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Papers by sumit chaurasia
Organic Letters, 2009
The 'Green Emission Defect' (GED) produced by fluorenones has significantly retarded the commerci... more The 'Green Emission Defect' (GED) produced by fluorenones has significantly retarded the commercial scope of fluorene-based B-OLEDs. In this communication, for the first time, it is demonstrated that the 'green light' emitting fluorenones 7 can be converted to 'blue light' emitting fluorenones 10 by appropriate positioning of donor-acceptor and chromophoric groups onto the fluorene/fluorenone backbone. Additionally, we report an elegant highly rapid synthetic route for donor-acceptor fluorenes and fluorenones at room temperature with excellent yields.
Bioorganic & Medicinal Chemistry Letters, 2007
A series of 5-[(5-aryl-1H-pyrazol-3-yl)methyl]-1H-tetrazoles 3a-h have been synthesized and evalu... more A series of 5-[(5-aryl-1H-pyrazol-3-yl)methyl]-1H-tetrazoles 3a-h have been synthesized and evaluated for their in vivo antihyperglycemic activity. Some of the synthesized compounds have shown significant glucose lowering activity in male Sprague-Dawley rats in sucrose loaded model. These compounds were also evaluated for their peroxisome proliferator activated receptor c agonistic property, but none of them displayed any significant activity.
Bioorganic & Medicinal Chemistry Letters, 2009
Various functionalized mono-and diarylanthranilo-1,3-dinitriles were synthesized and evaluated fo... more Various functionalized mono-and diarylanthranilo-1,3-dinitriles were synthesized and evaluated for their in vitro antihyperglycemic activity against the PTP-1B, glucose-6-phosphatase, glycogen phosphorylase and α-glucosidase enzymes. Among various screened compounds, 5,6-diaryl substituted anthranilo-1,3-dinitriles 3a, 3b, and 3d showed good inhibitory activity against PTP-1B with IC 50 values of 58-72 µM. Three of the test compounds showed significant (25-37%) lowering of plasma glucose level at 24 h in sucrose-challenged streptozotocin-induced diabetic Sprangue-Dawley rat model.
Cheminform, 2007
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Journal of Organic Chemistry, 2010
A novel series of thermally stable yellow light emitting fluoranthene with an amine donor and a n... more A novel series of thermally stable yellow light emitting fluoranthene with an amine donor and a nitrile acceptor was prepared from a ketene-S,S-acetal under mild conditions without using an organometal catalyst. The organic light emitting device of yellow fluoranthene 10b exhibited substantially low turn-on voltage (2.6 V) and maximum brightness of 470 Cd/m 2 with luminance efficiency of 2.0 Cd/A without using any dopant.
Journal of Cellular Biochemistry, 2009
Following a lead obtained from stem-bark extract of Butea monosperma, two structurally related me... more Following a lead obtained from stem-bark extract of Butea monosperma, two structurally related methoxyisoflavones; cajanin and isoformononetin were studied for their effects in osteoblasts. Cajanin had strong mitogenic as well as differentiation-promoting effects on osteoblasts that involved subsequent activation of MEK-Erk and Akt pathways. On the other hand, isoformononetin exhibited potent anti-apoptotic effect in addition to promoting osteoblast differentiation that involved parallel activation of MEK-Erk and Akt pathways. Unlike genistein or daidzein, none of these two compounds appear to act via estrogen receptors in osteoblast. Once daily oral (by gavage) treatment for 30 consecutive days was given to recently weaned female Sprague–Dawley rats with each of these compounds at 10.0 mg kg−1 day−1 dose. Cajanin increased bone mineral density (BMD) at all skeletal sites studied, bone biomechanical strength, mineral apposition rate (MAR) and bone formation rate (BFR), compared with control. BMD levels at various anatomic positions were also increased with isoformononetin compared with control however, its effect was less potent than cajanin. Isoformononetin had no effect on the parameters of bone biomechanical strength although it enhanced MAR and BFR compared with control. Isoformononetin had very mild uterotrophic effect, whereas cajanin was devoid of any such effect. Our data suggest that cajanin is more potent than isoformononetin in accelerating peak bone mass achievement. To the best of our knowledge, this work represents the first attempt to elucidate structure-activity relationship between the two methoxylated isoflavones regarding their effects in osteoblasts and bone formation. J. Cell. Biochem. 108: 388–399, 2009. © 2009 Wiley-Liss, Inc.
Tetrahedron Letters, 2007
2H-Pyran-2-ones are useful precursors for the synthesis of various aromatic and heterocyclic comp... more 2H-Pyran-2-ones are useful precursors for the synthesis of various aromatic and heterocyclic compounds. In this Letter, we describe substituent-controlled direct access to functionalized 4-(2-oxo-1,2-diarylethyl)-5,6-diaryl-pyran-2-ones by stirring a mixture of 3-cyano-5,6-diaryl ...
Synfacts, 2008
The authors report the design and synthesis of a series of quateraryl blue emittors containing am... more The authors report the design and synthesis of a series of quateraryl blue emittors containing amine donor and cyano acceptor moieties. Their method serves as an improvement over previous polyaryl-substituted benzene syntheses that require iterative coupling reactions on ...
Organic Letters, 2008
A novel series of thermally stable blue light emitting quateraryls with a piperidine donor and a ... more A novel series of thermally stable blue light emitting quateraryls with a piperidine donor and a nitrile acceptor was prepared from a ketene-S,S-acetal under mild conditions without using an organometal catalyst. The performance of a blue quateraryl 6e was investigated by fabricating a multilayer OLED with a configuration of ITO/PEDOT:PSS (40 nm)/quateraryl (60 nm)/BCP (6 nm)/Alq 3 (20 nm)/LiF (0.5 nm)/Al (200 nm), which exhibited blue emission with a low turn on voltage of 4 V at a brightness of 0.22 cd/m 2 .
Cheminform, 2009
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Cheminform, 2008
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Organic Letters, 2009
The 'Green Emission Defect' (GED) produced by fluorenones has significantly retarded the commerci... more The 'Green Emission Defect' (GED) produced by fluorenones has significantly retarded the commercial scope of fluorene-based B-OLEDs. In this communication, for the first time, it is demonstrated that the 'green light' emitting fluorenones 7 can be converted to 'blue light' emitting fluorenones 10 by appropriate positioning of donor-acceptor and chromophoric groups onto the fluorene/fluorenone backbone. Additionally, we report an elegant highly rapid synthetic route for donor-acceptor fluorenes and fluorenones at room temperature with excellent yields.
Bioorganic & Medicinal Chemistry Letters, 2007
A series of 5-[(5-aryl-1H-pyrazol-3-yl)methyl]-1H-tetrazoles 3a-h have been synthesized and evalu... more A series of 5-[(5-aryl-1H-pyrazol-3-yl)methyl]-1H-tetrazoles 3a-h have been synthesized and evaluated for their in vivo antihyperglycemic activity. Some of the synthesized compounds have shown significant glucose lowering activity in male Sprague-Dawley rats in sucrose loaded model. These compounds were also evaluated for their peroxisome proliferator activated receptor c agonistic property, but none of them displayed any significant activity.
Bioorganic & Medicinal Chemistry Letters, 2009
Various functionalized mono-and diarylanthranilo-1,3-dinitriles were synthesized and evaluated fo... more Various functionalized mono-and diarylanthranilo-1,3-dinitriles were synthesized and evaluated for their in vitro antihyperglycemic activity against the PTP-1B, glucose-6-phosphatase, glycogen phosphorylase and α-glucosidase enzymes. Among various screened compounds, 5,6-diaryl substituted anthranilo-1,3-dinitriles 3a, 3b, and 3d showed good inhibitory activity against PTP-1B with IC 50 values of 58-72 µM. Three of the test compounds showed significant (25-37%) lowering of plasma glucose level at 24 h in sucrose-challenged streptozotocin-induced diabetic Sprangue-Dawley rat model.
Cheminform, 2007
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Journal of Organic Chemistry, 2010
A novel series of thermally stable yellow light emitting fluoranthene with an amine donor and a n... more A novel series of thermally stable yellow light emitting fluoranthene with an amine donor and a nitrile acceptor was prepared from a ketene-S,S-acetal under mild conditions without using an organometal catalyst. The organic light emitting device of yellow fluoranthene 10b exhibited substantially low turn-on voltage (2.6 V) and maximum brightness of 470 Cd/m 2 with luminance efficiency of 2.0 Cd/A without using any dopant.
Journal of Cellular Biochemistry, 2009
Following a lead obtained from stem-bark extract of Butea monosperma, two structurally related me... more Following a lead obtained from stem-bark extract of Butea monosperma, two structurally related methoxyisoflavones; cajanin and isoformononetin were studied for their effects in osteoblasts. Cajanin had strong mitogenic as well as differentiation-promoting effects on osteoblasts that involved subsequent activation of MEK-Erk and Akt pathways. On the other hand, isoformononetin exhibited potent anti-apoptotic effect in addition to promoting osteoblast differentiation that involved parallel activation of MEK-Erk and Akt pathways. Unlike genistein or daidzein, none of these two compounds appear to act via estrogen receptors in osteoblast. Once daily oral (by gavage) treatment for 30 consecutive days was given to recently weaned female Sprague–Dawley rats with each of these compounds at 10.0 mg kg−1 day−1 dose. Cajanin increased bone mineral density (BMD) at all skeletal sites studied, bone biomechanical strength, mineral apposition rate (MAR) and bone formation rate (BFR), compared with control. BMD levels at various anatomic positions were also increased with isoformononetin compared with control however, its effect was less potent than cajanin. Isoformononetin had no effect on the parameters of bone biomechanical strength although it enhanced MAR and BFR compared with control. Isoformononetin had very mild uterotrophic effect, whereas cajanin was devoid of any such effect. Our data suggest that cajanin is more potent than isoformononetin in accelerating peak bone mass achievement. To the best of our knowledge, this work represents the first attempt to elucidate structure-activity relationship between the two methoxylated isoflavones regarding their effects in osteoblasts and bone formation. J. Cell. Biochem. 108: 388–399, 2009. © 2009 Wiley-Liss, Inc.
Tetrahedron Letters, 2007
2H-Pyran-2-ones are useful precursors for the synthesis of various aromatic and heterocyclic comp... more 2H-Pyran-2-ones are useful precursors for the synthesis of various aromatic and heterocyclic compounds. In this Letter, we describe substituent-controlled direct access to functionalized 4-(2-oxo-1,2-diarylethyl)-5,6-diaryl-pyran-2-ones by stirring a mixture of 3-cyano-5,6-diaryl ...
Synfacts, 2008
The authors report the design and synthesis of a series of quateraryl blue emittors containing am... more The authors report the design and synthesis of a series of quateraryl blue emittors containing amine donor and cyano acceptor moieties. Their method serves as an improvement over previous polyaryl-substituted benzene syntheses that require iterative coupling reactions on ...
Organic Letters, 2008
A novel series of thermally stable blue light emitting quateraryls with a piperidine donor and a ... more A novel series of thermally stable blue light emitting quateraryls with a piperidine donor and a nitrile acceptor was prepared from a ketene-S,S-acetal under mild conditions without using an organometal catalyst. The performance of a blue quateraryl 6e was investigated by fabricating a multilayer OLED with a configuration of ITO/PEDOT:PSS (40 nm)/quateraryl (60 nm)/BCP (6 nm)/Alq 3 (20 nm)/LiF (0.5 nm)/Al (200 nm), which exhibited blue emission with a low turn on voltage of 4 V at a brightness of 0.22 cd/m 2 .
Cheminform, 2009
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Cheminform, 2008
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.