Feature-based molecular networking analysis suggested the presence of naphthol tetramers in 047219, the same species but a different strain from one used previously for the discovery of naphthol trimers promoting adiponectin synthesis. The new tetramers were composed of 5-methoxy-4-naphthol, each of which was connected to one another in various positions. Targeted isolation afforded six previously unreported naphthol tetramers (-) together with 13 known polyketides (-) including naphthol monomers, dimers, and trimers. Structures of the isolated compounds were established by using NMR and mass spectroscopic analysis. Nodulisporin A (), nodulisporin B (), and 1,1',3',3″-ternaphthalene-5,5',5″-trimethoxy-4,4',4″-triol () demonstrated anti-inflammatory activities against NO production, but the new compounds were less active.
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http://dx.doi.org/10.1021/acs.jnatprod.3c00468 | DOI Listing |
J Nat Prod
August 2023
Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea.
Feature-based molecular networking analysis suggested the presence of naphthol tetramers in 047219, the same species but a different strain from one used previously for the discovery of naphthol trimers promoting adiponectin synthesis. The new tetramers were composed of 5-methoxy-4-naphthol, each of which was connected to one another in various positions. Targeted isolation afforded six previously unreported naphthol tetramers (-) together with 13 known polyketides (-) including naphthol monomers, dimers, and trimers.
View Article and Find Full Text PDFEnviron Pollut
September 2019
Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA, 01003, USA. Electronic address:
Reduced graphene oxide (rGO) is one of the most widely used carbon nanomaterials. When it is released into the environment, rGO can markedly affect the transformation of many pollutants, and change their fate and risk. In this work, the synergetic effects of rGO and Cu(II) on the oxidation of 2-naphthol were examined in water in the dark.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
September 2011
Department of Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain.
Members of the IclR family control bacterial genes involved in a number of physiological processes. The IclR-family member TtgV crystallizes as a tetramer, with each TtgV monomer consisting of two domains--a DNA binding domain and an effector recognition domain, which are interconnected by an extended α-helix. When bound to DNA, a kink is introduced so that the extended helix is split in two α-helices (helix-4 and -5).
View Article and Find Full Text PDFWater Res
June 2005
Department of Civil Engineering, Kansas State University, 2118 Fiedler Hall, Manhattan, KS 66506-5000, USA.
The oxidative polymerization of 1-naphthol was investigated in the presence of horseradish peroxidase (HRP). Naphthol polymerization products (NPP) were characterized for their relative polarity using octanol--water partitioning experiments and reverse-phase high pressure liquid chromatography, for structure using size exclusion chromatography and liquid chromatography-mass spectrometry (LC/MS), and for ecotoxicity using inhibition of bacterial bioluminescence. Peroxidase addition resulted in the production of soluble and insoluble NPP.
View Article and Find Full Text PDFBiochemistry
April 2005
Groupe de Chimie Organique Biologique, LSPCMIB UMR CNRS 5068, Université Paul Sabatier, Bâtiment IIR1, 118 Route de Narbonne, 31062 Toulouse Cedex 4, France.
Interactions of phosphate derivatives of 2,6-dihydroxynaphthalene (NA-P(2)) and 1,6-dihydroxy-2-naphthaldehyde (HNA-P, phosphate at position 6) with fructose-1,6-bisphosphate aldolase from rabbit muscle were analyzed by enzyme kinetics, difference spectroscopy, site-directed mutagenesis, mass spectrometry, and molecular dynamics. Enzyme activity was competitively inhibited by NA-P(2), whereas HNA-P exhibited slow-binding inhibition with an overall inhibition constant of approximately 24 nM. HNA-P inactivation was very slowly reversed with t(1/2) approximately 10 days.
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