17817-31-1Relevant articles and documents
A new approach towards acid catalysts with high reactivity based on graphene nanosheets
Wei, Zuojun,Yang, Yao,Hou, Yaxin,Liu, Yingxin,He, Xiaodong,Deng, Shuguang
, p. 2354 - 2363 (2014)
Solid acid catalysts of graphene oxide and sulfonated graphene oxide nanosheets have been prepared by using the modified Hummers and sulfonation methods. Physical characterization indicated that a number of functional groups such as -COOH, -OH, -O-, and -SO3H were introduced onto the surfaces of the as-synthesized nanosheets. The catalytic performance of the synthesized catalysts was evaluated in the hydrolysis of the glycosidic bond and Fischer esterification. The experimental results indicated that the catalytic activity of the sulfonated graphene oxide was superior to that of other solid acid catalysts with the same or higher acid strength and has also exceeded that of H2SO4 with 9.1 times of acid strength than that of the sulfonated graphene oxide. The high reactivity can be ascribed to the formation of hydrophobic cavities through the combination of graphene sheet and the oxygen-containing groups on its surface, which may facilitate the catalyst to anchor with reactants and promote the attack of protons.
Formation of 6,7,4'-trihydroxyisoflavone (factor 2) from soybean seed isoflavones by bacteria isolated from tempe
Klus,Borger-Papendorf,Barz
, p. 979 - 981 (1993)
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Harborne et al.
, p. 881 (1963)
Free-radical-scavenging, antityrosinase, and cellular melanogenesis inhibitory activities of synthetic isoflavones
Lu, Tzy-Ming,Ko, Horng-Huey,Ng, Lean-Teik,Hsieh, Yen-Pin
, p. 963 - 979 (2015/06/25)
In this study, we examined the potential of synthetic isoflavones for application in cosmeceuticals. Twenty-five isoflavones were synthesized and their capacities of free-radical-scavenging and mushroom tyrosinase inhibition, as well as their impact on cell viability of B16F10 murine melanoma cells and HaCaT human keratinocytes were evaluated. Isoflavones that showed significant mushroom tyrosinase inhibitory activities were further studied on reduction of cellular melanin formation and antityrosinase activities in B16F10 melanocytes in vitro. Among the isoflavones tested, 6-hydroxydaidzein (2) was the strongest scavenger of both ABTS.+ and DPPH. radicals with SC50 values of 11.3±0.3 and 9.4±0.1 μM, respectively. Texasin (20) exhibited the most potent inhibition of mushroom tyrosinase (IC50 14.9±4.5 μM), whereas retusin (17) showed the most efficient inhibition both of cellular melanin formation and antityrosinase activity in B16F10 melanocytes, respectively. In summary, both retusin (17) and texasin (20) exhibited potent free-radical-scavenging capacities as well as efficient inhibition of cellular melanogenesis, suggesting that they are valuable hit compounds with potential for advanced cosmeceutical development.