Tetrameric Acid Research Articles

Impacts of Hexafluoropropylene Oxide Tetrameric Acid (HFPO-TeA) on Neurodevelopment and GABAergic Signaling in Zebrafish Larvae

Hexafluoropropylene oxide oligomer acids (HFPOs), an emerging environmental pollutant, are increasingly utilized in the manufacture of fluorinated synthetic materials as a substitute for traditional perfluorooctanoic acid (PFOA), resulting in a corresponding rise in detection rates in aquatic environments, which may present inherent safety hazards to ecosystems and public health. However, few data are available on the issue of their toxicity and mechanism. This study aimed to investigate the potential toxic effects of hexafluoroepoxypropane tetrameric acid (HFPO-TeA), a typical HFPO, on the early developmental stages of zebrafish larvae. It revealed that HFPO-TeA exposure resulted in significant detrimental effects, including adverse impacts on general morphological characteristics, such as eye area, heart rate, and swimming bladder, in zebrafish embryos and larvae. Targeted metabolomics and transcriptomics inquiries clarified that HFPO-TeA exposure reduced the levels of the neurotransmitter gamma-aminobutyric acid (GABA) and downregulated the expression of genes related to the GABA pathway. Simultaneously, transgenic zebrafish exhibited that exposure to HFPO-TeA impedes the growth of GABAergic neurons. Moreover, the molecular docking analysis indicated that GABAA receptors might be the potential targets of HFPO-TeA. Taken together, the current data highlights that the HFPO-TeA might not be safe alternatives to PFOA. This study presented a model for HFPO-TeA-induced neurotoxicity in developing zebrafish that can aid in ecological risk assessments.

Degradation of hexafluoropropylene oxide tetrameric acid (HFPO-TeA) using electrocatalytic ozone technique

Hexafluoropropylene oxide tetrameric acid (HFPO-TeA) is an alternative to perfluorooctanecarboxylic acid (PFOA) and is commonly used in the production of perfluoropolymers. In this study, the performances of ozone oxidation, electrochemical oxidation, and electrocatalytic ozone techniques in the degradation of HFPO-TeA were compared. The experimental results indicated that the electrocatalytic ozone technique was best. The effects of different current densities, ozone concentrations, electrolyte types, and initial pollutant concentrations on HFPO-TeA degradation were investigated. The results showed that the ratio of HFPO-TeA degradation reached 95.9% after electrolysis for 120 ​min for an initial HFPO-TeA concentration of 100 ​mg/L, a reaction volume of 120 ​mL, an applied current density of 10 ​mA/cm2, and an ozone concentration of 20 ​mg/L. The intermediate products detected were hexafluoropropylene oxide dimeric acid [C3F7OCF(CF3)COO−], pentafluoropropionic acid [C2F5COO−], and trifluoroacetic acid [CF3COO−]. The mechanisms involved in HFPO-TeA degradation include direct electron transfer, indirect oxidation mediated by hydroxyl radicals (·OH), and ozone oxidation.

Efficiency and Persistence of Movento® Treatment against Myzus persicae and the Transmission of Aphid-Borne Viruses.

Neonicotinoids are widely used to protect fields against aphid-borne viral diseases. The recent ban of these chemical compounds in the European Union has strongly impacted rapeseed and sugar beet growing practices. The poor sustainability of other insecticide families and the low efficiency of prophylactic methods to control aphid populations and pathogen introduction strengthen the need to characterize the efficiency of new plant protection products targeting aphids. In this study, the impact of Movento® (Bayer S.A.S., Leverkusen, Germany), a tetrameric acid derivative of spirotetramat, on Myzus persicae and on viral transmission was analyzed under different growing temperatures. The results show (i) the high efficiency of Movento® to protect rapeseed and sugar beet plants against the establishment of aphid colonies, (ii) the impact of temperature on the persistence of the Movento® aphicid properties and (iii) a decrease of approximately 10% of the viral transmission on treated plants. These observations suggest a beneficial effect of Movento® on the sanitary quality of treated crops by directly reducing primary infections and indirectly altering, through aphid mortality, secondary infections on which the spread of disease within field depends. These data constitute important elements for the future development of management strategies to protect crops against aphid-transmitted viruses.

Cyclopiazonic acid induced p53-dependent apoptosis in the testis of mice: Another male related risk factor of infertility.

Cyclopiazonic acid (CPA) is an indole tetrameric acid mycotoxin. This study carried out to investigate the potential effects of CPA on male reproductive system. In the current study, 40 adult male mice were divided into five groups (n = 8). The control group did not expose to CPA, while animals in vehicle-received group; received the CPA-solvent (0.05% dimethyl sulfoxide) and the animals of third, fourth, and fifth groups received CPA 0.03, 0.06, and 0.12 mg/kg, body weight, respectively for 28 days. Morphometric and morphological deviations, spermatogenesis indices, malondialdehyde (MDA) content, total thiol molecules (TTM) concentration, total antioxidant capacity (TAC), protein carbonylation rate (CO), and nitric oxide (NO) concentration were examined. The expression changes of apoptotic genes (P53, Bcl-2, and Caspase III) at mRNA level were also evaluated by qPCR technique. Reduction in the Leydig and Sertoli cells population, diameter of seminiferous tubules, and spermatogenesis parameters was significant only in the group that received the highest dose of CPA. An increase in the level of MDA, NO, and CO in testicular tissue and reduction of TAC and TTM were observed in the CPA-exposed groups. Significant up-regulation (p < .05) in the expression of P53 and Caspase III genes and down-regulation of Bcl-2 gene were found in the CPA-received groups. These results are indicating the detrimental effects of CPA on the testicles, which may attribute to the CPA-induced oxidative stress and apoptosis. Moreover, results also help to understand a serious concern about the presence of CPA in foods as a potential risk factor in male-related infertility.

Influence of Asphaltenes on Gelation of Tetrameric Acid with Calcium Ion at the Oil/Water Interface under Flow-Model Condition

The first step in calcium naphthenate deposition is supposed to be the formation of an interfacial gel by crosslinking between ARN tetrameric acid and Ca2+. Several aspects of the inhibition of the...

Rheological Properties of Gels Formed at the Oil–Water Interface by the Reaction between Tetrameric Acid and Calcium Ion under Flow Conditions and at the Batch Scale

The interfacial reaction between ARN tetrameric acid and Ca2+, which leads to the formation of calcium naphthenate deposits, was studied using a coaxial capillary device fitted to a profile analysi...

Abstract NTOC-077: ORALLY ACTIVE LOW MOLECULAR WEIGHT HEPARIN TAUROCHOLATE AND DEOXYCHOLATE CONJUGATE FOR THE INHIBITION OF THE PROGRESSION OF METASTATIC OVARIAN CANCER

Abstract PURPOSE: Ovarian cancer is one of the major aggressive cancer which is not manageable blocking a single pathway. Recently, chemically modified low molecular weight heparin (LMWH) derivatives have shown good anti-cancer activity targeting various biochemical parameters, such as, transforming growth factor beta 1 (TGFβ-1), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), heparin-like growth factor (HGF), CXCL-12, and CXCL-9. In this study, we have focused on TGFβ-1 and VEGF that are known to promote metastatic ovarian cancer progression and use an orally LMWH-taurocholate conjugated with tetrameric deoxycholic acid, namely LHTD4, to successfully inhibit the progression at different stages of ovarian metastasis cancer. EXPERIMENTAL PROCEDURES: We performed the binding affinity of TGFβ-1 and VEGF with LHTD4. We carried out in vitro phosphorylation assays of the consecutive receptors of TGFβ-1 and VEGF (TGF-β-1R1 and VEGFR2, respectively). Effects of LHTD4 on in vitro SKOV3-LUC cell migration (induced by TGFβ-1 and VEGF), spheroid formation, and the epithelial to mesenchymal transition (EMT) were investigated. We prepared a formulation of LHTD4 and a synthetic bile acid-based absorption enhancer, DCK (L-lysine- deoxycholylethylamine), to enable the oral absorption. The in vivo anti-metastatic effect of LHTD4 was evaluated in an intraperitoneal adhesion model and an orthotopic SKOV3-LUC ovarian cancer model. We measured the luciferase activity of the mice every week to check the progression of the cancer. RESULTS: LHTD4 inhibited the migration of SKOV3-LUC cells 10-fold greater than the control group. LHTD4 also blocked the VEGF induced SKOV3-LUC spheroid formation. LHTD4 effectively inhibited ligand-induced VEGFR2 and TGFβ-1R1 phosphorylated. The expressions of EMT marker proteins such as Vimentin and Snail were prevented by LTHD4 treatment in in vitro studies with TGFβ-1 treated SKOV3-LUC cells. In orthotopic model ovarian metastasis model, the treatment with LHTD4 (5 mg/kg daily, orally) significantly inhibited the growth and organ metastasis progression compared to the control: LHTD4-treated mice showed 20-times lower luciferase activity than that of control mice. Finally, the intraperitoneal adhesion of the SKOV3-LUC cells was also decreased robustly in mice which received LHTD4 daily. CONCLUSION: LHTD4 is one of the promising candidate for the inhibition of the progression of epithelial ovarian cancer. We report that the oral formulation of LHTD4/DCK complex could be a good choice for the treatment of metastatic ovarian cancer as it can target multiple pathways of metastasis. LHTD4 primarily showed anti-metastatic effects via blocking of TGFβ-1 and VEGF signaling pathway at different stages of metastasis progress. Citation Format: Farzana Alam, Mohammad Rezwanul Haque, Taslim A. Al-Hilal, Fakhrul Ahsan, Youngro Byun. ORALLY ACTIVE LOW MOLECULAR WEIGHT HEPARIN TAUROCHOLATE AND DEOXYCHOLATE CONJUGATE FOR THE INHIBITION OF THE PROGRESSION OF METASTATIC OVARIAN CANCER [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr NTOC-077.

Interfacial dilational rheology properties of films formed at the oil/water interface by reaction between tetrameric acid and calcium ion

ABSTRACTThis article aims to determine the applicability of interfacial dilational rheology to study the formation of viscoelastic film at the oil/water interface by reaction between tetrameric acids ARN and calcium ions, and to determine the influence of asphaltenes and naphthenic acids (NA) on this film. It was first found that the formation of viscoelastic film by reaction between ARN and calcium ions is easily observed by dilational rheology: Significantly high values of E′ (130 mN/m) were measured for this system at low ARN concentration (10 µM). These values are at least 5 to 10 times higher than values obtained for ARN without Ca2+ or other crude oil components such as asphaltenes and naphthenic acids.The influence of asphaltenes and NA on the viscoelastic film formation has been studied. When asphaltenes or NA are present, the interfacial viscoelastic film is weakened: There is a gradual decrease of E′ and E″ when the asphaltenes or NA concentration increases. These two components can therefore inhibit the ARN/Ca2+ film formation. This decrease is similar to the one previously observed by shear rheology. Several explanations are proposed.

Interfacial Shear Rheology of Gels Formed at the Oil/Water Interface by Tetrameric Acid and Calcium Ion: Influence of Tetrameric Acid Structure and Oil Composition

The tetrameric acid ARN is present in crude oil and can form deposits that can cause plugging in oil production facilities during oil production in the presence of calcium ions. It has been previously shown that BP-10, a compound designed to mimic the properties of ARN, can form gel at the oil/water interface by reacting with Ca2+ if the pH is high enough to ionize BP-10s carboxylic acid functions. In this study, the BP-10 and ARN are compared. Although BP-10 forms a gel at the interface, ARN creates rather a viscoelastic material perhaps due to the presence of impurities like naphthenic acids in the sample analyzed. The amount of BP-10 required to form a gel at the interface was found to be ca. 0.45–0.76 mg·m–2. The influence of the presence of asphaltenes on the gel formation has then been studied. It has been found that the gel is weakened in the presence of asphaltenes and G′ is not measurable at high enough concentrations. This inhibition could result from either a competition between ARN and asphalt...

Aggregation of tetrameric acid in xylene and its interaction with asphaltenes by isothermal titration calorimetry

This paper describes the self-association of tetrameric acids (TA) and their interactions with asphaltenes using isothermal titration calorimetry. In order to visualize the importance of molecular structures of TA and asphaltenes, stearic acid (SA) and asphaltene model compounds are used for comparison. Both SA and TA form dimers in xylene solutions. However, the dimerization enthalpy for SA (ΔH) in absolute value is higher than the corresponding value for TA, indicating that the aggregation is less efficient for TA likely due to steric reasons. The interplay between asphaltenes and TA or SA is similar except at low concentrations. Interactions between TA and asphaltene model compounds are strongly dependent on the presence of acid group in model compounds, indicating hydrogen bonds as a central but not only element in the interactions.

Mixed Micelles of Tetrameric Acids and Naphthenic Acids in Water

This article presents a characterization of the structures formed in aqueous solution by a mixture of carboxylic acid and a tetrameric acid molecule: either C80-tetraacid (also known as ARN), which is an aliphatic molecule present in crude oil and responsible for the formation of deposits, or BP-10, a molecule designed to mimic the properties of the C80-tetraacid. These molecules have four carboxylic functions at the end of four interconnected hydrocarbon chains and can be dissolved in aqueous solution in basic media. The structures have been analyzed by dynamic light scattering (DLS) and small-angle neutron scattering (SANS) techniques. It has previously been shown from SANS measurements that BP-10 in sodium form (Na4BP-10) self-associate in solution to form nanosized micelles. We show here that sodium carboxylates, when present, can be incorporated into the BP-10 micelles. This incorporation is a function of the CMC of the sodium carboxylates. In contrast, the other tetrameric acid—C80-TA in sodium form...

Interactions of divalent cations with tetrameric acid aggregates in aqueous solutions

Interactions in aqueous solutions between a tetrameric naphthenic acid in sodium salt (BP10Na4) and divalent Mg2+ and Ca2+ cations were investigated by isothermal titration calorimetry (ITC) and dynamic light scattering (DLS). Colloidal aggregation of the tetrameric sodium naphthenates to vesicles and micelles enhances its binding with divalent cations. In vesicle systems, Ca2+ was found to bind first with carboxylate groups located at the external water/lipid interface of vesicles. The cations then diffuse through the membrane to interact with the inner carboxylate groups. Higher Ca2+ concentration and higher salinity gradients enhance cation diffusion. Under solution chemistry conditions where micelle dominates, Ca2+ reacts only with outer carboxylate groups of BP10Na4 without any significant cation diffusion through the aggregates. The binding of calcium with sodium naphthenate is an entropy-driven process where entropy gain comes from the dehydration of both cations and carboxylate groups of BP10Na4. The affinity of Mg2+ to BP10Na4 is much weaker than Ca2+ due to its stronger hydration and hence larger size of hydrated magnesium ions than hydrated calcium ions.

A histidine thiol 100 kDa, tetrameric acid phosphatase from lentil, Lens esculenta, seeds with the characteristics of protein tyrosine phosphatases

A non-specific acid phosphatase (APase) hydrolysing l-tyrosine- O-phosphate and 3′-AMP was purified to electrophoretic homogeneity from mature lentil seeds with apparent native molecular mass of 100 kDa and subunit molecular mass of 24 kDa. These activities appear to reside on the same protein which shows a single band in native and SDS-PAGE. The pH optimum is 5.5, while the K m (mM) and V max (μmoles/min/mg protein) for p-nitrophenyl phosphate (pNPP) are 0.7 and 9.2 and for l-tyrosine- O-phosphate 1.4 and 10.1, respectively, at 30°C and for 3′-AMP, 2 and 4.4 at 37°C. The protein also hydrolyses other phosphomonoesters to a lesser extent. l-Tyrosine- O-phosphate, 3′-AMP and pNPP hydrolysis is potently inhibited by micromolar orthovanadate and also to nearly the same extent by sodium fluoride, potassium tartrate and metal ions. Histidine and cysteine are likely to be involved in the catalysis. Thermal inactivation studies indicate that the active site conformations for pNPP and 3′-AMP hydrolytic activities are different. The enzyme shows the characteristics of the animal protein tyrosine phosphatase.