18512-30-6Relevant articles and documents
Identification and characterization of an anthrol reductase from: Talaromyces islandicus (Penicillium islandicum) WF-38-12
Singh, Shailesh Kumar,Mondal, Amit,Saha, Nirmal,Husain, Syed Masood
supporting information, p. 6594 - 6599 (2019/12/26)
An NADPH-dependent oxidoreductase from Talaromyces islandicus WF-38-12 has been identified through genome analysis. It has been shown to catalyze a regio- and stereoselective reduction of anthrols (formed in situ by the reduction of anthraquinones in the presence of Na2S2O4) to (R)-dihydroanthracenones, with high enantiomeric excess (>99%). The implications of results on the biosynthesis of deoxygenated (bis)anthraquinones and modified (bis)anthraquinones are discussed.
Characterization of a fungal thioesterase having claisen cyclase and deacetylase activities in melanin biosynthesis
Vagstad, Anna L.,Hill, Eric A.,Labonte, Jason W.,Townsend, Craig A.
, p. 1525 - 1534 (2013/02/25)
Melanins are a broad class of darkly pigmented macromolecules formed by oxidative polymerization of phenolic monomers. In fungi, melanins are known virulence factors that contribute to pathogenicity. Their biosynthesis generally involves polymerization of 1,8-dihydroxynaphthalene via a 1,3,6,8- tetrahydroxynaphthalene (THN) precursor assembled by multidomain, nonreducing polyketide synthases. Convergent routes to THN have evolved in fungi. Parallel heptaketide and hexaketide pathways exist that utilize conventional C-terminal thioesterase/Claisen cyclase domains and separate side-chain deacylases. Here, in vitro characterization of Pks1 from Colletotrichum lagenarium establishes a true THN synthase with a bifunctional thioesterase (TE) catalyzing both cyclization and deacetylation of an enzyme-bound hexaketide substrate. Chimeric TE domains were generated by swapping lid regions of active sites between classes of melanin TEs to gain insight into this unprecedented catalysis of carbon-carbon bond making and breaking by an α/β-hydrolase fold enzyme.
A peri-cyclised naphthalene dimer: Synthesis and properties of an unusual Vilsmeier-Haack product of 1,3,6,8-tetramethoxynaphthalene
Pittelkow, Michael,Nielsen, Christian B.,Brock-Nannestad, Theis,Schau-Magnussen, Magnus,Christensen, Jrn B.
, p. 4931 - 4936 (2012/11/13)
An unusual peri-dimerised product was obtained when subjecting 1,3,6,8-tetramethoxynaphthalene to Vilsmeier-Haack reaction conditions (POCl3/DMF). The formation of this peri-dimerised naphthalene product suggests that 1,3,6,8-tetramethoxynaphthalene has comparable reactivity to that of Proton Sponge [1,8-bis(dimethylamino)naphthalene]. The octamethoxy peri-dimer was characterised using NMR spectroscopy, mass spectrometry, UV/Vis spectroscopy, Raman spectroscopy, electrochemistry, X-ray crystallography and DFT calculations. The one-electron oxidation of the peri-dimerised naphthalene compound yielded a radical cation that was studied by EPR spectroscopy and UV/Vis spectroscopy at low temperatures. The experimental observations were confirmed by DFT calculations. The Vilsmeier-Haack reaction (POCl 3/DMF) of 1,3,6,8-tetramethoxynaphthalene gave an unusual peri-cyclised dimer as well as the 1-naphthaldehyde. The dimer is a potent donor molecule. Copyright
Tetrahydroxynaphthalene reductase: Catalytic properties of an enzyme involved in reductive asymmetric naphthol dearomatization
Schaetzle, Michael A.,Flemming, Stephan,Husain, Syed Masood,Richter, Michael,Guenther, Stefan,Mueller, Michael
supporting information; experimental part, p. 2643 - 2646 (2012/05/04)
In reduced circumstances: Tetrahydroxynaphthalene reductase shows a broad substrate range including alternate phenolic compounds and cyclic ketones. Structural modeling reveals major enzyme-substrate interactions; C-terminal truncation of the enzyme causes an altered substrate preference, in accordance with stabilization of the substrate by the C-terminal carboxylate (see picture). This effect allows the identification of a homologous enzyme. Copyright
Carbocations in action. Design, synthesis, and evaluation of a highly acid-sensitive naphthalene-based backbone amide linker for solid-phase synthesis
Pittelkow, Michael,Boas, Ulrik,Christensen, Jorn B.
, p. 5817 - 5820 (2007/10/03)
(Diagram presented) The design, synthesis, and properties of an extremely acid-labile backbone amide linker based on a regiospecifically substituted tetraalkoxy naphthaldehyde core are presented. This handle enables cleavage of peptide backbone amides (se
Exploiting the reaction flexibility of a type III polyketide synthase through in vitro pathway manipulation
Jeong, Jae-Cheol,Srinivasan, Aravind,Grueschow, Sabine,Bach, Horacio,Sherman, David H.,Dordick, Jonathan S.
, p. 64 - 65 (2007/10/03)
A synthetic metabolic pathway has been constructed in vitro consisting of the type III polyketide synthase from Streptomyces coelicolor and peroxidases from soybean and Caldariomyces fumago (chloroperoxidase). This has resulted in the synthesis of the pentaketide flaviolin and its dimeric derivative, and a wide range of pyrones and their coupled derivatives with flaviolin, as well as their halogenated derivatives. The addition of acyl-CoA oxidase to the pathway prior to the polyketide synthase resulted in unsaturated pyrone side chains, further broadening the product spectrum that can be achieved. The approach developed in this work, therefore, provides a new model to exploit biocatalysis in the synthesis of complex natural product derivatives. Copyright
Mechanistic studies on the biomimetic reduction of tetrahydroxynaphthalene, a key intermediate in melanin biosynthesis
Ichinose,Ebizuka,Sankawa
, p. 192 - 196 (2007/10/03)
1,3,6,8-Tetrahydroxynaphthalene (T4HN) is an aromatic polyketide, serving as a general precursor of fungal melanin. Melanin biosynthesis involves two consecutive deoxygenations of T4HN, consisting of the reduction of a phenolic carbon followed by dehydrat
Deoxygenation of polyphenols by ascomycetes : kinetic behaviour of the NADPH-dependent naphthol dehydrogenase and inhibition by tricyclazole and its analogues
Viviani, F.,Vors, J. P.,Gaudry, M.,Marquet, A.
, p. 395 - 404 (2007/10/02)
The mode of action of tricyclazole, a systemic fungicide that specifically inhibits the biosynthesis of fungal melanins, has been studied with the purified naphthol reductase from Pyricularia oryzae.The NADPH-dependent naphthol reductase transforms 1,3,6,8-tetrahydroxy-naphthalene (T4HN) into (+)scytalone and 1,3,8-trihydroxynaphthalene (T3HN) into (-)vermelone, and is very strongly inhibited by tricyclazole.Kinetic analysis reveals that the inhibition is noncompetitive with respect to T4HN or T3HN, and uncompetitive with respect to NADPH.An aza-analogue of tricyclazole has been synthesized and tested.Unexpectedly, it appears to be a competitive inhibitor of T4HN in spite of its similarity to tricyclazole. Keywords: melanin biosynthesis / polyphenol deoxygenation / naphthol dehydrogenase
Melanin Biosynthesis: A Study of Polyphenol Deoxygenation
Viviani, Fabrice,Gaudry, Michel,Marquet, Andree
, p. 1255 - 1259 (2007/10/02)
The 1,3,6,8-Tetrahydroxynaphthalene (T4HN) reductase of Verticillium dahliae has been studied in a cell-free system.The use of specifically labelled 4(R)- and NADPH in the reduction of T4HN to scytalone reveals that the l
