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PubMed2004

Phospholidines incorporating a beta N-sulfonylaminoalcohol moiety: first observed selectivity of phosphorus heterocycle aminolysis in the presence of water.

Eleven 2-oxo or 2-thioxo 3-sulfonyl 1,3,2-oxazaphospholidines were synthesized in one step by condensing P(IV) dichlorides with N-sulfonyl-ethanolamines, or -aminothexylalcohols or -ortho-aminophenols. These compounds, in contrast to all other phosphorus heterocycles studied so far, reacted easily with amines, sometimes selectively in the presence of water, leading to the corresponding amides. The results are rationalized by the involvement of the addition-elimination mechanism of phosphorylation with direct collapse of the primary zwitterionic intermediate formed by the amine attack on phosphorus.

Amino Alcohols↗
PubMed1998

Effects of phytase supplementation on calcium and phosphorus output, production traits and mechanical stability of the tibia in broiler chickens.

A feeding trial was performed using 4 x 60 day-old chickens (Ross 208 cockerels) raised up to 42 days of age to determine whether exogenous phytase addition increases phosphorus utilisation by broiler chickens, and to assess its effects on some production traits as well as on the ash content and mechanical stability of the tibia. The chickens' feed consisted of maize, wheat, soybean meal, fish meal, yeast, and fat powder. The basic feed was supplemented with inorganic phosphorus in groups A and B. In groups C and D, the amount of the inorganic phosphorus supplement (DCP) was decreased by 50%, at the same calcium/phosphorus ratio. The 50% reduction of inorganic phosphorus supplementation represents a 20% decrease of total phosphorus. To the diets of groups B and D a phytase enzyme preparation (Phytase Novo CT) was added. The calculated exogenous phytase activity was 600 FYT/kg feed. The decrease of inorganic phosphorus did not cause significant differences in the daily weight gain but lowered the feed conversion rate by 10%. Calcium and phosphorus excretion decreased by 18% and 15%, and the breaking strength of the tibia was also lower. Phytase supplementation of the feed at a lower rate of inorganic phosphorus supplementation did not cause changes in the body weight gain but improved the feed conversion rate by 5.6%. Phosphorus and calcium output decreased by 21% and 11%, respectively, but chemical composition and mechanical stability of the tibia were unaltered.

6-Phytase↗
PubMed2004

Phosphorus purification in a paddy field watershed using a circular irrigation system and the role of iron compounds.

In a paddy field watershed using a circular irrigation system, it was clear that the watershed tended to purify phosphorus by an analysis on the mass balance of pollutants. A reasonable hypothesis was that the phosphorus precipitation with iron compounds in a river may affect the purification. To verify this, an investigation on phosphorus and iron in the river water and sediments were conducted. Total iron (T-Fe) concentration in the river ranged from 3 to 10 mg/L, and the concentration increased with the river flowing down, whereas dissolved iron (D-Fe) concentrations tended to decrease. The concentrations of total phosphorus (T-P) and phosphate phosphorus (PO4-P) also tended to decrease as the river flowing down. From the analysis of mass balance, the study watershed was considered to be a substantial iron source, having 307 and 206 kg/ha of annual outflow loads. In the sediment of the river, T-P ranged from 834 to 2440 microg/g, and most of the inorganic compound was Fe-P. In addition, The Bray No.2 phosphorus (441-1030 microg/g) was much higher than in paddy soils. Therefore, the sediment contained a large amount of phosphorus and was fertile. From the results of laboratory-based experiments, it can be said that iron compounds in the river were sufficient for the precipitation of phosphorus. Since the accumulated sediment in the river was conventionally dredged up and transported to adjacent paddy fields, it was considered to be that this operation played a significant role in phosphorus resource recycling.

Agriculture↗
PubMed2002

The gas-phase on-line production of phosphorus thiotrihalides, SPX3 and their identification by infrared spectroscopy.

A new route has been devised, leading to the production of phosphorus thiotrihalides, SPX3 where X = F, Br and I by an on-line process using phosphorus thiotrichloride, SPCl3 as starting compound gassed over the following heated salts NaF, KBr and KI at 530, 800 and 440 degrees C, respectively. The products have been characterized by their IR spectra, showing bands with PQR type structure, centered at 985, 762, 744 and 715 cm(-1). These bands are assigned to v1(a1), the S=P stretching fundamental modes of SPF3, SPCl3, SPBr3 and SPI3, respectively.

Bromides↗
PubMed1994

Spectroscopic imaging of circular voxels with a two-dimensional Fourier-series window technique.

Spatial localization with the spectroscopic imaging technique is normally implemented with the Fourier-transform approach, yielding rectangular voxels, with potentially significant cross-voxel contamination. Multidimensional Fourier-series window (FSW) is an alternate approach that generates single voxels of predetermined shape, with minimal out-of-voxel contamination. The spatial location of the voxel is shifted by means of postacquisition processing. A two-dimensional circular voxel is introduced, which for many in vivo applications is a good match of the region of interest. Phantom images illustrate the spatial distribution of signal intensity within the circular FSW voxels. Phantom spectroscopic studies show excellent spatial localization, with no detectable out-of-voxel contamination. The circular FSW voxel approach is implemented in human and animal model studies, demonstrating the technique's utility. This arbitrary shape approach can be extended to three dimensions, defining, for example, cylinders, spheres, or ellipsoids.

Adenosine Triphosphate↗
PubMed1994

Microbial cometabolism of sucralose, a chlorinated disaccharide, in environmental samples.

During the rapid mineralization in soil of sucralose (4-chloro-4-deoxy-alpha, D-Galactopyranosyl-1,6-dichloro-1,6-dideoxy-beta, D-fructofuranoside), a metabolic product was formed that appears to be the corresponding unsaturated aldehyde. During the slow and incomplete mineralization of sucralose in lake water, which was not increased by the addition of nitrogen and phosphorus, the same compound was produced. That product was further metabolized by microorganisms in lake water and soil. Mineralization was also slow in sewage under aerobic conditions, but organic products were not detected. Little or no CO2 was formed from the disaccharide in flooded soil or anaerobic sewage. Bacteria in culture did not use sucralose as a carbon source but did convert it to the presumed unsaturated aldehyde, 1,6-dichloro-1,6-dideoxy-D-fructose and possibly the uronic acid of sucralose. Sucralose carbon was not incorporated into cells of two sucralose-metabolizing bacteria or the microbial biomass of sewage or lake water. The chlorinated disaccharide was slowly metabolized by a galactose oxidase preparation. It is concluded that the chlorinated sugar is acted on microbiologically by cometabolism.

Bacteria↗
PubMed1997

Reactive Phosphonic Acids as Prebiotic Carriers of Phosphorus

Phosphonic acids are the only phosphorus-containing organic compounds detected in the Murchison meteorite. We earlier described the synthesis of methyl-, hydroxymethyl-, and 1-hydroxyethyl phosphonic acids using sodium phosphite as a source of phosphite radicals. We now show that ultraviolet irradiation of dilute aqueous solutions of acetylene in the presence of sodium phosphite leads to the synthesis of vinyl phosphonic acid. At neutral to basic pH, vinyl phosphonic acid reacts under photochemical conditions to produce phosphonoacetaldehyde and 2-hydroxyethyl phosphonic acid as the major products, as well as smaller yields of 1-hydroxyethyl phosphonic acid, phosphonoacetic acid, and ethyl phosphonic acid. Of these products, phosphonoacetaldehyde is particularly interesting as a potential precursor of prebiotic carbohydrate derivatives.

Journal Article↗
PubMed2005

Effects of PRI-2191--a low-calcemic analog of 1,25-dihydroxyvitamin D3 on the seizure-induced changes in brain gene expression and immune system activity in the rat.

Apart from the essential role of 1alpha,25-dihydroxyvitamin D3 in calcium and phosphorus metabolism, this compound and its analogs are involved in regulating the functions of the central nervous and immune systems. Active forms of vitamin D3 have been reported to stimulate neurotrophin gene expression and to prevent neuronal damage against a variety of insults. In the present study, we evaluated the effects of PRI-2191-a low-calcemic analog of 1alpha,25-dihydroxyvitamin D3 (50 ng/kg i.p., once daily for 8 days) on seizure-related neuronal degeneration, changes in some brain gene expression and immune system activity. Seizures were induced by pilocarpine (400 mg/kg; i.p.) administration. An in situ hybridization study showed that the pilocarpine-induced seizures led to time-dependent changes in the brain-derived neurotrophic factor (BDNF), heat shock protein 70 (HSP-70) and prepro-thyreoliberin (prepro-TRH) gene expression in several cortical and hippocampal regions. The maximal induction of gene expression was 3 h for BDNF and 24 h for HSP-70 and prepro-TRH; however, only in the case of prepro-TRH that effect was long-lasting. PRI-2191 alone had no effect on gene expression, but it enhanced the seizure-evoked expression of HSP-70, had an opposite effect on BDNF mRNA level and did not affect prepro-TRH mRNA level. Moreover, PRI-2191 had a moderate inhibitory effect on the seizure-related hippocampal damage in the CA1 field only. An immunological study revealed that PRI-2191 reversed the seizure-induced decrease in the proliferative activity of splenocytes and their ability to produce interferon-gamma. Summing up, the present study demonstrated that subchronic administration of PRI-2191 significantly modulated the seizure-related changes in both the brain and the peripheral immune system of rats.

Animals↗
PubMed1991

A highly sensitive chemiluminescent assay for glycerylphosphorylcholine in human seminal plasma.

Glycerylphosphorylcholine (GPC), one of the major phosphorus-containing-choline compounds of seminal plasma, is secreted mainly by the epididymal epithelium under androgenic control. This study reports a new method that uses chemiluminescence to determine seminal GPC content, comparing it with a spectrophotometric technique. The results, obtained with both techniques studying 20 fertile patients (as control), 35 infertile patients with normospermia, 23 infertile patients with oligozoospermia and impaired motility and 9 patients with excretory azoospermia, demonstrate that the GPC chemiluminescent assay is more sensitive, simple and rapid than the spectrophotometric assay. Our data confirm that GPC may be used as a marker of vas deferens and ejaculatory duct perviousness, suggesting a possible role of this glycerophosphodiester in sperm motility.

Glycerylphosphorylcholine↗
PubMed1997

Selective Reactivity of the Phosphorus-Chlorine and Carbon-Chlorine Bonds in Cyclic Chlorocarbaphosphazenes: An Unusual Activation of a Carbon-Nitrogen Bond in Trialkylamines.

Acyclic tertiary amines such as triethylamine and tri-n-propylamine used as HCl scavengers in nucleophilic substitution reactions of cyclic chlorocarbaphosphazenes [N(3)PC(2)Cl(4) (I) and N(3)P(2)CCl(5) (II)] with (CF(2))(n)()(CF(2)CH(2)OH)(2) [n = 0 (III) or 1 (IV)] are found to undergo a facile C-N bond cleavage with the regiospecific substitution of the dialkylamino groups on the ring carbon atoms of the carbaphosphazene. In the case of cyclic amines such as 1-methylpiperidine and 4-methylmorpholine, the cleavage was found to occur regiospecifically at the N-CH(3) bond, resulting in the ring substitution of the cyclic secondary amino group on the dicarbaphosphazene ring carbon atoms. The polyfluoro diol III forms a spirocyclic ring exclusively at the phosphorus site in compounds [CF(2)CH(2)O](2)PN(3)C(2)[N(C(2)H(5))(2)](2) (1), [CF(2)CH(2)O](2)PN(3)C(2)[N(C(3)H(7))(2)](2) (2), [CF(2)CH(2)O](2)PN(3)C(2)[NCH(2)(CH(2))(3)CH(2)](2) (3), and [CF(2)CH(2)O](2)PN(3)C(2)[N(CH(2))(2)O(CH(2))(2)](2) (5) along with the formation of carbon-substituted carbaphosphazenes, Cl(2)PN(3)C(2)[NCH(2)(CH(2))(3)CH(2)](2) (4) and Cl(2)PN(3)C(2)[N(CH(2))(2)O(CH(2))(2)](2) (6). Reaction of II with III in the presence of triethylamine affords the dispiro product [CF(2)CH(2)O)(2)](2)P(2)N(3)C[N(C(2)H(5))(2)] (7), which crystallizes in a polar orthorhombic space group, Cmc2(1). Upon refluxing of I or II with R(3)N (R = C(2)H(5), n-C(3)H(7)) in toluene, the amino-substituted carbaphosphazenes, Cl(2)PN(3)C(2)[N(C(2)H(5))(2)](2) (8), Cl(4)P(2)N(3)C[N(C(2)H(5))(2)] (9), and Cl(4)P(2)N(3)C[N(n-C(3)H(7))(2)] (10) are obtained in good yields. Hydrolysis of 8 leads to the formation of Cl(O)PN(H)N(2)C(2)[N(C(2)H(5))(2)](2) (11). When lithium salts of the fluoro diols III and IV are reacted with I or II in diethyl ether, the P-Cl bond is selectively substituted, yielding the spirocyclic [CF(2)CH(2)O](2)PN(3)C(2)Cl(2) (12), [CF(2)(CF(2)CH(2)O)(2)]PN(3)C(2)Cl(2) (13), [CF(2)CH(2)O](2)P(2)N(3)CCl(3) (14), and [(CF(2)CH(2)O)(2)](2)P(2)N(3)CCl (15). The C-Cl bonds in 12 and 14 were easily substituted by their reaction with 4-FC(6)H(4)XNa (X = O or S) to form [CF(2)CH(2)O](2)PN(3)C(2)[4-FC(6)H(4)O](2) (16) and [CF(2)CH(2)O](2)PN(3)C(2)[4-FC(6)H(4)S](2) (17). Reactions of 12 and 13 with (CH(3))(3)SiN(CH(3))(2) under mild conditions result in the elimination of (CH(3))(3)SiCl along with the formation of [CF(2)CH(2)O](2)PN(3)C(2)[N(CH(3))(2)](2) (18). The X-ray analyses of 13 and 18 represent the first examples of eight-membered spirocyclic phosphazenes. The thermal behavior of II, 9, 10, 14, and15 has also been investigated at 120 degrees C. Single-crystal X-ray diffraction studies were carried out for 1, 2, 7, 9-14, and 16-19, and these compounds are also characterized using IR, (1)H, (13)C, (19)F and (31)P NMR spectroscopy, MS, and elemental analysis.

Journal Article↗
PubMed2005

Chemical shift correlations in disordered solids.

We show how two-dimensional chemical shift conditional probability distributions can be extracted from experimental NMR correlation spectra of disordered solids. We show that transverse dephasing times are of central importance in determining the resolution (and sensitivity) of these probability distributions. These conditional probability distributions provide a new source of structural information characteristic of disordered solids, which is much more sensitive to structure than the individual-atom chemical shift distributions. The structural information contained in these distributions is clearly a potentially extremely rich source for understanding disorder. This is illustrated with examples of a phosphorus-containing organic compound and with a sample of disordered cellulose where the different structural allomorphs present are identified from the distributions.

Cellulose↗
PubMed2002

Diastereoselective and intramolecular cycloadditions of asymmetric p-nitroso phosphine oxides.

Benzyl phenyl P-nitroso phosphine oxide (5) reacts as an N-O heterodienophile with 1,3-cyclopentadiene to give the diastereomeric cycloadducts 6a,b in a ratio of 1.5:1 (6a:6b). The same reaction in the presence of tin tetrachloride produces 6a,b in a ratio of 2.9:1 (6a:6b). Cycloaddition of the structurally modified P-nitroso phosphine oxide (18) with 1,3-cyclopentadiene forms the diastereomeric cycloadducts 16a,b in a ratio of 3.1:1 (16a:16b). These results suggest the reactions of these P-nitroso phosphine oxides and 1,3-cyclopentadiene occur through a transition state where the heterodienophile adopts an s-cis conformation and approaches the diene in an exo fashion syn to the phenyl group. This model resembles those proposed for the cycloadditions of the structurally similar asymmetric vinyl phosphine oxides. Reaction of 18 with 1,3-cyclopentadiene in the presence of a Lewis acid produces cycloadducts 16a,b in a ratio of 7:1 (16a:16b), which approaches synthetic utility. Similar experiments show that 1,3-cyclohexadiene likely reacts with P-nitroso phosphine oxides through a different transition state, limiting current predictions regarding the diastereoselectivity of these reactions. The intramolecular cycloaddition of an asymmetric P-nitroso phosphine oxide (19) for the first time produces a unique phosphorus-containing heterocyclic compound (20).

Journal Article↗
PubMed2005

Phytoplankton community and chlorophyll a as trophic state indices of Lake Skadar (Montenegro, Balkan).

BACKGROUND, AIMS AND SCOPE: Phytoplankton, as a first step in trophic cascades of lakes, can be a good indicator of trophic states, considering that every environmental change affects this community and many species of this community are sensitive to changes, and that they response very quickly. In this study, we tried to assess and predict the trophic state of Lake Skadar according to phytoplankton data. METHODS: Water samples were collected using Ruttner sampling bottle. Temperature, dissolved oxygen, ph, conductivity and transparence were measured in situ using portable equipment. Nutrients and chlorophyll a were measured using standard spectrophotometric methods. A determination of phytoplankton species was performed using relevant keys and the counting of cells was performed using sedimentation methods. RESULTS AND DISCUSSION: The species composition of Lake Skadar revealed 95 taxa, with Chlorophyceae and Bacillariophyceae being represented best. According to an average chlorophyll a concentration of 5.9 pg/l, Lake Skadar belongs to the mesotrophic level of the trophic scale. Developed prediction equation for chlorophyll a revealed a good prediction (R2 = 0.71) and the parameter Secchi depth was primarily correlated with chlorophyll a concentration. Trophic state indices derived from chlorophyll a and transparency, were close together, but both were below the phosphorous index. Values of trophic state indices rank the Lake Skadar as being mesotrophic. This study also showed that indices of diversity based on phytoplankton are weak indicators of trophic status and that they can well characterize only differences between assemblages and associations. According to calculated saprobic indices (ranging from 1.5 to 2.15), Lake Skadar is on betamesosaprobic level of saprobity, which means that it is moderately polluted with organic compounds. CONCLUSIONS: Total phosphorus is not the main limiting factor for the phytoplankton community in Lake Skadar. Disagreements between chlorophyll and the transparency index, on the one hand, and the total phosphorus index, on the other, suggest that the phytoplankton in Lake Skadar is probably limited by other factors than phosphorus, such as nitrogen, toxic substances or intense zooplankton grazing. According to the majority of investigated parameters and indices derived from phytoplankton data, Lake Skadar is mesotrophic, with tendencies toward eutrophic levels during the summer period. RECOMMENDATIONS AND OUTLOOK: Long-term monitoring is required for a better estimation of state and the conditions of Lake Skadar. Further studies on factors influencing the phytoplankton community, especially zooplankton grazing and toxic substances, which were not included in this study, should be continued in the future to improve the efficiency of phytoplankton usage in estimating the ecological and trophic conditions of Lake Skadar.

Albania↗
PubMed1989

Chromatographic conditions for separation of 32P-labeled phosphates of major polynuclear aromatic hydrocarbon--deoxyribonucleoside adducts.

The 3'-monophosphates of the major deoxyribonucleoside adducts of five representative polynuclear aromatic hydrocarbons (PAH)-benzo[a]pyrene, benz[a]anthracene, chrysene, 5-methylchrysene and 6-methylchrysene--were prepared by reaction with DNA of the appropriate bay-region diol epoxides followed by enzymatic hydrolysis and HPLC purification. These standards were converted to 3',[32P]-5'-bisphosphates as in the Randerath 32P-postlabeling assay. TLC and HPLC systems for their separation are described. HPLC conditions for separation of the corresponding 3'- and 5'-monophosphates are also reported. These data will be useful for determining whether unknown DNA adducts detected by the 32P-postlabeling assay may have resulted from reactions of DNA with PAH diol epoxides.

DNA↗
PubMed2003

Chilling-dependent photoinhibition, nutrition and growth analysis of Eucalyptus nitens seedlings during establishment.

Effects of chilling-dependent photoinhibition on gas exchange, chlorophyll fluorescence, growth and nutrition of Eucalyptus nitens (Deane and Maiden) Maiden seedlings were assessed for 70 weeks after transplanting 9-month-old seedlings in early winter. One month before transplanting, the seedlings were assigned to fertilized or nutrient-deprived treatments. Immediately after transplanting, half the seedlings in each nutrient treatment were placed in shadecloth tree shelters. The experimental site was at an altitude of 700 m, which is considered marginal for the establishment of E. nitens plantations in Tasmania because of low mean annual minimum temperatures. Overnight frosts followed by sunny morning conditions in the first 20 weeks after transplanting (early June to early October) caused severe photoinhibition. Predawn maximal photochemical efficiency (Fv/Fm) and maximum net photosynthesis (Amax) were depressed in nutrient-deprived seedlings compared with fertilized seedlings, although shading partially alleviated this difference. Neither Fv/Fm nor Amax recovered to values observed before transplanting until > 20 weeks after transplanting. During this period, non-photochemical quenching (NPQ) was high in seedlings in all treatments, although NPQ was lower in shaded, fertilized seedlings than in seedlings in the other treatments. Total foliar nitrogen (N) concentration increased up to 42 weeks after transplanting in the nutrient-deprived seedlings in parallel with increasing relative growth rate (RGR). Fractionation of N- and phosphorus (P)-containing compounds indicated that differences in protein N accounted for the treatment differences in total seedling N. Nucleic acid P increased and inorganic P decreased during growth periods, although total seedling P remained constant. Among treated seedlings, height growth was greatest in shaded seedlings: this was probably a result of apical dominance effects because RGR was higher in unshaded seedlings than in shaded seedlings. Thus, the shade treatment alleviated chilling-dependent photoinhibition and maximized growth during winter, but limited growth during warmer periods and therefore overall growth.

Chlorophyll↗
PubMed2005

Paucibacter toxinivorans gen. nov., sp. nov., a bacterium that degrades cyclic cyanobacterial hepatotoxins microcystins and nodularin.

Thirteen bacterial isolates from lake sediment, capable of degrading cyanobacterial hepatotoxins microcystins and nodularin, were characterized by phenotypic, genetic and genomic approaches. Cells of these isolates were Gram-negative, motile by means of a single polar flagellum, oxidase-positive, weakly catalase-positive and rod-shaped. According to phenotypic characteristics (carbon utilization, fatty acid and enzyme activity profiles), the G+C content of the genomic DNA (66.1-68.0 mol%) and 16S rRNA gene sequence analysis (98.9-100% similarity) the strains formed a single microdiverse genospecies that was most closely related to Roseateles depolymerans (95.7-96.3% 16S rRNA gene sequence similarity). The isolates assimilated only a few carbon sources. Of the 96 carbon sources tested, Tween 40 was the only one used by all strains. The strains were able to mineralize phosphorus from organic compounds, and they had strong leucine arylamidase and chymotrypsin activities. The cellular fatty acids identified from all strains were C(16:0) (9.8-19%) and C(17:1)omega7c (<1-5.8%). The other predominant fatty acids comprised three groups: summed feature 3 (<1-2.2%), which included C(14:0) 3-OH and C(16:1) iso I, summed feature 4 (54-62%), which included C(16:1)omega7c and C(15:0) iso OH, and summed feature 7 (8.5-28%), which included omega7c, omega9c and omega12t forms of C(18:1). A more detailed analysis of two strains indicated that C(16:1)omega7c was the main fatty acid. The phylogenetic and phenotypic features separating our strains from recognized bacteria support the creation of a novel genus and species, for which the name Paucibacter toxinivorans gen. nov., sp. nov. is proposed. The type strain is 2C20(T) (=DSM 16998(T)=HAMBI 2767(T)=VYH 193597(T)).

Bacterial Toxins↗