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Peter Spiteller - One of the best experts on this subject based on the ideXlab platform.
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formaldehyde as a chemical defence agent of fruiting bodies of mycena rosea and its role in the generation of the alkaloid mycenarubin c
ChemBioChem, 2020Co-Authors: Rieke Himstedt, Silke Wagner, Robert J R Jaeger, Michelelaure Lieunang Watat, Jana Backenkohler, Zeljka Rupcic, Marc Stadler, Peter SpitellerAbstract:Mycenarubin C, a previously unknown red Pyrroloquinoline alkaloid, was isolated from fruiting bodies of the mushroom Mycena rosea and its structure was elucidated mainly by NMR spectroscopy and mass spectrometry. Unlike mycenarubin A, the major Pyrroloquinoline alkaloid in fruiting bodies of M. rosea, mycenarubin C, contains an eight-membered ring with an additional C1 unit that is hitherto unprecedented for Pyrroloquinoline alkaloids known in nature. Incubation of mycenarubin A with an excess of formaldehyde revealed that mycenarubin C was generated nearly quantitatively from mycenarubin A. An investigation into the formaldehyde content of fresh fruiting bodies of M. rosea showed the presence of considerable amounts of formaldehyde, with values of 5 μg per gram of fresh weight in fresh fruiting bodies. Although mycenarubin C did not show bioactivity against selected bacteria and fungi, formaldehyde inhibits the growth of the mycoparasite Spinellus fusiger at concentrations present in fruiting bodies of M. rosea. Therefore, formaldehyde might play an ecological role in the chemical defence of M. rosea against S. fusiger. In turn, S. fusiger produces gallic acid-presumably to detoxify formaldehyde by reaction of this aldehyde with amino acids and gallic acid to Mannich adducts.
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Mycenaflavin A, B, C, and D: Pyrroloquinoline Alkaloids from the Fruiting Bodies of the Mushroom Mycena haematopus.
Chemistry - A European Journal, 2018Co-Authors: Julia S. Lohmann, Silke Wagner, Monika Von Nussbaum, Anna Pulte, Wolfgang Steglich, Peter SpitellerAbstract:Four so far unknown Pyrroloquinoline alkaloids, yellow mycenaflavins A, B, and C, and the purple mycenaflavin D, have been isolated from the fruiting bodies of Mycena haematopus. The structures of these new alkaloids were elucidated by NMR spectroscopy and HRMS (ESI+ ). The mycenaflavins are structurally related to mycenarubins and haematopodins, which have been previously identified in M. haematopus. However, compared with other known fungal Pyrroloquinoline alkaloids, the mycenaflavins contain an additional double bond within the Pyrroloquinoline moiety that accounts for the yellow colour of the monomeric mycenaflavins A, B, and C. The purple mycenaflavin D is the first known dimeric Pyrroloquinoline alkaloid with a C-C bridge between the two Pyrroloquinoline units. Although the minor Pyrroloquinoline alkaloid constituent mycenaflavin A exhibits only moderate bioactivity against the soil bacterium Azoarcus tolulyticus, the major Pyrroloquinoline alkaloid constituent haematopodin B is similarly active as the antibiotic gentamicin.
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Pelianthinarubins A and B, Red Pyrroloquinoline Alkaloids from the Fruiting Bodies of the Mushroom Mycena pelianthina
Journal of Natural Products, 2016Co-Authors: Anna Pulte, Silke Wagner, Herbert Kogler, Peter SpitellerAbstract:Pelianthinarubin A (1) and pelianthinarubin B (2), two previously unknown Pyrroloquinoline alkaloids, have been isolated from fruiting bodies of Mycena pelianthina. The structures of these alkaloids have been deduced from their HR-(+)-ESIMS and 2D NMR data. The absolute configurations of the pelianthinarubins A (1) and B (2) were assigned by analysis of the NOE correlations and coupling constants and by comparison of the CD spectra of 1 and 2 and of hercynine obtained by degradation of 1 with suitable compounds of known absolute configuration. The pelianthinarubins A (1) and B (2), which contain an S-hercynine moiety, differ considerably from the known Pyrroloquinoline alkaloids from marine organisms and other Mycena species, such as the mycenarubins, the haematopodins, and the sanguinones.
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Cover Picture: Mycenarubins A and B, Red Pyrroloquinoline Alkaloids from the Mushroom Mycena rosea (Eur. J. Org. Chem. 10/2007)
European Journal of Organic Chemistry, 2007Co-Authors: Silke Peters, Peter SpitellerAbstract:The cover picture shows the mushroom Mycena rosea whose fruiting bodies contain two new red Pyrroloquinoline alkaloids named mycenarubin A and B. So far, Pyrroloquinoline alkaloids are mainly known from marine sources. The new secondary metabolites have been detected by means of a comparative HPLC profiling of the fruiting bodies and the mycelial cultures. The absolute configuration of the mycenarubins was established by a stereoselective synthesis of the model compound (S)-4-carboxydamirone C and comparison of its CD spectrum with the CD spectra of the mycenarubins. Details are discussed in the article by S. Peters and P. Spiteller on p. 1571 ff.
Kazuo Nagasawa - One of the best experts on this subject based on the ideXlab platform.
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a tandem friedel crafts based method for the construction of a tricyclic Pyrroloquinoline skeleton and its application in the synthesis of ammosamide b
ChemInform, 2013Co-Authors: Yohei Takayama, Tatsuya Yamada, Shinya Tatekabe, Kazuo NagasawaAbstract:A tandem intramolecular Friedel—Crafts reaction sequence of substrate (I) leads to the desired tricyclic Pyrroloquinoline (II) as major product (low yield is due to the insolubility of the product during purification), which is used as a key intermediate in the total synthesis of ammosamide B (V).
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A tandem Friedel-Crafts based method for the construction of a tricyclic Pyrroloquinoline skeleton and its application in the synthesis of ammosamide B.
Chemical Communications, 2013Co-Authors: Yohei Takayama, Tatsuya Yamada, Shinya Tatekabe, Kazuo NagasawaAbstract:A total synthesis of ammosamide B (2), a member of the Pyrroloquinoline alkaloid family isolated from marine Streptomyces, is described. The characteristic core tricyclic structure of 2 was constructed using a novel, tandem Friedel–Crafts reaction sequence to transform the symmetric tetra-amino substituted benzene derivative 7 into the tricyclic Pyrroloquinoline product 8, which serves as an important intermediate in the route to the synthesis of the target natural product.
Tadafumi Kato - One of the best experts on this subject based on the ideXlab platform.
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Is Pyrroloquinoline quinone a vitamin? (Reply)
Nature, 2005Co-Authors: Takaoki Kasahara, Tadafumi KatoAbstract:Kasahara and Kato reply - Our announcement^ 1 that the redox cofactor Pyrroloquinoline quinone (PQQ) is a new vitamin has been challenged as being premature by Felton and Anthony ^ 2 and by Rucker et al .^ 3 .
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Biochemistry: Is Pyrroloquinoline quinone a vitamin? (Reply)
Nature, 2005Co-Authors: Takaoki Kasahara, Tadafumi KatoAbstract:Kasahara and Kato reply - Our announcement1 that the redox cofactor Pyrroloquinoline quinone (PQQ) is a new vitamin has been challenged as being premature by Felton and Anthony 2 and by Rucker .3.
Yohei Takayama - One of the best experts on this subject based on the ideXlab platform.
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a tandem friedel crafts based method for the construction of a tricyclic Pyrroloquinoline skeleton and its application in the synthesis of ammosamide b
ChemInform, 2013Co-Authors: Yohei Takayama, Tatsuya Yamada, Shinya Tatekabe, Kazuo NagasawaAbstract:A tandem intramolecular Friedel—Crafts reaction sequence of substrate (I) leads to the desired tricyclic Pyrroloquinoline (II) as major product (low yield is due to the insolubility of the product during purification), which is used as a key intermediate in the total synthesis of ammosamide B (V).
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A tandem Friedel-Crafts based method for the construction of a tricyclic Pyrroloquinoline skeleton and its application in the synthesis of ammosamide B.
Chemical Communications, 2013Co-Authors: Yohei Takayama, Tatsuya Yamada, Shinya Tatekabe, Kazuo NagasawaAbstract:A total synthesis of ammosamide B (2), a member of the Pyrroloquinoline alkaloid family isolated from marine Streptomyces, is described. The characteristic core tricyclic structure of 2 was constructed using a novel, tandem Friedel–Crafts reaction sequence to transform the symmetric tetra-amino substituted benzene derivative 7 into the tricyclic Pyrroloquinoline product 8, which serves as an important intermediate in the route to the synthesis of the target natural product.
Kazuo Mukai - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and crystal structure of Pyrroloquinoline quinol (PQQH2) and Pyrroloquinoline quinone (PQQ)
Acta Crystallographica Section B Structural Science Crystal Engineering and Materials, 2017Co-Authors: Kazuto Ikemoto, Shigeki Mori, Kazuo MukaiAbstract:Pyrroloquinoline quinone (PQQ) is a water-soluble quinone compound first identified as a cofactor of alcohol- and glucose-dehydrogenases (ADH and GDH) in bacteria. For example, in the process of ADH reaction, alcohol is oxidized to the corresponding aldehyde, and inversely PQQ is reduced to Pyrroloquinoline quinol (PQQH2). PQQ and PQQH2 molecules play an important role as a cofactor in ADH and GDH reactions. However, crystal structure analysis has not been performed for PQQ and PQQH2. In the present study, the synthesis of PQQH2 powder crystals was performed under air, by utilizing vitamin C as a reducing agent. By reacting a trihydrate of disodium salt of PQQ (PQQNa2·3H2O) with excess vitamin C in H2O at 293 and 343 K, yellowish brown and black powder crystals of PQQH2 having different properties were obtained in high yield, respectively. The former was PQQH2 trihydrate (PQQH2·3H2O) and the latter was PQQH2 anhydrate (PQQH2). Furthermore, sodium-free red PQQ powder crystal (a monohydrate of PQQ, PQQ·H2O) was prepared by the reaction of PQQNa2·3H2O with HCl in H2O. Single crystals of PQQH2 and PQQ were prepared from Me2SO/CH3CN mixed solvent, and we have succeeded in the crystal structure analyses of PQQH2 and PQQ for the first time.
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Pyrroloquinoline quinone (PQQ) is reduced to Pyrroloquinoline quinol (PQQH2) by vitamin C, and PQQH2 produced is recycled to PQQ by air oxidation in buffer solution at pH 7.4.
Bioscience Biotechnology and Biochemistry, 2015Co-Authors: Kazuo Mukai, Aya Ouchi, Shin-ichi Nagaoka, Masahiko Nakano, Kazuto IkemotoAbstract:Measurements of the reaction of sodium salt of Pyrroloquinoline quinone (PQQNa2) with vitamin C (Vit C) were performed in phosphate-buffered solution (pH 7.4) at 25 °C under nitrogen atmosphere, using UV-vis spectrophotometry. The absorption spectrum of PQQNa2 decreased in intensity due to the reaction with Vit C and was changed to that of Pyrroloquinoline quinol (PQQH2, a reduced form of PQQ). One molecule of PQQ was reduced by two molecules of Vit C producing a molecule of PQQH2 in the buffer solution. PQQH2, thus produced, was recycled to PQQ due to air oxidation. PQQ and Vit C coexist in many biological systems, such as vegetables, fruits, as well as in human tissues. The results obtained suggest that PQQ is reduced by Vit C and functions as an antioxidant in biological systems, because it has been reported that PQQH2 shows very high free-radical scavenging and singlet-oxygen quenching activities in buffer solutions.
