Ethyl Phosphonate Research Articles

Inactivation of the peroxidase isoenzyme groups, APrx and Lpl BPrx, markers of the in vitro culture of grapevine, by fosetyl-Al (aluminum tris[ethyl phosphonate

Grapevine ( Vitis vinifera cv. Monastrell) fruits contain, as the only component of peroxidase polymorphism, the peroxidase isoenzyme B 5 , which is the sole component of the peroxidase isoenzyme group HpI BPrx in grapevines. Establishment of suspension cell cultures from grapevine fruits is accompanied by the de novo expression of one acidic (APrx) and one basic (LpI BPrx) peroxidase isoenzyme group in the culture medium, which indicates that the in vitro culture is associated with the new expression of two groups of cell wall-located peroxidase isoenzymes. Treatment of suspension cultured cells with aluminum tris [ethyl phosphonate] (fosetyl-Al) reduces the level of peroxidase activity found in the culture medium, this effect being specific to those isoenzymes that are expressed de novo during cell culture, the isoenzyme groups APrx and LpI BPrx. Thus, fosetyl-Al selectively inactivates the peroxidase isoenzyme groups, APrx and LpI BPrx, which are markers of the process that accompanies the establishment of grapevine cell cultures.

Applicability of High-Performance Ion Chromatography (HPIC) to the Determination of Fosetyl-Aluminum in Commercial Formulations

An improved method for the determination of the systemic fungicide fosetyl-aluminum (aluminum tris(ethyl phosphonate)), in commercial formulations, via the quantitative determination of the phosphonate anion is described. The method employs HPIC using eluent suppression and conductivity detection. Two different kinds of chromatographic columns were utilized in the study, together with several eluents. The method has good sensitivity and reproducibility (CV% 3.2), and the sample preparation required is very simple. Under the analytical conditions adopted, the detection limit of fosetyl-aluminum in the commercial formulation "Aliette" was 0.008 g/kg. Chromatographic conditions for gradient elution were also investigated in the study, which were able to reveal the possible presence of phosphorous acid. The detection limit for this compound was 0.03 mg/liter. An atomic absorption spectroscopy name technique was also applied to the samples as an indirect analysis of fosetyl-aluminum via the determination of aluminum.

Zirconium 2-amino ethyl phosphonate: Preparation, characterization and preliminary study of its electrical conductivity and intercalation properties

Zirconium 2-amino ethyl phosphonate in the chloride form (α-Zr (O 3P(CH 2) 2NH 3 +Cl −) 2) was prepared by precipitating Zr IV with 2-amino ethyl phosphonic acid in the presence of hydrofluoric and hydrochloric acids. The compound is stable up to about 300 °C and possesses an α-type layered structure with the pendant alkyl chains oriented into the interlayer region where chloride ions are also accommodated; the interlayer distance is 14.3 Å. The titration with 0.1 M NaOH leads to the exchange of OH − for Cl − and to the formation of α-Zr(O 3P(CH 2) 2NH 2) 2 · 2H 2O (interlayer distance of 12.3 Å) which is able to intercalate n-alkyl carboxylic acids from 0.1 M aqueous solutions at 75 °C. α-Zr(O 3P(CH 2) 2NH 3 +Cl −) 2 and anhydrous α-Zr(O 3P(CH 2) 2NH 2) 2 were also investigated by conductivity measurements above 100 °C by using the complex impedance technique.

Ternary Complexes in Solution+ with Phosphonates as Ligands. Intramolecular Equilibria in the Mixed Ligand Cu2+ Complexes Formed by 2,2′-Bipyridyl or 1,10-Phenanthroline and the Dianion of Phosphonylmethoxyethane in Water-Dioxane Mixtures

The stability constants of the mixed ligand complexes formed by Cu2+, 2,2′-bipyridyl or 1,10-phenanthroline (= Arm), and the dianion of phosphonylmethoxyethane (PME2-), ethyl phosphonate (EtP2-), methyl phosphonate (MeP2-), or D-ribose 5′-monophosphate (RibMP2-) (= R–PO3 2-) were determined by potentiometric pH titrations in water containing 30 or 50% (v/v) 1,4-dioxane (I = 0.1 M, NaNO3; 25°C). The corresponding results regarding water as solvent were taken from our earlier work. Previous measurements with simple phosphate monoesters, together with the present results for RibMP2-, were used to establish log versus straight line plots. With the aid of the equilibrium constants determined for the MeP2- and EtP2- systems it is shown that simple phosphonates, i.e., those without an additional binding site, fit also on the same straight lines. Therefore, it could be demonstrated with these reference lines that the Cu(Arm)(PME) complexes in all solvents have a higher stability than expected for a sole phosphonate Cu2+ coordination. This increased stability is attributed to the formation of 5-membered chelates involving the ether oxygen present in the – CH2– O – CH2–PO3 2- residue of PME2-. The formation degree of the 5-membered chelates in the Cu(Arm)(PME) systems varies only between about 65 and 85% in the three mentioned solvents, despite the fact that the stabilities of the Cu(Arm)(PME) complexes increase by more than 1.8 log units by going from water to 50% dioxane-water. It is concluded that (i) such 5-membered chelates will also be formed in mixed ligand complexes of other metal ions in solvents with a reduced polarity, and (ii), more importantly, that the same interactions will also occur with the parent compound of PME2-, i.e. the dianion of 9-(2-phosphonylmethoxyethyl)adenine (PMEA2-), a compound which shows antiviral properties and for which the ether oxygen is important.

Oxidation of phosphorous acid and ethyl phosphonates by permanganate

The kinetics of the permanganate oxidation of P(III) compounds (phosphorous acid, mono- and diethyl phosphonate and their anions) have been investigated at pH 0–8.3 and pH>12. Results indicate that attack of the oxidant on the PH bond is rate-determining for all substrates in both acidic and basic solutions. Deprotonation of the PH bond prior to oxidation does not take place with the exception of diethyl phosphonate at pH>7, where the reaction proceeds via two parallel pathways. Although the products of the reaction do vary with pH, they can all be derived from the same Mn(V) intermediate. There is evidence to suggest that mixed anhydride formation of the type Mn VOP III may play an essential role in the formation of the final products.

Metal‐ion‐coordinating properties of various phosphonate derivatives, including 9−[2−(phosphonylmethoxy)ethyl]adenine (PMEA) – an adenosine monophosphate (AMP) analogue with antiviral properties

AbstractThe stability constants of the 1:1 complexes formed between Mg2+, Ca2+, Sr2+, Ba2+, Mn2+, Co2+, Ni2+, Cu2+, (in part) Zn2+, or Cd2+ and (phosphonylmethoxy)ethane (PME2−) or 9−[2−(phosphonylmethoxy)ethyl]adenine (PMEA2−) were determined by potentiometric pH titration in aqueous solution (I = 0.1M, NaNO3; 25°). The experimental conditions were carefully selected such that self‐association of the adenine derivative PMEA and of its complexes was negligibly small; i.e., it was made certain that the properties of the monomeric [M(PMEA)] complexes were studied. Recent measurements with simple phosphate monoesters, R–MP2– (where R is a non‐coordinating residue; S. S. Massoud, H. Sigel, Inorg. Chem. 1988, 27, 1447), were used to show that analogously simple phosphonates (RPO) – we studied now the complexes of methyl phosphonate and ethyl phosphonate – fit on the same log K/logK vs. pK/ pK straight‐line plots. With these reference lines, it could be demonstrated that for all the [M(PME)] complexes with the mentioned metal ions an increased complex stability is measured; i.e., a stability higher than that expected for a sole phosphonate coordination of the metal ion. This increased stability is attributed to the formation of five‐membered chelates involving the ether oxygen present in the OCH2PO residue of PME2− (and PMEA2−); the formation degree of the five‐membered [M(PME)] chelates varies between ca. 15 and 40% for the alkaline earth ions and ca. 35 to 65% for 3d ions and Zn2+ or Cd2+. Interestingly, for the [M(PMEA)] complexes within the error limits exactly the same observations are made indicating that the same five‐membered chelates are formed, and that the adenine residue has no influence on the stability of these complexes, with the exception of those with Ni2+ and Cu2+. For these two metal ions, an additional stability increase is observed which has to be attributed to a metal ion‐adenine interaction giving thus rise to equilibria between three different [M(PMEA)] isomers. These equilibria are analyzed, and for [Cu(PMEA)] it is calculated that 17(±3)% exist as an isomer with a sole Cu2+‐phosphonate coordination, 34(±10)% form the mentioned five‐membered chelate involving the ether oxygen, and the remaining 49(±10)% are due to an isomer containing also a Cu2+‐adenine interaction. Based on various arguments, it is suggested that this latter isomer contains two chelate rings which result from a metal‐ion coordination to the phosphonate group, the ether oxygen, and to N(3) of the adenine residue. For [Ni(PMEA)], the isomer with a Ni2+‐adenine interaction is formed to only 22(±13)%; for [Cd(PMEA)] and the other [M(PMEA)] complexes if at all, only traces of such an isomer are occurring. In addition, the [M(PMEA)] complexes may be protonated leading to [M(H·PMEA)]+ species in which the proton is mainly at the phosphonate group, while the metal ion is bound in an adenosine‐type fashion to the nucleic base residue. Finally, the properties of [M(PMEA)] and [M(AMP)] complexes are compared, and in this connection it should be emphasized that the ether oxygen which influences so much the stability and structure of the [M(PMEA)] complexes in solution is also crucial for the antiviral properties of PMEA.

Synthesis and characterization of an organoyttrium dimer produced via an Arbuzov dealkylation reaction

The reaction of anhydrous YCl{sub 3} with 2 equiv of the sodium salt of the anionic tripod complex [({eta}{sup 5}-C{sub 5}H{sub 5})Co((CH{sub 3}CH{sub 2}O){sub 2}P=O){sub 3}]{sup -} (L{sub OEt}) in tetrahydrofuran, under anaerobic conditions, leads to the high-yield formation of [L{sub OEt}Y((C{sub 5}H{sub 5})Co(P(=O)(OEt){sub 2}){sub 2}(P(=O)(OEt)- (O))){sub 2}YL{sub OEt}] (1). The complex has been characterized by standard analytical techniques. Nuclear magnetic resonance spectroscopic studies show a reduction of local symmetry of one of the ligands. To clearly illustrate the structural features of the isolated complex in the solid state, a low-temperature data collection X-ray cryatallographic investigation was performed. This study reveals 1 to be a dimer with bridging phosphonate oxygens (monoclinic system, space group P2{sub 1}/n, with a = 12.261 (4) A b = 21.110 (5) A, c = 19.529 (5) A, {Beta} = 94.77 (2){degrees}, V = 5037 (6) A{sup 3}, Z = 2, T = 102 (2) K, and D{sub calcd} = 1.477 g/cm{sup 3}). The structure also shows that one of the phosphonate ethyl groups has been cleaved in the course of the reaction. Analysis of the volatiles generated during the reaction clearly shows the formation of ethyl chloride, indicating that 1 is produced in conjunction withmore » the elimination of a phosphonate ethyl group in an Arbuzov-type dealkylation. 19 refs., 1 fig., 3 tabs.« less

Synthesis of a highly unsaturated fatty acid moiety of lipo oligosaccharides determining host‐specificity in rhizobium

AbstractThe phosphonate ethyl 6‐(diethylphosphono)‐2E,4E‐hexadienoic acid is a suitable synthon for the highly stereoselective preparation of 2E,4E,6E,11Z‐octadecatetraenoic acid and its 2E,4E,6E‐ analog.

Synthesis of the Simple Peptide Model Ac-Abu(PO3H2)-NHMe

The simple model substrate AC-L-Abu(PO3H2)- NHMe was prepared by the use of the protected 4( diethylphosphono ) butanoic acid derivative Boc -Abu(PO3Et2)-OH in the Boc mode of solution phase peptide synthesis. The protected peptide model Ac-Abu(P03Et2)- NHMe was prepared by initial reaction of the isobutoxycarbonyl mixed anhydride of Boc-Abu(PO3Et2)-OH with N-methylamine followed by cleavage of the Boc group from Boc -Abu(PO3Et2)- NHMe with 4 M HCl/dioxan and N- acetylation of H-Abu(PO3Et2)-NHMe.HCl with the isobutoxycarbonyl mixed anhydride of acetic acid. Cleavage of the phosphonate ethyl groups was effected with 33% hydrogen bromidelacetic acid or 10% bromotrimethylsilane/acetonitrile to give AC-L-Abu(PO3H2)-NHMe in near-quantitative yield.

A Study of the Atherton–Todd Reaction Mechanism

Abstract It has been shown that alkylammonium methyl phosphonates [CH3OP(O)HO]− [NCH3R3]+ and sodium ethyl phosphonate [CH3CH2OP(O)HO]− Na+ catalyse the Atherton–Todd reaction. It has been established that the alkylammonium salts themself react with carbon tetrachloride to give chloroform, resulting in the postulate that base activation leads to the monoalkyl phosphonate anion.

New O,O‐dimethyl (2,2,2‐trichloro‐1‐carbamoyloxy)‐ethyl phosphonates and their biological activity

Abstract A series of fifteen carbamoyl derivatives of O,O‐dimethyl (2,2,2‐trichloro‐l‐hydroxy) ethyl phosphonate (trichlorphon) was synthesized. A number of them showed higher insecticidal activity, having at the same time lower toxicity than the starting biologically active structure. A waste‐free technology for the production of the more promising representatives of this series could possibly be developed in the future.

Quantification of Phosphonate and Ethyl Phosphonate in Tobacco and Tomato Tissues and Significance for the Mode of Action of Two Phosphonate Fungicides

Quantification of Phosphonate and Ethyl Phosphonate in Tobacco and Tomato Tissues and Significance for the Mode of Action of Two Phosphonate Fungicides

Quantitative Analysis of Organic Phosphonates, Phosphonate, and Other Inorganic Anions in Plants and Soil by Using High-Performance Ion Chromatography

The current analytical method for quantitation of the systemic fungicide aluminum tris-O-ethyl phosphonate (Aliette) and its anionic metabolite phosphonate (HPO3-2) in plants is extremely tedious and requires the use of both high-pressure liquid chromatography and gas-liquid chromatography. We report here a simple and improved method that employs high-performance ion chromatography, using eluent suppression and conductivity detection, to determine residues of ethyl, diethyl, and dimethyl phosphonate, as well as the inorganic anions HPO3-2, HPO4-2, NO3-, and SO4-2 in aqueous extracts of plants and soil. The method has proved sensitive, reproducible, and requires only simple sample preparation. Two types of column and eluent are employed, one for inorganic anions and the other for organic phosphonate compounds. The efficiency of aquenous extraction of ethyl phosphonate and HPO3-2 from plants is about 70%. Aqueous extraction efficiency of organic phosphonates from soil is 90%, whereas that of HPO3-2 using 0.5 M NaHCO3 is 85%. Under the conditions employed, the limits of detection of the organic phosphonates from plants and soil are 2.0 microgram/g and 5.0 microgram/g, respectively; those of HPO3-2 and other inoganic anions in plants and soil are 0.5 microgram/g and 0.2 microgram/g, respectively

A small‐scale screening technique for evaluating fungicides against Phytophthora palmivora pod rot of cocoa

SUMMARYPlots of clonal Trinitario cocoa were sprayed with fungicides in the field. Ripe pods were harvested from the trial plots and artificially inoculated with Phytophthora palmivora using various techniques, the most suitable of which proved to be the zoospore spot method. Percentage infection results from the spot inoculation tests agreed well with the field percentage infection results and it was concluded that field spraying followed by zoospore spot inoculation of detached pods is a suitable preliminary screening technique for fungicides. Three systemic fungicides metalaxyl, aluminium tris (ethyl phosphonate) and DPX‐3217 in a mixture with captafol and copper oxychloride were compared with the protectant cuprous oxide. Metalaxyl was found to be the most effective of the systemic fungicides and when applied at the rate of 0·44 g ai/ha every 8 wk it gave a similar reduction in percentage infection to 4 weekly applications of cuprous oxide at the rate of 4·4 kg Cu++/ha during the wetter part of the year when pod rot is most severe.

Anion exchange on a N-protonated 2-amino ethyl phosphonate zirconium(IV) salt

Anion exchange on a N-protonated 2-amino ethyl phosphonate zirconium(IV) salt

An assessment of fungicides for the control of wilt and die‐back caused by Phytophthora cinnamomi in container‐grown Chamaecyparis lawsoniana cv. Ellwoodii

SUMMARYIn fungitoxicity tests against Phytophthora cinnamomi on Chamaecyparis lawsoniana cv. Ellwoodii, a drench of furalaxyl (1000 mg a.i./l) applied to the compost in which 1‐yr‐old plants were growing, 1 wk before they were inoculated with 650 000 zoospores, controlled disease for at least 12 months. With an inoculum dose of 650 zoospores/plant, furalaxyl at 500 mg a.i./l controlled disease even when inoculation was 12 wk after fungicide treatment.Aluminium tris (ethyl phosphonate) (2000 mg a.i./l) applied as a drench 1 wk before inoculation with 650 000 zoospores/plant did not prevent root infection but delayed foliar symptoms for 9 months: the same treatment, using etridiazole (500 mg a.i./l) only slightly reduced disease incidence.When applied as a single drench 2 days before inoculation, prothiocarb (2000 mg a.i./l) and cuprammonium compounds (200 mg a.i./l) were much less effective than furalaxyl (1200 mg a.i./l), sodium ethyl phosphonate (1500 mg a.i./l), aluminium tris (ethyl phosphonate) (1500 mg a.i./l) or etridiazole (500 mg a.i./l).However, a drench of furalaxyl at 1000 mg a.i./l, aluminium tris (ethyl phosphonate) at 2000 mg a.i./l or etridiazole at 500 mg'a.i./l did not eradicate P. cinnamomi from compost containing infected root debris. Pre‐planting drenching of the compost was ineffective.All fungicide treatments were non‐phototoxic to 1‐yr‐old C. lawsoniana cv. Ellwoodii.These results are of special relevance to the control of P. cinnamomi on container‐grown woody ornamentals.

The suppression of Phytophthora syringae in orchard soil by furalaxyl as a means of controlling fruit rot of apple and pear

SUMMARYApple orchard soil treated with Aaterra (etridiazole), A5430 (furalaxyl), copper sulphate, LS 74–783 (aluminium tris(ethyl phosphonate)) or water in mid‐August 1977 was assayed for Phytophthora syringae by an apple fruit baiting method immediately after fungicide application and at weekly intervals for 8 wk. There was no infection of baits placed in the orchard and this was attributed to low rainfall. When wetted and baited, samples of surface soil caused from 0 to 85% fruit infection depending on the time of sampling and soil treatment. In control soil, fungus activity was low in the first 4 wk, high in the fifth wk and fluctuated widely thereafter. In samples from soils treated with Aaterra, copper sulphate or LS 74–783 activity was first apparent in the fifth wk and then fluctuated roughly in parallel with that of control soil although at generally lower levels. Changing levels of activity were apparently related to air temperature during baiting. No infection of fruits occurred in any samples from soil treated with furalaxyl. Further assays of this soil indicated a complete suppression of P. syringae to at least 10 cm soil depth. Furalaxyl is sufficiently active to be considered as a soil treatment for controlling Phytophthora fruit rot of apple and pear.

Activation of stimulus-specific serine esterases (proteases) in the initiation of platelet secretion. I. Demonstration with organophosphorus inhibitors.

The effect of organophosphorus inhibitors of serine esterases (proteases) on secretion from washed rabbit platelets was examined. Five noncytotoxic stimuli were employed: collagen, thrombin, heterologous anti-platelet antibody (in the absence of complement), rabbit C3 bound to zymosan, and platelet activating factor derived from antigen-stimulated, IgE-sensitized rabbit basophils. Diisoprophyl phosphofluoridate, three series of p-nitrophenyl ethyl phosphonates, and a series of cyclohexyl phenylalkylphosphonofluridates were all found to be inhibitory to the platelet secretion. These are irreversible inhibitors of serine proteases but in this system were only inhibitory if added to the platelets concurrently with the stimuli. Pretreatment of either the platelets or the stimuli with the inhibitors followed by washing, was without effect on the subsequent reaction. This suggested the involvement of stimulus-activatable serine proteases in the secretory process. The concept was supported by finding that nonphosphorylating phosphonates or hydrolyzed phosphonates or phosphonofluoridates were without inhibitory action. The effect of a series of phosphonates or phosphonoflouridates in inhibiting each stimulus exhibited a unique activity-structure profile. The demonstration of such unique profiles with four series of inhibitors for each of the five stimuli was interpreted as demonstrating that a specific activatable serine protease was involved in the platelet secretory response to each stimulus.

Phosphonate Inhibition of the Accumulation and Retention of K+ by Rabbit Neutrophils in Relation to Chemotaxis

Abstract The finding that the accumulation of K+ by rabbit peritoneal neutrophils is inhibited by p-nitrophenyl ethyl phosphonate esters is confirmed. This inhibition does not increase with time. Moreover, phenyl ethyl phosphonates, which are very poor inactivators of known serine esterases, inhibit K+ accumulation as efficiently as do the corresponding p-nitrophenyl ethyl phosphonates. These findings support the previous conclusion that organophosphorus inhibitors of serine esterases do not inhibit K+ accumulation of rabbit leukocytes by inactivating a serine esterase. The cell-dependent inhibition of chemotaxis of rabbit neutrophils by p-nitrophenyl ethyl phosphonates increases with time. Phenyl ethyl phosphonates do not inhibit chemotaxis but may actually enhance it. These findings indicate that the cell-dependent inhibition of chemotaxis by p-nitrophenyl ethyl phosphonates does not depend on the inhibition of K+ accumulation. They provide further support for the hypothesis that the cell-dependent inhibition of chemotaxis depends on the inhibition of an “activated esterase.” The inhibition by p-nitrophenyl ethyl phosphonates of K+ retention by rabbit neutrophils increases with time. The phenyl ethyl phosphonates are much less active in this regard. Evidence is presented that the inhibition of K+ retention probably cannot account for the cell-dependent inhibition of chemotaxis.

The requirement of serine esterase function in complement-dependent erythrophagocytosis.

The p-nitrophenyl ethyl phosphonate esters have been shown to inhibit complement-dependent erythrophagocytosis when exposed to guinea pig polymorphonuclear leukocytes prior to the initiation of phagocytosis. Inhibition of phagocytosis occurred in a manner characteristic of the well-defined capacity of phosphonate esters to inactivate serine esterases: inhibition was irreversible, dependent upon the temperature of reaction and pH of the reaction medium, and proportional to the concentration of inhibitor used and the duration of exposure between leukocytes and inhibitor. Phosphonate inhibition was further shown to be independent of any general cell damaging effects of the compounds used. The phagocytic enzyme inhibited by phosphonate esters apparently exists in or on leukocytes in an already activated state prior to the initiation of the phagocytic process. The inhibitory profile of the activated phagocytic esterase was found to be essentially identical to the profile of inhibition previously obtained for the activated chemotactic esterase of rabbit polymorphonuclear leukocytes, suggesting that the same enzyme may function in both chemotaxis and phagocytosis. Various substrates including acetate esters reported to protect the activated chemotactic esterase from inhibition by phosphonate esters did not exhibit a clear protective effect in the phagocytic system and attempts to define the relationship between the two enzymes were unsuccessful. Suggestive evidence was also obtained for the requirement of the function of a second, activatable esterase in the phagocytic process.