Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, Jan 18, 2016
The interaction of DNA with six water soluble benzo[a]phenoxazinium chlorides mono- or di-substit... more The interaction of DNA with six water soluble benzo[a]phenoxazinium chlorides mono- or di-substituted with 3-chloropropyl groups at the O and N of 2- and 9-positions, along with methyl, hydroxyl and amine terminal groups at 5-positions, was investigated by photophysical techniques. The results indicated that almost all compounds intercalated in DNA base pairs at phosphate to dye ratio higher than 5. At lower values of this ratio, electrostatic binding mode with DNA was observed. Groove binding was detected mainly for the benzo[a]phenoxazinium dye with NH2·HBr terminal. The set of six benzo[a]phenoxazinium chlorides proved successful to label the migrating DNA in agarose gel electrophoresis assays. These finding proves the ability of these benzo[a]phenoxazinium dyes to strongly interact with DNA.
Proceedings of The 19th International Electronic Conference on Synthetic Organic Chemistry, 2015
Synthesis of new benzo[a]phenoxazinium chlorides possessing the (4,6-dichloro-1,3,5triazin-2-yl)a... more Synthesis of new benzo[a]phenoxazinium chlorides possessing the (4,6-dichloro-1,3,5triazin-2-yl)amino at 5-amino function of the heterocycles is described. The preliminary photophysical properties of these compounds in anhydrous ethanol when acidified with TFA or basified with TEAH is also investigated, as well as their response in aqueous media. These benzo[a]phenoxazinium chlorides exhibited fluorescence with maximum emission wavelengths between 628 and 676 nm, in anhydrous ethanol and water.
Proceedings of The 16th International Electronic Conference on Synthetic Organic Chemistry, Oct 30, 2012
Ultrasonic irradiation was demonstrated to be an efficient technique for activating various organ... more Ultrasonic irradiation was demonstrated to be an efficient technique for activating various organic transformations, allowing short reaction times, high yields and sometimes good selectivity. Three new benzo[a]phenoxazinium chlorides possessing isopentylamino, (2-cyclohexylethyl)amino and phenethylamino groups at 5-position of the heterocyclic systems were efficiently synthesized under ultrasound irradiation. Photophysical characterization in ethanol and water, as well as acid-base equilibrium studies of the probes were carried out.
Proceedings of The 16th International Electronic Conference on Synthetic Organic Chemistry
Ultrasonic irradiation was demonstrated to be an efficient technique for activating various organ... more Ultrasonic irradiation was demonstrated to be an efficient technique for activating various organic transformations, allowing short reaction times, high yields and sometimes good selectivity. Three new benzo[a]phenoxazinium chlorides possessing isopentylamino, (2-cyclohexylethyl)amino and phenethylamino groups at 5-position of the heterocyclic systems were efficiently synthesized under ultrasound irradiation. Photophysical characterization in ethanol and water, as well as acid-base equilibrium studies of the probes were carried out.
Proceedings of The 16th International Electronic Conference on Synthetic Organic Chemistry
The interaction with DNA phosphate of a series of water-soluble benzo[a]phenoxazinium chlorides m... more The interaction with DNA phosphate of a series of water-soluble benzo[a]phenoxazinium chlorides mono-or disubstituted with 3-chloropropyl groups at the amine of position 9, and also at the oxygen of position 2, was investigated. It was found that the type of substitution on the polycyclic system and the nature of terminal groups have a remarkable influence on the kind of interaction of these NIR fluorophores and an additional emission band was detected near 570 nm.
Proceedings of The 18th International Electronic Conference on Synthetic Organic Chemistry, 2014
The potential as fluorescent probes of two recently synthesised water-soluble benzo[a]phenoxazini... more The potential as fluorescent probes of two recently synthesised water-soluble benzo[a]phenoxazinium salts, mono-or dissubstituted with carboxylic ester groups as terminal of propyl substituents at the amine of position 9, were studied by fluorescence microscopy employing intact, live cells. With the aim of assessing the compounds cellular staining pattern and potential specificity, co-localization experiments were performed using yeast mutants expressing green fluorescent protein (GFP)-tagged proteins that localize to specific intracellular location/organelles. It was found that both compounds display a very high affinity for the vacuolar membrane, being the dissubstituted compound especially important due to its higher fluorescence at lower, less toxic concentrations.
Ultrasound irradiation was used for the first time towards the synthesis of new Nile Blue related... more Ultrasound irradiation was used for the first time towards the synthesis of new Nile Blue related benzo[a]phenoxazinium chlorides possessing isopentylamino, (2-cyclohexylethyl)amino and phenethylamino groups at 5-position of the heterocyclic system. The efficacy of sonochemistry was investigated with some of our earlier reported synthesis of benzo[a]phenoxazinium chlorides. This newer protocol proved competent in terms of reaction times and enhanced yields. Photophysical studies carried out in ethanol, water and simulated physiological conditions, revealed that emission maxima occurred in the range 644-656 nm, with high fluorescent quantum yields. Other attractive feature exhibited by these materials includes good thermal stability. These properties might be useful in the development of fluorescent probes for biotechnology.
A new and simple method for the C-alkylation of indoles by various BaylisHillman adducts and the... more A new and simple method for the C-alkylation of indoles by various BaylisHillman adducts and the one-pot reductive cyclization of C-alkylated indole derivatives generated from 2-nitro-BaylisHillman adduct to form indolylquinoline derivatives is described.
For Abstract see ChemInform Abstract in Full Text. ... Phenols are not acylated by acetic acid an... more For Abstract see ChemInform Abstract in Full Text. ... Phenols are not acylated by acetic acid and potassium fluoride. All other alcohols are acylated in excellent yields. ... JW John Bosco, B. Rama Raju, Anil K. Saikia, Potassium Fluoride Assisted Selective Acetylation of ...
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, Jan 18, 2016
The interaction of DNA with six water soluble benzo[a]phenoxazinium chlorides mono- or di-substit... more The interaction of DNA with six water soluble benzo[a]phenoxazinium chlorides mono- or di-substituted with 3-chloropropyl groups at the O and N of 2- and 9-positions, along with methyl, hydroxyl and amine terminal groups at 5-positions, was investigated by photophysical techniques. The results indicated that almost all compounds intercalated in DNA base pairs at phosphate to dye ratio higher than 5. At lower values of this ratio, electrostatic binding mode with DNA was observed. Groove binding was detected mainly for the benzo[a]phenoxazinium dye with NH2·HBr terminal. The set of six benzo[a]phenoxazinium chlorides proved successful to label the migrating DNA in agarose gel electrophoresis assays. These finding proves the ability of these benzo[a]phenoxazinium dyes to strongly interact with DNA.
Proceedings of The 19th International Electronic Conference on Synthetic Organic Chemistry, 2015
Synthesis of new benzo[a]phenoxazinium chlorides possessing the (4,6-dichloro-1,3,5triazin-2-yl)a... more Synthesis of new benzo[a]phenoxazinium chlorides possessing the (4,6-dichloro-1,3,5triazin-2-yl)amino at 5-amino function of the heterocycles is described. The preliminary photophysical properties of these compounds in anhydrous ethanol when acidified with TFA or basified with TEAH is also investigated, as well as their response in aqueous media. These benzo[a]phenoxazinium chlorides exhibited fluorescence with maximum emission wavelengths between 628 and 676 nm, in anhydrous ethanol and water.
Proceedings of The 16th International Electronic Conference on Synthetic Organic Chemistry, Oct 30, 2012
Ultrasonic irradiation was demonstrated to be an efficient technique for activating various organ... more Ultrasonic irradiation was demonstrated to be an efficient technique for activating various organic transformations, allowing short reaction times, high yields and sometimes good selectivity. Three new benzo[a]phenoxazinium chlorides possessing isopentylamino, (2-cyclohexylethyl)amino and phenethylamino groups at 5-position of the heterocyclic systems were efficiently synthesized under ultrasound irradiation. Photophysical characterization in ethanol and water, as well as acid-base equilibrium studies of the probes were carried out.
Proceedings of The 16th International Electronic Conference on Synthetic Organic Chemistry
Ultrasonic irradiation was demonstrated to be an efficient technique for activating various organ... more Ultrasonic irradiation was demonstrated to be an efficient technique for activating various organic transformations, allowing short reaction times, high yields and sometimes good selectivity. Three new benzo[a]phenoxazinium chlorides possessing isopentylamino, (2-cyclohexylethyl)amino and phenethylamino groups at 5-position of the heterocyclic systems were efficiently synthesized under ultrasound irradiation. Photophysical characterization in ethanol and water, as well as acid-base equilibrium studies of the probes were carried out.
Proceedings of The 16th International Electronic Conference on Synthetic Organic Chemistry
The interaction with DNA phosphate of a series of water-soluble benzo[a]phenoxazinium chlorides m... more The interaction with DNA phosphate of a series of water-soluble benzo[a]phenoxazinium chlorides mono-or disubstituted with 3-chloropropyl groups at the amine of position 9, and also at the oxygen of position 2, was investigated. It was found that the type of substitution on the polycyclic system and the nature of terminal groups have a remarkable influence on the kind of interaction of these NIR fluorophores and an additional emission band was detected near 570 nm.
Proceedings of The 18th International Electronic Conference on Synthetic Organic Chemistry, 2014
The potential as fluorescent probes of two recently synthesised water-soluble benzo[a]phenoxazini... more The potential as fluorescent probes of two recently synthesised water-soluble benzo[a]phenoxazinium salts, mono-or dissubstituted with carboxylic ester groups as terminal of propyl substituents at the amine of position 9, were studied by fluorescence microscopy employing intact, live cells. With the aim of assessing the compounds cellular staining pattern and potential specificity, co-localization experiments were performed using yeast mutants expressing green fluorescent protein (GFP)-tagged proteins that localize to specific intracellular location/organelles. It was found that both compounds display a very high affinity for the vacuolar membrane, being the dissubstituted compound especially important due to its higher fluorescence at lower, less toxic concentrations.
Ultrasound irradiation was used for the first time towards the synthesis of new Nile Blue related... more Ultrasound irradiation was used for the first time towards the synthesis of new Nile Blue related benzo[a]phenoxazinium chlorides possessing isopentylamino, (2-cyclohexylethyl)amino and phenethylamino groups at 5-position of the heterocyclic system. The efficacy of sonochemistry was investigated with some of our earlier reported synthesis of benzo[a]phenoxazinium chlorides. This newer protocol proved competent in terms of reaction times and enhanced yields. Photophysical studies carried out in ethanol, water and simulated physiological conditions, revealed that emission maxima occurred in the range 644-656 nm, with high fluorescent quantum yields. Other attractive feature exhibited by these materials includes good thermal stability. These properties might be useful in the development of fluorescent probes for biotechnology.
A new and simple method for the C-alkylation of indoles by various BaylisHillman adducts and the... more A new and simple method for the C-alkylation of indoles by various BaylisHillman adducts and the one-pot reductive cyclization of C-alkylated indole derivatives generated from 2-nitro-BaylisHillman adduct to form indolylquinoline derivatives is described.
For Abstract see ChemInform Abstract in Full Text. ... Phenols are not acylated by acetic acid an... more For Abstract see ChemInform Abstract in Full Text. ... Phenols are not acylated by acetic acid and potassium fluoride. All other alcohols are acylated in excellent yields. ... JW John Bosco, B. Rama Raju, Anil K. Saikia, Potassium Fluoride Assisted Selective Acetylation of ...
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