Fig. 2

Production of rosmarinic acid and analogues in yeast. Representative LC–MS chromatograms obtained from analysis of the culture medium of a S. cerevisiae strain expressing 4CL5 and LaAT1 are shown. The strain was fed with 4-hydroxyphenyllactate and p-coumarate, caffeate and ferulate for the synthesis of p-coumaroyl 4′-hydroxyphenyllactate (a), caffeoyl 4′-hydroxyphenyllactate (b) and feruloyl 4′-hydroxyphenyllactate (c), respectively. Feeding the strain with 3,4-dihydroxyphenyllactate and p-coumarate, caffeate and ferulate allowed the synthesis of p-coumaroyl 3′,4′-dihydroxyphenyllactate (d), rosmarinic acid (e) and feruloyl 3′,4′-dihydroxyphenyllactate (f), respectively. The LC–MS chromatogram of a solution of authentic rosmarinic acid is also shown (g)