Synthetic and preliminary hemodynamic and whole animal toxicity studies on (R,S)-, (R)-, and (S)-2-methyl-3-(2,4,5-trihydroxyphenyl)alanine.

The synthesis, resolution, and absolute configuration assignment of 2-methyl-3-(2,4,5-trihydroxphenyl)alanine (6-OH-alpha-Me-Dopa) are reported. Hemodynamic studies in the rat have shown that this structural analogue and potential metabolite of the clinically useful drug (S)-alpha-Me-Dopa possesses weak hypotensive activity which resides in the R enantiomer. LD50 studies in mice have established that 6-OH-alpha-Me-Dopa is over four times more toxic than alpha-Me-Dopa. Chronic exposure to 6-OH-alpha-Me-Dopa leads to renal and hepatic lesions. The case of oxidation of this hydroquinone to the electrophilic quinone species may contribute to its enhanced toxicity compared to alpha-Me-Dopa.