| abstract |
The invention relates to the preparation of water-soluble L-tyrosine derivatives having the formula <IMAGE> where R1 is a L-malyl, L-lactyl, L-glutamyl or L-aspartyl group, R2 is a -OH, -OM, methoxy, ethoxy or amino group and M is an alkaline metal, by enzymatic condensation of an acid selected among L-malic, L-lactic, L-glutamic and L-aspartic acids, with a L-tyrosine derivatives selected among the ethyl and methyl esters and the amide of L-tyrosine. The enzyme is obtained from a culture of Micrococcus casealyticus. The compounds where R1 is a L-malyl or L-lactyl group are new. Said L-tyrosine derivatives are useful in cosmetic and pharmaceutical compositions, such as tanning and sun compositions. |