77301-42-9Relevant articles and documents
Naproxen sodium salt photochemistry in aqueous sodium dodecyl sulfate (SDS) ellipsoidal micelles
Valero,Sultimova, Natalya B.,Houston, Judith E.,Levin, Peter P.
, (2020/11/27)
The photochemistry and other properties of the anti-inflammatory drug (NSAID) naproxen (NP) in sodium dodecyl sulfate, SDS, micellar aqueous solutions at pH = 7 (NP is in anionic form) were studied. The large value of the partition coefficient (P) was obtained, logP = 2.7, showing that the most part of NP is localized in the micellar phase. The solubilization in SDS micelles results in NP fluorescence and photodegradation quantum yields decrease. The photoproducts 6-methoxy-2-(1-hydroxyethyl)-naphthalene and 6-methoxy-2-acetyl-naphthalene were found by gas chromatography/mass spectrometry (GC/MS). Both photoproducts were formed in SDS solution in significantly smaller amounts than in water. Small angle neutron scattering (SANS) showed that the presence of NP has small effect on the micellar structure. Only a slight decrease of the ionization degree of the micelle was observed by SANS, suggesting that NP was localized in the vicinity of micellar surface. The NP triplet excited state, hydrated electron, NP radical cation and some other relatively long lived intermediate were observed by laser flash photolysis of NP in micellar solution. The decay kinetics of these intermediates was different with respect to that in the homogeneous media. The reactivity of NP in SDS micellar environment was compared to that in the homogeneous media and the probable nature of the intermediate precursors of the final photoproducts are under the discussion.
Application of a heme-binding protein eluted from encapsulated biomaterials to the catalysis of enantioselective oxidation
Nagaoka, Hiroyuki
, p. 553 - 565 (2014/03/21)
A protein complex (PX) eluted from an encapsulated pea protein (PP) under aeration can be used as two types of biocatalysts: a polyethylene glycol (PEG) (1000/4000 = 2/1)-aggregated PX (AGPX) and a glutaraldehyde (GA)/compound- modified PX (CMPX). These biocatalysts have the following functional activities: AGPX can catalyze the oxidation of rac-1-(6-methoxynaphthalen-2-yl)ethanol (rac-1) to the corresponding ketone (～95% chemical yield) via the selective oxidation of (S)-(+)-1, leaving highly enantiopure (R)-(-)-1 (>99% ee; ～50% chemical yield); CMPX can catalyze the kinetic resolution of (S)-(+)-1 ((S)-naproxen precursor, >99% ee, ～50% chemical yield) via the selective oxidation of (R)-(-)-1 to the corresponding ketone. Both reactions occur in the absence of an added cofactor (e.g., NAD(P)) in aqueous media. The specific activities of AGPX and CMPX were determined to be 0.8 ± 0.03 mU (mean ± SD) and 0.6 ± 0.02 mU (mean ± SD), respectively, and the exact nature of the species engaged in the key reaction was consistent with that of a heme-binding protein (HBP), on the basis of an N-terminal sequence comparison, which showed 93% similarity with a 20.853 kDa hemophore HasA gene product [Pseudomonas fluorescens Pf-5, a plant commensal bacterium]. PP-HBP can be regenerated via successive asymmetric catalytic events using an incorporated iron electron-transfer system (Fe2+ a? Fe3+) in the presence of oxygen, a process seemingly similar to that utilized by hemoglobin. The use of a raw biomaterial as a PX-catalytic system with an incorporated redox cofactor for asymmetric oxidation overcomes the apparent difficulties in working with pure dehydrogenase enzyme/redox cofactor systems for biotransformation.
Scope of enantioselective Palladium(II)-catalyzed aerobic alcohol oxidations with (-)-sparteine
Mandal, Sunil K.,Jensen, David R.,Pugsley, Jacob S.,Sigman, Matthew S.
, p. 4600 - 4603 (2007/10/03)
Evaluation of the substrate scope for Pd(II)/ (-)-sparteine catalyzed aerobic oxidative kinetic resolution of secondary alcohols is disclosed. An improved system is found with use of tert-butyl alcohol solvent in which benzylic and aliphatic alcohols as well as alcohols containing olefins are effectively oxidatively resolved. For substrates that successfully undergo oxidative kinetic resolution, krel values are generally between 10 and 20. Successful scale-up of various substrates to 10-mmol scale is described. Extension to oxidative desymmetrization of 1,3-meso-diols is successful with enantiomeric excesses ranging from 78 to 85%.
