- Novel riboflavin-inspired conjugated bio-organic semiconductors
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Flavins are known to be extremely versatile, thus enabling routes to innumerable modifications in order to obtain desired properties. Thus, in the present paper, the group of bio-inspired conjugated materials based on the alloxazine core is synthetized using two efficient novel synthetic approaches providing relatively high reaction yields. The comprehensive characterization of the materials, in order to evaluate the properties and application potential, has shown that the modification of the initial alloxazine core with aromatic substituents allows fine tuning of the optical bandgap, position of electronic orbitals, absorption and emission properties. Interestingly, the compounds possess multichromophoric behavior, which is assumed to be the results of an intramolecular proton transfer.
- Richtar, Jan,Heinrichova, Patricie,Apaydin, Dogukan Hazar,Schmiedova, Veronika,Yumusak, Cigdem,Kovalenko, Alexander,Weiter, Martin,Sariciftci, Niyazi Serdar,Krajcovic, Jozef
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- Synthesis and evaluation of antitumour activities of novel fused tri-And tetracyclic uracil derivatives
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Simple one-pot syntheses of indenopyrrolopyrimidines and indolopyrrolopyrimidines were achieved via the cyclocondensation of 6-Aminouracils and, respectively, ninhydrin and isatin in the presence of catalytic amounts of glacial acetic acid. Similarly, 5,6-diaminouracil derivatives were used as starting materials for the synthesis of indenopteridines and indolopteridines via their reaction with ninhydrin and isatin, respectively. The synthesised compounds were evaluated for antitumour activity against a human hepatocellular carcinoma cell line (HepG2), some showing antitumour activity comparable with 5-fluorouracil and imatinib.
- Elkalyoubi, Samar,Fayed, Eman
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p. 771 - 777
(2017/01/03)
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- Hydroxyl radical induced oxidation of theophylline in water: A kinetic and mechanistic study
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Oxidative destruction and mineralization of emerging organic pollutants by hydroxyl radicals (OH) is a well established area of research. The possibility of generating hazardous by-products in the case of OH reaction demands extensive investigations on the degradation mechanism. A combination of pulse radiolysis and steady state photolysis (H2O2/UV photolysis) followed by high resolution mass spectrometric (HRMS) analysis have been employed to explicate the kinetic and mechanistic features of the destruction of theophylline, a model pharmaceutical compound and an identified pollutant, by OH in the present study. The oxidative destruction of this molecule, for intermediate product studies, was initially achieved by H2O 2/UV photolysis. The transient absorption spectrum corresponding to the reaction of OH with theophylline at pH 6, primarily caused by the generation of (T8-OH), was characterised by an absorption band at 330 nm (k2 = (8.22 ± 0.03) × 109 dm3 mol-1 s-1). A significantly different spectrum (λmax: 340 nm) was observed at highly alkaline pH (10.2) due to the deprotonation of this radical (pKa ~ 10.0). Specific one electron oxidants such as sulphate radical anions (SO4-) and azide radicals (N 3) produce the deprotonated form (T(-H)) of the radical cation (T+) of theophylline (pKa 3.1) with k2 values of (7.51 ± 0.04) × 109 dm3 mol-1 s-1 and (7.61 ± 0.02) × 109 dm3 mol-1 s-1 respectively. Conversely, oxide radicals (O -) react with theophylline via a hydrogen abstraction protocol with a rather slow k2 value of (1.95 ± 0.02) × 109 dm3 mol-1 s-1. The transient spectral studies were complemented by the end product profile acquired by HRMS analysis. Various transformation products of theophylline induced by OH were identified by this technique which include derivatives of uric acids (i, iv & v) and xanthines (ii, iii & vi). Further breakdown of the early formed product due to OH attack leads to ring opened compounds (ix-xiv). The kinetic and mechanistic data furnished in the present study serve as a basic frame work for the construction of OH induced water treatment systems as well as to understand the biological implications of compounds of this kind. the Partner Organisations 2014.
- Sunil Paul,Aravind,Pramod,Saha,Aravindakumar
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p. 5611 - 5620
(2014/07/22)
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- PROCESS FOR STRAIGHTENING KERATIN FIBRES WITH A HEATING MEANS AND DENATURING AGENTS
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The invention relates to a process for straightening keratin fibres, comprising: (i) a step in which a straightening composition containing at least two denaturing agents is applied to the keratin fibres, (ii) a step in which the temperature of the keratin fibres is raised, using a heating means, to a temperature of between 110 and 250° C.
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- Method of treating bone loss by stimulation of calcitonin
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Compounds of the formula R1and R2are independently alkyl of 1 to 6 carbon atoms, allyl, or substituted allyl of 3 to 6 carbon atoms; R3is hydrogen, alkyl of 1 to 6 carbon atoms, or cycloalkyl of 3 to 10 carbon atoms; and R4is phenyl or naphthyl substituted with alkyl of 1 to 6 carbon atoms, alkoxy of 1 to 6 carbon atoms or NR5R6; substituted or unsubstituted phenylalkyl wherein the alkyl group contains 1 to 6 carbon atoms; substituted or unsubstituted 5 to 10 membered heteroaryl having 1 to 3 heteroatoms selected from N, S and O; substituted or unsubstituted cycloalkyl of 3 to 10 carbon atoms; or substituted or unsubstituted cycloalkylalkyl of 4 to 10 carbon atoms; provided that phenyl or naphthyl is substituted with NR5R6when R1and R2 is alkyl, are useful in the treatment of various disorders associated bone loss by increased transcription and elevation of plasma calcitonin levels. Such disorders include, but are not limited to: Paget's Disease, post menopausal osteoporosis, senile osteoporosis, and glucocorticoid-induced osteoporosis.
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- Hair dye compositions and process comprising and utilizing a combination of isatin and aminopyridine derivatives
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The invention relates to a process for dyeing keratinous fibers, comprising the simultaneous or sequential application of a component (A) containing at least one compound of formula (I): STR1 in which: R1 denotes hydrogen, alkyl, acetyl, benzoyl, phenyl or carboxyalyl; R2 and R3 denote a hydrogen, alkyl, hydroxyl, halogen, nitro, alkylphenyl, phenyl or alkoxy; and a component (B) containing at least one compound of formula (II): STR2 in which: R4 denotes a hydrogen atom or a β-hydroxyethyl group; n=0, 1 or 2, and m=0 or 1; as well as its cosmetically acceptable salts; or one compound of formula (III): STR3 in which: R5 denotes a hydrogen atom, a hydroxyl group or a group STR4 R6 denotes a hydroxyl group or a group N STR5 R7 denotes H or NH2, R8 denotes a group STR6 R9 and R10, independently of one another, representing a hydrogen atom, a C1 -C4 alkyl, a group (CH2)p --Z, where p=1 to 4 and Z represents OH, halogen, NH2, NHR' or NHR'R", where R' and R" denote a C1 -C4 alkyl or form a heterocycle with the nitrogen atom to which they are attached; with the proviso that one of R5 to R8 denotes NH2 ; and its cosmetically acceptable salts, as well as to the dyeing agents employed.
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- Nitrated coupler compounds useful in direct dyeing and simultaneous oxidation and direct dyeing of keratinic fibers
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A cosmetic composition for application to the hair contains either (a) at least one compound having the formula STR1 wherein: R is hydrogen, alkyl or halogen; and R' is hydrogen, alkyl, hydroxyalkyl, carbamylalkyl, mesylaminoalkyl, aminoalkyl, acylaminoalkyl, monoalkylaminoalkyl, dialkylaminoalkyl, piperidinoalkyl, morpholinoalkyl, carbamoyl, acyl or carbalkoxy; or (b) at least one of said compounds having formula I above and at least one benzene or heterocyclic oxidation base. The invention also relates to new couplers of formula I as well as to new indo compounds which result from the coupling of said compounds with an oxidation base. These cosmetic compositions for application to the hair are useful in direct dyeing, oxidation dyeing or simultaneous oxidation and direct dyeing of said hair.
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