81201-90-3

Upstream product

• 56-45-1 L-serin 
• 29809-11-8 <1-13C>phenol 
• 3881-07-0 <1-13C>-p-nitro-phenol 
• 3881-08-1 [1-¹³C]₄-aminophenol 
• 100790-30-5 C₅⁽¹³⁾CH₇NO*ClH 

Downstream Products

• 100790-35-0 L-<4'-13C>tyrosine benzyl ester p-toluenesulfonate 

Relevant academic research and scientific papers

Synthesis and NMR spectroscopy of stable isotope-labelled phenols and L-tyrosines

The syntheses of (17O)phenol from (17O)water, (18O)phenol from (18O)water, (1-13C)-phenol and (4-13C)phenol from (2-13C)acetone and (2-13C)phenol and (3-13C)phenol from (1-13C)acetone with high isotopic enrichment are described.The labelled phenols are converted into their corresponding L-tyrosines by the bacterium Erwinia herbicola.A full analysis of the 1H and 13C NMR spectra of phenol and L-tyrosine is reported.

An Efficient Chemomicrobiological Synthesis of Stable Isotope-Labeled L-Tyrosine and L-Phenylalanine

L-Tyrosine specifically labeled with 2H, 13C, 18O, or 15N has been synthesized by using a combination of organic synthetic methods and the β-tyrosinase enzyme activity of the bacterium Erwinia herbicola.The following L-tyrosine isotopomers were prepared: L-tyrosine from phenol and L-serine, L-tyrosine from phenol and L-serine, L-tyrosine from phenol and L-serine, L-tyrosine from ammonium sulfate, phenol, and pyruvate, and L-tyrosine from phenol and L-serine.The β-tyrosinase activitywas also used to prepare 2'-fluoro-L-tyrosine and 3'-fluoro-L-tyrosine from 3-fluorophenol and 2-fluorophenol, respectively.Phenol enriched with 13C was prepared by the condensation of acetone with nitromalonaldehyde, reduction of the resulting p-nitrophenol to p-aminophenol, and reductive removal of the nitrogen from the diazonium salt to form either - or phenol in a 40percent overall yield from acetone.The yields of L-tyrosine were typically around 90percent from labeled phenol.Labeled L-phenylalanine was chemically prepared from L-tyrosine in a 75percent overall yield.This was deemed the best approach to labeled L-phenylalanine, given the efficient method for preparing L-tyrosine from phenol.The approach to labeled L-phenylalanine represents a unique combination of chemical synthesis (phenol), biosynthesis (L-tyrosine), and finally chemical synthesis (L-phenylalanine).The chirality is introduced by the biochemical step, obviating the need for elaborate and inherently inefficient chiral manipulations.