Chemical Aspects of Soil

Paul, Eldor A.; Huang, P. M.

doi:10.1007/978-3-540-38516-5_4

Cited by 4 publications

(5 citation statements)

References 15 publications

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“…Aluminum can be released from minerals to soil solutions and natural waters through chemical and biochemical weathering reactions. Both inorganic and organic ions are an integral part of the environment (Paul and Huang, 1980;Forstner, 1981;Robert and Berthelin, 1986). They are important weathering agents of primary and secondary minerals.…”

Section: Introductionmentioning

confidence: 98%

Ionic Factors Affecting Aluminum Transformations and the Impact on Soil and Environmental Sciences

Huang¹

1988

Advances in Soil Science

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Section: Introductionmentioning

confidence: 98%

Ionic Factors Affecting Aluminum Transformations and the Impact on Soil and Environmental Sciences

Huang¹

1988

Advances in Soil Science

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“…5-Fluorouracil, Fluoxetine (Prozac), Atorvastatin (Lipitor), Ciprofloxacin (Ciprobay), or Efavirenz (Sustiva and Stocrin) are representative examples of fluorine containing top-selling drugs that benefit from the aforementioned features . In addition, the excellent NMR properties of 19 F (100% natural abundance, high sensitivity) and the long half-life of the radioactive 18 F nucleus broaden the applicability of fluorinated molecules, especially in medicinal chemistry. , Despite its widespread distribution in nature, fluorine is the most abundant halogen and the 13th most abundant element in the Earth’s crust; the incorporation of fluorine in natural occurring organic molecules is very scarce mainly due to the lack of fluoroperoxidase enzymes analogous to chloro- and bromoperoxydases that account for the large number of natural products bearing other halogen atoms . For this reason, most of the known organofluorine compounds are manmade.…”

Section: Introductionmentioning

confidence: 99%

Olefin Metathesis Reactions with Fluorinated Substrates, Catalysts, and Solvents

et al. 2014

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“…Organofluorine compounds are relatively rare in nature compared with other organohalogen compounds, despite the fact that fluorine is the most abundant halogen in the Earth̓;s crust, ranking 13th in abundance of all the elements (Paul & Huang, 1980). This scarcity is attributable in part to the insoluble nature of fluorine-containing minerals which renders the element biologically unavailable.…”

Section: Introductionmentioning

confidence: 99%

“…the fact that fluorine is the most abundant halogen in the Earth's crust, ranking 13th in abundance of all the Organofluorine compounds are relatively rare in nature compared with other organohalogen compounds, despite elements (Paul & Huang, 1980). This scarcity is attributable in part to the insoluble nature of fluorinecontaining minerals which renders the element biologicall)' Unavailable.…”

Section: Introductionmentioning

confidence: 99%

Biosynthesis of fluorinated secondary metabolites by Streptomyces cattleya

et al. 1995

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The biosynthesis of organof luorine compounds by Streptomyces cattleye NRRL 8057 was examined using 19F N M R spectroscopy. The organism produced 1.2 mM fluoroacetate and 0 5 mM 4-fluorothreonine as secondary metabolites when cultured for 28 d on a chemically defined medium containing 2 mM fluoride. Cell suspensions from batch cultures harvested at the growth maximum of 4 d were not capable of fluoride uptake or fluorometabolite biosynthesis, but by 6 d had developed an efficient fluoride-uptake system and biosynthesized the two f luorometabolites in almost equal proportions. As the harvest age increased, the proportion of f luoroacetate to 4-f luorothreonine formed by cell suspensions rose progressively so that 1640ld cells showed a ratio of 76:26 for the two compounds. Fluoride uptake and fluorometabolite production by cell suspensions were highly dependent on pH, with both processes showing a maximum rate a t pH 6 9 but declining rapidly at higher pH values. This decrease was particularly marked in the case of fluoroacetate biosynthesis which was barely detectable a t pH 7.5. Fluoroacetate and 4-f luorothreonine showed only low levels of interconversion by cell suspensions, suggesting that the carbon skeleton of neither was derived by metabolism of the other. The limited interconversion observed is explicable in terms of a small degree of biological def luorination occurring with each compound, followed by reincorporation of the resulting fluoride ion into the organic form by the active fluorinating system, a phenomenon also noted on incubation of cell suspensions with a number of other fluorinated biochemical intermediates. Cell suspensions were supplemented with a variety of amino acids and tricarboxylic acid cycle intermediates to determine the identity of the carbon substrate of the fluorinating system. No compound tested significantly increased the total amount of fluorometabolites formed or altered their relative proportions. However, in studies with 14C-labelled precursors, the highest level of incorporation into f luoroacetate by cell suspensions was recorded with [U-14C]glycolate, suggesting that this compound or an activated derivative may be the substrate for the fluorinating system in the biosynthesis of f luoroacetate.

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Chemical Aspects of Soil

Cited by 4 publications

References 15 publications

Ionic Factors Affecting Aluminum Transformations and the Impact on Soil and Environmental Sciences

Ionic Factors Affecting Aluminum Transformations and the Impact on Soil and Environmental Sciences

Olefin Metathesis Reactions with Fluorinated Substrates, Catalysts, and Solvents

Biosynthesis of fluorinated secondary metabolites by Streptomyces cattleya

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