The quantum chemical investigations of some representative bis-adducts of C60, C60O2, C60（NH）2, C60（CH2NHCH2）2 and C60（SO4）2 have been carried out at the AM1 and PM3 semi-empirical molecular orbital levels. The ...The quantum chemical investigations of some representative bis-adducts of C60, C60O2, C60（NH）2, C60（CH2NHCH2）2 and C60（SO4）2 have been carried out at the AM1 and PM3 semi-empirical molecular orbital levels. The relative energies of various isomers of these C60 bis-adducts have been calculated. For C60O2 and C60（NH）2 with the sterically non-demanding addends, cis-1 isomer resulted from 1,2-additions to adjacent 6/6 ring fusion is the lowest energy structure; for C60（CH2NHCH2）2 and C60（SO4）2 with sterically demanding addends, the most energetically preferred structure is e isomer. This is consistent with and enhances the general rule for regio-selectivity of fullerene C60 established by Hirsch, though Hirschs rule is summarized on the basis of methanofullerenes. The thermodynamic analysis is not significant to explain the experimentally observed regiochemistry for C60 bis-adducts, and the kinetic reasons or mechanisms may dominant in determining the regioselectivity of fullerene bis-adducts. Further addition patterns for multiple addition were also discussed.展开更多
Recently, the anti-glycation and anticancer properties of curcumin longa and okra seed extract were studied alone and also in combination with the well-established drug metformin. The combined effect of curcumin with ...Recently, the anti-glycation and anticancer properties of curcumin longa and okra seed extract were studied alone and also in combination with the well-established drug metformin. The combined effect of curcumin with metformin and metformin with okra seed extract was found to be highly efficacious in inhibiting Advanced Glycation End-products （AGEs）. In order to understand the mechanistic implications of curcumin combined with metformin and its enhanced anti-glycation activity, a Curcumin-Metformin Adduct was chemically synthesized. This adduct was fully characterized by thin-layer chromatography, Nano Drop spectrophotometry and electrospray-ionization mass spectrometry. The adduct may be helpful not only in elucidating the mechanism of anti-glycation and anti-cancer activities but also in studying the role of curcumin in binding of AI3-oligomers and disaggregating fibrillar formation in Alzheimer＇s disease.展开更多
文摘The quantum chemical investigations of some representative bis-adducts of C60, C60O2, C60（NH）2, C60（CH2NHCH2）2 and C60（SO4）2 have been carried out at the AM1 and PM3 semi-empirical molecular orbital levels. The relative energies of various isomers of these C60 bis-adducts have been calculated. For C60O2 and C60（NH）2 with the sterically non-demanding addends, cis-1 isomer resulted from 1,2-additions to adjacent 6/6 ring fusion is the lowest energy structure; for C60（CH2NHCH2）2 and C60（SO4）2 with sterically demanding addends, the most energetically preferred structure is e isomer. This is consistent with and enhances the general rule for regio-selectivity of fullerene C60 established by Hirsch, though Hirschs rule is summarized on the basis of methanofullerenes. The thermodynamic analysis is not significant to explain the experimentally observed regiochemistry for C60 bis-adducts, and the kinetic reasons or mechanisms may dominant in determining the regioselectivity of fullerene bis-adducts. Further addition patterns for multiple addition were also discussed.
文摘Recently, the anti-glycation and anticancer properties of curcumin longa and okra seed extract were studied alone and also in combination with the well-established drug metformin. The combined effect of curcumin with metformin and metformin with okra seed extract was found to be highly efficacious in inhibiting Advanced Glycation End-products （AGEs）. In order to understand the mechanistic implications of curcumin combined with metformin and its enhanced anti-glycation activity, a Curcumin-Metformin Adduct was chemically synthesized. This adduct was fully characterized by thin-layer chromatography, Nano Drop spectrophotometry and electrospray-ionization mass spectrometry. The adduct may be helpful not only in elucidating the mechanism of anti-glycation and anti-cancer activities but also in studying the role of curcumin in binding of AI3-oligomers and disaggregating fibrillar formation in Alzheimer＇s disease.
