DL-Dopa

C14H71N 112-18-5) see Dodeclonium bromide dodecyl(2-phenoxyethyl)amine (C20H35NO) see Domiphen bromide DL-dopa... 

Sawaguchi T, Goldman-Rakic PS. 1994. The role of Dl-dopa-mine receptor in working memory Local injections of dopamine antagonists into the prefrontal cortex of rhesus monkeys performing an oculomotor delayed-response task. J Neurophysiol 71 515-528. 

Further ternary complexes, e.g. [Cu(L-aspartateXL-ornithine)], have been studied spectrophotometrically. A range of spectral techniques have been used to look at the copper(ii) complex of DL-3,4-dihydroxyphenylalanine (dl-DOPA) and copper(ii)-amino-acid-catechol, e.g. (142), systems. 2f-Ray absorption edge spectrometry... 

Further evidence implicating betalamic acid (176) in betalain biosynthesis comes from a study of the biosynthesis of the acid itself in Portulaca grandifiora Both [2- CJ- and [l- C]-DL-dopa were incorporated into betalamic acid. Degradation of the betalamic acid (176) derived from [l- C]dopa showed that the incorporation was specific, almost all the activity being confined to the carboxy-groups (and presumably only C-19 is labelled). This pattern of dopa incorporation is the same as for the betalains, a requirement if (176) is to be an intermediate in betalain biosynthesis. 

DL-Dopa may be first prepared from vanilline and glycine which is then converted to the DL-N-acetyl-3-methoxy-4-acetoxy phenylalanine. The resulting product is then resolved by means of a-phe-nyl-ethyl amine which upon hydrolysis with aqueous HBr forms levodopa. 

Fig. 2. Purified mushroom PPO fractions run on a non-denaturing polyacrylamide gel (10% PAGE). Lanes 1 and 9 are blanks where sample buffer only was applied lanes 2, 5 and 3, 6 correspond to aliquots of peaks A and B of the Igg-Sepharose column, respectively. Lanes 4 and 7 are of unpurlfled enzyme and lane 8 is an aliquot of redlssolved freeze dried unpurlfled enzyme (Sigma Chemical Co.). The left part of the gel (lanes 1, 2, 3 and 4) was stained by substrate (DL-dopa 5 nM) reaction In 0.1 sodium phosphate buffer, pH 7.0, with oxygen replenished by bubbling through the Incubation solution. The band In zone a stained brown immediately, while there was a delay of 10 min In the start of color appearance In zone b. The right hand side of the gel (lanes 5, 6, 7, 8, 9) was stained for protein with Coomassle brilliant blue.

An alternative strategy relies on differing crystal sizes of the two reaction products, which therefore can be successfully separated. For example, in the resolution of DL-DOPA and its hemihydrochloride DL-DOPA 0.5 HCl, the following reaction occurs ... 

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