10030-74-7Relevant academic research and scientific papers
Potent Anti-HIV Ingenane Diterpenoids from Euphorbia ebracteolata
Huang, Ya-Si,Lu, Yan,Chen, Chin-Ho,Lee, Kuo-Hsiung,Chen, Dao-Feng
, p. 1587 - 1592 (2019/07/03)
Two new (1 and 2) and 14 known (3-16) ingenane diterpenoids were isolated from the roots of Euphorbia ebracteolata by bioassay-guided fractionation together with UPLC-MSn analysis. The absolute configurations of the new diterpenoids were established from electronic circular dichroism (ECD) data and ECD calculations. Except for ingenol (16), the ingenane diterpenoids with long aliphatic chain substituents (1-15) exhibited potent activities against HIV-1, with IC50 values of 0.7 to 9.7 nM and selectivity index values of 96.2 to 20 263. From the results, it was concluded that long aliphatic chain substituents are required for the enhanced anti-HIV activity of ingenane diterpenoids.
One-electron reduction of methanesulfonyl chloride. The fate of MeSO 2CI?- and MeSO2? intermediates in oxygenated solutions and their role in the cis-trans isomerization of mono-unsaturated fatty acids
Tamba, Maurizio,Dajka, Katalin,Ferreri, Carla,Asmus, Klaus-Dieter,Chatgilialoglu, Chryssostomos
, p. 8716 - 8723 (2008/02/13)
The one-electron reduction of methanesulfonyl chloride (MeSO2Cl) leads, in the first instance, to an electron adduct MeSO2Cl ?- which lives long enough for direct detection and decays into sulfonyl radicals MeSO2? and Cl-, with k = 1.5 × 106 s-1. Both, MeSO2Cl ?- and MeSO2? showed a similar absorption in the UV with λmax of 320 nm. In the presence of oxygen, MeSO 2Cl?- transfers an electron to O2 and establishes an equilibrium with superoxide. The rate constant for the forward reaction was measured to 4.1 × 109 M-1 s -1, while for the back reaction only an interval of 1.7 × 105 to 1.7 × 106 M-1 s-1 could be estimated, with a somewhat higher degree of confidence for the lower value. This corresponds to an equilibrium constant in the range of 2.4 × 10 3 to 2.4 × 104. With reference to E°(O 2/O2?-) = -155 mV, the redox potential of the sulfonyl chloride couple, E°(MeSO2Cl/MeSO2Cl ?-), thus results between being equal to -355 and -414 mV (vs NHE). MeSO2Cl?- reduces (besides O2) 4-nitroacetophenone. The underlying electron transfer took place with k = 1.5 × 109 M-1 s-1, corroborating an E° for the sulfonyl chloride couple significantly exceeding the above listed lower value. The MeSO2? radical added to oxygen with a rate constant of 1.1 × 109 M-1 s-1. Re-dissociation of O2 from MeSO2OO? occurred only very slowly, if at all, that is, with k ? 105 s-1. MeSO 2? radicals can act as the catalyst for the cis-trans isomerization of several Z- and E-mono-unsaturated fatty acid methyl esters in homogeneous solution. The effectiveness of the isomerization processes has been addressed, and in the presence of oxygen the isomerization is completely suppressed.
SINGLE-STAGE ESTERIFICATION OF OILS AND FATS
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Page/Page column 10-12, (2008/06/13)
A process for producing alkyl esters useful as biofuels and/or lubricants. An alkyl ester product produced by the process. The process comprises a single- stage reaction for esterifying a de-watered glyceride-containing feedstock with an anhydrous short chain alcohol in the presence of a basic esterification catalyst to produce a reaction product comprising alkyl esters and a reaction by-product comprising glycerol-containing substances and the catalyst-containing alcohol. The single-stage esterification reaction is conducted within a temperature and negative-pressure controllable vessel. The alkyl ester product is separated from the reaction by-product and may be further de-watered and/or purified. The catalyst-containing alcohol may be separated from the reaction by-product, de- watered and reused. The glycerol-containing substances may be separated from the reaction by-product and further purified. Useful glyceride-containing feedstocks include those prepared from plant or animal or fish materials, particularly those produced from seeds of mustard, canola, soybean, corn, cotton, flax and palm.
The kinetics of thiyl radical-induced reactions of monounsaturated fatty acid esters
Chatgilialoglu, Chryssostomos,Altieri, Alessio,Fischer, Hanns
, p. 12816 - 12823 (2007/10/03)
The time-dependent isomerizations and thiol additions of several Z- and E-monounsaturated fatty acid methyl esters catalyzed by alkanethiyl radicals during γ-radiolysis of tert-butyl alcohol solutions are analyzed on the basis of the radiation chemical yield of radicals and established rate data. This provides room-temperature rate constants for the reversible thiyl addition. Within experimental errors, they do not depend on the double bond position in the alkyl chains. Particularly noteworthy is the very fast β-elimination of thiyl radicals from alkyl radicals which carry a second β-substituent. It is supported by additional evidence obtained with a radical clock methodology, and the large preference of fragmentation to the E-isomers is attributed to different barriers for the formation of the E- and Z-transition states from the equilibrium radical structure.
