Figure 4

Mass spectrometry analysis of reaction products.

Electrospray ionization mass spectra were obtained after liquid chromatography–mass spectrometry analysis of the culture medium of recombinant strains and of authentic standards; the corresponding mass spectra are shown in this figure. Negative ion data for the standard compounds were as follows: p-coumaric acid, m/z = 163.0401; caffeic acid, m/z = 179.0350; ferulic acid, m/z = 193.0506; resveratrol, m/z = 227.0714; naringenin, m/z = 271.0612; bisdemethoxycurcumin, m/z = 307.0976 and vanillin, m/z = 151.0415. (a) Sample from recombinant strain harboring sam8/pACYC (upper panel) and authentic 4-coumaric acid standard (lower panel). (b) Sample from recombinant strain harboring sam8-sam5/pACYC (upper panel) and authentic caffeic acid standard (lower panel). (c) Sample from recombinant strain harboring sam8-sam5-comt/pACYC (upper panel) and authentic ferulic acid standard (lower panel). (d) Sample from recombinant strain harboring fcs-ech/pET (upper panel) and authentic vanillin standard (lower panel).