- Enantioselective biocatalytic reactions on (±)-aryl alkyl ketones with native and modified porcine pancreatic lipase
-
Porcine pancreatic lipase (PPL), pre-incubated with acetophenone in tetrahydrofuran, fails to recognize ortho-and para-acyloxy functions with respect to the nuclear carbonyl group in (±)-2,4-diacyloxyphenyl alkyl ketones and produces novel aryl alkyl keto
- Husain, Mofazzal,Kumar, Vineet,Kumar, Rajesh,Shakil, Najam A.,Sharma, Sunil K.,Prasad, Ashok K.,Olsen, Carl E.,Gupta, Rajendra K.,Malhotra, Sanjay V.,Van Der Eycken, Erik,Depass, Anthony L.,Levon, Kalle,Parmar, Virinder S.
-
experimental part
p. 172 - 184
(2011/12/01)
-
- Synthesis of various kinds of isoflavones, isoflavanes, and biphenyl- ketones and their 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activities
-
Forty-eight kinds of isoflavones (8), thirty-one isoflavanes (9), and forty-seven biphenyl-ketones (10, 10') were synthesized from eleven kinds of substituted phenols (11) and six phenylacetic acids (12). Among them, seventy-five compounds are new. The radical scavenging activities of these compounds were evaluated using 1,1- diphenyl-2-picrylhydrazyl (DPPH) at pH 6.0. We found that thirty-nine out of forty-three compounds having a catechol moiety on either the A- or the B-ring exhibited a high activity (ED50=12-54 μM) similar to that of catechin. In these cases, the remaining part of their structure seemed to have little effect on their activity. Many 6- or 8-hydroxyisoflavanes (9E-I) and their biphenyl-ketone derivatives (10E-H) also showed a high activity (ED50=50=26-32 μM). This study suggests that natural isoflavones have the possibilities of exhibiting antioxidant activities through the hydroxylation at the C6-, C8-, or C3'-position or the formation of the isoflavanes (9) and/or the biphenyl-ketone derivatives (10') by metabolism or biotransformation.
- Goto, Hideyuki,Terao, Yoshiyasu,Akai, Shuji
-
experimental part
p. 346 - 360
(2009/12/27)
-
- Synthesis of α-methyldeoxybenzoins
-
Reduction of hydroxy and/or methoxy-substituted isoflavones using LiAlH4 in refluxing THF provides an easy access to a number of α-methyldeoxybenzoins, possible metabolites of phytoestrogens in man. The synthesis of O-demethylangolensin 2b, 6′-hydroxyangolensin 2c, angolensin 2d, 1-(2,4-dihydroxyphenyl)-2-phenylpropan-1-one 2e, 1-(2-hydroxy-4-methoxyphenyl)-2-(4-hydroxyphenyl)propan-1-one2f, 4′-O-methylangolensin 2g, 1-(2-hydroxy-4-methoxyphenyl)-2-phenylpropan-1-one 2h, and 1-(2-hydroxyphenyl)-2-phenylpropan-1-one 2i is described. The Royal Society of Chemistry 1999.
- Salakka,Waehaelae
-
p. 2601 - 2604
(2007/10/03)
-
- Optically active compound and chiral liquid crystal composition containing the same
-
An optically active compound represented by the general formula (I) of: In the general formula (I); R is an alkyl or alkoxy group having 4 to 22 carbon atoms; Z is the one selected from the group consisting of --Ph--, --Ph(X)--, --Ph--Ph--, Ph(X)--Ph--, --Ph--cy--, --Ph(X)--cy-- and --py--Ph-- is a 1,4-substituted phenylene group; --Ph--Ph-- is a 4,4'-substituted diphenylene group; --cy-- is a trans-1,4-cyclohexane group, --py is 2,5-substituted pyrimide group; X is a halogen atom at the ortho-position to R; k is zero or 1, Y is the one selected from the group consisting of H, OH, halogen atoms and methyl group; C* is an asymmetric carbon atom; E is the one selected from the group consisting of methyl group, halogen atoms and CF3 ; L is an alkyl, aryl or aralkyl group having not more than 10 carbon atoms; and m is an integer of zero to 6 where m takes zero when Y is H and Z is --Ph-- or --Ph--Ph--. The optically active compound is usable as an ingredient for a liquid crystal composition which has high spontaneous polarization, exhibits the Sc* phase (chiral smectic C liquid crystalline phase) in a wide temperature range and high speed response.
- -
-
-
- HYDROGEN TRANSFER REDUCTION OF ISOFLAVONES
-
Hydrogen transfer reduction of isoflavones using ammonium formate and palladium charcoal provides an easy access to polyoxyisoflavanones and also to isoflavan-4-ols without the need for protection of the hydroxy groups.Optimized reaction conditions for im
- Waehaelae, K.,Hase, T. A.
-
p. 183 - 186
(2007/10/02)
-