- Photophysical studies on covalently-linked naphthalene and TEMPO free radical systems: Observation of a charge transfer state in the ground state
-
A series of molecules containing a naphthalene chromophore and a stable free radical 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) covalently linked by a spacer group of different lengths have been synthesized. In n-hexane solution, their photophysical behavior was studied and compared with a system of freely moving naphthalene and the free radical TEMPO. The linked molecules showed strong quenching of the singlet and triplet states of the naphthalene moiety, compared to when naphthalene and TEMPO were not linked. The quenching efficiency decreased with increasing the length of the spacer group. In addition, new electronic absorption and emission bands, along with the usual bands of the individual moieties, were also seen. These news bands have been attributed to the formation of electron donor-acceptor charge-transfer complexes in the ground state, arising from the interaction between the two moieties in close proximity. The photophysical dynamics of the linked molecules has been rationalized by assuming the existence of two types of population of the linked molecules: folded and extended. The ground state complex formation is proposed to occur only in the folded conformation of the linked molecules. To our knowledge, this is possibly the first example of a ground state charge-transfer complex formation involving a TEMPO free radical and naphthalene.
- Rane, Vinayak,Kundu, Sushma,Das, Ranjan
-
-
Read Online
- AMINOPEPTIDASE A INHIBITORS AND PHARMACEUTICAL COMPOSITIONS COMPRISING THE SAME
-
The present invention relates to a novel compound, to a composition comprising the same, to methods for preparing the compound, and the use of this compound in therapy. In particular, the present invention relates to compound that is useful in the treatment and prevention of primary and secondary arterial hypertension, ictus, myocardial ischaemia, cardiac and renal insufficiency, myocardial infarction, peripheral vascular disease, diabetic proteinuria, Syndrome X and glaucoma.
- -
-
Page/Page column 70
(2020/06/10)
-
- Mutagenicity of N-acyloxy-N-alkoxyamides as an indicator of DNA intercalation part 1: Evidence for naphthalene as a DNA intercalator
-
N-Acyloxy-N-alkoxyamides are direct-acting mutagens in S. typhimurium TA100 with a linear dependence upon log P that maximises at log P0 = 6.4. Eight N-acyloxy-N-alkoxyamides (2-9) bearing a naphthalene group on any of the three side-chains and with log P0 6.4 have been demonstrated to be significantly and uniformly more mutagenic towards S. typhimurium TA100 than 50 mutagens without naphthalene. The activity enhancement of 2-9 is likely due to intercalative binding of naphthalene to bacterial DNA as a number are also active in TA98, a frame-shift strain of S. typhimurium, which is modified by intercalators. DNA damage profiles for naphthalene-bearing mutagens confirm enhanced reactivity with DNA when naphthalene is incorporated and a different binding mode when compared to mutagens without naphthalene. The effect is independent of whether the naphthalene is attached to an electron-donating alkyl or electron-withdrawing acyl group, alkyl tether length or, in the case of 6 and 7, the point of attachment to naphthalene. A new quantitative structure activity relationship has been constructed for all 58 congeners incorporating log P and an indicator variable, I, for the presence (I = 1) or absence (I = 0) of naphthalene and from which the activity enhancing effect of a naphthalene has been quantified at between three and four log P units. Contrary to conventional views, simple naphthalene groups could target molecules to DNA through intercalation.
- Banks, Tony M.,Clay, Samuel F.,Glover, Stephen A.,Schumacher, Rhiannon R.
-
supporting information
p. 3699 - 3714
(2016/05/09)
-
- FUNCTIONALISED AND SUBSTITUTED INDOLES AS ANTI-CANCER AGENTS
-
The present invention relates to anti-tropomyosin compounds, processes for their preparation, and methods for treating or preventing a disease or disorder, such as a proliferative disease (preferably cancer), using compounds of the invention.
- -
-
Page/Page column 58; 59
(2016/02/05)
-
- Plasticity of the Nickel(II) coordination environment in complexes with hemilabile phosphino thioether ligands
-
A series of homoligated Ni(II) complexes formed from two phosphino thioether (P,S) chelating ligands has been synthesized and characterized. Interestingly, this included octahedral Ni(II) complexes which, unlike previously characterized d8 Rh(I), Pt(II), and Pd(II) analogues, exhibit in situ exchange processes centered around chloride ligand dissociation. This was verified and studied through the controlled abstraction from and introduction of chloride ions to this system, which showed that these processes proceed through complexes with square pyramidal, tetrahedral, and square planar geometries. These complexes were studied with a variety of characterization methods, including single-crystal X-ray diffraction studies, solution 31P{1H} NMR spectroscopy, UV-vis spectroscopy, and DFT calculations. A general set of synthetic procedures that involve the use of coordinating and noncoordinating counteranions, as well as different hemilabile ligands, to mediate geometry transformations are presented.
- MacHan, Charles W.,Spokoyny, Alexander M.,Jones, Matthew R.,Sarjeant, Amy A.,Stern, Charlotte L.,Mirkin, Chad A.
-
body text
p. 3023 - 3033
(2011/04/24)
-
- Conversion of thioureas to fluorescent isothiouronium-based photoinduced electron transfer sensors for oxoanion sensing
-
A convenient conversion is described of thiourea-based receptors to fluorescent isothiouronium-based photoinduced electron transfer (PET) sensors for oxoanion sensing. Naphthalene- or anthracene-functionalized mono-isothiouroniums are synthesized from the corresponding thioureas, in which the fluorophore is connected to the sulfur atom of the thiourea moiety by a methylene or an ethylene spacer. Even though all of the isothiouroniums with a methylene spacer readily decompose in MeOH upon excitation of the fluorophore moiety, the isothiouronium with an ethylene spacer shows good stability under identical conditions. The naphthyl isothiouronium with an ethylene spacer shows a significant fluorescence enhancement upon formation of a 1 : 1 complex with oxoanions in MeOH, and the selectivity follows the order of hydrogen phosphate > acetate ? dihydrogen phosphate ? chloride. The results in the present work indicate that various types of fluorescent PET sensors might be readily obtainable from non-fluorescent thiourea-based receptors by the introduction of appropriate fluorophores at the sulfur atom of thiourea-binding sites.
- Nishizawa, Seiichi,Cui, Ying-Yu,Minagawa, Masakazu,Morita, Kotaro,Kato, Yuichi,Taniguchi, Shinichiro,Kato, Ryo,Teramae, Norio
-
p. 866 - 870
(2007/10/03)
-
- Inhibitors of histone deacetylase
-
The invention relates to the inhibition of histone deacetylase. The invention provides compounds and methods for inhibiting histone deacetylase enzymatic activity. The invention also provides compositions and methods for treating cell proliferative diseases and conditions.
- -
-
-
- Synthesis of Novel HMG-CoA Reductase Inhibitors, I Naphthalene Analogs of Mevinolin
-
The title compounds 2 and their corresponding (6S) epimers 18 are prepared in several steps by starting with chiral formyl ester 5, and α-tetralones 10: (1) coupling reaction with the ylide generated from 11 to yield unsaturated ester 13, (2) reduction to the corresponding alcohol 14, (3) addition of the Grignard reagent derived from 14 to formyl ester 5 to afford the hydroxy esters 16 and 17, and (4) lactonization.This procedure is also used to synthesize the β-naphthyl analogs 29 and 30.Some results obtained from HMG-CoA reductase inhibitor screening are also reported. Key Words: HMG-CoA reductase inhibitors / Naphthylacetates / Pig liver esterase / Glutarate, 3-hydroxy / Lactones
- Novak, Lajos,Rohaly, Janos,Poppe, Laszlo,Hornyanszky, Gabor,Kolonits, Pal,et al.
-
p. 145 - 158
(2007/10/02)
-
- ARALKOXY AND ARYLOXYALKOXY KOJIC ACID DERIVATIVES
-
This invention relates to substituted aralkoxy and aryloxyalkoxy kojic acid derivatives, which are useful as leukotriene D. sub.4 (LTD 4) inhibitors and therefore useful in the treatment of allergies, inflammatory conditions, and coronary vasoconstriction.
- -
-
-