3240-72-0Relevant articles and documents
Novel riboflavin-inspired conjugated bio-organic semiconductors
Richtar, Jan,Heinrichova, Patricie,Apaydin, Dogukan Hazar,Schmiedova, Veronika,Yumusak, Cigdem,Kovalenko, Alexander,Weiter, Martin,Sariciftci, Niyazi Serdar,Krajcovic, Jozef
, (2018/09/12)
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.
Hydroxyl radical induced oxidation of theophylline in water: A kinetic and mechanistic study
Sunil Paul,Aravind,Pramod,Saha,Aravindakumar
, p. 5611 - 5620 (2014/07/22)
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.
Method of treating bone loss by stimulation of calcitonin
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, (2008/06/13)
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.
