Resolution of racemic phenylalanine, tyrosine, and tryptophan.

A Crystallization-Induced Asymmetric Transformation using Racemic Phenyl Alanine Methyl Ester Derivatives as Versatile Precursors to Prepare Amino Acids

L-Tyrosine and L-Dopa are the precursors in the biological synthesis of amine neurotransmitters. On the other hand, phenylalanine as an aromatic amino acid (AAA) is a precursor in the synthesis of L-Tyrosine and L-Dopa. For some substrates such as amino acids, resolution by the formation of diastereomers offers an attractive alternative. Among different methods in this case, crystallization-ind...

Resolution of racemic phenylalanine.

Phenylalanine has previously been resolved by fractional crystallization of the brucine salt of formyl-nn-phenylalanine (1) or of the cinchonine salt of benzoyl-nn-phenylalanine (2). Enzymatic methods have also been used for the resolution. According to the method of Gilbert, Price, and Greenstein (3), racemic phenylalanine is resolved by subjecting its Nchloroacetylated derivative to asymmetri...

Effect of phenylalanine and tryptophan on morphological and physiological characteristics in colocynth (Citrullus colocynthis L.)

The medicinal plant bitter apple belongs to Cucurbitaceae family. To study the effect of phenylalanine and tryptophan amino acids on morphological and physiological characteristics of Citrullus colocynthis L., an investigation was conducted according to a completely randomized block design with four treatments and three replications in University of Zanjan, Iran. The studied factors were consis...

Comparison of phenylalanine and tyrosine in urine of patients with vitiligo and normal subjects

Amino acids are one of the most necessary substances in intracellular metabolic processes.aromatic aminoacids such as phenylalanine and tyrosine are precursor of melanin so are important materials for the skin pigmentation.metabolic disorders in the melanin synthesis causes milky macules on the skin of patients,known as vitiligo.these patients are hypersensitive to sunlight and consequently at ...

Phenylalanine Hydroxylase, Tyrosine Hydroxylase, and Tryptophan Hydroxylase