. Aspects of the origin of life. Life; Biochemistry; Biochemistry; Biogenesis. 110 E. I. KLABUNOVSKli The action of the catalyst, in this case, resembles that of carboxylase. The action of alkaloids on the asymmetric reduction of/3-methyl- and j8-(a-naphthyl)- ciimamic acid in the presence of hydrocinchonine [46] would appear to be analogous, as would their action in the bromination of cinchonine salts of cin- namic acid or glucosamine cinnamate [47]. There is, of course, a catalytic action by alkaloids which is even more like that of enzymes. It is seen in cases when the possibihty of the for
. Aspects of the origin of life. Life; Biochemistry; Biochemistry; Biogenesis. 110 E. I. KLABUNOVSKli The action of the catalyst, in this case, resembles that of carboxylase. The action of alkaloids on the asymmetric reduction of/3-methyl- and j8-(a-naphthyl)- ciimamic acid in the presence of hydrocinchonine [46] would appear to be analogous, as would their action in the bromination of cinchonine salts of cin- namic acid or glucosamine cinnamate [47]. There is, of course, a catalytic action by alkaloids which is even more like that of enzymes. It is seen in cases when the possibihty of the formation of individual chemical compounds is ruled out. There are many such examples [48] of the formation of an excess of one antipode of esters by the catalytic action of brucine or strychnine. They are obtained by acetylation or benzoylation of racemic secondary alcohols or by the esterification of racemic chloranhydrides of acids. The dehydration of methylphenylcarbinol [49] also belongs to this group of reactions; it occurs in the presence of 2% camphorsulphonic acid with the formation of the optically active oxide. The asymmetric dehydration of a di- phenyldinaphthylallyl alcohol with the formation of a substituted allene [50] has also been reported. The general nature of the index is such that, in spite of their variety, all these reactions belong to the group of reactions catalysed by esterases. (+)-Camphorsulphonic acid is of special interest, being an asymmetric catalyst which, besides acting as an esterase, can also function asymmetrically as a ketoaldomutase. Asymmetric synthesis in the flavone series can be brought about by the catalytic action of (+)-bromocamphorsulphonic acid. Optically active 4'-methoxy-5 : 6-benzoflavonone has been obtained by the method of Fujise & Sasaki [51]. (4-)-7-Hydroxyflavone was obtained from 2 :4- dihydroxychalcone, and (+)-6 : 8-dimethyl-5 : 7-diacetoxy-4'-methoxyfiavone was obtained from 2' : 4' : 6'-triacetoxy-3' : 5'-dimethyl-4-
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