Figure 3
The biosynthetic pathways reconstituted on eYACs in the FL1 library included PAL (phenylalanine amonialyase), C4H (cinnamate 4-hydroxylase), 4 CL (4 coumarate:CoA ligase), CHS (chalchone synthase), CHI (chalchone isomerase), F3H (flavanone 3-hydroxylase), and FLS (flavonol synthase). No specific TAL (tyrosine ammonialyase) was used, but some PAL enzymes are known to also have this function. For the FL2 library the enzymes PAL and C4H were omitted. As shown for cinnamate the phenyl ring can be differently substituted. Cinnamate has hydrogen in all 3 positions, whereas coumarate has R4 = OH, caffeate has R3 = OH; R4 = OH, and umbelleate has R2 = OH; R4 = OH. Some unnatural derivatives, substituted with halogens at the R3 and R4 positions, were also used as precursors in this study.