Phosphorus Groups Research Articles

Substituted Esters of Coumarin-3-phosphonic Acid—Linear-Polarized IR-Spectroscopic Elucidation

Correlation between the structure and IR-spectroscopic properties of two halogen and one amino substituted esters of coumarin-3-phosphonic acid has been studied by means of linear-polarized IR-spectroscopy of oriented colloid suspensions in nematic host. The influence of the ester group on the peak positions of the IR-characteristic bands of these derivatives and in particular, on phosphorus group is investigated by a comparison with the data for corresponding coumarin-3-phosphonic acids. Theoretical quantum chemical DFT calculations (B3LYP/6-311++G**) are carried out, thus supporting the experimental assignment of the IR-bands and predicting the electronic structure of all of the compounds studied.

NMR study of the humification process during sewage sludge treatment

Humic acids, extracted from sludge at the biologic–mechanical sewage treatment plant in Jastrzebie Zdroj, have been investigated by means of 1H, 13C and 31P NMR spectroscopy. Sludge samples for studies were taken from the primary settling tank, the nitrification chamber, the digestion chamber and the sludge drying beds. The 1H NMR analysis of humic acid extracted from sludge at various stages of sewage treatment confirmed the presence of the functional groups that are characteristic for humic substances, and the analysis showed changes in their relative intensities. The 13C NMR indicated that the aromatisation of the humic acid increased during sewage treatment. Moreover, the analysis of the 31P NMR spectra allowed us to observe the changes in the phosphorus groups of the studied humic acids.

Enantioselective silicon–boron additions to cyclic 1,3-dienes catalyzed by the platinum group metal complexes

Silaborations of 1,3-cyclohexadiene and 1,3-cycloheptadiene were achieved using catalysts prepared from different combinations of phosphorus ligands and group 10 metal compounds. For the six-membered compound, 1,4-adducts with up to 82% ee were obtained employing Pt(0) and phosphoramidite ligands. For the seven-membered diene optimal conditions were found using catalysts based on Ni(0), but the highest selectivity observed was merely 22% ee. No improvement of the chiral induction was obtained using chiral silylboranes in combination with chiral phosphoramidite ligands in the additions to 1,3-cyclohexadiene. The adduct obtained from cyclohexadiene was used in allylborations of aldehydes under microwave irradiation to produce homoallylic alcohols with moderate to good diastereoselectivity.

Effects of homeopathy in mice experimentally infected with Trypanosoma cruzi

The aim of this study was to evaluate the action of homeopathic treatment on mice experimentally infected with Trypanosoma cruzi. Eighty adult male C57BL/6 inbred mice were randomly allocated to five groups treated with biotherapy (nosode) of T. cruzi 12dH (12x) pre- and post-infection; Phosphorus 12dH post-infection; infected control treated with control solution and uninfected control. The biotherapy was prepared by the Costa method from the blood of mice experimentally infected with the Y strain of T. cruzi. Phosphorus was used because of its clinical and reportorial similarity to Chagas disease. T. cruzi (10(4)) sanguineous forms were inoculated intraperitoneally per animal. Parasitaemia was monitored, leukocyte and serological responses were evaluated at 0, 7, 14 and 42 days after infection. The prepatent and patent periods of parasitaemia, maximum of parasitaemia, day of maximum parasitaemia and mortality rates were compared between groups. A significantly shorter period of patent parasitaemia was observed in the group treated with the biotherapy before infection (p<0.05) than in the other groups. This group also had the lowest parasitaemias values at 9, 13, 15 (p<0.05), 17 (p<0.05), 22, 24 and 28 days, a lower rate of mortality and a significant increase of lymphocytes compared to the infected control group. The Phosphorus group had the longest period of patent parasitaemia, higher maximum parasitaemia, and a significant reduction of lymphocyte numbers, but no mortality. The infected control group had the highest mortality rate (not statistically significant), and the highest IgG titres at 42 days post-infection (p<0.05). The results suggest that pre-treatment with biotherapy modulates host immune response to T. cruzi, mainly during the acute phase of the infection. Phosphorus shows an action on the pathogenicity by T. cruzi infection. Homeopathic treatment of T. cruzi infection should be further investigated.

Ordered Macroporous Titanium Phosphonate Materials: Synthesis, Photocatalytic Activity, and Heavy Metal Ion Adsorption

A three-dimensionally ordered macroporous titanium phosphonate material (TOP) was synthesized by an inverse opal method using 1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP). The β-cyclodextrin (β-CD)-added derivative (TOPβ) with hydroxy ethylidene groups inside the frameworks was also performed, having morphology modification and catalytic and adsorptive ability improvement. The samples were characterized by SEM, TEM, XRD, TG-DTA, FT-IR, and UV−vis absorption spectroscopy techniques. The introduced macroporous structure and the presence of the phosphorus and organic groups within the titanium phosphonate framework are believed to contribute the improvement of photocatalytic activity and heavy metal ion adsorption ability, demonstrated by the photodecomposition of Rhodamine B and the adsorption test of Cu2+, Cd2+, and Pb2+, respectively. A comparable photocatalytic activity with commercial P-25 and a selective complexation affinity for Cu2+ were observed in the synthesized hybrid materials, suggesting t...

Cationic Lipids Based on Phosphonate and Phosphoramidate Chemistry: Synthesis and Application to Gene Therapy

Cationic lipids having a phosphorus group (phosphonate or phosphoramidate) to link the lipidic part to a cationic head form an efficient family of vectors for DNA delivery. The synthesis of these types of vectors is summarized, including the recent contributions to this field.

Bis-phosphorus stabilised carbene complexes

The stabilisation of the carbene centre in a complex can be achieved either by the metal moiety or the carbon substituents. The balance between these two stabilising effects determines the nature of the M=C bond and therefore the reactivity of the metal complexes. Introducing two vicinal phosphorus groups as substituents of the carbene centre proved to be rewarding, since depending on the coordination number of this atom different electronic properties are observed. Indeed, a sigma(3)-P atom possesses a lone pair that can interact with a carbene centre by destabilising its vacant p(pi) orbital. On the contrary a sigma(4)-P group presents low lying sigma* orbitals which can be involved in delocalising electronic density in the carbene p(pi) orbital by negative hyperconjugation. Therefore, PCP carbene complexes can exhibit either an electrophilic or nucleophilic reactivity depending on the nature of the phosphorus group and the metal centre. Carbenes complexes of early and late transition metals, but also of lanthanides are discussed in this perspective.

New Polyesterimides Containing Bulky, Cyclic Phosphorus Groups

A new phosphorus-containing monomer, bis( N-hydroxyethyl-phthalimidyl)-bis(9,10-dihydro-9-oxa-10-oxide-10-phosphaphenanthrene-10-yl)methane, that contains preformed imide rings and flexible linking groups was synthesized. This compound was used to synthesize new phosphorus-containing polyesterimides by solution polycondensation with various aromatic diacide chlorides such as terephthaloyl chloride, terephthaloyl-bis-(4-oxybenzoylchloride), 4-chloroformyl- N( p-chloroformylphenyl)-phthalimide and 2,2-bis(4-chloroformyl- N-phthalimidyl)-diphenylmethane. The rates of the polycondensation reactions were calculated from kinetic investigations. The polymers were readily soluble in polar organic solvents, such as N-methylpyrrolidone, N, N-dimethylacetamide and N, N-dimethylformamide. The polymers were analytically, spectrally and thermally characterized.

Synthesis of a novel phosphorus-containing polysiloxane and its use as the modifier of thermal properties of an epoxy resin

A novel epoxy resin modifier, phosphorus-containing epoxide siloxane (PES) with pendant epoxide and cyclic phosphorus groups in the side chains of the polysiloxane backbone, was synthesized via the ring-opening reaction of epoxy siloxane (ES) with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO). 1 H NMR and FT-IR measurements were employed to characterize its chemical structure. The PES at various ratios was used to modify a bisphenol A epoxy resin (Ep828) by pre-reaction with curing agent 4,4'-diaminodiphenylmethane (DDM). The cured samples were investigated using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA) and limited oxygen index (LOI). The results showed that the epoxy resins modified with PES exhibited higher glass transition temperatures (Tg), higher initial degradation temperatures (T d 5 %) and better flame retardancy than the unmodified.

Studies on the Thermal Properties and Flame Retardancy of Epoxy Resins Modified with Polysiloxane Containing Organophosphorus and Epoxide Groups

A novel epoxy resin modifier, phosphorus-containing epoxide siloxane (PES) with pendant epoxide and cyclic phosphorus groups on the side chain of the polysiloxane backbone, was synthesized by the ring-opening reaction of epoxy-siloxane with 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO). PES was characterized by 1H NMR and FT-IR measurements, and then it was employed to modify an epoxy resin at various ratios via pre-reaction with 4, 4′-diaminodiphenyl-methane (DDM) as curing agent. In order to compare with the epoxy resins modified with PES, DOPO-containing epoxy resins also cured under the same conditions. The thermal, thermomechanical, and flame-retardant properties of all cured polymers were investigated by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), the limited oxygen index (LOI) and cone calorimetry. The results showed that the epoxy resins modified with PES exhibited much better thermal properties and flame retardancy than the DOPO-containing epoxy resins at the same phosphorus content and the neat epoxy resin.

Regiodirected phosphorylation of 2,2′,7,7′-tetrahydroxydinaphthylmethane

The phosphorylation of 2,2′,7,7′-tetrahydroxydinaphthylmethane was studied and the influence of molecule pre-organization on the regioselectivity of functionalization was investigated. The reactions of 2,2′,7,7′-tetrahydroxydinaphthylmethane with phosphorous amides containing 1–3 amide bonds gave oligophosphorylated derivatives differing in the number and the nature of phosphorus fragments and in the size of phosphorus rings: tetraphosphorus macrocycles containing one 24-membered and two eight-membered phosphorus rings, triphosphorus compounds containing a phosphocine ring and two acyclic phosphorus fragments, and tetraphosphorylated derivatives with four phosphorus groups in the molecule. The possibility of controlling the regioselectivity of phosphorylation by using reagents differing in the number and activity of P–N bonds was demonstrated.

Hypophosphatemia Observed in Chronic Myeloid Leukemia Patients Treated with Imatinib Mesylate (Gleevec®) Is Related to Digestive Side-Effects.

The therapeutic strategy in chronic myeloid leukemia (CML) has been totally modified with the development of Imatinib Mesylate (Gleevec®), a specific inhibitor of Bcr/Abl tyrosine kinase activity. However, many side-effects are reported with Gleevec, generally low grade. We report a new side-effect in patients treated with Glevec® for CML: hypophosphatemia. Between September 2001 and February 2005, 38 patients with CML were treated with Gleevec®. Thirty-four patients (18 males, 16 females) had a complete clinical and biological follow-up including into bone metabolism. Fifteen patients presenting a low level of serum phosphorus. Hyphosphatemia appeared within a median of 15 months (range: 1–47). Comparison of normal and hypophosphatemic patients did not show any statistically significant difference regarding age, treatment duration and dose of Gleevec®. Moreover, in 17 patients, we investigated the plasma level of Gleevec® as described by Mahon FX et coll. And did not find a correlation between the phosphorus level and concentration of Gleevec® (1). We next investigated phosphorus metabolism starting with digestive excretion because Gleevec® is known to induce gastro-intestinal side-effects. A multivariate analysis showed a correlation between hypophosphatemia and diarrhea (p<0.05). It suggests that the hypophosphatemia is related to digestive dysfunction. Moreover, we gave oral phosphorus supplementation for 3 months to 3 patients and failed to rescue normal phosphorus levels but exacerbated in all patients the digestive side-effects. This finding does not support interest in phosphorus supplementation.Interestingly, we observed a low cross-laps serum level in all patients, independently of their phosphatemia status. A similar observation was recently reported by Berman E and coll in 16 patients treated for gastrointestinal stromal tumors and CML (2). They suggested inhibition of the platelet-derived growth factor (PDGF) receptor b. Parathyroid hormone levels were similar in both groups and the low levels in the phosphorus group tended to correlate with an increased level of serum 1,25-dihydroxyvitamin D, but did not reach significance. This is could be in favour of an inhibition of bone remodelling by Gleevec® independently of hypophosphatemia. This suggests a possible implication of FGF23, a major regulator of phosphorus metabolism, that need to be further investigated.

New progesterone receptor antagonists: Phosphorus-containing 11β-aryl-substituted steroids

A new series of phosphorus-containing 11β-aryl-substituted steroids have been synthesized in an eight-step sequence involving a palladium-catalyzed coupling reaction to introduce a phosphorus group onto the aromatic ring. The compounds were evaluated for progesterone receptor (PR) antagonist activity in a T47D cell-based assay and for glucocorticoid receptor (GR) antagonist activity in an A549 cell-based assay. The structure–activity relationships of these compounds are discussed. Selected compounds were tested in vivo in a rat complement C3 assay.

Osteopontin Expression in Vascular Smooth Muscle Cells in Patients With End‐Stage Renal Disease

beta-glycerophosphate, a phosphate donor, and uremic sera induce osteopontin (OPN) expression in bovine vascular smooth muscle cells (VSMCs). However, the correlations of serum phosphorus level with OPN expression, and blood urea nitrogen (BUN) level with OPN expression in humans have not previously been reported. The purpose of the current study is to compare the expression of OPN in VSMCs with clinical data in patients with end-stage renal disease (ESRD). The radial arteries of 33 patients (21 male and 12 female patients) were examined to determine the expression of OPN and collagen type I (Col I) by immunohistochemistry. The correlation of the expression of bone matrix proteins with clinical data was analyzed. Between the low-serum phosphorus (<6 mg/dL) group and high-serum phosphorus (> or =6 mg/dL) group, significant differences were detected in the expression of OPN (P = 0.0049) and the levels of BUN (P = 0.0005), serum phosphorus (P < 0.0001) and calcium x phosphorus products (P < 0.0001). Moreover, between the low-BUN (<70 mg/dL, N = 19) group and high-BUN (> or =70 mg/dL) group, significant differences were detected in the expression of OPN (P = 0.0039) and the levels of BUN (P = 0.0002), serum phosphorus (P = 0.0002) and calcium x phosphorus products (P = 0.0003). We have shown that hyperphosphatemia or azotemia is associated with the expression of OPN in VSMCs in patients with ESRD.

Characterization of Active Phosphorus Surface Sites at Synthetic Carbonate-Free Fluorapatite Using Single-Pulse 1H, 31P, and 31P CP MAS NMR

The chemically active phosphorus surface sites defined as PO(x), PO(x)H, and PO(x)H2, where x = 1, 2, or 3, and the bulk phosphorus groups of PO4(3-) at synthetic carbonate-free fluorapatite (Ca5(PO4)3F) have been studied by means of single-pulse 1H,31P, and 31P CP MAS NMR. The changes in composition and relative amounts of each surface species are evaluated as a function of pH. By combining spectra from single-pulse 1H and 31P MAS NMR and data from 31P CP MAS NMR experiments at varying contact times in the range 0.2-3.0 ms, it has been possible to distinguish between resonance lines in the NMR spectra originating from active surface sites and bulk phosphorus groups and also to assign the peaks in the NMR spectra to the specific phosphorus species. In the 31P CP MAS NMR experiments, the spinning frequency was set to 4.2 kHz; in the single-pulse 1H MAS NMR experiments, the spinning frequency was 10 kHz. The 31P CP MAS NMR spectrum of fluorapatite at pH 5.9 showed one dominating resonance line at 2.9 ppm assigned to originate from PO4(3-) groups and two weaker shoulder peaks at 5.4 and 0.8 ppm which were assigned to the unprotonated PO(x) (PO, PO2-, and PO3(2-)) and protonated PO(x)H (PO2H and PO3H-) surface sites. At pH 12.7, the intensity of the peak representing unprotonated PO(x) surface sites has increased 1.7% relative to the bulk peak, while the intensity of the peaks of the protonated species PO(x)H have decreased 1.4% relative to the bulk peak. At pH 3.5, a resonance peak at -4.5 ppm has appeared in the 31P CP MAS NMR spectrum assigned to the surface species PO(x)H2 (PO3H2). The results from the 1H MAS and 31P CP MAS NMR measurements indicated that H+, OH-, and physisorbed H2O at the surface were released during the drying process at 200 degrees C.

Flame‐retarding effects of dialkyl‐p‐vinylbenzyl phosphonates in copolymers with acrylonitrile

AbstractSeveral dialkyl‐p‐vinylbenzyl phosphonates have been synthesized and free‐radically copolymerized with acrylonitrile to give copolymers with phosphorus contents ranging from 1 to 14 wt%. The flammability and thermal degradation characteristics of these copolymers have been assayed by limiting oxygen index and thermogravimetric methods. It has been found that, despite the negative effect of the vinylbenzyl entity upon the stability of polyacrylonitrile, the incorporation of a small percentage of phosphonate has a significant effect on retarding combustion of the copolymers. The differing effects of the polymerizable function (backbone group) and the pendant phosphonate on thermal stability and flame retardance are deconvoluted by comparison of the behaviours of the acrylonitrile–dialkyl‐p‐vinylbenzyl phosphonate copolymers with the corresponding acrylonitrile–styrene copolymers. The increased flammability and reduced char formation in acrylonitrile–styrene copolymers, compared with those of polyacrylonitrile itself, are shown to recover in the presence of pendant phosphorus groups, and the particular effects of these groups are discussed. Copyright © 2005 Society of Chemical Industry

Hydroxyoligophosphites and -Phosphonites on the Basis of 1,4:3,6-Dianhydro-D-sorbitol

The interaction of 1,4:3,6-dianhydro-D-sorbitol with phosphorous and phenylphosphonous acid amidochlorides leads to oligophosphites and -phosphonites with free hydroxyl groups on the periphery of their molecules. The obtained compounds were introduced into reactions via the transformation of trivalent phosphorus and hydroxyl groups.

Bone Alkaline Phosphatase besides Intact Parathyroid Hormone in Hemodialysis Patients – Any Advantage?

Background/Aim: Bone alkaline phosphatase (bAP) is known to be an important biochemical marker of bone formation. Through the present study, we intended to find out whether there is any advantage in bAP determination, as a routine biochemical marker, besides intact parathyroid hormone (iPTH) in hemodialysis patients. Methods: In a population of 140 hemodialysis patients, bAP and iPTH were determined on four quarterly consecutive occasions. According to the values of iPTH (pg/ml) and bAP (ng/ml), patients were divided into four groups: group I: iPTH >200 and bAP >20, group II: iPTH >200 and bAP <20, group III: iPTH <200 and bAP <20 and group IV: iPTH <200 and bAP >20. Patients with higher serum phosphorus (P) (group A: p ≧7 mg/dl) were compared with those with lower serum P levels (group B: p <7 mg/dl). Results: The global correlation between iPTH and bAP (total evaluations, n = 503) was 0.32 (p < 0.001). Group IV patients tended to show a slight increase of serum aluminum (sAl) levels, which were 12.48 ± 5.35 µg/l higher than in the patients from group I (sAl = 9.97 ± 4.39 µg/l), group II (sAl = 10.86 ± 4.45 µg/l) or group III (sAl = 10.92 ± 3.92 µg/l). Significance values (Mann-Whitney) in each group, in comparison with group IV, were the following: group I: 0.004; group II: 0.062; group III: <0.001. Group A (n = 66) showed higher iPTH levels than group B (n = 430), although bAP and sAl were both similar in these two groups of patients (Mann-Whitney): iPTH (A) = 631.0 ± 487.7 vs. iPTH (B) = 253.3 ± 191.6, p < 0.001; bAP (A) = 22.9 ± 17.4 vs. bAP (B) = 20.4 ± 13.1, p = n.s.; sAl (A) = 10.2 ± 3.5 vs. sAl (B) = 10.8 ± 4.4, p = n.s. For similar Al and bAP values, group A showed a much stronger iPTH/bAP correlation than group B: r = 0.67 (p < 0.001) vs. r = 0.30 (p < 0.001), respectively. Conclusion: Although iPTH and bAP are frequently in agreement, it seems important to separate parathyroid activity given by iPTH, from bone remodelling reflected by bAP, in the presence of either a higher aluminum exposition or a well-controlled phosphatemia.

Thermal degradation behaviour of aromatic poly(ester-amide) with pendant phosphorus groups investigated by pyrolysis-GC/MS

The thermal stability of a novel phosphorus-containing aromatic poly(ester-amide) ODOP-PEA was investigated by thermogravimetric analysis (TGA). The weight of ODOP-PEA fell slightly at the temperature range of 300–400 °C in the TGA analysis, and the major weight loss occurred at 500 °C. The structural identification of the volatile products resulted from the ODOP-PEA pyrolysis at different temperatures was performed by pyrolysis-gas chromatography/mass spectrometry (pyrolysis-GC/MS). The P–C bond linked between the pendant DOPO group and the polymer chain disconnected first at approximately 275 °C, indicating that it is the weakest bond in the ODOP-PEA. The P–O bond in the pendant DOPO group was stable up to 300 °C. The cleavage of the ester linkage within the polymer main chain initiated at 400 °C, and the amide bond scission occurred at greater than 400 °C. The structures of the decomposition products were used to propose the degradation processes happening during the pyrolysis of the polymer.

Synthesis and properties of novel flame retardant poly(butylene terephthalate)

The phosphorus comonomer [(6-oxido-6H-dibenz<c,e=<1,2=oxaphosphorin-6-yl)methyl]-methyl butanedioate (DOP-MBDA) was synthesized through the addition reaction of dimethyl itaconate (DMI) with 9,10-dihydro-9-oxa-10-phosphaphenan threne-10-oxide (DOP). A series of novel flame retardant poly(butylene terephthalate)s (PBTs) containing different amounts of phosphorus were prepared using DOP-MBDA as a comonomer. These novel polymers were characterized by1H-NMR, IR, and differential scanning calorimetry (DSC). The novel phosphorus-containing poly(butylene terephthalate)s, referred to as FR-PBTs, exhibited interesting thermal and mechanical behavior, as well as superior flame retardancy. These properties are attributed to the effect of incorporating the rigid structure of DOP-MBDA and the pendant phosphorus group into the poly(butylene terephthalate) (PBT) homopolymer. The UL 94-V2 rating could be achieved with this novel flame retardant PBT, which has a phosphorus content as low as 0.5 wt%, and the FR-PBTs emitted less fumes and toxic gases than the PBT homopolymer.