Diester Research Articles

Biological Activity and Structural Diversity of Steroids Containing Aromatic Rings, Phosphate Groups, or Halogen Atoms.

This review delves into the investigation of the biological activity and structural diversity of steroids and related isoprenoid lipids. The study encompasses various natural compounds, such as steroids with aromatic ring(s), steroid phosphate esters derived from marine invertebrates, and steroids incorporating halogen atoms (I, Br, or Cl). These compounds are either produced by fungi or fungal endophytes or found in extracts of plants, algae, or marine invertebrates. To assess the biological activity of these natural compounds, an extensive examination of referenced literature sources was conducted. The evaluation encompassed in vivo and in vitro studies, as well as the utilization of the QSAR method. Numerous compounds exhibited notable properties such as strong anti-inflammatory, anti-neoplastic, anti-proliferative, anti-hypercholesterolemic, anti-Parkinsonian, diuretic, anti-eczematic, anti-psoriatic, and various other activities. Throughout the review, 3D graphs illustrating the activity of individual steroids are presented alongside images of selected terrestrial or marine organisms. Additionally, the review provides explanations for specific types of biological activity associated with these compounds. The data presented in this review hold scientific interest for academic science as well as practical implications in the fields of pharmacology and practical medicine. The analysis of the biological activity and structural diversity of steroids and related isoprenoid lipids provides valuable insights that can contribute to advancements in both theoretical understanding and applied research.

Occurrence and Release of Organophosphite Antioxidants and Novel Organophosphate Esters from Plastic Food Packaging.

Organic phosphite antioxidants (OPAs) are widely added in plastic products and can be oxidized to generate oxidized derivatives (OPAs = O), namely organic phosphate esters (OPEs), during production and use processing. Herein, the occurrence of OPEs and OPAs in five plastic food packages was detected by liquid chromatography-tandem mass spectrometry. Three OPEs (TPhP, TCEP, and AO168 = O) and three OPAs (TPhPi, TCEPi, and AO168) were found in the plastic packages, with concentrations of <MQL-124 ng/g (∑3OPAs) and 196-831 ng/g (∑3OPEs), respectively. The migration potential of OPAs and OPEs to food was measured by simulation experiments. OPAs and OPEs in plastic can efficiently migrate to oily simulants, alkaline simulants, and acidic simulants. After 14 days, the total concentration of all OPAs and OPEs in the food simulants reached <MQL-1.21 (acidic food simulants), <MQL-0.32 (alkaline food simulants), and 11.4-31.4 ng/mL (oily food simulants), respectively. OPAs and OPEs in 12 kinds of plastic-packaged foods were detected, with high concentrations in dairy food (∑3OPAs + ∑3OPEs: 18.3-28.9 ng/mL) and in oils (∑3OPAs + ∑3OPEs: 32.7-60.9 ng/mL). Accordingly, the estimated ingestion of OPAs and OPEs through plastic-packaged food can reach 2.6 and 32.7 ng/kg in children and 1.1 and 6.5 ng/kg in adults, indicating a non-negligible exposure risk of organic phosphorus pollutants.

On the Structure–Activity Relationship of Glyceryl oleate Friction Modifiers and Its Synergistic Mechanism on Phosphate ester Antiwear Additives

On the Structure–Activity Relationship of Glyceryl oleate Friction Modifiers and Its Synergistic Mechanism on Phosphate ester Antiwear Additives

The Influence of Phosphate-Ester-Based Additives on Metal Cutting Fluid Behavior during the Machining of Titanium Alloy

The behavior of four phosphate ester additives with varying levels of phosphorus concentrations (very high, high, medium, and low) was examined through the course of drilling a Ti-6Al-4V titanium alloy at a constant metal removal rate (4.2 mm3/s). Cutting fluid (CF) additives were evaluated using torque, specific cutting energy (SEC), and tool wear. The drilling conditions employed had a significant influence on the performance of the phosphate ester additives. At 0.105 m/s and 0.188 m/s, the phosphate ester with very high phosphorous levels possessed the lowest SCE and torque values. The high-phosphorous-level phosphate ester displayed enhanced drilling performance at 0.293 m/s. At 0.419 m/s, the SCE and torque performance of the medium-phosphorous-level phosphate ester was preferable. The drilling performance of the phosphorus esters was observed to be related to the working mechanisms of the additives, which, in turn, was associated with the formation of a phosphorus-rich tribolayer and an organophosphate tribolayer on the cutting blade.

Zn(II)-complex-based hydrolytic nanozymes prepared by nanoprecipitation for the hydrolysis of carboxylic esters and methyl parathion

Zn(II)-complex-based nanozymes have been extensively used for the cleavage of carboxylic esters and phosphate esters. Cooperativity between neighboring Zn(II) complexes is of paramount importance for the development of Zn(II)-complex-based nanozymes with excellent efficiency. Here, we have developed a controllable synthetic strategy for the construction of Zn(II)-complex-based nanozymes by using the nanoprecipitation technique, which could bring Zn(II) complexes in close proximity and regulate their microenvironments. Linear copolymers containing di(2-picolyl)amine moieties were used for the preparation of Zn(II)-complex-based nanozymes by the coordination between di(2-picolyl)amine and Zn(II) ion. These Zn(II)-complex-based nanozymes displayed excellent catalytic performance in the hydrolysis of carboxylic esters. Moreover, hydrophobic Fe3O4 nanoparticles could be incorporated into Zn(II)-complex-based nanozymes via the one-step nanoprecipitation approach, enabling the recovery of nanozymes by using a permanent magnet. Such nanozymes effectively catalyzed the hydrolysis of methyl parathion, which is highly resistant to spontaneous hydrolysis and is extremely hazardous. These nanozymes may find application in the hydrolysis of hazardous carboxylic esters and phosphate esters.

Boosting interfacial solar steam generation by three-dimensional bilayer cellulose aerogels

Interfacial solar steam generation (ISSG) provides a sustainable approach of clean water production through desalination and water purification. It is still needed to pursue a fast evaporation rate, high-quality freshwater production, and low-cost evaporators. Herein, a three-dimensional (3D) bilayer aerogel was fabricated using cellulose nanofiber (CNF) as a skeleton filled with polyvinyl alcohol phosphate ester (PVAP), and carbon nanotubes (CNT) as a light absorbing material in the top layer. The CNF/PVAP/CNT aerogel (CPC) had broadband light absorption ability and exhibited an ultrafast water transfer rate. The lower thermal conductivity of CPC effectively confined the convert heat in the top surface and minimized heat loss. Additionally, a large amount of intermediate water caused by water activation decreased the evaporation enthalpy. Under 1 sun irradiation, the CPC-3 (3.0 cm height of CPC) achieved a high evaporation rate of 4.02 kg m−2 h−1 with an energy conversion efficiency of 125.1%. The additional convective flow and environmental energy made CPC achieve an ultrahigh evaporation rate of 11.37 kg m−2 h−1, surpassing 673% of the solar input energy. More importantly, the continuous solar desalination and higher evaporation rate (10.70 kg m−2 h−1) in seawater revealed that CPC was a promising candidate for practical desalination. Outdoor cumulative evaporation was up to 73.2 kg m−2 d−1 in weak sunlight and lower temperature, which would meet the daily drinking water demands of 20 people. The excellent cost-effectiveness of 1.085 L h−1 $−1 presented its potential for a wide range of practical applications, such as solar desalination, wastewater treatment, and metal extractions.

Oxygen-doped graphite carbon nitride as a fiber coating material for headspace solid-phase microextraction of organic phosphate esters

Efficient enrichment of trace organic phosphate ester (OPEs) pollutants from complex matrixes is essential for chromatographic analysis. Herein, oxygen-doped graphite carbon nitride (denoted as O-g-C3N4) was fabricated though thermal polycondensation of urea using H2O2 as an oxygen source. The resulting O-g-C3N4 material was loose and had homogeneous pores structure, with a specific surface area of 73.74 m2/g. The O-g-C3N4 was served as fiber coating material to create solid phase microextraction (SPME) device, with silica sol as adhesive for OPEs determination. Owing to the well-developed porosity of O-g-C3N4, which provides effective mass transfer channels for OPEs, the whole SPME procedure could be accomplished within 25 min. The O-g-C3N4 fiber coating offers excellent mechanical strength and high stability and being workable after 180 sampling. The developed approach revealed a good linearity for OPEs in ultrapure water at the concentrations of 0.01–100 µg/L with the LODs between 0.001 µg/L and 0.003 µg/L. In addition, relative recoveries of 85.24% ∼99.73% were achieved in tap water and river water. These findings suggested that the oxygen-doped g-C3N4 material has potential for headspace SPME of trace OPEs in various matrixes.

Friction Performance of Self-Emulsifying Esters and Organic Phosphate Esters Mixed Aqueous Solution on the Surface of TB6 Titanium Alloy

Water-based lubrication, due to the poor film-forming ability of water, faces challenges in achieving effective lubrication for titanium alloys. This study systematically investigates the frictional performance of phosphorus-based extreme pressure (EP) additives and self-emulsifying esters (SEE) on the surface of titanium alloy (TB6) under different pressures and temperatures. The core lubricant consists of SEE with nonylphenol polyoxyethylene ether phosphate ester (NPEP), polyoxyethylene oleyl ether phosphate ester (POEP), and alcohol ether phosphate ester (AEP). Results show that SEE significantly improves the film-forming ability of the aqueous solution, while phosphate ester forms a strong chemical adsorption film on the alloy surface via P-O-Ti covalent bonds, enhancing the strength of the lubricating film. The combination of SEE and phosphate esters in the water-based solution enables effective lubrication for titanium alloys. Particularly, the mixture of POEP and SEE demonstrates excellent synergistic effects, making it an ideal blend for water-based cutting fluids for titanium alloys. This study elucidates the lubrication mechanisms and action ranges between different additives, providing important guidance for the development and promotion of water-based cutting fluids.

Transcriptome Analysis of Vicia villosa in Response to Low Phosphorus Stress at Seedling Stage

Vicia villosa, a high-quality green manure crop, helps to increase the content of soil phosphorus (P) by returning to the field. Soil P deprivation is a severe constraint on crop productivity that triggers the low P stress response in plants, which is controlled by various transcriptional regulatory network pathways. Identifying key genes from these transcriptional regulatory networks can help in developing low P-tolerant crops. In this study, we performed physiological observations and transcriptome sequencing of seedlings from the two Vicia villosa varieties, Xu Shao 3 and Soviet Vicia villosa, under P starvation conditions. The results showed that the main root length, plant height, shoot dry weight, root acid phosphatase activity, and inorganic P content of Xu Shao 3 were significantly higher than those of Soviet Vicia villosa under low P conditions. Based on transcriptome data analysis, 183 (shoot) + 144 (root) differential genes (DEGs) between the two varieties were identified; 144 (shoot) + 79 (root) were upregulated, and 69 (shoot) + 65 (root) were downregulated. KEGG analysis found that DEGs in shoots were significantly enriched in photosynthesis pathways, such as vitamin B6 and riboflavin metabolism. Meanwhile, DEGs in roots were enriched in plant signal transduction, fatty acid degradation, citric acid cycle, pentose, glucuronic acid conversion, etc. GO enrichment analysis suggested that DEGs in shoots were significantly enriched in biological processes, including cell response to P stress, intracellular ion homeostasis, etc., and molecular functions, including phosphate ester hydrolase, phosphatase, acid phosphatase activity, etc. Furthermore, DEGs associated with low P tolerance included three acid phosphatases, a phosphoesterase, a sulfoquinovosyl diacylglycerol synthase, a phosphoenolpyruvate carboxylase, six phosphate transporters and glycerol-3-phosphate transporters, eight SPX, and two PHL genes. In conclusion, Xu Shao 3 exhibited stronger inorganic P accumulation ability and a lesser effect on growth than Soviet Vicia villosa under low P conditions, which might result from photosynthesis, sugar, and P metabolism differences between the two varieties. Acid phosphatase, phosphoesterase, phosphoenolpyruvate carboxylase, sulfoquinovosyl diacylglycerol synthase, phosphate transporter, glycerol-3-phosphate transporter, and SPX were key DEGs leading to the difference in low P stress tolerance between the two varieties.

Highly fire safe and flexible nanoarchitectures with tunable interface towards excellent electromagnetic interference shielding

To meet the demand for practical applications, it is imperative to develop flexible electromagnetic interference (EMI) shielding materials with fire safety. In this work, highly fire safe and flexible thermoplastic polyurethane (TPU)-based EMI shielding nanocomposites were prepared via melt blending polyphenyl phosphate ester amide (PPPEA) with MXene/carboxylic multiwalled carbon nanotubes hybrid (MC), air-assisted thermocompression and layer-by-layer stacking. Combining PPPEA with MC led to peak of heat release rate, total heat release and total smoke release of TPU nanocomposite containing 5.0 wt% PPPEA and 2.0 wt% MC decreased by 39.0%, 24.5% and 23.8%, respectively. Furthermore, the hierarchical TPU/5PA/2.0MC/carbon fiber cloth (CF) nanocomposite showed a prominent averaged EMI shielding effectiveness (SE) of 35.5 dB and a high normal SE value of 29.6 dB/mm, which were superior to most previously reported results. Catalytic carbonization of PPPEA and multiply reflected and scattered effect of MC together with continuous conductive network of CF were responsible for the improvement of these performances.

The Effective Combination of Humic Acid Phosphate Fertilizer Regulating the Form Transformation of Phosphorus and the Chemical and Microbial Mechanism of Its Phosphorus Availability

In the process of phosphate fertilizer production, adding humic acid to produce humic-acid-value-added phosphate fertilizer can improve fertilizer efficiency and promote crop growth. Although studies have primarily focused on investigating the impact of humic acid’s structure and function on phosphorus availability in humic-acid-added phosphate fertilizers, there is limited research on the regulatory effects of phosphorus fertilizer structure and the synergistic mechanisms involving microorganisms. Therefore, this study aimed to examine the chemical and biological mechanisms underlying the increased efficiency of humic-acid-added phosphate fertilizers by implementing various treatment processes. These processes included physically blending humic acid with phosphate fertilizer (HA+P), chemically synthesizing humic acid phosphate fertilizer (HAP), using commercially available humic acid phosphate fertilizer (SHAP), employing ordinary potassium phosphate fertilizer (P), and implementing a control treatment with no phosphate fertilizer (CK). Investigating the synergistic mechanism of humic-acid-added phosphate fertilizers holds significant importance. The results showed that during the preparation of HAP at high temperature, a new absorption peak appeared at 1101 cm−1, and a new chemical bond -O- was formed. The hydroxyl fracture in humic acid combined with phosphoric acid to form a phosphate ester (P-O-C=O) structure. HAP residues were concentrated on the surface and loaded with more soil minerals. The content of highly active oxygen-containing functional groups—such as aromatic C-O, carboxyl/amide carbon and carbonyl carbon—increased significantly, while the content of alkyl carbon, oxyalkyl carbon, and aromatic carbon decreased. Upon combining humic acid with potassium phosphate, the carboxyl group and calcium ions formed the HA-m-P complex, increasing the content of soluble phosphate (H2PO4−) in the soil by 1.71%. Compared to HA+P treatment, HAP treatment significantly increased the soil’s available P content by 13.8–47.7% (P &lt; 0.05). The plant height, stem diameter, and above-ground biomass of HAP treatment were increased by 21.3%, 15.31%, and 61.02%, respectively, and the total accumulations of N, P, and K nutrient elements were increased by 6.71%, 31.13%, and 41.40%, respectively, compared to the control treatment. The results of high-throughput sequencing showed that the rhizosphere soil of HA+P and HAP treatment was rich in bacterial groups, the soil microbial structure was changed, and the bacterial community diversity was increased under HAP treatment. The number of genes encoding phytase and alkaline phosphatase associated with organophosphorus dissolution increased by 3.23% and 2.90%, respectively, in HAP treatment. Humic acid phosphate fertilizer forms phosphate esters in the process of chemical preparation. After application, the soil’s microbial community structure is changed, and soil enzyme activity related to phosphorus transformation is improved to promote tomatoes’ absorption of soil nutrients, thus promoting tomato plant growth and nutrient accumulation.

Phosphorus fluoride exchange: Multidimensional catalytic click chemistry from phosphorus connective hubs

Phosphorus Fluoride Exchange (PFEx) represents a cutting-edge advancement in catalytic click-reaction technology. Drawing inspiration from Nature's phosphate connectors, PFEx facilitates the reliable coupling of P(V)-F loaded hubs with aryl alcohols, alkyl alcohols, and amines to produce stable, multidimensional P(V)-O and P(V)-N linked products. The rate of P-F exchange is significantly enhanced by Lewis amine base catalysis, such as 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD). PFEx substrates containing multiple P-F bonds are capable of selective, serial exchange reactions via judicious catalyst selection. In fewer than four synthetic steps, controlled projections can be deliberately incorporated along three of the four tetrahedral axes departing from the P(V) central hub, thus taking full advantage of the potential for generating three-dimensional diversity. Furthermore, late-stage functionalization of drugs and drug fragments can be achieved with the polyvalent PFEx hub, hexafluorocyclotriphosphazene (HFP), as has been demonstrated in prior research.

CVM-1118 (foslinanib), a 2-phenyl-4-quinolone derivative, promotes apoptosis and inhibits vasculogenic mimicry via targeting TRAP1.

CVM-1118 (foslinanib) is a phosphoric ester compound selected from 2-phenyl-4-quinolone derivatives. The NCI 60 cancer panel screening showed CVM-1125, the major active metabolite of CVM-1118, to exhibit growth inhibitory and cytotoxic effects at nanomolar range. CVM-1118 possesses multiple bioactivities, including inducing cellular apoptosis, cell cycle arrest at G2/M, as well as inhibiting vasculogenic mimicry (VM) formation. The TNF receptor associated protein 1 (TRAP1) was identified as the binding target of CVM-1125 using nematic protein organization technique (NPOT) interactome analysis. Further studies demonstrated CVM-1125 reduced the protein level of TRAP1 and impeded its downstream signaling by reduction of cellular succinate levels and destabilization of HIF-1α. The pharmacogenomic biomarkers associated with CVM-1118 were also examined by Whole Genome CRISPR Knock-Out Screening. Two hits (STK11 and NF2) were confirmed with higher sensitivity to the drug in cell knock-down experiments. Biological assays indicate that the mechanism of action of CVM-1118 is via targeting TRAP1 to induce mitochondrial apoptosis, suppress tumor cell growth, and inhibit vasculogenic mimicry formation. Most importantly, the loss-of-function mutations of STK11 and NF2 are potential biomarkers of CVM-1118 which can be applied in the selection of cancer patients for CVM-1118 treatment. CVM-1118 is currently in its Phase 2a clinical development.

Revealing the Combined Effect of Active Sites and Intra-Particle Diffusion on Adsorption Mechanism of Methylene Blue on Activated Red-Pulp Pomelo Peel Biochar.

Phosphoric acid-activated biochar has been proven to be a promising adsorbent for pollutant removal in an aqueous solution. It is urgent to understand how surface adsorption and intra-particle diffusion synergistically contribute to the adsorption kinetic process of dyes. In this work, we prepared a series of PPC adsorbents (PPCs) from red-pulp pomelo peel under different pyrolysis temperatures (150-350 °C), which have a broad specific surface area range from 3.065 m2/g to 1274.577 m2/g. The active sites on the surface of PPCs have shown specific change laws of decreasing hydroxyl groups and increasing phosphate ester groups occurring as the pyrolysis temperature rises. Both reaction models (PFO and PSO models) and diffusion models (intra-particle diffusion models) have been applied to simulate the adsorption experimental data to verify the hypothesis deduced from the Elovich model. PPC-300 exhibits the highest adsorption capacity of MB (423 mg/g) under given conditions. Due to its large quantities of active sites on the external and internal surfaces (1274.577 m2/g), a fast adsorption equilibrium can be achieved within 60 min (with an initial MB concentration of 100 ppm). PPC-300 and PPC-350 also exhibit an intra-particle-diffusion-controlled adsorption kinetic process with a low initial MB concentration (100 ppm) or at the very beginning and final stage of adsorption with a high initial MB concentration (300 ppm) at 40 °C, considering that the diffusion is likely hindered by adsorbate molecules through internal pore channels at the middle stage of adsorption in these cases.

Effect of phosphate ester grinding aids on cement grinding and water-reducing performance

Phosphate ester polymers were prepared from phosphate ester monomers for the first time and their effects as cement grinding aids and water-reducing performance were studied. Fourier-transform infrared (FTIR) spectroscopy and tests for standard viscosity, setting time, mortar fluidity, mortar compressive strength were conducted. The results showed that hydroxyethyl dibutyl phosphate reduced the residues of 45 μm and 80 μm grinding sieves by 68.67% and 98.67%, respectively. Compared with triethanolamine, the grinding effect of hydroxyethyl dibutyl phosphate was not only better but also the optimal mixing amount was less (only 0.167%). For the same amount of grinder, the grinding time was shortened by 30% and, for the same grinding time, the grinding output was increased by at least 20%. The polymer grinding aids significantly improved the fluidity of cement paste (by 40.06%), meaning the water-reduction rate of cement mortar could reach over 20%. The experimental results show that, as a new generation of grinding aids, phosphate esters not only have a significant grinding effect but also have high molecular designability, which will significantly enrich the grinding aids market and effectively promote energy conservation and emissions reductions in the grinding process.

Prodrug Strategies for the Development of β-l-5-((E)-2-Bromovinyl)-1-((2S,4S)-2-(hydroxymethyl)-1,3-(dioxolane-4-yl))uracil (l-BHDU) against Varicella Zoster Virus (VZV).

Varicella zoster virus (VZV) establishes lifelong infection after primary disease and can reactivate. Several drugs are approved to treat VZV diseases, but new antivirals with greater potency are needed. Previously, we identified β-l-5-((E)-2-bromovinyl)-1-((2S,4S)-2-(hydroxymethyl)-1,3-(dioxolane-4-yl))uracil (l-BHDU, 1), which had significant anti-VZV activity. In this communication, we report the synthesis and evaluation of numerous l-BHDU prodrugs: amino acid esters (14-26), phosphoramidates (33-34), long-chain lipids (ODE-l-BHDU-MP, 38, and HDP-l-BHDU-MP, 39), and phosphate ester prodrugs (POM-l-BHDU-MP, 41, and POC-l-BHDU-MP, 47). The amino acid ester l-BHDU prodrugs (l-phenylalanine, 16, and l-valine, 17) had a potent antiviral activity with EC50 values of 0.028 and 0.030 μM, respectively. The phosphate ester prodrugs POM-l-BHDU-MP and POC-l-BHDU-MP had a significant anti-VZV activity with EC50 values of 0.035 and 0.034 μM, respectively, and no cellular toxicity (CC50 > 100 μM) was detected. Out of these prodrugs, ODE-l-BHDU-MP (38) and POM-l-BHDU-MP (41) were selected for further evaluation in future studies.

Phosphate Ester Bond Chemistry with Zirconium (IV) Catalysts

Earth’s infancy was a time of immense chemical complexity. Over many millions of years, steady chemical cycles were formed and driven by thermodynamics and organic precursors left over from the planet’s formation. In aqueous environments, this chemistry may have led to the formation of catalytic RNA species capable of information storage and replication. Presumably, the formation of these oligonucleotides was catalyzed by primordial Earth’s abundant mineral content. However, the species that accelerated these types of transformations are unknown. In this study, the role of Zr+4 in the catalytic formation of phosphate ester bonds was explored. Through TLC screening, it was found that most of the test conditions produced no observable phosphorylated products. In the final samples, there were highly polar spots which may have contained phosphate-bearing compounds. These findings provide mixed certainty about zirconium’s catalytic capacity for ester formation but suggest that zirconium metal organic frameworks (MOFs) and alternative metal ions may be viable routes for future investigation. Lay Summary Earth began as a planet of rock and magma, hardly recognizable without the biological adornments that characterize it today. For nearly a billion years, consistent comet and asteroid impacts heated the planet and vaporized any reservoirs of water or organic matter that covered the surface. As this bombardment subsided, life came to fruition in half the time that the mineral rain had lasted. The question of how this transition occurred is one of the most elusive in the biochemical field. In particular, it is still unknown how all life, whether primordial or modern, came to share polynucleotides as an essential coding system for all their requisite biological functions. This study explored the role of Zr+4, an abundant mineral on early Earth, in the catalytic formation of phosphate ester bonds, the core linkages in DNA and RNA. Through TLC screening, it was found that most of the test conditions produced no observable phosphorylated products. In the final samples, highly polar spots may have contained phosphate-bearing compounds. These findings provide mixed certainty about zirconium’s capacity for ester formation but suggest that zirconium metal-organic frameworks (MOFs) and alternative metal ions that reflect early Earth’s composition may be viable routes for future investigation into this grand mystery. To see the complete thesis, please visit https://scholar.colorado.edu/concern/undergraduate_honors_theses/cf95jc857.

Synthesis of Dinucleotide Non-Symmetrical Triester Phosphate Phosphoramidites and Their Incorporation Within Oligonucleotides.

In this protocol article, the synthesis of dinucleotide non-symmetrical triester phosphate phosphoramidites will be highlighted. Specifically, we use a selective transesterification starting with tris(2,2,2-trifluoroethyl) phosphate to afford a dinucleotide derivative phosphate ester. Substitution of the final trifluoroethyl group with various alcohols affords a dinucleotide triester phosphate with a hydrophobic group, which can then be deprotected and converted to a phosphoramidite for incorporation within oligonucleotides. © 2023 Wiley Periodicals LLC. Basic Protocol 1: Synthesis of a DMT- and TBS-protected unsymmetrical dinucleotide Basic Protocol 2: Synthesis of a DMT-protected unsymmetrical dinucleotide phosphotriester monoalcohols Basic Protocol 3: Synthesis of DMT-protected phenylethyl phosphotriester dinucleotide phosphoramidites Basic Protocol 4: Synthesis, purification, and characterization of RNAs containing triester phosphate modifications.

Ultrahigh solar vapor evaporation rate of super-hydrophilic aerogel by introducing environmental energy and convective flow

The renewable solar energy provides one of promising pathways of interfacial vapor evaporation for freshwater resources with minimized carbon footprint. The high-throughput evaporation rate needs to be further achieved for the demand of practical application. Herein, a three-dimensional hybrid aerogel (rGP) with reduced graphene oxide (rGO) and polyvinyl alcohol phosphate ester (PVAP) was fabricated by hydrothermal method. The rGP aerogel had broadband light absorption ability and interconnected pore structure. This evaporator achieved fully hydrated state within 5 s due to the superabsorbent PVAP. The existence of intermediate water in rGP reduced the energy requirement for evaporation. The 3D aerogel also harvested additional energy from surroundings caused by evaporation cooling effect. Therefore, the rGP with height of 3 cm (rGP-3) achieved a higher evaporation rate of 4.89 kg m-2h−1 with the energy efficiency of 124.8% under 1 sun irradiation. The vapor diffusion could be assisted by convective flow and minimized the stagnation of vapor in the pores. Then the evaporation rate of rGP-3 increased to 16.22 kg m-2h−1 under the convective flow of 2.5 m s−1. Additionally, the 3D rGP can be consistently evaporated for 8 h in 3.5 wt% brine and no salt deposition occurred. More importantly, the evaporated fresh water from actual seawater was up to 156.30 kg m−2 in 8 h under outdoor sunlight and directional convective flow, which implied the remarkable potential in practical application. This rGP evaporation platform with 3D pore structure, high light absorption, efficient water activation, rapid water transport, extra heat collection, and effective vapor diffusion provides a new inspiration for designing high-throughput evaporators of superhigh evaporation rate and a large-scale application in desalination under convective flow.

Mechanisms for the structural dependent transformation of 6:2 and 8:2 polyfluoroalkyl phosphate diesters in wheat (Triticum aestivum L.)

Polyfluoroalkyl phosphate esters (PAPs) are widely used and detected in various environmental media and organisms, but little is known about their behaviors in plants. In this study, the uptake, translocation and transformation of 6:2 and 8:2 diPAP in wheat using hydroponic experiments were investigated. 6:2 diPAP was more easily taken up by roots and translocated to shoots than 8:2 diPAP. Their phase I metabolites were fluorotelomer saturated carboxylates (FTCAs), fluorotelomer unsaturated carboxylates (FTUCAs) and perfluoroalkyl carboxylic acids (PFCAs). PFCAs with even-numbered chain length were the primary phase I terminal metabolites suggesting that they were mainly generated through β-oxidation. Cysteine and sulfate conjugates were the primary phase II transformation metabolites. The higher levels and ratios of phase II metabolites in the 6:2 diPAP exposure group indicated that the phase I metabolites of 6:2 diPAP were more susceptible to phase II transformation than that of 8:2 diPAP, which was confirmed by density functional theory calculation. Enzyme activity analyses and in vitro experiments demonstrated that cytochrome P450 and alcohol dehydrogenase actively participated in the phase Ⅰ transformation of diPAPs. Gene expression analyses showed that glutathione S-transferase (GST) was involved in the phase Ⅱ transformation, and the subfamily GSTU2 played a dominant role.