14066-20-7

Novel compounds capable of inhibiting methionine metabolic pathway are provided. These compounds are used in inhibiting cystathionin γ-synthase (CGS) in general, and in plants, fungi and bacteria, in particular. These compounds of the invention are used as herbicides, pesticides, fungicides, agricultural plant stimulants or antimicrobial agents. The compounds of the present invention can be used for seed treatment. In particular, the compounds of the invention are used as selective herbicides, non-selective herbicides, agricultural herbicides, non-agricultural herbicides or weed killers, herbicides in integrated pest management, herbicides in gardening, herbicides in clearing waste ground, herbicides in clearing industrial or constructions sites, or herbicides in clearing railways and railway embankments.

Diffusion ordered NMR spectroscopy (DOSY NMR) is shown to be an excellent tool for observing reactive transients in the hydrolysis of the phosphatase model substrate (p-nitrophenyl)phosphate (NPP) promoted by polyoxomolybdate. The Royal Society of Chemistry.

The titration of phosphoric acid by sodium hydroxide was performed by infrared (IR) spectroscopy with the objective of obtaining the infrared spectra of the pure ionic species and determining their abundance as a function of pH. In the series of spectra, taken in the pH range of 0.18-13.4, the subtraction of neutral water, acidic water, and basic water was made. Factor analysis (FA) was then applied to the series of spectra to obtain the objective. First, we found the four most abundant species: H3PO4 (pH 0-4), H2PO4- (pH 0-9), HPO4-2 (pH 4-14), and PO4-3 (pH 9-14). Secondly, we found three complexes in small quantities: H3PO4-H2PO4- (pH 0-4), H2PO4--HPO4-2 (pH 4-9), and HPO4-2-PO4-3 (pH 9-14). The equilibrium constants of these species with the parent molecules are 0.65, 0.63, and 0.4 L/mol, respectively. Thirdly, we found residual water that was closely bound to the ionic species which formed hydrates. The pKa values obtained from the IR titration were used to obtain the theoretical concentration of the four principal species as a function of pH. The resulting distribution curve was found to be coincident with the distribution curve obtained by IR.

A kinetic study of the title reaction (i) was made in acetate buffers by estimating peroxodiphosphate (pdp) iodometrically. Silver(I) 2HnP2O8n-4 + N2H5+ → 4H2PO4- + N2 + (2n - S)H+ (i) catalysis occurs through its complexation with pdp or N2H5+. The empirical rate law (ii) holds where K3 is the acid dissociation (Equation Presented) constant of H2P2O82- and K is the complex formation constant of Ag(O2CCH3). A and B are complex rate constants equal to 3.0 × 10-4 M-1 s-1 and 1.5 × 10-2 M-1 s-1, respectively, at 40°C and I = 1.0 M. K3 was found to be 4.4 × 10-5 M under the same conditions. kuncat is the second-order rate constant for the uncatalyzed reaction and is given by (iii) where k1′ and k2′ are (Equation Presented) the rate constants for the (H2P2O82- + N2H5+) and (HP2O83- + N2H5+) reactions and were found to be 2.25 × 10-3 M-1 s-1 and 7.5 × 10-3 M-1 s-1, respectively, at 40°C and I = 1.0 M.

Oxidation of phosphite with peroxodiphosphate has been carried out in acetate buffers in the presence of silver(I).The order in peroxodiphosphate, phosphite and silver(I) is found to be one in each case and the third order rate constant (k3) at pH 4.70, I = 1.0 mol dm-3 and 65 deg C is (9.7+/-0.5) dm6 mol-2 s-1.Hydrogen-ion dependence is complicated.Values of k3 calculated at different pH values are similar to experimental values.Silver(I) catalysis operates through complex formation with peroxodiphosphate though complex formation with Ag(II) or Ag(III) cannot be ruled out.