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Structural Assignment (structural + assignment)
Selected AbstractsHeterocyclic compounds from 4h -3,1-benzoxazin-4-one derivatives as anticancer agentJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 7 2005Taha M Abdel-Rahman Behaviour of 2-(4-oxo-4H -benzo[d][l,3]oxazin-2-yl)-benzoic acid (1) towards nitrogen nucleophiles namely, hydrazine hydrate, in different solvents, ammonium acetate, and o -phenylenediamine has been investigated to give aminoquinazolin-4-one, benzotriazepinone, spiro-type compound, and nitrogen bridgehead compounds 3-5, respectively. Also, reactivity of the aminoquinazolin-4-one 2 towards carbon elec-trophiles such as ethyl acetoacetate, ethyl phenylacetate, ethyl chloroacetate, and aromatic aldehydes has been discussed. Reaction of Schiff s base 8 with sulfur nucleophiles namely o -aminothiophenol and/or thio-glycolic acid afforded Michael type adducts. Structural assignments, of products 1-24 have been confirmed by elemental analysis and spectral data (1H- and 13C -NMR and MS fragmentation). The bioassay indicates that some of the target compounds obtained have good selective anticancer activity. [source] Improved sample preparation method for glycan analysis of glycoproteins by CE-LIF and CE-MSELECTROPHORESIS, Issue 8 2010Zoltan Szabo Abstract CE is a high-resolution separation technique broadly used in the biotechnology industry for carbohydrate analysis. The standard sample preparation protocol for CE analysis of glycans released from glycoproteins generally requires derivatization times of overnight at 37°C, using ,100 fold excess of fluorophore reagent, 8-aminopyrene-1,3,6-trisulfonic-acid, if the sample is unknown, or it is a regulated biotherapeutic product, possibly containing terminal sialic acid(s). In this paper, we report on significant improvements for the standard CE sample preparation method of glycan analysis. By replacing the conventionally used acetic acid catalyst with citric acid, as low as 1:10 glycan to fluorophore molar ratio (versus the typical 1:,100 ratio) maintained the >95% derivatization yield at 55°C with only 50,min reaction time. Terminal sialic acid loss was negligible at 55°C during the derivatization process, and indicating that the kinetics of labeling at 55°C was faster than the loss of sialic acid from the glycan. The reduced relative level of 8-aminopyrene-1,3,6-trisulfonic-acid simplified the removal of excess reagent, important in both CE-LIF (electrokinetic injection bias) and CE-MS (ion suppression). Coupling CE- ESI-MS confirmed that the individual peaks separated by CE corresponded to single glycans and increased the confidence of structural assignment based on glucose unit values. [source] Reactions of Di(tert -butyl)diazomethane with Acceptor-Substituted Ethylenes,HELVETICA CHIMICA ACTA, Issue 5 2007Rolf Huisgen Abstract Di(tert- butyl)diazomethane (4) is a nucleophilic 1,3-dipole with strong steric hindrance at one terminus. In its reaction with 2,3-bis(trifluoromethyl)fumaronitrile ((E)- BTE), a highly electrophilic tetra-acceptor-substituted ethene, an imino-substituted cyclopentene 9 is formed as a 1,:,2 product. The open-chain zwitterion 10, assumed as intermediate, adds the second molecule of (E)- BTE. The 19F- and 13C-NMR spectra allow the structural assignment of two diastereoisomers, 9A and 9B. The zwitterion 10 can also be intercepted by dimethyl 2,3-dicyanofumarate (11) and furnishes diastereoisomeric cyclopentenes 12A and 12B; an X-ray-analysis of 12B confirms the ,mixed' 1,:,1,:,1 product. Competing is an (E)- BTE -catalyzed decomposition of 4 to give 2,3,4,4-tetramethylpent-1-ene (7)+N2; the reaction of (E)- BTE with a trace of water appears to be responsible for the chain initiation. The H2SO4 -catalyzed decomposition of diazoalkane 4, indeed, produced the alkene 7 in high yield. The attack on the hindered diazoalkane 4 by 11 is slower than that by (E)- BTE; the zwitterionic intermediate 21 undergoes cyclization and furnishes the tetrasubstituted furan 22. In fumaronitrile, electrophilicity and steric demand are diminished, and a 1,3-cycloaddition produces the 4,5-dihydro-1H -pyrazole derivative 25. The reaction of 4 with dimethyl acetylenedicarboxylate leads to pyrazole 29+isobutene. [source] Dimerization of ionized 4-(methyl mercapto)-phenol during ESI, APCI and APPI mass spectrometryJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 9 2009Lianming Wu Abstract A novel ion/molecule reaction was observed to occur under electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI), and atmospheric pressure photo ionization (APPI) conditions, leading to dimerization of ionized 4-(methyl mercapto)-phenol followed by fast H· loss. The reaction is particularly favored during ESI, which suggests that this ion/molecule reaction can occur both in the solution inside the ESI-charged droplets and in the gas-phase environment of most other atmospheric pressure ionization techniques. The dimerization reaction is inherent to the electrolytic process during ESI, whereas it is more by ion/molecule chemistry in nature during APCI and APPI. From the tandem mass spectrometry (MS/MS) data, accurate mass measurements, hydrogen/deuterium (H/D) exchange experiments and density functional theory (DFT) calculations, two methyl sulfonium ions appear to be the most likely products of this electrophilic aromatic substitution reaction. The possible occurrence of this unexpected reaction complicates mass spectral data interpretation and can be misleading in terms of structural assignment as reported herein for 4-(methyl mercapto)-phenol. Copyright © 2009 John Wiley & Sons, Ltd. [source] Screening for Wound-induced Oxylipins in Arabidopsis thaliana by Differential HPLC-APCI/MS Profiling of Crude Leaf Extracts and Subsequent Characterisation by Capillary-scale NMRPHYTOCHEMICAL ANALYSIS, Issue 3 2008Aly Thiocone Abstract A simple non-targeted differential HPLC-APCI/MS approach has been developed in order to survey metabolome modifications that occur in the leaves of Arabidopsis thaliana following wound-induced stress. The wound-induced accumulation of metabolites, particularly oxylipins, was evaluated by HPLC-MS analysis of crude leaf extracts. A generic, rapid and reproducible pressure liquid extraction procedure was developed for the analysis of restricted leaf samples without the need for specific sample preparation. The presence of various oxylipins was determined by head-to-head comparison of the HPLC-MS data, filtered with a component detection algorithm, and automatically compared with the aid of software searching for small differences in similar HPLC-MS profiles. Repeatability was verified in several specimens belonging to different series. Wound-inducible jasmonates were efficiently highlighted by this non-targeted approach without the need for complex sample preparation as is the case for the ,oxylipin signature' procedure based on GC-MS. Furthermore this HPLC-MS screening technique allowed the isolation of induced compounds for further characterisation by capillary-scale NMR (CapNMRTM) after HPLC scale-up. In this paper, the screening method is described and applied to illustrate its potential for monitoring polar and non-polar stress-induced constituents as well as its use in combination with CapNMR for the structural assignment of wound-induced compounds of interest. Copyright © 2008 John Wiley & Sons, Ltd. [source] Polymers with benzofuro-benzofuran structures,POLYMER INTERNATIONAL, Issue 10 2002Behzad Pourabas Abstract Several kinds of molecules and also polymers are going to be discussed in the present article. Common feature in these molecules and polymers is the possessing of a specific structural part, namely benzofuro,benzofuran. This structure will appear in several molecules and kinds of polymers in the text. A condensation reaction between glyoxal and phenols is the reaction needed to produce the mentioned structural part, ie benzofuro,benzofuran. Because of the importance of this reaction, a brief historical background in the initial section of the article, and some discussion on the structural assignment of the reaction product and the reaction mechanism is also given in sections later on. Types of polymers, which are discussed in this article, are mainly heat stable polymers including polyamide, poly(ether ketone sulfone), polybenzimidazole, poly(amide-benzimidazole) and polyarylates. Polyester, polyhaydrezide and polymers with NLO property are the other kinds of the discussed polymers in the text with the benzofuro,benzofuran structure in their main chain. There is not any detailed procedure provided in the text about the synthesis of the molecules or even the polymers and the general procedures provided follow only the methodological purposes of the authors. Thermal properties of the polymers are discussed in the final section of the article with an attempt to provide a comparative argument in order to reach a relationship between structure and thermal properties. © 2001 Society of Chemical Industry. [source] Analysis of immunoglobulin glycosylation by LC-ESI-MS of glycopeptides and oligosaccharidesPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 14 2008Johannes Stadlmann Abstract Two LC-ESI-MS methods for the analysis of antibody glycosylation are presented. In the first approach, tryptic glycopeptides are separated by RP chromatography and analyzed by ESI-MS. This "glycopeptide strategy" allows a protein- and subclass-specific quantitation of both neutral and sialylated glycan structures. Additional information about under- or deglycosylation and the protein backbone, e.g., termini, can be extracted from the same data. In the second LC-ESI-MS method, released oligosaccharides are separated on porous graphitic carbon (PGC). A complete structural assignment of neutral and sialylated oligosaccharides occurring on antibodies is thereby achieved in one chromatographic run. The two methods were applied to polyclonal human IgG, to commercial mAb expressed in CHO cells (Rituximab, Xolair, and Herceptin), in SP2/0 (Erbitux and Remicade) or NS0 cells (Zenapax) and the anti-HIV antibody 4E10 produced either in CHO cells or in a human cell line. Both methods require comparably little sample preparation and can be applied to SDS-PAGE bands. They both outperform non-MS methods in terms of reliability of peak assignment and MALDI-MS of underivatized glycans with regard to the recording of sialylated structures. Regarding fast and yet detailed structural assignment, LC-MS on graphitic carbon supersedes all other current methods. [source] Ultra-performance liquid chromatography coupled to linear ion trap mass spectrometry for the identification of drug metabolites in biological samplesRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 8 2006G. J. Dear The coupling of ultra-performance liquid chromatography, operating at elevated pressures, to a linear ion trap mass spectrometer provides a high-performance system suitable for drug metabolite characterisation. This system demonstrates improved chromatographic efficiency and sensitivity and at the same time provides diagnostic MSn data often critical for metabolite structural assignment. The linear ion trap was capable of dealing with the high chromatographic efficiencies and hence narrow peak widths associated with 1.7,µm particle-packed column separations. Polarity switching and data-dependent MSn data were generated with ease, and applied to the identification of metabolites found in human plasma. Copyright © 2006 John Wiley & Sons, Ltd. [source] Mixed-Transition-Metal Acetylides: Synthesis and Characterization of Complexes with up to Six Different Transition Metals Connected by Carbon-Rich Bridging UnitsCHEMISTRY - A EUROPEAN JOURNAL, Issue 16 2008Rico Packheiser Dipl.-Chem. Abstract The synthesis and reaction chemistry of heteromultimetallic transition-metal complexes by linking diverse metal-complex building blocks with multifunctional carbon-rich alkynyl-, benzene-, and bipyridyl-based bridging units is discussed. In context with this background, the preparation of [1-{(,2 -dppf)(,5 -C5H5)RuCC}-3-{(tBu2bpy)(CO)3ReCC}-5-(PPh2)C6H3] (10) (dppf=1,1,-bis(diphenylphosphino)ferrocene; tBu2bpy=4,4,-di- tert -butyl-2,2,-bipyridyl; Ph=phenyl) is described; this complex can react further, leading to the successful synthesis of heterometallic complexes of higher nuclearity. Heterotetrametallic transition-metal compounds were formed when 10 was reacted with [{(,5 -C5Me5)RhCl2}2] (18), [(Et2S)2PtCl2] (20) or [(tht)AuCC-bpy] (24) (Me=methyl; Et=ethyl; tht=tetrahydrothiophene; bpy=2,2,-bipyridyl-5-yl). Complexes [1-{(,2 -dppf)(,5 -C5H5)RuCC}-3-{(tBu2bpy)(CO)3ReCC}-5-{PPh2RhCl2(,5 -C5Me5)}C6H3] (19), [{1-[(,2 -dppf)(,5 -C5H5)RuCC]-3-[(tBu2bpy)(CO)3ReCC]-5-(PPh2)C6H3}2PtCl2] (21), and [1-{(,2 -dppf)(,5 -C5H5)RuCC}-3-{(tBu2bpy)(CO)3ReCC}-5-{PPh2AuCC-bpy}C6H3] (25) were thereby obtained in good yield. After a prolonged time in solution, complex 25 undergoes a transmetallation reaction to produce [(tBu2bpy)(CO)3ReCC-bpy] (26). Moreover, the bipyridyl building block in 25 allowed the synthesis of Fe-Ru-Re-Au-Mo- (28) and Fe-Ru-Re-Au-Cu-Ti-based (30) assemblies on addition of [(nbd)Mo(CO)4] (27), (nbd=1,5-norbornadiene), or [{[Ti](,-,,,-CCSiMe3)2}Cu(NCMe)][PF6] (29) ([Ti]=(,5 -C5H4SiMe3)2Ti) to 25. The identities of 5, 6, 8, 10,12, 14,16, 19, 21, 25, 26, 28, and 30 have been confirmed by elemental analysis and IR, 1H, 13C{1H}, and 31P{1H} NMR spectroscopy. From selected samples ESI-TOF mass spectra were measured. The solid-state structures of 8, 12, 19 and 26 were additionally solved by single-crystal X-ray structure analysis, confirming the structural assignment made from spectroscopy. [source] A Combined ESI- and MALDI-MS(/MS) Study of Peripherally Persulfonylated Dendrimers: False Negative Results by MALDI-MS and Analysis of Defects,CHEMISTRY - A EUROPEAN JOURNAL, Issue 19 2005Thorsten Felder Dipl.-Chem. Abstract Mass spectrometry, in particular MALDI-MS, has often been used as a valuable means to characterize dendritic molecules with respect to their molecular masses. Also, it is a valuable tool for analyzing potential defects in their structure which result from incomplete synthetic steps. This article presents a comparison of ESI and MALDI mass spectrometric experiments on dendrimers persulfonylated at their periphery. While the ESI mass spectra easily permit impurities and defects to be identified and thus provide evidence for sample purity, reactions with acidic matrices occur during the MALDI process. The resulting defects are identical to those expected from incomplete substitution. Thus, in these cases, MALDI-MS yields false negative results. With mass-selected, ESI-generated ions, collision experiments were performed in an FT-ICR mass spectrometer cell to provide detailed insight into the fragmentation patterns of the various dendrimers. Different fragmentation patterns are observed depending on the exact structure of the dendrimer. Also, the nature of the charge is important. The fragmentation reactions for protonated species differ much from those binding a sodium or potassium ion. These differences can be traced back to different sites for binding H+ versus Na+ or K+. Tandem MS experiments on mass-selected dendrimer ions with defects can be used to distinguish different types of defects. A concise structural assignment can thus be made on the basis of these experiments. Even mixtures of two isobaric defect variants with the same elemental composition can be identified. Massenspektrometrie, insbesondere MALDI-MS wurde oft als wertvolle Analysenmethode für die Charakterisierung von Dendrimeren hinsichtlich ihrer Molekülmasse, aber auch hinsichtlich einer Analyse potentieller Strukturdefekte eingesetzt, die aus unvollständig verlaufenden Synthesestufen resultieren. In diesem Artikel berichten wir über einen Vergleich von ESI- und MALDI-massenspektrometrischen Experimenten mit an ihrer Peripherie persulfonylierten Dendrimeren. Während die ESI-Massenspektren eine einfache Identifizierung von Verunreinigungen und Defekten erlauben und damit eine Reinheitskontrolle ermöglichen, laufen während der Ionisierung mittels MALDI Reaktionen mit sauren Matrices ab, die genau solche Defekte erzeugen, wie man sie aus einer unvollständigen Synthese erwarten würde. MALDI-MS führt hier also zu einem falsch-negativen Ergebnis. Mit massenselektierten Ionen aus der Electrospray-Ionisierung wurden Stoßexperimente in einer FT-ICR-Zelle durchgeführt, um einen detaillierten Einblick in das Fragmentierungsmuster der verschiedenen Dendrimere zu erhalten. Man beobachtet unterschiedliche Fragmentierungsmuster in Abhängigkeit von der genauen Struktur der Dendrimere. Auch die Art der Ladung ist wichtig, da die Fragmentierungswege der protonierten Dendrimere sich deutlich von denen ihrer Na+ - und K+ -Addukte unterscheiden. Diese Unterschiede können auf unterschiedliche Bindungsstellen für H+gegenüber Na+oder K+zurückgeführt werden. Tandem MS-Experimente mit massenselektierten, strukturdefekten Dendrimer-Ionen erlauben eine genaue Unterscheidung verschiedener Typen von Defekten. Sie können daher für eine detaillierte Strukturaufklärung verwendet werden. Sogar Mischungen zweier isobarer Defektvarianten mit gleicher Elementarzusammensetzung werden zuverlässig identifiziert. [source] Structure determination of chiral sulfoxide in diastereomeric bicalutamide derivativesCHIRALITY, Issue 6 2009Wei Li Abstract We report on the synthesis and investigation of two diastereomers (5a and 5b) of a new bicalutamide analog with an asymmetric carbon atom and a chiral sulfoxide group. These bicalutamide analogs are novel androgen receptor antagonists with biological activities that depend significantly on the configuration of their stereogenic centers. We determined the absolute configuration at the SO center by combining X-ray and NMR measurements with quantum chemical calculations. Since 5a and 5b failed to yield satisfactory crystals for X-ray crystal structure determination, analogs 6a and 6b differing in only one remote functional group relative to the chiral sulfoxide were synthesized, which yielded satisfactory crystals. X-ray structure determination of 6a and 6b provided the absolute configuration at the chiral sulfoxide. Since the structural difference between 5 and 6 is remote from the chiral sulfoxide, the structural assignment was extended from the diastereomers of 6 to those of 5 provisionally. These assignments were verified with the help of measured and DFT-calculated proton and carbon NMR chemical shifts. Chirality, 2008. © 2009 Wiley-Liss, Inc. [source] Rational, Facile Synthesis and Characterization of the Neutral Mixed-Metal Organometallic Oxides Cp*2MoxW6,xO17 (Cp* = C5Me5, x = 0, 2, 4, 6)EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 34 2009Gülnur Taban-Çal Abstract The reaction of the bis(pentamethylcyclopentadienyl)pentaoxidodimetal complexes Cp*2M2O5 with four equivalents of Na2M,O4 (M, M, = Mo, W) in acidic aqueous medium constitutes a soft and selective entry into neutral Lindqvist-type organometallic mixed-metal oxides Cp*2MoxW6,xO17 [x = 6 (1), 4 (2), 2 (3), 0 (4)]. The identity of the complexes is demonstrated by elemental analyses, thermogravimetric analyses and infrared spectroscopy. Thermal degradation of 1,4 up to above 500 °C leads to Mox/6W1,x/6O3. The molecular identity and geometry of compound 2 is further confirmed by a fit of the powder X-ray diffraction pattern with a model obtained from previously reported single-crystal X-ray structures of 1 and 4, with which 2 is isomorphous. DFT calculations on models obtained by replacing Cp* with Cp (I,IV) validate the structural assignments and assist in the assignment of the M,M,,O vibrations. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Homocapsaicin: nomenclature, indexing and identificationFLAVOUR AND FRAGRANCE JOURNAL, Issue 4 2007Robert Q. Thompson Abstract The complete literature of homocapsaicin, one of the spicy principals of chilli pepper (Capsicum spp.), is reviewed and analysed. Name, structure, and topic searches in Chemical Abstracts and other relevant databases, conducted in September 2006, found 74 references to the homocapsaicin isomers. Nearly all resulted from searches on homocapsaicin or homocapsaicin I or 7-decenamide, N -[(4-hydroxy-3-methoxyphenyl)methyl]-9-methyl, (7E)-, names treated, unfortunately, as synonyms by Chemical Abstracts. A mere nine citations were linked to the 6-ene homocapsaicin isomers. Of the 74 citations, 28 did not refer to a specific homocapsaicin isomer and another 27 provided no evidence for their particular structural assignments. Consequently, the name ,homocapsaicin isomer', meaning a homocapsaicin isomer with unspecified positions of the double bond and methyl group along the acyl chain, would be a more accurate indexing term for the majority (74%) of the literature. Only nine journal articles described analytical studies with convincing evidence for the existence of specific homocapsaicin isomers. These studies found (E)-6-ene-8-methyl homocapsaicin and (E)-6-ene-9-methyl homocapsaicin, but not the (E)-7-ene-9-methyl isomer, in chilli peppers. The need, relevant to all the capsaicinoids, for new nomenclature, better indexing, more accurate identification of isomers, and available chemical standards is presented, and suggestions for improvements are made. Copyright © 2007 John Wiley & Sons, Ltd. [source] Structure determination of N -methyl-tetrahydro-5H -indazol-5-onesJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2006Kurt A. Josef This paper communicates the (regio) synthesis and a convenient NMR structural assignment method for N -methyl-tetrahydro-5H -indazol-5-one isomers. The cyclization reaction of 7-(hydroxymethylene)-1,4-dioxaspiro[4,5]decan-8-one (3) with methylhydrazine yields, after de-protection predominately the N-2 methyl isomer 2. Analysis of the product ratio and structural assignments are based on NMR data including NOE difference experiments and subsequently confirmed with X-ray crystallography. These findings are in sharp contrast with the literature. The experimental conditions used to optimize the synthesis of the individual isomers are discussed. [source] Synthesis of nitrogen-containing heterocycles 9,.JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 6 2000- a][, Preparation, ]-triazolo[, ]triazine] derivatives, carbon-carbon bond cleavage of spiro[cycloalkane[, related compounds Diaminomethylenehydrazones of cyclic ketones 1,5 reacted with ethyl N -cyanoimidate (I) at room temperature or with bis(methylthio)methylenecyanamide (II) under brief heating to give directly the corresponding spiro[cycloalkane[1,,2,,4,]triazolo[1,,5,,- a][1,,3,-5,]triazine] derivatives 7,12 in moderate to high yields. Ring-opening reaction of the spiro[cycloalkanetriazolotriazine] derivatives occurred at the cycloalkane moiety upon heating in solution to give 2-alkyl-5-amino[1,2,4]triazolotriazines 13,16. Diaminomethylenehydrazones 17,19, of hindered acyclic ketones, gave 2-methyl-7-methylthio[1,2,4]-triazolo[1,5- a][1,3,5]triazines 21,23 by the reaction with II as the main products with apparent loss of 2-methylpropane from the potential precursor, 2- tert -butyl-2-methyl-7-methylthio[1,2,4]triazolo[1,5- a]-[1,3,5]triazines 20, in good yields. In general, bis(methylthio)methylenecyanamide II was found to be a favorable reagent to the one-step synthesis of the spiro[cycloalkanetriazolotriazine] derivatives from the diaminomethylenehydrazones. The spectral data and structural assignments of the fused triazine products are discussed. [source] Tebuconazole dissipation and metabolism in Tifton loamy sand during laboratory incubation,PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 7 2004Timothy C Strickland Abstract The fungicide tebuconazole is widely used to control soil-borne and foliar diseases in peanuts and other crops. No published data are currently available on the extent and rate at which this compound degrades in soil. Unpublished data summarized in registration documents suggest that the compound is persistent, with 300,600 days half-life. We conducted a 63-day laboratory incubation to evaluate tebuconazole's dissipation kinetics and impact on soil microbial activity in Tifton loamy sand. Tifton soils support extensive peanut production in the Atlantic Coastal Plain region of Georgia and Alabama. Products containing tebuconazole are applied to an estimated 50% of the peanut acreage in the region. At the end of the incubation, 43 (±42)% of the parent compound was recovered in soil extracts. The first-order kinetic model, which gave a good fit to the dissipation data (r2 = 0.857), yielded a soil half-life (t1/2) of 49 days. This is 6,12 times more rapid than t1/2 values described in unpublished tebuconazole registration documents. Four degradates were identified. Tentative structural assignments indicated that degradates were derived from hydroxylation of the parent compound and/or chlorophenyl ring cleavage. Cleavage products showed a steady increase during the incubation, and on a molar basis were equal to 63% of the time zero tebuconazole concentration. No significant effect on soil microbial biomass was observed, indicating that when the compound is applied at normal agronomic rate it does not impact soil metabolic activity. Use of the soil-half life data derived in this study should improve the accuracy of tebuconazole fate assessments for Coastal Plain peanut production. The study also indicated that environmental assessment of selected degradates may be needed to fully evaluate risks of tebuconazole use. Published in 2004 for SCI by John Wiley & Sons, Ltd. [source] | |||||||||||||||||||||||||