Search Results (174)

Palmitoleic acid (POA; 16:1 n-7 or cis-9 16:1) is a bioactive monounsaturated fatty acid (FA) with emerging metabolic and skin-health relevance, yet conventional botanical and animal sources provide limited and variable levels. Here we report on the development of a high-yield POA product platform in the heterotrophic microalga Prototheca moriformis through targeted genetic engineering. A Δ9-fatty acid desaturase from Macadamia integrifolia (MiSAD1618) was integrated using a phosphite-based selection system. Primary screening identified stable transformants producing up to 54% POA of total fatty acids, compared to 0.8% in the parental strain. In 1 L shake-flask cultivation, POA reached up to 58.2% of total fatty acids. In a 1 L fed-batch fermentation, the engineered strain accumulated 47.8 g/L of lipids with 43.5% POA after 96 h of fermentation, corresponding to 20.8 g/L of POA. GC–MS analysis of 4,4-dimethyloxazoline (DMOX) derivatives confirmed that the major 16:1 isomer was 16:1 n-7 (Δ9). Together, these results establish P. moriformis as a scalable fermentation platform for producing POA-rich oil and highlight its potential as an efficient alternative source of POA, providing a foundation for further strain and process optimization toward commercial production. Full article

Background: It is known that the α-hydroxyphosphonates and their derivatives may have potential biological activity. Methods: Within the prominent class of α-hydroxyphosphonates, α-hydroxy-alkylphosphonates and their derivatives were prepared as new representatives in the hope of obtaining biologically active species. During our work the Pudovik reaction, acylation and phosphinoylation/phosphorylation methods were used. The new compounds were characterized by NMR and MS spectroscopy. The antiproliferative effects were tested on U266 (myeloma multiplex) and A2058 (melanoma) cells. Results: Ethyl methyl ketone–dialkyl phosphite and secondary phosphine oxide adducts were synthesized by the Pudovik reaction on the earlier analogy of acetaldehyde– and acetone adducts. The hydroxyphosphonates and hydroxyphosphine oxides were acylated and phosphinoylated/phosphorylated. Due to the steric hindrance in the case of the preparation of the acetone–and ethyl methyl ketone–diethyl phosphite adducts, a two-step procedure was elaborated that was also suitable for the thiophosphinoylation of the adducts. A part of the α-hydroxyphosphonates could be successfully methanesulfonylated. The new derivatives prepared were tested on myeloma and melanoma cells, and it was found that the antiproliferative activity is primarily driven by phosphinoylation, particularly by diphenylthiophosphinoylation. The most promising compound, the diphenylthiophosphinoylated hydroxyphosphine oxide, reduced the viability of the U266 cells to less than 20% after a treatment with 100 µM concentration in a long-term experiment. Conclusions: A subset of the synthesized α-hydroxyphosphonate derivatives exhibited cytotoxic activity, supporting further structural optimization to identify compounds with enhanced biological efficacy. Full article

Potentially biologically active α-aminophosphonic derivatives were prepared by the Kabachnik–Fields condensation of α-amino-α-aryl-methylphosphonates, arylaldehydes, and diethyl phosphite to afford bis(α-aryl-methylphosphonoyl)-amines as a mixture of racemic and meso isomers. To go “green”—performing the transformations under microwave irradiation—there was no need for a catalyst. On the other hand, the phospha-Mannich reaction of α-amino-α-phenyl-methylphosphonate with arylaldehydes led to (α-aryl-methylphosphonoyl)-(α-phenyl-methylphosphonoyl)-amines as a mixture of SS/RR and SR/RS racemates. Moreover, the respective symmetric products with identical aryl groups were also present. The outcome was similar, when α-amino-α-aryl-methyl-phosphonates were condensed with benzaldehyde and diethyl phosphite. The products were analyzed by 1D and 2D NMR spectroscopy. The combined NMR analysis of the products confirmed their structure. Full article

Background: Thirty-five analogues of a promising antiosteoporotic drug, incadronate, have been synthesized and evaluated for their antiproliferative activity against mouse macrophage-like J774E cells. These cells originated from identical precursors as osteoclasts and served to select the most active compounds. Two of them, n-heptyl- and n-octyl-aminomethylenebispohosphonic acids, were then used for the medication of sheep with induced osteoporosis. They demonstrated mild antiosteoporotic activity that was documented using bone histopathology. Additionally, a decrease in the immunological response to Corynebacterium pseudotuberculosis was observed as a major side effect accompanied by this medication. Methods: Aminomethylenebisphosphonates may be obtained in the three-component reaction of aliphatic amine, triethyl orthoformate and diethyl phosphite with the further acid hydrolysis of crude esters. The obtained N-substituted alkiloaminomethylenebisphosphonic acids are presented alongside with their in vitro activity toward mouse macrophages J774E. Results: The new families of aminomethylenebisphosphonic compounds synthesized by our approach may be of practical importance due to the significant cytotoxic activity in the cell cultures investigated. Two of them were chosen for further evaluation in the treatment of induced osteoporosis in sheep. Conclusions: In vivo studies confirmed the mild therapeutic effects of compounds 4 (N-(n-heptylamino)methylenebisphosphonic acid and 5 (N-(n-octylamino)methylenebisphosphonic acid; however, they are not suitable analogues of incadronate for consideration as potential drugs. Full article

In electric vehicle (EV) drivetrains, lubricant films must not only mitigate friction and wear but also manage stray currents to safely dissipate stray charge and avoid micro-arcing. This study directly compares how a conventional antiwear additive (ZDDP) and a long-chain, ashless, sulfur-free phosphite ester (Duraphos AP240L) manage this balance under current-carrying boundary lubrication conditions. Reciprocating steel-on-steel tests were conducted at fixed load and speed with applied current densities of 0, 0.02, and 42.4 A/cm². Friction and four-probe electrical contact resistance (ECR) were measured in situ, and impedance of tribofilms was measured over a 1–10⁵ Hz range after friction test. In the presence of ZDDP, ECR initially increased and then decreased to a value that was as low as the initial direct contact of two solid surfaces or even lower sometimes. During the initial stage with high ECR, a well-defined impedance semicircle was observed in the Nyquist plot; after forming the tribofilm with low ECR, frequency dependence of impedance could not be measured due to the very low resistance. The decrease in ECR suggested a structural evolution of the anti-wear film on the substrate. However, post-test wear analysis indicated that the formation of this film was accompanied by tribochemical polishing of the countersurface and sometimes pitting of the substrate, which may have been due to localized electrical discharge producing trenches deeper than ~0.5 µm; in additive-free base oil, wear was dominated by ploughing with micro-cutting of the substrate. In contrast, AP240L performed better in terms of friction and wear, showing a remarkable ~30% lower coefficient of friction, while the overall cycle dependence of ECR was similar to the ZDDP case. AP240L showed negligible boundary film controlled wear producing a shallow, smooth track (depth < 0.2 µm) during the friction test, and there was no sign of electrical arc damage. These findings support long-chain, ashless, sulfur-free phosphite esters as promising candidates for EV boundary lubrication where both mechanical and electrical protection are required. Full article

Studying the origin of life requires identifying chemical and physical processes that could have supported early self-replicating and evolving molecular systems. Besides the requirement of information storage and transfer, an essential aspect is an energy source that could have thermodynamically driven the formation and replication of these molecular assemblies. Chemical energy sources such as cyclic trimetaphosphate are attractive because they could drive replication with relatively simple catalysts. Here, we focus on cyclic trimetaphosphate (cTmp), and compare its solubility in water to linear triphosphate, pyrophosphate, and phosphite when Mg²⁺ or Ca²⁺ are present. These solubilities are important for facilitating the reactions under prebiotically plausible conditions. The results showed that cTmp was soluble even at molar concentrations of Mg²⁺ and little precipitation with 200 mM Ca²⁺. In contrast, pyrophosphate and linear triphosphate precipitated efficiently even at low divalent metal ion concentrations. The precipitation of phosphate was pH-dependent, showing similar precipitation with Mg²⁺ and Ca²⁺ at a prebiotically plausible pH of 6.5. Phosphite was soluble at high Mg²⁺ concentrations but started precipitating with increasing Ca²⁺ concentration. At conditions that model Archaean seawater, cTmp was the most soluble of these compounds. Together, this experimental overview may help to identify promising conditions for lab-based investigations of phosphate-based energy metabolisms in early life forms. Full article

Two single-crystal X-ray structure determinations of 2-aminopyrimidinium hydrogen tri oxofluorophosphate, (C₄H₆N₃)⁺·(HFO₃P)⁻, (I), and bis(2-aminopyrimidinium) trioxofluorophosphate, 2(C₄H₆N₃)⁺·(FO₃P)²⁻, (II), as well as their vibration spectra (FTIR on powder samples and the Raman spectra on unoriented single crystals) with a detailed assignment of vibrational modes are reported. The structure (I) consists of one independent 2-aminopyrimidinium cation and one hydrogen trioxofluorophosphate anion, while (II) consists of two symmetry independent 2-aminopyrimidinium cations and one trioxofluorophosphate anion. In (I), there is an O-H···O hydrogen bond of a moderate strength. A pair of these hydrogen bonds is situated about the symmetry centre and involved in the graph set motif R²₂(8). There are also N-H···O hydrogen bonds of a moderate strength, which are present in both structures while being involved in the graph set motifs R²₂(8), too. In addition, the N-H···O hydrogen bonds form R³₄(10) graph set motifs in (II). The latter motifs form ribbons which propagate parallel to the unit-cell axis a. In both structures, there are present π···π-electron ring interactions into which the primary amine groups are involved. In both structures, there are also present weak C-H···N hydrogen bonds with participation of the non-protonated ring N-atoms. The fluorine participates in the C-H···F hydrogen bonds in both title structures. The P-F distances are normal in both anions. The structure (I) differs from the known structure of 2-aminopyrimidinium hydrogen phosphite, the compositional isomer, though the main hydrogen bonds show similar geometry in both structures. The crystal of (I) was twinned. Full article

Phosphate (Pi) is a vital macronutrient for plant growth and development, and precise monitoring of its cellular dynamics is essential to understanding Pi homeostasis and its interaction with stress responses. Genetically encoded FRET-based biosensors such as FLIPPi enable real-time, non-invasive visualization of cytosolic Pi levels in living tissues. In this study, Arabidopsis and rice lines expressing a FLIPPi biosensor were used to monitor cytosolic Pi dynamics in root epidermal cells. Sensor functionality was confirmed by measuring FRET responses to graded Pi supplies, revealing a consistent reduction in FRET ratios with increasing Pi concentrations, reflecting elevated cytosolic Pi levels. Comparisons with a Pi-insensitive FLIPPi variant confirmed the specificity of the observed changes. Furthermore, live imaging demonstrated rapid and dynamic alterations in cytosolic Pi upon treatment with defense-related hormones and elicitors of immune responses supporting a link between Pi signaling and plant immunity. Finally, the application of phosphite, an analog of Pi, altered Pi dynamics in both Arabidopsis and rice, suggesting an interference with Pi accumulation. Collectively, our findings establish FLIPPi as a reliable tool for in vivo monitoring of Pi in Arabidopsis and rice plants, the model systems for studies in dicotyledonous and monocotyledonous species, respectively. Full article

Chromium (Cr), a toxic heavy metal, poses significant environmental and health risks when industrial effluents containing Cr are discharged untreated. Addressing this challenge, this study developed a selective chromium removal strategy using IRA-900 resin in a sulfuric acid system with sodium phosphite (NaH₂PO₃) as a complexing agent. In the NaH₂PO₃-H₂SO₄ system, IRA-900 resin exhibited exceptional selectivity for Cr³⁺ with minimal co-adsorption of competing ions. The adsorption process followed the Langmuir isotherm model (R² > 0.99), indicating monolayer chemisorption dominated by homogeneous active sites, and achieved a maximum capacity of 103.56 mg·g⁻¹. Characterization via XPS, FT-IR, and SEM-EDS revealed a two-step mechanism: Cr³⁺ reacts with H₂PO₃⁻ to form an anionic complex, and then the complex undergoes electrostatic interaction and ion exchange with chloride ions (Cl⁻) on the quaternary ammonium groups of the resin. The chromium-loaded resin demonstrated remarkable structural stability, resisting Cr³⁺ desorption under conventional elution conditions. This property provides a novel pathway for chromium solidification in industrial wastewater, effectively minimizing secondary pollution risks. This work advances the design of ligand-assisted ion-exchange systems for targeted heavy metal removal, offering both high selectivity and environmental compatibility in wastewater treatment. Full article

An efficient and practical procedure for the synthesis of (E)-α,β-unsaturated amides incorporating α-aminophosphonates, derived from readily accessible phosphonoacetamides, via the Horner–Wadsworth–Emmons (HWE) reaction was developed. The influence of reaction parameters, including base, solvent, and temperature, as well as the scope of the method with different aldehydes, was examined, affording the target compounds in good yields and with high (E)-selectivity. The required phosphonoacetamides were conveniently prepared through a Kabachnik–Fields reaction of aldehydes, benzylamine and dimethyl phosphite followed by hydrogenolytic cleavage of the N-Bn bond, acylation with bromoacetyl bromide, and a subsequent Arbuzov reaction. This HWE protocol provides straightforward access to a broad range of (E)-α,β-unsaturated amides incorporating α-aminophosphonates under mild conditions, offering valuable scaffolds with potential pharmacological relevance as anticancer agents. Full article

Rapid on-site detection of chemical warfare agents (CWAs) is vital for security and environmental monitoring. In this work, copper(I) oxide (Cu₂O) nanowire (NW) chemiresistors were investigated as gas sensors for low-concentration organophosphorus chemical warfare agent (CWA) simulants. The NWs were hydrothermally synthesized and deposited onto microheater platforms, enabling them to operate at elevated working temperatures. Their sensing performance was tested against a range of vapor-phase simulants, including dimethyl methylphosphonate (DMMP), triethyl phosphate (TEP), diethyl ethylphosphonate (DEEP), diphenyl phosphoryl chloride (DPPCl), parathion, diethyl phosphite (DEP), diethyl adipate (DEA), and cyanogen chloride (ClCN). Fully oxidized P(V) simulants (DMMP, DEEP, TEP) produced modest, predominantly reversible responses (~3–6% RR). On the contrary, DPPCl and DEP induced the strongest relative responses (RR −94.67% and >200%, respectively), accompanied by irreversible surface modification as revealed by SEM and EDS. ClCN produced a substantial but reversible negative response (RR −9.5%), consistent with transient oxidative interactions. Surface poisoning was confirmed after exposure to DEP and DPPCl, which left phosphorus or chlorine residues on the Cu₂O surface. These results highlight both the promise and limitations of Cu₂O NW chemiresistors for selective CWA detection. Full article

The flammability and volatility of conventional lithium hexafluorophosphate (LiPF₆)-based electrolytes with organic carbonate solvents remain critical issues to the safety and thermal stability of lithium-ion batteries (LIBs). This study investigates the incorporation of phosphate-based additives including ammonium dihydrogen phosphate (ADP), trimethyl phosphate (TMP), and trimethyl phosphite (TMPi) into LiPF₆ electrolytes for improving the ionic conductivity, safety, and electrochemical performance of LIBs. Self-extinguishing time (SET) measurements demonstrated that the ADP-based LiPF₆ electrolyte significantly reduced flammability, achieving a shorter SET of 04 min 53 s, compared to 12 min for the pristine LiPF₆ electrolyte. The ADP-based LiPF₆ electrolyte possessed the highest ionic conductivity (14.08 mS·cm⁻¹) with an excellent lithium-ion transference number of 0.0076. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (C-V) analyses demonstrated that ADP lowered interfacial resistance and stabilized long-term cycling behavior. In particular, the 1% ADP-based LiPF₆ electrolyte maintained improved charge-discharge profiles and Coulombic efficiency over 200 cycles. These results highlight ADP’s dual functionality in suppressing gas-phase flammability and enhancing condensed-phase electrochemical stability, making it a promising candidate for next-generation, high-safety, high-performance LIB electrolytes. Full article

The structures of hexaammine solvated indium(III) and thallium(III) ions in liquid ammonia solution are determined by EXAFS. Both complexes have regular octahedral coordination geometry with mean In-N and Tl-N bond distances of 2.23(1) and 2.29(2) Å, respectively. Ammine solvated thallium(III) in liquid ammonia is characterized with ²⁰⁵Tl NMR measurements. Solvents such as liquid ammonia, N,N-dimethylthioformamide (DMTF), trialkyl and triphenyl phosphite and phosphine are strong electron pair donors and thereby able to form bonds with a large covalent contribution with strong electron pair acceptors. A survey of reported structures of ammine, DMTF, trialkyl and triphenyl phosphite and phosphine solvated metal ions in the solid state and solution is presented. The M-N and M-S bond distances in ammine and DMTF solvated metal ions are compared with the M-O bond distance in the corresponding metal ion hydrates, expected to form mainly electrostatic interactions with metal ions. The d¹⁰ metal ions have high ability to form bonds with a high degree of covalency with increasing ability down the group and with decreasing charge of the metal ion. The difference in M-N and M-O bond distances between ammine solvated and hydrated metal ions with the same coordination geometry decreases significantly with the increasing ability of the metal ion to form bonds with a large covalent contribution. This difference correlates well with the covalent bonding index, γ_M²*r. Full article

With the widespread application of lithium-ion batteries (LIBs), safety performance has become a critical factor limiting the commercialization of large-scale, high-capacity LIBs. The main reason for the safety problem is that the electrolytes of LIBs are extremely flammable. Adding flame retardants to conventional electrolytes is an effective method to improve battery safety. In this paper, trimethyl phosphate (TMP) and trimethyl phosphite (TMPi) were used as research objects, and the flame-retardant test and differential scanning calorimetry (DSC) of the electrolytes configured by them were first carried out. The self-extinguishing time of the electrolyte with 5% TMP and TMPi is significantly reduced, achieving a flame-retardant effect. Secondly, the electrochemical performance of LiFePO₄|Li half-cells after adding different volume ratios of TMP and TMPi was studied. Compared with TMPi5, the peak potential difference between the oxidation peak and the reduction peak of the LiFePO₄|Li half-cell with TMP5 added is reduced, the battery polarization is reduced, the discharge specific capacity after 300 cycles is large, the capacity retention rate is as high as 99.6%, the discharge specific capacity is larger at different current rates, and the electrode resistance is smaller. TMPi5 causes the discharge-specific capacity to attenuate, which is more obvious at high current rates. LiFePO₄|Li half-cells with 5% volume ratio of flame retardant have the best electrochemical performance. Finally, the influence mechanism of the phosphorus valence state on battery safety and electrochemical performance was compared and studied. After 300 cycles, the surface of the LiFePO₄ electrode with 5% TMP added had a smoother and more uniform CEI film and higher phosphorus (P) and fluorine (F) content, which was beneficial to the improvement of electrochemical performance. The cross-section of the LiFePO₄ electrode showed slight collapse and cracks, which slowed down the attenuation of battery capacity. Full article

Mexico is the world’s leading producer of avocado (Persea americana); however, its productivity is threatened by various diseases, especially root rot caused by Phytophthora. While P. cinnamomi is the most commonly reported species worldwide, this study identified P. mengei for the first time as a causal agent of root rot and trunk canker in avocado orchards in the state of Michoacán, México. The morphological and molecular characterization of four isolates (three from canker and one from root rot) confirmed their identity: semi-papillate sporangia and plerotic oospores with paragynous antheridia, with sequence identities of 99.87% (ITS) and 100% (COI) with type sequences of P. mengei. Pathogenicity tests demonstrated the ability to infect roots, stems, and fruits, although with a low reisolation percentage in roots (10%), suggesting an opportunistic pathogen behavior. Sensitivity tests to potassium phosphite (EC₅₀ of 3.67 μg/mL⁻¹ a.i.) and metalaxyl-M (0.737 μg/mL⁻¹ a.i.) revealed possible limitations for chemical control. These findings position P. mengei as an emerging pathogen with important implications for integrated crop management. To the best of our knowledge, this is the first report of P. mengei causing root rot and trunk canker in avocado in Michoacán, Mexico. Full article