Seminar in Department of Chemistry : The role of quinone-hydroquinone tautomers in biosynthesis of natural products
Speaker : Dr. Syed Masood Husain, a postdoctoral fellow at the University of Freiburg, Germany working on enzyme catalysis using NADPH dependent enzymes.
Seminar Title: The role of quinone-hydroquinone tautomers in biosynthesis of natural products.
Venue : L3
Date & Time : 09th January, 2013: 4.00 - 5:00 pm
Abstract:-
The role of quinone-hydroquinone tautomers in biosynthesis of natural products
Dr. Syed Masood Husain, University of Freiburg, Germany An NADPH dependent enzyme, tetrahydroxynaphthalene reductase (T4HNR) from Magnaporthe gresea was used in the chemoenzym- atic synthesis of several natural products.1 Reduction of hydroxynaphthoquinones to cis-ketodiols by T4HNR and the isolation of a rare hydroxyquinone tautomer, established a twostep mechanism, proved by labeling experiments.2 This also modifies the generally accepted view of fungal dihydroxy-naphthalene melanin biosynthesis.In another example the in situ production of anthrahydroquinone tautomer and the subsequent reduction by MdpC implies for the first step in monodictyphenone biosynthesis, and has implications for chrysophanol formation as well as several other natural products.3 Furthermore, I will demonstrates that DHN melanin biosynthes -is constitutes a diversity-oriented metabolic network, comprising cis-ketodiol and 4-hydroxy-1- tetralone biosyntheses as branching points, reflecting the idea of a matrix biosynthetic pathway.
Dr. Syed Masood Husain, University of Freiburg, Germany An NADPH dependent enzyme, tetrahydroxynaphthalene reductase (T4HNR) from Magnaporthe gresea was used in the chemoenzym- atic synthesis of several natural products.1 Reduction of hydroxynaphthoquinones to cis-ketodiols by T4HNR and the isolation of a rare hydroxyquinone tautomer, established a twostep mechanism, proved by labeling experiments.2 This also modifies the generally accepted view of fungal dihydroxy-naphthalene melanin biosynthesis.In another example the in situ production of anthrahydroquinone tautomer and the subsequent reduction by MdpC implies for the first step in monodictyphenone biosynthesis, and has implications for chrysophanol formation as well as several other natural products.3 Furthermore, I will demonstrates that DHN melanin biosynthes -is constitutes a diversity-oriented metabolic network, comprising cis-ketodiol and 4-hydroxy-1- tetralone biosyntheses as branching points, reflecting the idea of a matrix biosynthetic pathway.
1) S. M. Husain, M. A. Schätzle, C. Röhr, S. Lüdeke, M. Müller “Biomimetic Asymmetric Synthesis of (R)-GTRI-02 and (3S,4R)-3,4-Dihydroxy-3,4-dihydronaphthalene-1(2H)- ones” Org. Lett. 2012, 14, 3600-3603.
2) S. M. Husain, M. A. Schätzle, S. Lüdeke, M. Müller “Breaking the Redox Cycle: The Role of Hydronaphthoquinone Tautomers in Biosynthesis” submitted, 2012.
3) M. A. Schätzle, S. M. Husain, S. Ferlaino, M. Müller “Tautomers of Anthrahydroquinones: Enzymatic Reduction and Implications for Chrysophanol, Monodictyphenone, and Related Xanthone Biosyntheses” J. Am. Chem. Soc. 2012, 134, 14742-14745.
2) S. M. Husain, M. A. Schätzle, S. Lüdeke, M. Müller “Breaking the Redox Cycle: The Role of Hydronaphthoquinone Tautomers in Biosynthesis” submitted, 2012.
3) M. A. Schätzle, S. M. Husain, S. Ferlaino, M. Müller “Tautomers of Anthrahydroquinones: Enzymatic Reduction and Implications for Chrysophanol, Monodictyphenone, and Related Xanthone Biosyntheses” J. Am. Chem. Soc. 2012, 134, 14742-14745.
English
Dates:
Wednesday, 9 January, 2013 - 16:00 to 17:00
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