Salicylic acid soils

Szabo, G., Guczi, J., Bulman, R.A. (1995) Examination of silica-salicylic acid and silica-8-hydroxyquinoline HPLC stationary phases for estimation of the adsorption coefficient of soil for some aromatic hydrocarbons. Chemosphere 30, 1717-1727. 

A pure culture of Arthrobacter sp. was capable of degrading isofenphos at different soil concentrations (10, 50, and 100 ppm) in less than 6 h. In previously treated soils, isofenphos could be mineralized to carbon dioxide by indigenous microorganisms (Racke and Coats, 1987). Hydrolyzes in soil to salicylic acid (Somasundaram et al., 1991). 

It seems unlikely that the allelopathic chemicals that may be extracted from plant material are actually those that reach the host plant, yet nearly all our information on allelopathic compounds is derived from extracts that have never been exposed to the soil. Some compounds, such as juglone, may remain unchanged in the soil under some circumstances ( ), but many compounds, such as ferulic or salicylic acid, are converted to other chemicals in the soil. 

IR spectra, 469 soils, 962 structure, 471 Salt hydrates, 296 Samarium(III) complexes salicylic acid... 

Swan, T.H., Mack, Jr., E. (1925) Vapor pressures of organic crystals by an effusion method. J. Am. Chem. Soc. 47, 2112-2116. Swift, Jr., E., Hochanadel, H.P. (1945) The vapor pressure of trimethylamine from 0 to 40°C. J. Am. Chem. Soc. 67, 880-881. Szabo, G., Guczi, J., Bulman, R.A. (1995) Examination of silica-salicylic acid and silica-8-hydroxyquinoline HPLC stationary phases for estimation of the adsorption coefficient of soil for some aromatic hydrocarbons. Chemosphere 30, 1717-1727. 

Obviously, a large number of compounds would seem to fit these two definitions. (Salicylic acid and galacturonic acid, for example, would fit the solubility parameters for soil humic and fulvic acids, respectively.) However, the added restrictions of elemental analysis (see Table 1)—dark color (e.g., absorption spectra) titration data, and molecular weight—would narrow the possible chemical structures. 

There are methods, similar to the indophenol method, in which coloured products of ammonia reaction are formed in alkaline media with the use of salicylic and dichlorocyanuric acids [25], phenol, hypochlorite and nitroprusside [26], or salicylic acid, hypochlorite, and nitroprusside (e = 1.5-10" at 698 nm) [27,28], The last method has been used for determining ammonia in soils [29],... 

Nitrogen has been determined in soils and plants by the FIA technique with the use of salicylic acid, nitroprusside, and dichloroisocyanurate [56]. Nessler s method has been applied in the FIA technique [50,53,57]. 

Isofennhos. Exposure of soils to salicylic acid, the secondary hydrolysis product of isofenphos, resulted in enhanced degradation of isofenphos (Table IV). Nearly two-thirds of the applied isofenphos was converted to soil-bound residues in soil pretreated 3 and 4 times with salicylic acid. Seventy-eight percent of the applied isofenphos was recovered at the end of the 3-week incubation in the control treatment as compared with 34 to 65% in soils pretreated with salicylic acid. The ability of microbes to metabolize structurally similar compounds such as 3,5-dichlorosalicylate, 3,6-dichlorosalicylic acid (24), and 5-chlorosalicylate (25) to their benefit has been reported. The low microbial toxicity, relative availability (as discussed later in this chapter), and nutritive value of salicylic acid may contribute to its potential to condition soils for enhanced degradation of isofenphos. 

Implications of Mobility on the Availability and Degradation of Pesticides in Soil. Repeated application of 2,4-dichlorophenol, p-nitrophenol, and salicylic acid (as observed in current studies) and carbofuran phenol (20) has induced enhanced microbial degradation of their parent compounds. Rf values of these hydrolysis products indicate intermediate to high mobility in soils. The p-nitrophenol, 2,4-dichlorophenol, and salicylic acid were utilized as energy sources by microbes, and their availability in soil may contribute to the induction of rapid microbial metabolism. Carbofuran phenol did not serve as a microbial substrate but also enhanced the degradation of its parent compound, carbofuran (20). Carbofuran phenol is freely available in anaerobic soils, but the significance of its availability is yet to be understood. 

Loss and detoxification of dicamba from treated plants occur by exudation through the roots and leaves and by metabolism in the plant. The main metabolite of dicamba is 5-hydroxy-2-methoxy-3,6-dichlorobenzoic acid, which forms conjugates (Broadhurst et ai, 1966 Chang and Van den Born, 1971). Dicamba is mobile in the soil, so its leaching depends on seasonal precipitation. It is readily metabolised by microorganisms in the soil. The major metabolite is 3,6-dichloro-salicylic acid (Harris, 1967). 

Bismuth Subsalicylate. (2-Hvdroxybenzoato-O )-oxobismuth 2-hydraxybenzoic acid bismuth (3+) soil, basic bismuth salicylate, basic basic bismuth salicylate oxo(salic-ylato)bismuth salicylic acid basic bismuth salt Bismogenol "Tosse" Inj. Siabisol C,HsBiO, mol wt 362.11. C 23.22%, H 1.39%, Bi 57.72%, O 17.67%. HOC,H4COOBiO. Prepn Fischer, Griitzner. Arch. Pharm. 231, 680 (1893). 

From the cinnamic acids or phenyl propanoids described above, / -oxidation and truncation of side chains yields a variety of benzoic or simple phenolic acids [28], Rao et al., [22] identified gallic acid (18), gentisic acid (19), protocatechuic acid (20), />-hydroxybenzoic acid (21), oc-resorcyclic acid (22), vanillic acid (23) and salicylic acid (24) in C. arietinum and showed that overall, leaf content of all phenolic compounds was much greater than in roots and stem. They postulated that the production of these compounds may enhance the activity of indole acetic acid oxidase or may express antimicrobial properties when leached into the soil. However, Singh et al. [24] showed that the production of both 18 and 24 by C. arietinum was induced when treated by the culture filtrate of Sclerotium rolfsii along with the phenyl propanoids 14, 15 and 17 mentioned above. 

IR spectra, 469 soils, 962 structure, 471 Salt hydrates, 296 Samarium(III) complexes salicylic acid crystal structure, 481 Sapphyrins, 888 demetallation, 891 metallation, 891 reactions, 891 synthesis, 889 Scandium reactions... 

Iron(III) oxides, especially hematite, Fc203, were found to catalyze the oxidation of the common soil phenolic acids, sinapic acid (29), and (to a lesser extent) ferulic acid (30 Lehmann et al., 1987). Salicylic acid (31), while strongly bound by iron oxide, was resistant to oxidation (McBride, 1987). 

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