The Experts below are selected from a list of 96 Experts worldwide ranked by ideXlab platform
Spas D Kolev - One of the best experts on this subject based on the ideXlab platform.
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LC-MS and GC-MS metabolite profiling of nickel(II) complexes in the latex of the nickel-hyperaccumulating tree Sebertia acuminata and identification of methylated Aldaric Acid as a new nickel(II) ligand.
Phytochemistry, 2008Co-Authors: Damien L Callahan, Ute Roessner, Vincent Dumontet, Nicolas Perrier, Anthony G Wedd, Richard A J O'hair, Alan J M Baker, Spas D KolevAbstract:Targeted liquid chromatography-mass spectrometry (LC-MS) technology using size exclusion chromatography and metabolite profiling based on gas chromatography-mass spectrometry (GC-MS) were used to study the nickel-rich latex of the hyperaccumulating tree Sebertia acuminata. More than 120 compounds were detected, 57 of these were subsequently identified. A methylated Aldaric Acid (2,4,5-trihydroxy-3-methoxy-1,6-hexan-dioic Acid) was identified for the first time in biological extracts and its structure was confirmed by 1D and 2D nuclear magnetic resonance (NMR) spectroscopy. After citric Acid, it appears to be one of the most abundant small organic molecules present in the latex studied. Nickel(II) complexes of stoichiometry Ni(II):Acid=1:2 were detected for these two Acids as well as for malic, itaconic, erythronic, galacturonic, tartaric, aconitic and saccharic Acids. These results provide further evidence that organic Acids may play an important role in the transport and possibly in the storage of metal ions in hyperaccumulating plants.
Erwin Dominguez - One of the best experts on this subject based on the ideXlab platform.
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analysis of hydroxycinnamic Acids derivatives in calafate berberis microphylla g forst berries by liquid chromatography with photodiode array and mass spectrometry detection
Journal of Chromatography A, 2013Co-Authors: Antonieta Ruiz, Claudia Mardones, Carola Vergara, Isidro Hermosingutierrez, Dietrich Von Baer, Patricio Hinrichsen, Roberto Rodriguez, Diego Arribillaga, Erwin DominguezAbstract:Calafate (Berberis microphylla G. Forst) is a Patagonian barberry very rich in anthocyanins and one of the fruits with the highest levels of these polyphenols. Other phenolic compounds have also been described in calafate berries. However, to the best of our knowledge there is no available information on hydroxycinnamic Acid derivatives. The complexity of hydroxycinnamic Acids determination in calafate berries, due to their structure similarities and the interference of high anthocyanin concentration is addressed by means of solid liquid extraction, followed by solid phase extraction clean-up on MCX columns and HPLC-DAD-ESI-MS/MS. The optimized extraction, clean-up and HPLC separation method allowed the assignation of identity and quantification of 20 hydroxycinnamic Acids from calafate fruits. 5-Caffeoylquinic Acid was the main compound found in all the studied samples. Other 13 hydroxycinnamoyl quinic Acids and 6 caffeic Acid esters with Aldaric Acid derivatives assigned as glucaric Acid were also identified. Moreover, the glucaric-based hydroxycinnamic Acid derivatives accounted for almost the half of total content of this kind of phenolic compounds. The total concentration of hydroxycinnamic Acids derivatives ranged between 0.32±0.00 μmol/g and 8.28±0.01 μmol/g. Effect of ripening and geographical location on hydroxycinnamic Acid profiles and concentrations are also evaluated. The methodology allows the determination of hydroxycinnamic Acids from calafate despite of the high anthocyanin concentrations, showing a much higher concentration of these Acids than other widely consumed berries. Thus suggesting that calafate could be considered a very interesting fruit from the point of view of their nutraceutical composition. However, geographical location and ripening have incidence in levels of studied compounds.
Damien L Callahan - One of the best experts on this subject based on the ideXlab platform.
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LC-MS and GC-MS metabolite profiling of nickel(II) complexes in the latex of the nickel-hyperaccumulating tree Sebertia acuminata and identification of methylated Aldaric Acid as a new nickel(II) ligand.
Phytochemistry, 2008Co-Authors: Damien L Callahan, Ute Roessner, Vincent Dumontet, Nicolas Perrier, Anthony G Wedd, Richard A J O'hair, Alan J M Baker, Spas D KolevAbstract:Targeted liquid chromatography-mass spectrometry (LC-MS) technology using size exclusion chromatography and metabolite profiling based on gas chromatography-mass spectrometry (GC-MS) were used to study the nickel-rich latex of the hyperaccumulating tree Sebertia acuminata. More than 120 compounds were detected, 57 of these were subsequently identified. A methylated Aldaric Acid (2,4,5-trihydroxy-3-methoxy-1,6-hexan-dioic Acid) was identified for the first time in biological extracts and its structure was confirmed by 1D and 2D nuclear magnetic resonance (NMR) spectroscopy. After citric Acid, it appears to be one of the most abundant small organic molecules present in the latex studied. Nickel(II) complexes of stoichiometry Ni(II):Acid=1:2 were detected for these two Acids as well as for malic, itaconic, erythronic, galacturonic, tartaric, aconitic and saccharic Acids. These results provide further evidence that organic Acids may play an important role in the transport and possibly in the storage of metal ions in hyperaccumulating plants.
Ritsuo Nishida - One of the best experts on this subject based on the ideXlab platform.
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Hydroxybenzoic Acid Derivatives in a Nonhost Rutaceous Plant, Orixa japonica, Deter Both Oviposition and Larval Feeding in a Rutaceae-Feeding Swallowtail Butterfly, Papilio xuthus L.
Journal of Chemical Ecology, 2004Co-Authors: Yasumasa Kuwahara, Ritsuo NishidaAbstract:A Rutaceae-feeding swallowtail butterfly, Papilio xuthus L., feeds on various rutaceous plants but always rejects Orixa japonica Thunb. (Rutaceae). Females were strongly deterred from laying eggs by a methanolic extract of O . japonica leaves. Larvae also rejected a diet leaf medium impregnated with O . japonica leaf extracts. Several components in the water-soluble fraction of the leaf extract were found to deter both oviposition and feeding responses. Two major deterrent compounds were characterized as 5-{[2- O -(β-D-apiofuranosyl)-β-D-glucopyranosyl]oxy}-2-hydroxybenzoic Acid and a disyringoyl Aldaric Acid. These compounds induced potent deterrence of both oviposition and larval feeding by P . xuthus , which suggests a congruent chemosensory mechanism of allomonal chemicals acting on both female tarsal chemoreceptors and larval maxillary taste receptors.
Tadahisa Iwata - One of the best experts on this subject based on the ideXlab platform.
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conformation analysis of d glucaric Acid in deuterium oxide by nmr based on its jhh and jch coupling constants
Magnetic Resonance in Chemistry, 2016Co-Authors: Yukiko Enomotorogers, Hisaharu Masaki, Tetsuya Ito, Kazuo Furihata, Tadahisa IwataAbstract:d-Glucaric Acid (GA) is an Aldaric Acid and consists of an asymmetric acyclic sugar backbone with a carboxyl group positioned at either end of its structure (i.e., the C1 and C6 positions). The purpose of this study was to conduct a conformation analysis of flexible GA as a solution in deuterium oxide by NMR spectroscopy, based on J-resolved conformation analysis using proton-proton ((3) JHH ) and proton-carbon ((2) JCH and (3) JCH ) coupling constants, as well as nuclear overhauser effect spectroscopy (NOESY). The (2) JCH and (3) JCH coupling constants were measured using the J-resolved heteronuclear multiple bond correlation (HMBC) NMR technique. NOESY correlation experiments indicated that H2 and H5 were in close proximity, despite the fact that these protons were separated by too large distance in the fully extended form of the chain structure to provide a NOESY correlation. The validities of the three possible conformers along the three different bonds (i.e., C2C3, C3C4, and C4C5) were evaluated sequentially based on the J-coupling values and the NOESY correlations. The results of these analyses suggested that there were three dominant conformers of GA, including conformer 1, which was H2H3:gauche, H3H4:anti, and H4H5:gauche; conformer 2, which was H2H3:gauche, H3H4:anti, and H4H5:anti; and conformer 3, which was H2H3:gauche, H3H4: gauche, and H4H5:anti. These results also suggested that all three of these conformers exist in equilibrium with each other. Lastly, the results of the current study suggested that the conformational structures of GA in solution were 'bent' rather than being fully extended. Copyright © 2016 John Wiley & Sons, Ltd.
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Synthesis of Crystalline and Amphiphilic Polymers from d-Glucaric Acid
ACS Sustainable Chemistry & Engineering, 2016Co-Authors: Wu Yuxin, Yukiko Enomoto-rogers, Hisaharu Masaki, Tadahisa IwataAbstract:d-Glucaric Acid (GA), an Aldaric Acid isolated from various vegetables and fruits, is an important biobased building block. Glucaric Acid acetate (GAA), which is acyclic, was synthesized in an acetic anhydride/sulfuric Acid mixture. GAA was converted to glucaric Acid chloride acetate (GACA) and then polymerized with various diols and diamines in dimethylacetamide solution or by interfacial polymerization in water and chloroform solutions. The polyesters and polyamides were amphiphilic and soluble in water and common organic solvents. The weight-average molecular weights of the polyesters were (0.4–0.7) × 103; those of the polyamides obtained by solution and interfacial polymerizations were (5.9–8.0) × 103 and (14.5–20.8) × 103, respectively. Differential scanning calorimetry showed that the polyamides were thermoplastic and melted at ca. 140 °C, indicating crystallinity; the melting points increased with increasing number of diamine alkyl carbons. Novel biobased crystalline amphiphilic polymers were synth...
