- Formononetin derivatives and preparation methods and medical application thereof
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The invention relates to the field of pharmaceutical chemistry, and relates to formononetin derivatives and preparation methods and medical application thereof, in particular to formononetin derivatives with the general formula as shown in (I), preparation methods thereof, pharmaceutical compositions containing the compounds and medical application of the derivatives and the pharmaceutical compositions, particularly, application of the derivatives and the pharmaceutical compositions serving as drugs for preventing or treating hyperlipidaemia or obesity or type-II diabetes. Please see the formula in the description.
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Paragraph 0174; 0175; 0176
(2017/04/29)
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- Supramolecular Ga4L612- cage photosensitizes 1,3-rearrangement of encapsulated guest via photoinduced electron transfer
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The K12Ga4L6 supramolecular cage is photoactive and enables an unprecedented photoreaction not observed in bulk solution. Ga4L612- cages photosensitize the 1,3-rearrangement of encapsulated cinnamylammonium cation guests from the linear isomer to the higher energy branched isomer when irradiated with UVA light. The rearrangement requires light and guest encapsulation to occur. The Ga4L612- cage-mediated reaction mechanism was investigated by UV/vis absorption, fluorescence, ultrafast transient absorption, and electrochemical experiments. The results support a photoinduced electron transfer mechanism for the 1,3-rearrangement, in which the Ga4L612- cage absorbs photons and transfers an electron to the encapsulated cinnamylammonium ion, which undergoes C-N bond cleavage, followed by back electron transfer to the cage and recombination of the guest fragments to form the higher energy isomer.
- Dalton, Derek M.,Ellis, Scott R.,Nichols, Eva M.,Mathies, Richard A.,Dean Toste,Bergman, Robert G.,Raymond, Kenneth N.
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p. 10128 - 10131
(2015/09/01)
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- Enolization of aldehydes and ketones: Structural effects on concerted acid-base catalysis
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The third-order term (k(AB)) for the concerted acid-base catalyzed enolization of a selection of simple aldehydes and ketones has been measured in a series of substituted acetic acids at 25°C at constant ionic strength 2.0 (NaNO3). While there is no direct correlation of the magnitude of the third-order term with either the rate constants for acid (k(A)) or base (k(B)) catalysis, a simple log-log relationship exists between the product of the consecutive rate constants (k(A)·k(B)) and the concerted (third order) rate constants (k(AB)). This implies that the concerted pathway is important only when both the general acid and the general base terms are significant; this will be useful in designing other systems which might show such concerted catalysis. In the case of aldehydes, a slope of 0.97 was found for this plot, which compares to the result for 4-substituted cyclohexanones (0.51) and other ketones (0.59), as measured in acetic acid buffers. The resultant Bronsted β(AB) value of 0.20 found for propanal (2) is consistent with the overall observation that concerted catalysis is largely independent of the buffering species, and that process is overall base catalyzed. The solvent isotope effect on the concerted acid-base catalyzed enolization rate term, k(AB)(H2O)/k(AB)(D2O) = 1.33, indicates that the transition state for proton transfer to the carbonyl is more advanced than in the case of ketones. In general we have found that carbonyl compounds with large measured (or estimated) enol contents show significant third-order terms.
- Hegarty, Anthony F.,Dowling, Joseph P.,Eustace, Stephen J.,McGarraghy, Michelle
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p. 2290 - 2296
(2007/10/03)
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