Phenyl lactic acid

L-2-Hydroxy-3-phenylpropionic acid (3-phenyl lactic acid) [20312-36-1 ] M 166.2, m 125-126 , [aJo -18.7 (EtOH), pK see below. Crystd from water, MeOH, EtOH or benzene. 

Sakai, K., and Kitagawa, T., An atypical case of tyrosinosis (1-parahydroxy-phenyl lactic acid uria), Jikeikai Med. J. 4, 1-15 (1957). 

Additionally, note that base hydrolysis of hyoscyamine gives ( )-tropic acid and tropine, with racemization preceding hydrolysis. Base hydrolysis of littorine gives optically pure phenyl-lactic acid, so we deduce that hydrolysis is a more favourable process than racemization. 

Figure 1. GC-MS analysis of phenyl lactic acid 3-methylbutyl ester (2) and of the corresponding 2-methylbutyl ester (3) after sample preparation I (SP I) and subsequent preparative enrichment using MDGC. GC column DB-1.

Robins, R.J., Woolley, J.G., Ansarin, M., Eagles, J. and Goodfellow, B.J. (1994a) Phenyl-lactic acid but not tropic acid is an intermediate in the biosynthesis of tropane alkaloids in Datura and Brugmansia transformed root cultures. Planta, 194, 86-94. 

Fig. 9.34. Influence of chromatographic conditions on retention and/or enantioseicctivity using CSP I (see Fig. 9.32) a.s the stationary phase (conditions T. 2.5°C flou rate. I ml/min UV detection), (a) Influence of mobile phase pH on k , and u of B/-lcucine (mohilc phase McOH-ammonium acetate (80 20) pHa adjusted with AcOH). (b) Influence of buffer concentration on retention (In/ , ) and enantioseicctivity (Inor) of B/-leucine (mobile phase MeOH-ammonium acetate (80 20) pH., = 6.0). (c) Influence of mobile phase solvent type on enantioseicctivity (Ina) of 3-phenyl lactic acid at different buffer cxincentrations (mobile phases water, methanol, acetonitrile, respectively, and acetic acid (mM sec plot -triethylaniine = 4 I). (d) Influence of temperature on Ina of DNS-valine (mobile phase MeOH-O.I M ammonium aeetate (80 20) pHa = 6.0) (reprinted with permission from Ref. 1388 ),...

The origin of the phenyl-lactic acid moiety of littorine (33) in Datura sanguinea has been shown to be from phenylalanine." A specific incorporation of [1- " C]-and [3- C]-phenylalanine was observed into carbons 1 and 3 respectively of the side chain of the phenyl-lactic acid moiety in littorine. That phenylalanine was a better precursor for littorine than for hyoscyamine (30) and hyoscine suggests perhaps that phenylalanine is a more immediate precursor of phenyl-lactic acid than of tropic acid. 

Phenylpyruvic acid (36) has been found to be a similarly efficient precursor for tropic acid as phenylalanine, but the ready interconversion of phenylalanine and (36) in vivo makes it difficult to say which is closer biosynthetically to tropic acid. Phenyl-lactic acid (37), as it appears in the alkaloid littorine (35), is known to be derived from phenylalanine, and it was found to be a better precursor than phenylalanine for the tropic acid moiety of tropane alkaloids. ... 

The tropic acid moiety (1) found in some tropane alkaloids, e.g. (39), is known to be derived from phenylalanine, and the necessary skeletal rearrangement involves intramolecular shift of the carboxy-group of the amino-acid cf. ref. 7. Competitive feeding experiments with phenylpyruvic acid, phenyl-lactic acid (42), and phenylalanine in Datura stramonium plants has given results which indicate that phenyl-lactic acid is a later intermediate in the formation of tropic acid than phenylalanine. ... 

Chemical simulation" of the formation of tropic acid (28) in vivo from optically active phenylalanine was achieved by trifluoroacetolysis of O-p-nitroben-zenesulphonyl 3-phenyl-lactic acid (27). 

Atrolactinic Acid Phenyl-lactic acid, 1-phenyl-l-hydroxypropionic acid, atrolactic acid) HC... 

The direct polycondensation technique can be applied to the syntheses of various copolymers that should have different properties and degradability. For example, copolymers of L-lactic acid and phenyl-substituted a-hydro)q acids, such as l- and o-mandelic acids (l-, d-MA) and phenyl-lactic acid (Phe-LA) have been prepared. Polyglactin is also obtainable by the direct co-polycondensation of glycolic acid and L-lactic acid. ... 

Several inborn errors of metabolism are concerned with the metabolism of L-phenylalanine and L-tyrosine in mammals. In several cases it has been possible to demonstrate that such biochemical disorders are associated with the absence or partial deficiency of a particular enzymatic activity. Phenylketonuria results from the absence of a normal L-phenylalanine hydroxylase activity and individuals suffering from this disease are unable to convert L-phenylalanine to L-tyrosine. Under these conditions the metabolism of the amino acid to phenylpyruvic acid, phenyl-lactic acid and phenyl acetyl glutamine is greatly exaggerated. Phenylketonuria is a severe disorder and results in a marked mental retardation, particularly in children. It is generally assumed that it is the accumulation of abnormal metabolites which is responsible for the mental symptoms associated with the disease. 

DIBOA was quantified and purified. Phytotoxicity was compared in bioassays for germination and seedling growth inhibition against weeds and tomato with P-phenyl-lactic acid (PLA) and P-hydroxybutyric acid (HBA), two previously identified and known phytotoxins from rye. Both DIBOA and BOA were consistently more toxic than PLA and HBA (Barnes Putnam 1987). 

DL-[2- C]-2-Hydroxy-3-phenylpropanoic acid (phenyl-lactic acid)... 

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