Real-Time On-Site Multielement Analysis of Environmental Waters with a Portable X-ray Fluorescence (pXRF) System.

Strict regulations are in place to control the effluents of mining sites and other industries. Heavy metal contamination of aquatic systems caused by leakages is difficult to mitigate as it takes time to detect and localize the leak. Dynamic sampling would drastically reduce the time to locate leakages and allow faster actions to reduce the impact on the environment. The present study introduces a novel portable multielement water analysis system to simultaneously measure Mn, Ni, Cu, Zn, Pb, and U in water samples from natural sources within 15 min from the sampling. The metals are preconcentrated from a 10 mL water sample into a nanoporous filter based on bisphosphonate-modified thermally carbonized porous silicon. The metals can be conveniently analyzed from the filter with a portable XRF analyzer in field conditions. The system was empirically calibrated for a lake water matrix with neutral pH and low alkaline metal concentration. A strong correlation between the XRF intensities and the ICP-MS results was obtained in a concentration range from 50 to 10 000 µg/L. With a DPO-2000C XRF analyzer, the detection limits were 103, 86, 92, 35, 44, and 43 µg/L for Mn, Ni, Cu, Zn, Pb, and U, respectively. The corresponding values with X-MET8000 Expert Geo were 137, 46, 62, 38, 29, and 54. The system was successfully validated with simulated multielement lake water samples and piloted in field conditions. The system provides an efficient way to monitor metals in environmental waters in cases where quick on-site results are needed.

Green and Efficient Esterification Method Using Dried Dowex H+/NaI Approach.

The usefulness of dried Dowex H+ cation-exchange resin with or without sodium iodide (NaI) as a catalyst system for different kinds of esterifications using carboxylic acids and alcohols as starting materials has been systematically investigated. The Dowex H+/NaI approach is very effective, generally high yielding, energy-efficient, and nontoxic, and the Dowex H+ resin is reusable. Since the whole procedure from start to product isolation is also very simple, these features make the method environmentally friendly. The method is regioselective, and its potential for separation of valuable carboxylic acids like resin acids from mixtures containing other kinds of carboxylic acids has been demonstrated. Examples for green and straightforward esterification of highly important natural amino acids are also presented.

Altered Polyamine Profiles in Colorectal Cancer.

BACKGROUND: The declining mortality rate of patients with colorectal cancer (CRC) can be explained, at least partially, with early diagnosis. Simple diagnostic methods are needed to achieve a maximal patient participation rate in screening. MATERIALS AND METHODS: Liquid chromatography electrospray tandem mass spectrometry (LC-MS/MS) was used to determine urinary polyamine (PA) profiles. In a prospective setting, 116 patients were included in the study: 57 with CRC, 13 with inflammatory bowel disease (IBD), 12 with adenoma, and 34 controls. RESULTS: N1,N12-diacetylspermine (DiAcSPM) level was significantly higher in patients with CRC than controls (sensitivity=78.0%, specificity=70.6%; p=0.00049). The level of diacetylated cadaverine (p=0.0068) was lower and that of diacetylated putrescine (p=0.0078) was higher in patients with CRC than in those with IBD. Cadaverine (p=0.00010) and spermine (p=0.042) levels were lower and that of DiAcSPM (p=0.018) higher in patients with CRC than in those with adenoma. CONCLUSION: The simultaneous determination of urinary PAs by means of LC-MS/MS can be used to discriminate CRC from controls and patients with benign colorectal diseases.

Urinary Polyamines as Biomarkers for Ovarian Cancer.

OBJECTIVES: Elevated concentrations of polyamines have been found in urine of patients with malignant tumors, including ovarian cancer. Previous research has suffered from poorly standardized detection methods. Our liquid chromatography-tandem mass spectrometry (LC-MS/MS) method is capable of simultaneous standardized analysis of most known polyamines. Liquid chromatography-tandem mass spectrometry has not previously been used in the differential diagnostics of ovarian tumors in postmenopausal women. MATERIALS AND METHODS: In this prospective study, postmenopausal women (n = 71) presenting with an adnexal mass and, as controls, women with genital prolapse or urinary incontinence scheduled for surgery (n = 22) were recruited in the study. For analysis of the polyamines, a morning urine sample was obtained before surgery. Preoperative serum CA125 concentrations were determined in the study group. RESULTS: Twenty-three women with benign and 37 with malignant ovarian tumors were eligible. Of all analyzed polyamines, only urinary N,N-diacetylspermine showed statistically significant differences between all groups except controls versus benign tumors. N,N-diacetylspermine was elevated in malignant versus benign tumors (P < 0.001), in high-grade versus low malignant potential tumors (P < 0.001), in stage III to IV versus stage I to II cancers (P < 0.001), and even in early-stage cancer (stage I-II) versus benign tumors (P = 0.017). N,N-diacetylspermine had better sensitivity (86.5%) but lower specificity (65.2%) for distinguishing benign and malignant ovarian tumors than CA125 with a cut-off value of 35 kU/L (sensitivity, 75.7%; specificity, 69.6%). CONCLUSIONS: Urinary N,N-diacetylspermine seems to be able to distinguish benign and malignant ovarian tumors as well as early and advanced stage, and low malignant potential and high-grade ovarian cancers from each other, respectively.

Advanced material and approach for metal ions removal from aqueous solutions.

A Novel approach to remove metals from aqueous solutions has been developed. The method is based on a resin free, solid, non-toxic, microcrystalline bisphosphonate material, which has very low solubility in water (59 mg/l to ion free Milli-Q water and 13 mg/l to 3.5% NaCl solution). The material has been produced almost quantitatively on a 1 kg scale (it has been prepared also on a pilot scale, ca. 7 kg) and tested successfully for its ability to collect metal cations from different sources, such as ground water and mining process waters. Not only was this material highly efficient at collecting several metal ions out of solution it also proved to be regenerable and reusable over a number of adsorption/desorption, which is crucial for environmental friendliness. This material has several advantages compared to the currently used approaches, such as no need for any precipitation step.

Quantitative metabolite profiling of edible onion species by NMR and HPLC-MS.

Allium genus is a treasure trove of valuable bioactive compounds with potentially therapeutically important properties. This work utilises HPLC-MS and a constrained total-line-shape (CTLS) approach applied to (1)H NMR spectra to quantify metabolites present in onion species to reveal important inter-species differences. Extensive differences were detected between the sugar concentrations in onion species. Yellow onion contained the highest and red onion the lowest amounts of amino acids. The main flavonol-glucosides were quercetin 3,4'-diglucoside and quercetin 4'-glucoside. In general, the levels of flavonols were, higher in yellow onions than in red onions, and garlic and leek contained a lower amount of flavonols than the other Allium species. Our results highlight how (1)H NMR together with HPLC-MS can be useful in the quantification and the identification of the most abundant metabolites, representing an efficient means to pinpoint important functional food ingredients from Allium species.

Metabolite profiling of leek (Allium porrum L) cultivars by (1) H NMR and HPLC-MS.

INTRODUCTION: Leek (Allium ampeloprasum var. porrum) is consumed as a vegetable throughout the world. However, little is known about the metabolites of leek cultivars, especially those with potentially important beneficial properties for human health. OBJECTIVE: We provide new information for the overall metabolite composition of several leek cultivars grown in Europe by using HPLC-MS and (1) H NMR. METHODS: The use of a novel CTLS/NMR (constrained total-line-shape nuclear magnetic resonance) approach was found to be capable of reliable quantification, even with overlapping metabolite signals in the (1) H NMR of plant metabolites. Additionally, a new application for leek flavonoids was optimised for HPLC-MS. RESULTS: The total concentration of carbohydrates (glucose, fructose, kestose/nystose and sucrose) and nine amino acids varied by fourfold in leek juice from different cultivars, while the total concentrations of four organic acids were similar in all cultivars. All the quantified flavonols were kaempferol derivatives or quercetin derivatives and threefold differences in flavonol concentrations were detected between cultivars. CONCLUSION: In this study, various phytochemical profiles were determined for several leek cultivars by (1) H NMR spectroscopy with CTLS combined with HPLC-MS. The wide variation in bioactive compounds among commercial leek cultivars offers promising opportunities for breeders to raise the levels of important biochemical compounds in leek breeding lines, and also provides some objective measure for quality assurance for the leek industry.

Preparation of mixed trialkyl alkylcarbonate derivatives of etidronic acid via an unusual route.

A method to prepare four (3a-d) trialkyl alkylcarbonate esters of etidronate from P,P'-dimethyl etidronate and alkyl chloroformate was developed by utilizing unexpected demethylation and decarboxylation reactions. The reaction with the sterically more hindered isobutyl chloroformate at a lower temperature (90 °C) produced the P,P'-diester (2) as a stable intermediate product. A possible reaction mechanism is discussed to explain these methyl substitutions. These unusual reactions also clarify why it is difficult to prepare alkylcarbonate prodrugs from bisphosphonates. The compounds prepared were analysed by spectroscopic techniques.

A novel and efficient method to prepare 2-aryltetrahydrofuran-2-ylphosphonic acids.

A novel one-pot method was developed for the synthesis of the title compounds starting from 4-chloro-1-aryl-1-butanones 1, phosphorus trichloride and acetic acid. The end products 2 were obtained in 20-94% yield. The cyclization step under acidic conditions probably occurs as a result of anchimeric assistance of the phosphonic acid group.

Unexpected degradation of the bisphosphonate P-C-P bridge under mild conditions.

Unexpected degradation of the P-C-P bridge from novel bisphosphonate derivative 1a and known etidronate trimethyl ester (1b) has been observed under mild reaction conditions. A proposed reaction mechanism for the unexpected degradation of 1a and 1b is also reported.

A novel strategy for the preparation of naturally occurring phosphocitrate and its partially esterified derivatives.

A novel method for the synthesis of phosphocitrate (1, PC) starting from triethyl ester of citric acid and MeOPCl2 is described. The method is based on selective stepwise hydrolysis of ester moieties from the intermediate Me-O-P(O)(Cl)(Z) (Z = triethylcitrate), 4a, which also allows one to prepare partially esterified derivatives of PC with good yield and purity without chromatographic purifications.

Synthesis of novel (1-alkanoyloxy-4-alkanoylaminobutylidene)-1,1-bisphosphonic acid derivatives.

A novel strategy for the synthesis of (1-alkanoyloxy-4-alkanoylaminobutylidene)-1,1-bisphosphonic acid derivatives (1a-d) via (1-hydroxy-4-alkanoylaminobutylidene)-1,1-bisphosphonic acid derivatives (2a-d), starting from alendronate has been developed with reasonable 51-77% overall yields. Intermediate products, (1-hydroxy-4-alkanoylaminobutylidene)-1,1-bisphosphonic acid derivatives (2a-d), were prepared in water with reasonable to high yields (52-94%).

Alpha-methyl polyamines: efficient synthesis and tolerance studies in vivo and in vitro. First evidence for dormant stereospecificity of polyamine oxidase.

Efficient syntheses of metabolically stable alpha-methylspermidine 1, alpha-methylspermine 2, and bis-alpha,alpha'-methylated spermine 3 starting from ethyl 3-aminobutyrate are described. The biological tolerance for these compounds was tested in wild-type mice and transgenic mice carrying the metallothionein promoter-driven spermidine/spermine N(1)-acetyltransferase gene (MT-SSAT). The efficient substitution of natural polyamines by their derivatives was confirmed in vivo with the rats harboring the same MT-SSAT transgene and in vitro with the immortalized fibroblasts derived from these animals. Enantiomers of previously unknown 1-amino-8-acetamido-5-azanonane dihydrochloride 4 were synthesized starting from enantiomerically pure (R)- and (S)-alaninols. The studies with recombinant human polyamine oxidase (PAO) showed that PAO (usually splits achiral substrates) strongly favors the (R)-isomer of 4 that demonstrates for the first time that the enzyme has hidden potency for stereospecificity.

Isolation and characterization of yuremamine, a new phytoindole.

Yuremamine was isolated and characterized from the stem bark of Mimosa tenuiflora. This plant is still used by indigenous peoples in North-eastern Brazil to make yurema, a psychoactive beverage that is used for medico-religious purpose ( jurema preta or vinho da jurema, in Portuguese). The characterization of this novel compound by NMR and mass spectrometry introduces a new class of phytoindoles.

Structures of bisphosphonate metal complexes: zinc and cadmium complexes of clodronate and its partial ester derivatives.

Four new zinc and cadmium bisphosphonates [{NaZn(Cl2CP2O6H)(H2O)5}]n (1), [{Cd2(Cl2CP2O6)(H2O)4}.H2O]n (2), [{Zn(Cl2CP2O6Pri2)(H2O)3}.H2O]n (3), and [{Cd2(Cl2CP2O6Pri2)2(MeOH)2(H2O)2}.H2O]2 (4) have been prepared and their crystal structures determined by single-crystal X-ray diffractometry. Two bisphosphonate ligands were used: clodronate, (dichloromethylene)bis(phosphonate) and its symmetrical P,P'-diisopropyl ester derivative. The structure of the Zn complex 1 is three-dimensional, consisting of one-dimensional Zn-clodronate chains connected to the three-dimensional network by Na+ ions. The structure of Cd complex 2 consists of double layers, and a unique bond was found between the Cd2+ cation and a Cl atom of clodronate. Zn complex 3 consists of one-dimensional chains, but the binding of the bisphosphonate ligands is unique: in 3 the bisphosphonate ligand is only bidentate. Compound 4 is a tetramer, and hydrogen bonds hold the tetramers together, forming a layered structure.

Poly[[tetraaqua(mu7-hydrogen dichloromethylenebisphosphonato)(mu5-hydrogen dichloromethylenebisphosphonato)tribarium(II)] monohydrate].

The title compound, [[Ba(3)(CHCl(2)O(6)P(2))(2)(H(2)O)(4)].H(2)O](n) or [[Ba(3)(Cl(2)CP(2)O(6)H)(H(2)O)(4)].H(2)O](n), is two-dimensional. The asymmetric unit contains three independent Ba(2+) atoms, two chelating and bridging Cl(2)CP(2)O(6)H(3-) ligands and four aqua ligands, connected in layers parallel to the (100) plane. There are pores between the layers in the direction of the b axis filled with lattice water molecules.

First synthesis of etidronate partial amides starting from PCl3.

Methods for the preparation of mixed tetra-amide esters 1 and 2, the partial amide ester 3, and tri- and P,P-diamides 4 and 5 from monophosphorus spieces 12, 8 and 9, respectively, were developed. Compounds 8 and 9 were obtained from phosphorus trichloride via MeOPCl2, which was treated with 2 eq. and 4 eq. of piperidine, followed by water or acetyl chloride, respectively. Tetrasubstituted amide bisphosphonates 1 and 2 were selectively dealkylated with lithium or silyl halide to achieve target compounds 3-5. Piperidine was found to be a good desilylation reagent. Quantum mechanical calculations illustrate why derivative 2 was produced in low yield. The usefulness of compounds 1, 3 and 4 as prodrugs of etidronate was determined in aqueous buffer and human serum.

Bisphosphonate prodrugs.

Bisphosphonates (BP) are pyrophosphate analogs having a P-C-P backbone. The oral bioavailability of BPs is ca. 1%, due to high ionisation at physiological pH. Using the prodrug approach, oral absorption can be increased by masking one or more ionizable groups (clodronate, etidronate), or using a targeting carrier system (alendronate, pamitronate).