/multigrain flours comprising cowpea sourdough (CS) and quinoa malt (QM) were used to prepare the snacks, and their structural characteristics were determined. Compared with the traditional biscuits, the 3D-printed biscuits showed considerable distinction in terms of consistent structural design and color intensities. The in-barrel shearing effect on dough biopolymers, automated printing of replicated dough strands in layers, and expansion during baking might have caused the biscuits' structural differences. The composite biscuit formulations had a proportional share of CS and QM characteristics. The 80% CS and 20% QM printed biscuit had a low redness and BI, increased cell volume, average cell area, and total concavity. The 60% CS and 40% QM printed snack showed improved lightness and yellowness, increased average cell elongation, and less hardness. The 3D-printed composite biscuits may be recommended based on their unique structural characteristics. Such attributes can enhance the acceptability of printed foods and reinvent locally prepared meals as trendy, sustainable, and functional foods.

Transfer hydrogenation of ketone; an in situ approach toward an eco-friendly reduction.

The use of water as a solvent in chemical reactions has recently been brought to public attention, especially in the exploration of eco-friendly procedures. It is readily available, abundantly accessible, non-toxic, non-flammable, and at a low cost. As opposed to the previous limitation of reactant solubilities associated with aqueous media, a hydrogel such as a hydroxypropyl methylcellulose (HPMC) solution can significantly improve the reactant solubility. This investigation employed water and HPMC as the reaction solvent, and the reaction medium viscosity was impressively enhanced. Silica-supported Pd particles (Pd@SiO2) were synthesized and effectively catalyzed the reduction of acetophenone in the presence of sodium borohydride (NaBH4) as the hydrogen source. The conversion of acetophenone to 1-phenyl ethanol remained at a very high value of >99.34% with 100% selectivity towards 1-phenyl ethanol.

Processing-properties-performance triad relationship in a Washingtonia robusta mesoporous carbon materials-based supercapacitor device.

Two-electrode electrochemical tests provide a close performance approximation to that of an actual supercapacitor device. This study presents mesoporous carbon materials successfully derived from Washingtonia robusta bark (Mexican fan palm) and their electrical performance in a 2-electrode supercapacitor device. The triad relationship among carbon materials "processing, properties, and performance" was comprehensively investigated. X-ray diffraction reveal that amorphousness increases with activating KOH ratio and decreases with both activation time and temperature. Raman spectroscopy shows an increase in structural defects and degree of graphitization with an increase in KOH ratio, temperature and time while transmission electron microscopy shows conversion of aggregated particles to materials with interconnected porosity and subsequent destruction of porosity with an increase in KOH ratio. A nitrogen-sorption study reveals varying trends between BET, micro and mesopore surface areas, however, pore size and volume and hysteresis loop size decreases with KOH ratio and temperature. Electrochemical studies on the other hand reveal that both the specific capacitance and charge-discharge time increase with KOH ratio, temperature and time while both charge transfer and Warburg resistances decrease and the phase angles increases towards the ideal -90° with an increase in KOH ratio, temperature and time. The device fabricated with the HHPB sample prepared at 700 °C, KOH ratio 3 for 60 min attained a specific capacitance of 179.3 and 169 F g-1 at a scan rate of 5 mV s-1 and current density of 0.5 A g-1, respectively, good cycling stability with 95% capacitance retention and 100% coulombic efficiency when cycled 5000 times at a current density of 2 A g-1. HHPB electrodes reveal perfect EDLC behavior with an energy density of 20 W h kg-1 and power density of 2000 W kg-1 when used in a symmetric coin supercapacitor cell with 6 M KOH solution. These findings show the potential of fan palm bark as electrode materials with good stability and high-rate capability for supercapacitor application.

(Nitrito-κ2 O,O')bis-[tris-(4-methyl-phen-yl)phosphane-κP]silver(I).

The mol-ecular structure of the title compound, [Ag(NO2)(C21H21P)2], exhibits a pseudo-tetra-hedral coordination around the central AgI atom. The compound crystallizes with one mol-ecule in the asymmetric unit in the monoclinic space group P21/n with a rather long b axis [33.8752 (2) Å]. Weak C-H⋯O and C-H⋯N inter-actions consolidate the crystal packing. The nitrite-O atoms each occupy a single position in the coordination geometry.

Tris(benzyl-diphenyl-phosphane-κP)(nitrato-κO)silver(I).

The mol-ecular structure of the title complex, [Ag(NO3)(C19H17P)3], exhibits a severely distorted tetra-hedral coordination environment around the central AgI atom, comprising one O and three P atoms. Apart from a primary Ag-O coordination of the nitrato ligand of 2.667 (3) Å, a second (weaker) secondary inter-action of the nitrato ligand via the other O atom of 3.118 (4) Šis observed. The compound crystallizes with a complete mol-ecule in the asymmetric unit. Weak C-H⋯O inter-actions consolidate the packing.

Current and future trends of additive manufacturing for chemistry applications: a review.

Three-dimensional (3-D) printing, also known as additive manufacturing, refers to a method used to generate a physical object by joining materials in a layer-by-layer process from a three-dimensional virtual model. 3-D printing technology has been traditionally employed in rapid prototyping, engineering, and industrial design. More recently, new applications continue to emerge; this is because of its exceptional advantage and flexibility over the traditional manufacturing process. Unlike other conventional manufacturing methods, which are fundamentally subtractive, 3-D printing is additive and, therefore, produces less waste. This review comprehensively summarises the application of additive manufacturing technologies in chemistry, chemical synthesis, and catalysis with particular attention to the production of general laboratory hardware, analytical facilities, reaction devices, and catalytically active substances. It also focuses on new and upcoming applications such as digital chemical synthesis, automation, and robotics in a synthetic environment. While discussing the contribution of this research area in the last decade, the current, future, and economic opportunities of additive manufacturing in chemical research and material development were fully covered.

Molybdenum-modified mesoporous SiO2 as an efficient Lewis acid catalyst for the acetylation of alcohols.

A suitable, expeditious and well-organized approach for the acetylation of alcohols with acetic anhydride in the presence of 5%MoO3-SiO2 as an optimum environmentally benign heterogeneous catalyst was developed. The high surface area obtained for 5%MoO3-SiO2, 101 m2 g-1 compared to other catalysts, 22, 23, and 44 m2 g-1 for 5%WO3-ZrO2, 5%WO3-SiO2, and 5%MoO3-ZrO2, respectively, appears to be the driving force for better catalytic activity. Amongst the two dopants used, molybdenum oxide is the better dopant compared to its tungsten oxide counterpart. High yields of up to 86% were obtained with MoO3 doping while WO3 containing catalysts did not show any activity. Other reaction parameters such as reactor stirring speed, and solvent variation were studied and revealed that the optimum stirring speed is 400 rpm and cyclohexane is the best solvent. Thus, the utilization of affordable and nontoxic materials, short reaction times, reusability, and producibility of excellent yields of the desired products are the advantages of this procedure.

Alkali-modified heterogeneous Pd-catalyzed synthesis of acids, amides and esters from aryl halides using formic acid as the CO precursor.

To establish an environmentally friendly green chemical process, we minimized and resolved a significant proportion of waste and hazards associated with conventional organic acids and molecular gases, such as carbon monoxide (CO). Herein, we report a facile and milder reaction procedure, using low temperatures/pressures and shorter reaction time for the carboxyl- and carbonylation of diverse arrays of aryl halides over a newly developed cationic Lewis-acid promoted Pd/Co3O4 catalyst. Furthermore, the reaction proceeded in the absence of acid co-catalysts, and anhydrides for CO release. Catalyst reusability was achieved via scalable, safer, and practical reactions that provided moderate to high yields, paving the way for developing a novel environmentally benign method for synthesizing carboxylic acids, amides, and esters.

Adsorption of Cu(II) ions from aqueous solution using pyridine-2,6-dicarboxylic acid crosslinked chitosan as a green biopolymer adsorbent.

In this study, crosslinked chitosan (CCS) has been synthesized by anchoring a bifunctional ligand, namely pyridine-2,6-dicarboxylic acid (PDC) with chitosan through ion exchange. The functionalized biopolymer has been characterized using different instrumental analyses including elemental (CHN), spectroscopic (UV-visible, NMR, powder XRD, and FTIR), thermal analyses (TGA and DSC), surface and morphological (BET and SEM) analyses. The PDC-CCS was utilized for the recovery of Cu(II) from water contaminated with Cu. The adsorption limit/capacity of PDC-CCS has been examined for solution pH, temperature, Cu(II) ion concentration, and the contact time of the adsorbent. An extreme adsorption limit of 2186 mmol·g-1 has been found for the PDC-CCS. Equilibrium was quickly attained within 60 min from the start of adsorption. Also, it was discovered that the adsorption limit/capacity exceedingly relies upon temperature and pH. On testing the experimental data with the two most popular adsorption models (fundamentally, Freundlich and Langmuir), we found that Cu(II) ion adsorption suit both models. Similarly, the experimental adsorption kinetics is in reality, second-order. Thermodynamic studies also revealed that the adsorption process was spontaneous and enthalpy driven. DFT calculations suggest that the main adsorption mechanism is by chelation through charge transfer from the adsorbent to the Cu(II) ions in solution.

Inorganic Perovskite-Induced Synergy on Highly Selective Pd-Catalyzed Hydrogenation of Cinnamaldehyde.

The transformation of various organic molecules into value-added chemicals has been driven by the success in development of highly active catalytic systems. Heterogeneous catalysts have found use in many industrial processes by virtue of their ease of separation and high activities in various reactions. However, many processes employing heterogeneous catalysts in the transformation of organic molecules suffer significantly when it comes to product selectivity. Herein, we report on the synthesis of highly selective palladium nanoparticle (Pd NP)-containing catalysts. The heterogeneous catalysts reported herein consist of active mixed-metal oxides, in the form of perovskites as catalysts, and as catalytic supports for Pd NPs. The activity of pure perovskites when applied as catalysts in the hydrogenation of cinnamaldehyde is 3 factors lower compared with Pd NPs immobilized on them. However, considering the fact that perovskites achieved percentage conversions between 18 and 25% in a short period of time makes them perfect candidates to replace platinum group metals in the future. In addition to being earmarked as the future of catalysis, perovskites induced a synergistic effect on the conversion of the substrate compared to when Pd NPs are immobilized on the silica support. Furthermore, these catalysts are 100% selective to hydrocinnamaldehyde and stable for up to five catalytic cycles. With regard to reusability of the catalysts, Pd/LaFeO3 was used as a benchmark catalyst and revealed the need for surface restructuring of the catalyst for optimum activity.

The ability of silver(I) thiocyanate 4-methoxyphenyl phosphine to induce apoptotic cell death in esophageal cancer cells is correlated to mitochondrial perturbations.

First generation silver(I) phosphines have garnered much interest due to their vast structural diversity and promising anticancer activity. Increasing incidences of cancer, side-effects to chemotherapeutic agents and redevelopment of tumors due to resistance prompts the exploration of alternative compounds showing anticancer activity. This study revealed the effective induction of cell death by a silver(I) thiocyanate 4-methoxyphenyl phosphine complex in a malignant esophageal cell line. Apoptotic cell death was confirmed in treated cells. Moreover, mitochondrial targeting via the intrinsic cell death pathway was evident due to low levels of ATP, altered ROS activity, mitochondrial membrane depolarization, cytochrome c release and caspase-9 cleavage. The complex displayed low cytotoxicity towards two human non-malignant, skin and kidney, cell lines. The findings reported herein give further insight into the selective targeting of silver(I) phosphines and support our belief that this complex shows great promise as an effective chemotherapeutic drug.

A Comparison of the Toxicity of Mono, Bis, Tris and Tetrakis Phosphino Silver Complexes on SNO Esophageal Cancer Cells.

BACKGROUND: A broad range of metal-coordinated complexes have been studied for their anticancer activities. However, some of these complexes display high toxicity profiles to non-malignant cells, therefore limiting their use in cancer therapeutics. Aims/Method: Several silver(I) triphenylphosphine adducts were prepared as 1:1 to 1:4 ratios of silver nitrate to triphenylphosphine. They were further used to determine their anticancer activity in a malignant SNO esophageal cell line. The silver(I) phosphine adducts include: [Ag(PPh3)]NO3 (1); [Ag(PPh3)2]NO3 (2); [Ag(PPh3)3]NO3 (3) and [Ag(PPh3)4]NO3 (4). In addition, the activity of complexes 1-4 was compared to previously reported complexes [Ag(Ph2P(CH2)2PPh2)2]NO3 (5) and [Ag(Ph2P(CH2)3PPh2)2]NO3 (6). The cytotoxicity of complexes 1-6 was also evaluated in non-malignant human dermal fibroblast cells (HDF-a). RESULTS: The majority of the complexes (specifically those containing PPh3) were found to be highly toxic to the SNO cells and less toxic towards HDF-a cells, as determined by the alamarBlue® assay. Morphological studies and flow cytometry confirmed that the silver(I) complexes induced apoptosis in the malignant cells. CONCLUSION: These results may have an impact on research related to drug discovery and silver(I) phosphine complexes could be added to the arsenal of anticancer agents in addition to the silver-bis-diphenylphosphinoethane and silver-bis-diphenylphosphinopropane adducts.

Synergistic Effects of Gold-Palladium Nanoalloys and Reducible Supports on the Catalytic Reduction of 4-Nitrophenol.

Herein we report on the catalytic activity of mesoporous nickel, iron, cerium, cobalt, and manganese oxides prepared using KIT-6 as a hard template via evaporation-assisted precipitation. The mesoporous metal oxides (MMOs) were characterized and used as heterogeneous catalysts in the reduction of 4-nitrophenol (4-Nip) by sodium borohydride (BH4-). Furthermore, polyamidoamide (PAMAM) dendrimers were used to synthesize gold-palladium nanoalloy particles. The size of AuPd/PAMAM was found to be 3.5 ± 0.8 nm in diameter before being immobilized on the aforementioned mesoporous metal oxides and used as catalysts in the reduction of 4-Nip. Prior to catalytic evaluation, the reduction profiles of the mesoporous metal oxides were investigated by hydrogen-temperature-programmed reduction (H2-TPR) and showed that mesoporous metal oxides can be easily reduced at lower temperatures and that the immobilization of gold-palladium nanoalloy particles lowers their reduction temperatures. Mesoporous cobalt and manganese oxides showed catalytic activity toward 4-Nip reduction, and the activity was enhanced after immobilization of the gold-palladium nanoalloys. Isolation of nanoparticles activity was achieved by immobilization of the gold-palladium nanoalloys on the inert silica support. From this we postulated an electron relay mechanism for the reduction of 4-nitrophenol. With the use of power rate law we showed that 4-Nip reduction follows pseudo-first-order kinetics.

Apoptosis-inducing ability of silver(I) cyanide-phosphines useful for anti-cancer studies.

Metal-based drugs have shown early promise as anticancer agents suggesting the potential application of silver(I) complexes as apoptosis-inducing agents. The ability of a silver(I) cyanide containing phosphine complex to induce cell death was evaluated in both a malignant (SNO esophageal cancer) and non-malignant (HDF-a skin and HEK293 kidney) cell lines. A dose-dependent decrease in cell viability was observed in the SNO cells. Light microscopy revealed morphological features indicative of apoptotic cell death. The mode of cell death was confirmed as apoptosis by phosphatidylserine externalization, DNA fragmentation and nuclear condensation. Furthermore, both the non-malignant cell lines showed morphological features indicative of apoptosis when exposed to complex 1. We propose the use of this silver(I) cyanide phosphine complex as an highly effective positive apoptosis control for use in anticancer studies of phosphine complexes.

Catalytic Behavior of Different Sizes of Dendrimer-Encapsulated Au(n) Nanoparticles in the Oxidative Degradation of Morin with H2O2.

Different sizes of icosahedral-like dendrimer-encapsulated Au nanoparticles (Au55- and Au147-DENs) were prepared in the presence of generation 6 amine-terminated dendrimers (G6-PAMAM-NH2) as a template. The synthesis is carried out by the complexation of a Au metal precursor (AuHCI4) with the tertiary amine groups within the dendrimer framework. The addition of excess reducing agent, NaBH4, results in the formation of Au nanoparticles encapsulated within the dendrimer cavities. The as-prepared catalysts were characterized using UV-visible (UV-vis) spectroscopy, high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray analysis (EDX), and Fourier transform infrared (FTIR). The average sizes of Au55- and Au147-DENs were determined to be 1.7 ± 0.4 and 2.0 ± 0.3 nm, respectively. The catalytic activity of these Au-DEN catalysts was evaluated in the oxidative decomposition of morin by H2O2. Since morin has a maximum absorption band at λ 410 nm at pH 10, this catalyzed oxidation process was monitored by time-resolved UV-vis spectroscopy. The catalytic activities of these two catalysts were compared by fitting the kinetic data to the Langmuir-Hinshelwood model. This model allows the determination of adsorption constants of both morin (K(morin)) and H2O2 (K(H2O2)) on the catalyst surface. A full kinetic study for this Au-DEN-catalyzed oxidative degradation of morin is reported.

The effect of 1:2 Ag(I) thiocyanate complexes in MCF-7 breast cancer cells.

There is much interest currently in the design of metal compounds as drugs and various metal compounds are already in clinical use. These include gold(I) compounds such as auranofin and the anti-cancer platinum(II) complex, cisplatin. Bis-chelated gold(I) phosphine complexes have also shown great potential as anticancer agents, however, their efficacy has been limited by their high toxicity. In this study, silver(I) thiocyanate compounds linked to four specific ligands, were synthesized and characterized. These silver-phosphine adducts included [AgSCN{P(4-MeC6H4)3}2]2 (1); [AgSCN{P(4-ClC6H4)3}2]2 (2); [AgSCN{P(4-MeOC6H4)3}2]2 (3); [AgSCN(PPh3)2]2 (4). The compounds were found to be toxic to MCF-7 breast cancer cells while the ligands on their own were not toxic. Our findings further indicate that the silver(I) phosphine compounds induce apoptotic cell death in these breast cancer cells. In addition, the compounds were not toxic to nonmalignant fibroblast cells at the IC50 concentrations. This is an indication that the compounds show selectivity towards the cancer cells.

The induction of cell death by phosphine silver(I) thiocyanate complexes in SNO-esophageal cancer cells.

Esophageal cancer is one of the least studied cancers and is found to be prominent in black South African males. It is mainly diagnosed in the late stages, and patients tend to have a low 5-year survival rate of only 10%. Silver is generally used as an antimicrobial agent, with limited reports on anticancer studies. In this study, dimeric silver(I) thiocyanate complexes were used containing a variation of 4-substitued triphenylphosphines, including [AgSCN(PPh(3))(2)](2) (1), [AgSCN{P(4-MeC(6)H(4))(3)}(2)](2) (2), [AgSCN{P(4-FC(6)H(4))(3)}(2)](2) (3) and [AgSCN{P(4-ClC(6)H(4))(3)}(2)](2) (4). All four complexes, with their respective phosphine ligands, PPh(3) (L1), P(4-MeC(6)H(4))(3) (L2), P(4-FC(6)H(4))(3) (L3) and P(4-ClC(6)H(4))(3) (L4), were subjected to in vitro toxicity studies in SNO-esophageal cancer cells, using an alamarBlue(®) assay. Morphological changes, including blebbing and apoptotic body formation, were observed. Phosphatidylserine externalization, a marker of apoptosis, was quantified by flow cytometry. The phosphine ligands L1-L4, on their own, had minimal effect on the malignant while complexes 1-4 resulted in significant cell death. A 10x decreased concentration of these complexes had similar effects than cisplatin, used as the positive control. These complexes show promise as anticancer agents.