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Xiangru Tang - One of the best experts on this subject based on the ideXlab platform.
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Foliar application of sodium selenate induces regulation in yield formation, grain quality characters and 2-acetyl-1-Pyrroline biosynthesis in fragrant rice
BMC plant biology, 2019Co-Authors: Haowen Luo, Axiang Zheng, Shenggang Pan, Xiangru TangAbstract:Selenium (Se) is a beneficial element for higher plants and essential for mammals. To study the effect of the foliar application of sodium selenate on fragrant rice performance, a pot experiment was conducted in Guangdong, China. At the initial heading stage, one-time foliar application of sodium selenate with concentrations of 0, 10, 20, 30, 40 and 50 μmol·L− 1 (named CK, Se1, Se2, Se3, Se4 and Se5, respectively) were foliar applied on two fragrant rice varieties, ‘Meixiangzhan-2’ and ‘Xiangyaxiangzhan’. Selenate application at the initial heading stage not only improved the grain yield of fragrant rice by increasing the seed-setting rate and grain weight, but also promoted the grain quality by increasing crude protein contents and lowering the chalky rice rate. Furthermore, Se applications enhanced the biosynthesis of 2-acetyl-1- pyrroline (2-AP), the main aromatic compound, by increasing the contents of precursors (△1- pyrroline, proline and pyrroline-5-carboxylic acid (P5C)) and the activities of enzymes (proline dehydrogenase (PRODH), △1-Pyrroline-5-carboxylic acid synthetase (P5CS), and ornithine aminotransferase (OAT)) in fragrant rice. The results also showed that foliar application of sodium selenate enhanced the antioxidant system of both varieties by promoting the activities of peroxidase (POD), superoxide dismutase (SOD), catalase (CAT) and reducing the contents of malondialdehyde (MDA). Furthermore, the real-time PCR analyses depicted that foliar application of selenate up-regulated the GPX1, GPX4 and CATC transcripts. The higher antioxidative enzymatic activities might strength the stress resistant to ensure the stability of yield in fragrant rice form abiotic stress. Foliar applications of sodium selenate at the initial heading stage increased the grain 2-AP content by enhancing the biosynthesis-related enzymes and precursors. The grain yield and quality of fragrant rice also increased due to selenate application. Furthermore, foliar application of selenate promoted the activities of enzymes such as POD, SOD and CAT and up-regulated the expression of gene GPX4, GPX1 and CATC.
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Molecular basis for increased 2-acetyl-1-Pyrroline contents under alternate wetting and drying (AWD) conditions in fragrant rice.
Plant physiology and biochemistry : PPB, 2018Co-Authors: Gegen Bao, Umair Ashraf, Chunling Wang, Xiaoshan Wei, Axiang Zheng, Xiangru TangAbstract:Factors affecting rice aroma biosynthesis have been well documented previously, however the molecular mechanism lies behind the regulations in grain 2-acetyl-1-Pyrroline (2AP) biosynthesis under alternate wetting and drying (AWD) remained largely unexplored. Present study investigated the effects of three irrigation regimes i.e., conventional irrigation (CI), alternate wetting and moderate drying (WMD), and alternate wetting and severe drying (WSD) on the yield, quality traits, intermediates, enzyme activities and genes involved in 2-acetyl-1-Pyrroline biosynthesis in two fragrant rice cultivars viz, Meixiangzhan2 and Xiangyaxiangzhan. Results revealed that the levels of intermediates such as Δ1-Pyrroline-5-carboxylate (P5C) and Δ1-Pyrroline, and the activity of enzymes such as proline dehydrogenase (PRODH), Δ1-Pyrroline-5-carboxylate synthetase (P5CS), diamine oxidase (DAO), and gene expressions of PRODH, P5CS2 and DAO were comparatively higher under AWD than CI in both aromatic rice cultivars. The levels of gamma-aminobutyric acid (GABA), betaine aldehyde dehydrogenase 2 (BADH2) and BADH2 gene were lower that together led to enhanced 2-AP contents in rice grains. Moreover, WMD irrigation improved yield and yield characters, while WSD irrigation reduced yield and quality traits of rice. Overall, up-regulation of P5C and Δ1-Pyrroline and down-regulation of GABA under AWD treatments resulted in enhanced 2AP biosynthesis in both rice cultivars. Evaluation and adoption of AWD (within safe limits) at field level could be an alternative option to conventional flooded rice to get better yield and quality.
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Manganese-induced regulations in growth, yield formation, quality characters, rice aroma and enzyme involved in 2-acetyl-1-Pyrroline biosynthesis in fragrant rice
Plant physiology and biochemistry : PPB, 2016Co-Authors: Umair Ashraf, Hua Tian, Shenggang Pan, Shakeel Ahmad Anjum, Meiyang Duan, Xiangru TangAbstract:Micro-nutrient application is essential for normal plant growth while a little is known about manganese (Mn)-induced regulations in morpho-physiological attributes, aroma formation and enzyme involved in 2-acetyl-1-Pyrroline (2-AP) biosynthesis in aromatic rice. Present study aimed to examine the influence of four levels of Mn i.e., Mn1 (100 mg MnSO4 pot(-1)), Mn2 (150 mg MnSO4 pot(-1)), Mn3 (200 mg MnSO4 pot(-1)), and Mn4 (250 mg MnSO4 pot(-1)) on the growth, yield formation, quality characters, rice aroma and enzyme involved in 2-acetyl-1-Pyrroline biosynthesis in two fragrant rice cultivars i.e., Meixiangzhan and Nongxiang 18. Pots without Mn application were served as control (Ck). Each pot contained 15 kg of soil. Effects on agronomic characters, quality attributes, 2-AP contents and enzymes involved in 2-AP biosynthesis have been studied in early and late season rice. Results depicted that Mn improved rice growth, yield and related characters, and some quality attributes significantly. It further up-regulated proline, pyrroline-5-carboxylic acid (P5C) (precursors of 2-AP), soluble proteins and activities of proline dehydrogenase (ProDH), Δ(1) pyrroline-5-carboxylic acid synthetase (P5CS) ornithine aminotransferase (OAT) that led to enhanced 2-AP production in rice grains. Moreover, higher Mn levels resulted in increased grain Mn contents in both rice cultivars. Along with growth and yield improvement, Mn application significantly improved rice aromatic contents. Overall, Nongxiang 18 accumulated more 2-AP contents than Meixiangzhan in both seasons under Mn application. This study further explored the importance of Mn in rice aroma formation and signifies that micro-nutrients can play significant roles in rice aroma synthesis; however, intensive studies at molecular levels are still needed to understand the exact mechanisms of Mn to improve rice aroma formation.
Tadashi Yoshihashi - One of the best experts on this subject based on the ideXlab platform.
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Sensory test for aroma and quantitative analysis of 2-acetyl-1-Pyrroline in Asian aromatic rice varieties.
Plant Production Science, 2006Co-Authors: Nguyen Loc Hien, Tadashi Yoshihashi, Wakil Ahmad Sarhadi, Yutaka HirataAbstract:(2006). Sensory Test for Aroma and Quantitative Analysis of 2-Acetyl-1-Pyrroline in Asian Aromatic Rice Varieties. Plant Production Science: Vol. 9, No. 3, pp. 294-297.
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quantitative analysis on 2 acetyl 1 pyrroline of an aromatic rice by stable isotope dilution method and model studies on its formation during cooking
Journal of Food Science, 2002Co-Authors: Tadashi YoshihashiAbstract:A quantitative analysis of 2-acetyl-1-Pyrroline from aromatic rice samples using a stable isotope dilution method was developed. The compound was extracted from seedlings, roots, and husks at room temperature for 2 h, whereas milled or brown rice samples were extracted at 75 °C. The recovery of 2-acetyl- 1-Pyrroline was linear from 5 to 5000 ng/g with sensitivity of less than 0.1 ng/g. 2-Acetyl-1-Pyrroline showed tautomerism with an imide form. The results revealed that 2-acetyl-1-Pyrroline present in aromatic rice samples did not form during cooking or postharvest processes. Le 2-acetyl-1-Pyrroline (AcPy), apportant un arome de pop corn, est un compose de flaveur important dans le riz aromatique. Cette etude decrit le developpement d'une methode de dosage par chromatographie gazeuse - spectrometrie de masse - controle d'ion selectionne pour l'analyse de AcPy dans du riz en utilisant une methode de dilution d'isotope stable. Elle evalue aussi les effets d'un traitement thermique en tant que modele de cuisson du riz sur la formation de AcPy.
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precursors of 2 acetyl 1 pyrroline a potent flavor compound of an aromatic rice variety
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Tadashi Yoshihashi, Nguyen Thi Thu Huong, Hideo InatomiAbstract:The biological formation of a potent flavor compound, 2-acetyl-1-Pyrroline, in the aromatic rice variety (Khao Dawk Mali 105) was studied in seedlings and callus of the rice. Concentrations of 2-acetyl-1-Pyrroline were determined by GC-MS-SIM using an isotope dilution method. Increases in concentration occurred when proline, ornithine, and glutamate were present in solution, with proline increasing the concentration by more than 3-fold compared to that of the control. Results of tracer experiments using (15)N-proline, (15)N-glycine, and proline-1-(13)C indicated that the nitrogen source of 2-acetyl-1-Pyrroline was proline, whereas the carbon source of the acetyl group was not the carboxyl group of proline. 2-acetyl-1-Pyrroline was formed in the aromatic rice at temperatures below that of thermal generation in bread baking, and formed in the aerial part of aromatic rice from proline as the nitrogen precursor.
Paul Tordo - One of the best experts on this subject based on the ideXlab platform.
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detection of superoxide anion using an isotopically labeled nitrone spin trap potential biological applications
FEBS Letters, 2000Co-Authors: Hao Zhang, Paul Tordo, Joy Joseph, Jeannette Vasquezvivar, Hakim Karoui, Cline Nsanzumuhire, Pavel Martasek, Balaraman KalyanaramanAbstract:We describe the synthesis and biological applications of a novel nitrogen-15-labeled nitrone spin trap, 5-ethoxycarbonyl-5-methyl-1-Pyrroline N-oxide ([15N]EMPO) for detecting superoxide anion. Superoxide anion generated in xanthine/xanthine oxidase (100 nM min−1) and NADPH/calcium-calmodulin/nitric oxide synthase systems was readily detected using EMPO, a nitrone analog of 5,5′-dimethyl-1-Pyrroline N-oxide (DMPO). Unlike DMPO-superoxide adduct (DMPO–OOH), the superoxide adduct of EMPO (EMPO–OOH) does not spontaneously decay to the corresponding hydroxyl adduct, making spectral interpretation less confounding. Although the superoxide adduct of 5-(diethoxyphosphoryl)-5-methyl-pyrroline N-oxide is more persistent than EMPO–OOH, the electron spin resonance spectra of [14N]EMPO–OOH and [15N]EMPO–OOH are less complex and easier to interpret. Potential uses of [15N]EMPO in elucidating the mechanism of superoxide formation from nitric oxide synthases, and in ischemia/reperfusion injury are discussed.
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5 diethoxyphosphoryl 5 methyl 1 pyrroline n oxide a new efficient phosphorylated nitrone for the in vitro and in vivo spin trapping of oxygen centered radicals
Journal of Medicinal Chemistry, 1995Co-Authors: Claudine Frejaville, Beatrice Tuccio, Robert Lauricella, Marcel Culcasi, Sylvia Pietri, H Karoui, Le F Moigne, Paul TordoAbstract:5-(Diethoxyphosphoryl)-5-methyl-1-Pyrroline N-oxide (DEPMPO, 2), a new spin trap, has been synthesized via a two-step synthetic route, and its ability to spin trap oxy radicals in biological milieu has been addressed. The in vitro spin trapping of hydroxyl and superoxide radicals was investigated in a phosphate buffer 0.1 M, and the hyperfine coupling constants of the spin adducts were determined. The rates of spin trapping of hydroxyl and superoxide radicals with 2 were found to be close to those reported for 5,5-dimethyl-1-Pyrroline N-oxide (DMPO). However, the DEPMPO-superoxide spin adduct was shown to be significantly more persistent (15 times at pH 7) than the DMPO--superoxide spin adduct. Using 2 as a spin trap, the production of superoxide has been clearly characterized during the reperfusion of ischemic isolated rat hearts.
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decay of the hydroperoxyl spin adduct of 5 diethoxyphosphoryl 5 methyl 1 pyrroline n oxide an epr kinetic study
Journal of The Chemical Society-perkin Transactions 1, 1995Co-Authors: Beatrice Tuccio, Robert Lauricella, Claudine Frejaville, Jeanclaude Bouteiller, Paul TordoAbstract:The decay kinetics of the hydroperoxyl spin adduct of both 5-diethoxyphosphoryl-5-methyl-1-Pyrroline N-oxide (DEPMPO), a new β-phosphorylated cyclic nitrone and 5,5-dimethyl-1-Pyrroline N-oxide (DMPO) were studied in various media by EPR spectroscopy. In organic solvents, both first- and second-order processes were shown to contribute to the decay of the two spin adducts. However, in aqueous solution the DMPO–hydroperoxyl spin adduct decay was pure first-order. The half-lives of the two spin adducts were determined in every medium tested and the DEPMPO–hydroperoxyl spin adduct was shown to be significantly more persistent (from five times in organic solvents to 30 times in a pH 5.6 buffer) than the DMPO–hydroperoxyl spin adduct.
Shinichi Fukuzawa - One of the best experts on this subject based on the ideXlab platform.
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Silver-Catalyzed Diastereo- and Enantioselective Michael Addition and 1,3-Dipolar Cycloaddition Reactions of Imino Esters to 3‑Methyl-4-nitro-5-styrylisoxazoles
2018Co-Authors: Shuma Kato, Yuko Suzuki, Kota Suzuki, Ryosuke Haraguchi, Shinichi FukuzawaAbstract:The AgOAc/ThioClickFerrophos complex catalyzed conjugate additions and 1,3-dipolar cycloadditions of 3-methyl-4-nitro-5-styrylisoxazoles with 1-Pyrroline-5-carboxylates and glycine imino esters to give the corresponding Michael adducts and cycloadducts, respectively, in good yields with excellent diastereo- and enantioselectivities. These reactions can provide pyrroline- or pyrrolidine-containing isoxazole hybrid molecules that have potential biological and pharmaceutical activities
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copper and silver catalyzed diastereo and enantioselective conjugate addition reaction of 1 pyrroline esters to nitroalkenes diastereoselectivity switch by chiral metal complexes
Journal of Organic Chemistry, 2015Co-Authors: Akihiro Koizumi, Midori Kimura, Yuri Arai, Yuichiro Tokoro, Shinichi FukuzawaAbstract:syn-Diastereoselective conjugate addition of 1-Pyrroline esters to nitroalkenes in good yields with an excellent enantioselectivity by using CuOAc/Me-FcPHOX catalyst in the presence of pyridine. In contrast, AgOAc/tBu-ThioClickFerrophos catalyzed the anti diastereoselective conjugate addition with a high enantioselectivity without additional base. Thus, the preparation of chiral 1-Pyrroline derivatives bearing diverse stereochemistry could be achieved. The diastereoselective reduction of the imine group in the conjugate adduct could afford the 2,5-cis-proline ester derivative.
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Copper- and Silver-Catalyzed Diastereo- and Enantioselective Conjugate Addition Reaction of 1‑Pyrroline Esters to Nitroalkenes: Diastereoselectivity Switch by Chiral Metal Complexes
2015Co-Authors: Akihiro Koizumi, Midori Kimura, Yuri Arai, Yuichiro Tokoro, Shinichi FukuzawaAbstract:syn-Diastereoselective conjugate addition of 1-Pyrroline esters to nitroalkenes in good yields with an excellent enantioselectivity by using CuOAc/Me-FcPHOX catalyst in the presence of pyridine. In contrast, AgOAc/tBu-ThioClickFerrophos catalyzed the anti diastereoselective conjugate addition with a high enantioselectivity without additional base. Thus, the preparation of chiral 1-Pyrroline derivatives bearing diverse stereochemistry could be achieved. The diastereoselective reduction of the imine group in the conjugate adduct could afford the 2,5-cis-proline ester derivative
Sylvia Pietri - One of the best experts on this subject based on the ideXlab platform.
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new perspectives on the cardioprotective phosphonate effect of the spin trap 5 diethoxyphosphoryl 5 methyl 1 pyrroline n oxide an hemodynamic and 31p nmr study in rat hearts
Free Radical Biology and Medicine, 1999Co-Authors: Eziana Maurelli, Marcel Culcasi, Mariechristine Delmasbeauvieux, Malvina Miollan, Jeanlouis Gallis, Thierry Tron, Sylvia PietriAbstract:Abstract The spin trap 5-(diethoxyphosphoryl)-5-methyl-1-Pyrroline N-oxide (DEPMPO) is an improved ESR probe to assess superoxide (O 2 •− ) formation in the postischemic heart. We recently found that DEPMPO pretreatment improves recovery of cardiac function with the concomitant inhibition of postischemic O 2 •− production. By perfusing diethyl methylphosphonate MeP(O)(OEt) 2 to ischemic-reperfused isolated rat hearts, we provide hemodynamic evidence that this preservation, which exerts during ischemia, is in fact specific to the phosphonate group. Using 31 P NMR on intact rat hearts, it was also found that the “phosphonate effect” of DEPMPO is related to the preservation of ATP levels during ischemia, when compared to 5,5-dimethyl-1-Pyrroline N-oxide. This mechanism may be a means of reducing the potency of cardiac tissue to produce O 2 •− during reperfusion.
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5 diethoxyphosphoryl 5 methyl 1 pyrroline n oxide a new efficient phosphorylated nitrone for the in vitro and in vivo spin trapping of oxygen centered radicals
Journal of Medicinal Chemistry, 1995Co-Authors: Claudine Frejaville, Beatrice Tuccio, Robert Lauricella, Marcel Culcasi, Sylvia Pietri, H Karoui, Le F Moigne, Paul TordoAbstract:5-(Diethoxyphosphoryl)-5-methyl-1-Pyrroline N-oxide (DEPMPO, 2), a new spin trap, has been synthesized via a two-step synthetic route, and its ability to spin trap oxy radicals in biological milieu has been addressed. The in vitro spin trapping of hydroxyl and superoxide radicals was investigated in a phosphate buffer 0.1 M, and the hyperfine coupling constants of the spin adducts were determined. The rates of spin trapping of hydroxyl and superoxide radicals with 2 were found to be close to those reported for 5,5-dimethyl-1-Pyrroline N-oxide (DMPO). However, the DEPMPO-superoxide spin adduct was shown to be significantly more persistent (15 times at pH 7) than the DMPO--superoxide spin adduct. Using 2 as a spin trap, the production of superoxide has been clearly characterized during the reperfusion of ischemic isolated rat hearts.