2-carboxyethyl Phenyl Phosphinic Acid Research Articles

The Biological Impact of Some Phosphonic and Phosphinic Acid Derivatives on Human Osteosarcoma.

Osteosarcoma malignancy currently represents a major health problem; therefore, the need for new therapy approaches is of great interest. In this regard, the current study aims to evaluate the anti-neoplastic potential of a newly developed phosphinic acid derivative (2-carboxyethylphenylphosphinic acid) and, subsequently, to outline its pharmaco-toxicological profile by employing two different in vitro human cell cultures (keratinocytes-HaCaT-and osteosarcoma SAOS-2 cells), employing different techniques (MTT assay, cell morphology assessment, LDH assay, Hoechst staining and RT-PCR). Additionally, the results obtained are compared with three commercially available phosphorus-containing compounds (P1, P2, P3). The results recorded for the newly developed compound (P4) revealed good biocompatibility (cell viability of 77%) when concentrations up to 5 mM were used on HaCaT cells for 24 h. Also, the HaCaT cultures showed no significant morphological alterations or gene modulation, thus achieving a biosafety profile even superior to some of the commercial products tested herein. Moreover, in terms of anti-osteosarcoma activity, 2-carboxyethylphenylphosphinic acid expressed promising activity on SAOS-2 monolayers, the cells showing viability of only 55%, as well as apoptosis features and important gene expression modulation, especially Bid downregulation. Therefore, the newly developed compound should be considered a promising candidate for further in vitro and in vivo research related to osteosarcoma therapy.

Experimental and density functional theory studies of the effects and mechanisms of Cu2+ on flotation separation of cassiterite from fluorite

Cu2+ was found to have intensive and selective depressing effects on fluorite in the flotation separation of cassiterite from fluorite using 2-carboxyethylphenylphosphinic acid (CEPPA) as a collector at pH 4.0. The depressing mechanism was investigated by flotation tests, zeta potential measurements, X-ray photoelectron spectroscopy (XPS) analyses and density functional theory (DFT) calculations. Flotation test results demonstrated that Cu2+ selectively depressed the fluorite in an artificially mixed cassiterite-fluorite ore. Zeta potential measurement and XPS analysis results indicated that Cu2+ could be anchored on cassiterite surface by adsorption or substitution but not on fluorite surface, and the adsorption of CEPPA on fluorite surface was cut off by Cu2+. DFT calculation results demonstrated that CEPPA had stronger affinity for Cu2+ than for fluorite, and the adsorption or substitution of Cu2+ on cassiterite (110) surface showed no negative effects on the adsorption of CEPPA monoanion on cassiterite (110) surface. Based on these results, the depressing mechanism of Cu2+ on fluorite was that Cu2+ consumed the collector CEPPA in solution, and little free CEPPA was left to be adsorbed on fluorite surface while the adsorption of CEPPA on cassiterite was normal. Thus, the floatation of fluorite was selectively and intensively weakened.

Comprehensive investigation of the adsorption of 2-carboxyethylphenylphosphinic acid on cassiterite

ABSTRACT The structure–property relationship and adsorption mechanism of a novel collector for cassiterite, 2-carboxyethylphenylphosphinic acid (CEPPA), were comprehensively investigated and compared with those of styrene phosphonic acid (SPA) by density functional theory (DFT) calculations and flotation tests. The net Mulliken charge and frontier molecular orbital (FMO) theory study results indicated that CEPPA exhibited stronger electron-donating ability and higher chemical reactivity than SPA. The flotation test results demonstrated that CEPPA had stronger collecting ability for cassiterite in a much wider effective pH range than SPA. The adsorption simulation results confirmed that the CEPPA molecule was adsorbed on cassiterite (110) surface by two hydrogen bonds. CEPPA monoanion and dianion were adsorbed on cassiterite (110) surface by a series of O-Sn bonds, and the interactions between the O atoms in CEPPA phosphinic group with the Sn atoms on cassiterite (110) surface were stronger than those between the O atoms in CEPPA carboxyl group with the Sn atoms on cassiterite (110) surface. The formation of the O-Sn bonds was mainly contributed from the 2p orbital of O atoms and 5s and 5p orbitals of Sn atoms. The various adsorption configurations of CEPPA on cassiterite accounted for the better collecting ability of CEPPA for cassiterite than that of SPA. The quantitative analysis results were in good agreement with the qualitative experimental test results in a previous paper.

Study on flotation performances and adsorption mechanism of 2-carboxyethylphenylphosphinic acid to cassiterite

ABSTRACTA novel collector, 2-carboxyethylphenylphosphinic acid (CEPPA), was first used in the flotation of cassiterite. The flotation performances and the adsorption mechanism of CEPPA on cassiterite were investigated by flotation tests, adsorption experiments, zeta potential measurements, Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses. The results indicated that CEPPA had strong collecting power for cassiterite and fluorite over a wide pH range but little on quartz. In the separation of the cassiterite–quartz mixture, a concentrate containing 90.9% SnO2 was obtained with a recovery of 95.7% at pH 7.0. The cassiterite in the cassiterite–fluorite mixture could be effectively separated using 300 mg/L sodium silicate in conjunction with 60 mg/L CEPPA, and a concentrate with a grade of 90.3% SnO2 and a recovery of 92.6% was achieved at neutral pH. Zeta potential analysis demonstrated that the adsorption process involved both physical and specific forces. The results of FTIR and XPS further suggested that the four O atoms of CEPPA reacted with the Sn atoms on cassiterite surface, forming a complex which was similar to the Sn–CEPPA precipitate, and hydrogen bonding adsorption could have taken place between the terminal hydroxyl groups and CEPPA anions.

Thermolysis parameter and kinetic research in copolyamide 66 containing 2-carboxyethyl phenyl phosphinic acid

Polyamide 66 (PA66) containing phosphorus with flame-retardant property (FR-PA66) was synthesized with adipic acid hexamethylene salt and 2-carboxyethyl phenyl phosphinic acid as raw materials. The thermal degradation kinetics of FR-PA66 and PA66 were measured using a thermogravimetric analyzer, and the data obtained were analyzed with Flynn–Wall–Ozawa and Coast–Redfern methods. The results show that the activation energy ( Ea) of PA66 fabricated under different conditions will be different, while the mechanism functions of thermal decomposition remain the same. Comparing the limit Ea value of PA66 with FR-PA66 at different stages of thermolysis, FR-PA66 keeps the initial thermolysis Ea almost unchanged, reduces the middle thermolysis Ea to 139.1 kJ mol−1, and increases the last thermolysis Ea to 454 kJ mol−1, that is 223 kJ mol−1 higher than that of PA66 with 231 kJ mol−1. This result may be explained by the first cleavage of P–C bond and the formation of the carbonized protective layer. In addition, the most probable kinetic mechanism functions ( F( α)) of thermolysis of FR-PA66 in three different stages were when the rate of decomposition ( α) is lower than 0.4, F( α) = −ln(1 − α); when α is between 0.4 and 0.65, F( α) = [−ln(1 − α)]; and when α is beyond 0.65, F( α) = [−ln(1 − α)].

Characterization of MCM-41 Mesoporous Silica Supported 2-Carboxyethyl Phenyl Phosphinic Acid

MCM-41 mesoporous silica was prepared by hydrothermal method. 2-carboxyethyl phenyl phosphinic acid (CEPPA) was loaded on MCM-41 by solution method. The structure of MCM-41 and its supported CEPPA was studied by X-ray diffraction (XRD), transmission electron microscope (TEM) and scanning electron microscopy (SEM) coupled with energy dispersive spectrometer (EDS). The results revealed that CEPPA was successfully loaded on MCM-41 with Si/P molar ratio of about 20:1. The XRD spectrum of MCM-41 supported CEPPA was different from MCM-41, indicating the structure of MCM-41 was changed after loading of CEPPA. CEPPA molecule moved into the mesoporous structure and filled in the mesopores, leading to the disappearance of characteristic diffraction peaks of MCM-41. The interaction between hydroxyl group of CEPPA and silanol of MCM-41 made it stable for CEPPA to be in the mesopores and on the surface of MCM-41. MCM-41 supported CEPPA also showed the similar mesoporous structure with long-range order to MCM-41 when observed by TEM. SEM provided further evidences of the similar particle size and different morphology.

Effect of a phosphorus-containing oligomer on flame-retardant, rheological and mechanical properties of poly (lactic acid)

A new flame retardant poly (1, 2-propanediol 2-carboxyethyl phenyl phosphinate) (PCPP) was synthesized with 2-carboxyethyl phenylphosphinic acid (CEPPA) and 1, 2-propanediol (PD). The structure of PCPP has been studied by FTIR and 13C NMR spectra. A series of poly (lactic acid) (PLA) blends were prepared by direct melt compounding with PCPP as flame retardant and plasticizer. And it was proved to be an effective flame retardant for the PLA as evidenced by increasing limiting oxygen index (LOI) value, which increasing from 19.7 for pristine PLA to 28.2 for the PLA with 10 wt% PCPP. Additionally, the introduction of PCPP also amended the rheological and mechanical properties of the PLA. When the content of PCPP in the composites was up to 15 wt%, the flame retardant and the mechanical properties were improved simultaneously.

Solubilities of Phosphorus-Containing Compounds in Selected Solvents

Phosphorus-containing flame retardants (FRs) 3,9-dihydroxy-2,4,8,10-tetraoxa-3,9-diphosphaspiro-[5.5]-undecane-3,9-dioxide (dihydroxy-TDUD), 3,9-diphenoxy-2,4,8,10-tetraoxa-3,9-diphosphaspiro-[5.5]-undecane-3,9-dioxide (diphenoxy-TDUD), hydroxymethylphenylphosphinic acid (HMPPA), 2-carboxyethylphenylphosphinic acid (CEPPA), tri(p-methoxyphenyl)phosphine (TMOPP), and tri(p-methoxyphenyl)phosphine oxide (TMOPPO) were characterized by elemental analysis, infrared spectroscopy, 1H and 31P nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Using a static analytical method, the solubilities of solutes in selected solvents were measured and correlated with an empirical equation. The estimated uncertainty of all of the solubility values based on error analysis and repeated observations was within 2.0 %.

Solubilities of 2-Carboxyethylphenylphosphinic Acid and 4-Carboxyphenylphenylphosphinic Acid in Water

The solubilities of 2-carboxyethylphenylphosphinic acid (CEPPA) and a potential reactive flame retardant, 4-carboxyphenylphenylphosphinic acid (CPPPA), in water were measured. The concentration of the solution was determined by sodium hydroxide titration with phenolphthalein as the indicator. The solubilities of CEPPA were measured from 25.10 °C to 76.32 °C with an uncertainty of 2.2%, and the solubilities of CPPPA were measured from 26.70 °C to 94.52 °C with an uncertainty of 2.1%.