Results 41 to 50 of about 10,666 (255)

Theoretical Study on the Relative Energies of Anionic Pterin Tautomers

Pteridines, 2009
Pterins exist as several tautomeric forms and behave as weak acids in aqueous solutions. Therefore, several acidbase equilibria may be present. For several pterin derivatives, the range of the experimental pKa lies in the range 6-8.
Soniat Michael, Martin Christopher B.
doaj   +1 more source

Novel role of folate (vitamin B9) released by fermenting bacteria under Human Intestine like environment

Scientific Reports, 2023
The anaerobic region of the gastrointestinal (GI) tract has been replicated in the anaerobic chamber of a microbial fuel cell (MFC). Electroactive biomolecules released by the facultative anaerobes (Providencia rettgeri) under anoxic conditions have been
Sharda Nara, Gulshan Parasher, Bansi Dhar Malhotra, Manmeet Rawat   +3 more
doaj   +1 more source

Eumelanin and pheomelanin are predominant pigments in bumblebee (Apidae: Bombus) pubescence [PDF]

, 2017
Background: Bumblebees (Hymenoptera: Apidae: Bombus) are well known for their important inter- and intra-specific variation in hair (or pubescence) color patterns, but the chemical nature of the pigments associated with these patterns is not fully ...
Alberto, Jorge, Ornosa Gallego, Concepción, Polidori, Carlo   +2 more
core   +2 more sources

Structure-based design and synthesis of antiparasitic pyrrolopyrimidines targeting pteridine reductase 1 [PDF]

, 2014
The treatment of Human African Trypanosomiasis remains a major unmet health need in sub-Saharan Africa. Approaches involving new molecular targets are important and pteridine reductase 1 (PTR1), an enzyme that reduces dihydrobiopterin in Trypanosoma spp.
Abedawn I. Khalaf, Addie M., Arcari J. T., Baker N., Barrett M. P., Barrett M. P., Bridges D. J., Brun R., Bursavich M. G., Carter N. S., Cavazzuti A., Colin J. Suckling, Colin L. Gibson, Creek D. J., Dawson A., Dincer S., Federica Giordani, Gangjee A., Gibson C. L., Gourley D. G., Judith K. Huggan, Kaspersen S. J., Keri L. Barrack, Kirsten Stewart, Le Brazidec J.-Y., Matovu E., Michael P. Barrett, Mohamed M. S., Mpamhanga C. P., Pui Ee Wong, Raz B., Sienkiewicz N., Simarro P. P., Spinks D., Tari L. W., Taylor E. C., Tessier P. R., Trzoss M., Tulloch L. B., William N. Hunter, Xie H., Zhu G.   +41 more
core   +5 more sources

No QTcF Prolongation with Sepiapterin: Results From a Thorough QT Study in Healthy Subjects at Therapeutic and Supratherapeutic Doses

The Journal of Clinical Pharmacology, Volume 66, Issue 1, January 2026.
Abstract Sepiapterin and its major metabolite 6R‐L‐erythro‐5,6,7,8‐tetrahydrobiopterin (BH4) bind to distinct variants of phenylalanine hydroxylase (PAH), which converts excess phenylalanine to tyrosine, thereby stabilizing, enhancing, and prolonging PAH activity.
Lan Gao, Hongqi Xue, Borje Darpo, Kimberly Ingalls, Diksha Kaushik, Neil Smith, Ronald Kong, Lee Golden   +7 more
wiley   +1 more source

Pigments, Chromatophore Structure, and Gene Expression Underlying Colour Polytypy of a Panamanian Poison Frog

Molecular Ecology, Volume 35, Issue 1, January 2026.
ABSTRACT Colour polytypism represents an example of phenotypic diversification shaped by genetic divergence and ecological pressures. Poison frogs of the genus Oophaga (Dendrobatidae) are highly polytypic in coloration, making them an ideal system for investigating the genetic and physiological basis of colour variation.
Vasiliki Mantzana‐Oikonomaki, Giselle Tamayo‐Castillo, Víctor Vásquez‐Cháves, Abel Mora‐Machado, William J. Zamora Ramirez, Roberto Ibáñez, Heike Pröhl, Ariel Rodríguez   +7 more
wiley   +1 more source

Crystal structure of (2-amino-7-methyl-4-oxidopteridine-6-carboxylato-κ3O4,N5,O6)aqua(1,10-phenanthroline-κ2N,N′)copper(II) trihydrate

Acta Crystallographica Section E, 2014
In the title compound, [Cu(C8H5N5O3)(C12H8N2)(H2O)]·3H2O, the CuII cation is O,N,O′-chelated by the 2-amino-7-methyl-4-oxidopteridine-6-carboxylate anion and N,N′-chelated by the 1,10-phenanthroline (phen) ligand.
Siddhartha S. Baisya, Parag S. Roy
doaj   +1 more source

Sulfite: Cytochrome \u3cem\u3ec\u3c/em\u3e Oxidoreductase from \u3cem\u3eThiobacillus novellus\u3c/em\u3e [PDF]

, 2000
Direct oxidation of sulfite to sulfate occurs in various photo- and chemotrophic sulfur oxidizing microorganisms as the final step in the oxidation of reduced sulfur compounds and is catalyzed by sulfite:cytochrome c oxidoreductase (EC1.8.2.1).
Bennett, Brian, Dahl, Christiane, Deutzmann, Rainer, Kappler, Ulrike, McEwan, Alistair G., Rethmeier, Jörg, Schwarz, Günter   +6 more
core   +1 more source

Drug Discovery Applications of Nitroso (Hetero)Arene Derivatives

ChemPlusChem, Volume 90, Issue 12, December 10, 2025.
Nitroso (hetero)aromatic compounds are bioactive molecules with antiviral, anticancer, neuroprotective, and antimicrobial properties. This review highlights their mechanisms of action—oxidative stress, DNA damage, and enzyme inhibition—alongside synthesis, structure–activity relationships, and toxicity challenges, offering insight into their ...
Silvia Roscales, Aurelio G. Csáky
wiley   +1 more source

Photoinduced cleavage of plasmid DNA in the presence of pterin

Pteridines, 2000
The photoinduced cleavage of plasmid DNA by UV -A light in the presence of pterin was investigated. Electrophoretic analysis of the irradiated plasmid pUCI8 in the presence of pterin showed that UV light of 350 nm induced the transformation of a ...
Lorente Carolina, Thomas Andrés Héctor, Villata Laura Sofia, Hozbor Daniela, Lagares Antonio, Capparelli Alberto   +5 more
doaj   +1 more source