Although the carcinogenic potential of ultraviolet radiation is well-known, UV light may interact with DNA by direct absorption or through photosensitization endogenous exogenous chromophores. These chromophores can extend "active" fraction solar spectrum to UVA region and beyond, which means that photosensitizers increase probability developing skin cancer upon exposure sunlight. Therefore researchers would like understand mechanisms involved in photosensitized damage both anticipate...

Six 2-quinolones, which bear a terminal alkene linked by three- or four-membered tether to carbon atom C4 of the quinolone, were synthesized and subjected an intramolecular [2 + 2]-photocycloaddition. The reaction delivered respective products in high yields (78–99%) with good regioselectivity favor straight isomer. If conducted presence chiral hydrogen-bonding template (2.5 equiv) at low temperature toluene as solvent, proceeded enantioselectively (83–94% ee). An organocatalytic was...

A new family of chromogenic ionophores for anion sensing has been developed with 1,3,5-triarylpent-2-en-1,5-diones. These species form yellow solutions that undergo a color change to magenta in the presence certain inorganic ions or nucleotides, depending on derivative. The reaction ATP is particulary remarkable and therefore these compounds are reagents "naked-eye" ATP. picture shows changes induced one derivative GMP, ADP, (from left right).

Abstract Irradiation of ketoprofen in neutral aqueous medium gave rise to 3‐ethylbenzophenone as the major photoproduct. Its formation is justified via protonation a benzylic carbanion or hydrogen abstraction by radical. Minor amounts eight additional compounds were isolated. Four them are derived from radical: 3‐(1‐hydroperoxyethyl)benzophenone, 3‐(1‐hydroxyethyl)benzophenone, 3‐acetylbenzophenone and 2,3‐bis‐ (3‐benzoylphenyl)butane. The other four products involve initial excited...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and Pharmacological Evaluation of 2'-Hydroxychalcones Flavones as Inhibitors Inflammatory Mediators GenerationJ. F. Ballesteros, M. J. Sanz, A. Ubeda, Miranda, S. Iborra, Paya, AlcarazCite this: Med. Chem. 1995, 38, 14, 2794–2797Publication Date (Print):July 1, 1995Publication History Published online1 May 2002Published inissue 1 July 1995https://pubs.acs.org/doi/10.1021/jm00014a032https://doi.org/10.1021/jm00014a032research-articleACS...

Discrimination of isomeric anions: The selective, shape-controlled colorimetric sensing dicarboxylate ions has been achieved and represents a development in the "naked-eye" detection certain organic isomers. photograph shows diverse colors solutions 1,3,5-triarylpent-2-en-1,5-dione dioxane/water solution (70:30 v/v) at approximately pH 6, presence either maleate (cis isomer, magenta) or fumarate (trans yellow) ions.

Novel sunscreens are required providing active protection in the UVA and UVB regions. On other hand, there is an increasing concern about photosafety of UV filters, as some them not sufficiently photostable. Avobenzone one most frequently employed sunscreen ingredients, but it has been reported to partially decompose after irradiation. In present work, photophysical photochemical studies on a methylated avobenzone-derivative have shown that diketo form responsible for photodegradation. A...

Triplet-mediated pyrimidine (Pyr) dimerisation is a key process in photochemical damage to DNA. It may occur the presence of photosensitiser, provided that number requirements are fulfilled, such as favourable intersystem crossing quantum yield and high triplet energy. The attention has been mainly focused on cyclobutane dimers, they by far most relevant Pyr photoproducts obtained sensitisation. present perspective deals with involved chemistry, not only DNA but also its simple building...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHighly Efficient Photoinduced Electron Transfer with 2,4,6-Triphenylpyrylium Cation Incorporated inside Extra Large Pore Zeotype MCM-41Avelino Corma, Vicente Fornes, Hermenegildo Garcia, Miguel A. Miranda, and Maria J. SabaterCite this: Am. Chem. Soc. 1994, 116, 21, 9767–9768Publication Date (Print):October 1, 1994Publication History Published online1 May 2002Published inissue 1 October...

Norfloxacin (NFX) photosensitizes formation of thymine dimers (T<>T) in DNA, while its N(4') acetyl derivative (ANFX) does not. This is evident from the observation single-strand breaks after enzymatic treatment with T4 endonuclease V and subsequent gel electrophoresis. The triplet energies NFX ANFX are estimated at 273 268 kJ/mol, respectively, on basis triplet-triplet energy transfer quenching by a set biphenyl naphthalene derivatives. Hence, DNA (i.e., value for photosensitizer to produce...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotoinduced Electron Transfer within Zeolite Cavities: cis-Stilbene Isomerization Photosensitized by 2,4,6-Triphenylpyrylium Cation Imprisoned inside YAvelino Corma, Vicente Fornes, Hermenegildo Garcia, Miguel A. Miranda, Jaime Primo, and Maria-Jose SabaterCite this: J. Am. Chem. Soc. 1994, 116, 6, 2276–2280Publication Date (Print):March 1, 1994Publication History Published online1 May 2002Published inissue 1 March...

A remarkable stereodifferentiation has been observed in the interaction between excited triplet state of carprofen (CP) and human serum albumin (HSA). Time-resolved measurements using laser flash photolysis reveal presence two components with different lifetimes decay. This is explained by complexation CP to possible HSA binding sites. The shorter-lived are ascribed CP/HSA complexes site I, where more important (τR/τS ca. 4). correlated formation a dehalogenated photoproduct upon...

The triplet excited state of flurbiprofen methyl ester (FBPMe) has been used as a chiral reporter for the two binding sites human serum albumin (HSA). occupation level estimated from regression analysis decays at several [FBPMe]/[HSA] ratios. data agree with high affinity (I and II) that are populated to different extent. A remarkable stereodifferentiation found in drug lifetimes within protein microenvironment.

Abstract The photodegradation of Ibuprofen, a widely used non‐steroidal anti‐inflammatory drug (NSAID), was examined. Several photoproducts (I‐VI) were isolated and identified on the basis their IR‐ 1 H‐NMR‐ 13 C‐NMR‐ spectra. chemical structures confirmed by unambiguous alternative synthesis from available reagents. most significant primary photochemical process cleavage C‐C bond to carboxy group. Subsequent secondary processes (hydrogen abstraction, dimerization, incorporation methanol, or...

A series of fluoroquinolones (FQs), including enoxacin (ENX), pefloxacin (PFX), norfloxacin (NFX), its N(4')-acetyl derivative (ANFX), ofloxacin (OFX), and rufloxacin (RFX) have been investigated to determine their potential as DNA photosensitizers via thymine cyclobutane dimer (T<>T) formation in DNA. At fluoroquinolone concentrations light doses insufficient produce direct single strand breaks, ENX, PFX, NFX were able T<>T dimers DNA, revealed by enzymatic treatment with T4 endonuclease V....