Analysis of products. GC-MS analysis of C6- (A) and C9-aldehydes (B) formed by incubation of linoleic acid and yeast cell crude extracts of Cm-9/13-HPL (Cm), Cl-13-HPL (Cl), Nb-9-LOX (Nb), and Nb-9-LOX in combination with Cl-13-HPL (Nb+Cl) or Cm-9/13-HPL (Nb+Cm). The mass spectra of peaks 1 to 4 yield fragmentation patterns identical to n-hexanal (1), (3Z)-nonenal (2), putative (2Z)-nonenal (3), and (2E)-nonenal (4), respectively. (C) LC-MS analysis of the products generated by incubation of linoleic acid with yeast cell extracts of Nb-9-LOX (Nb), Nb-9-LOX and Cl-13-HPL (Nb-Cl), or Nb-9-LOX and Cm-9/13-HPL (Nb-Cm). The product was detected by monitoring m/z 171. (D) MS/MS spectrum of the [M-H]- ion (m/z 171) of peak 5. Judging by the fragmentation pattern, peak 5 is assumed to be 9-oxo-nonanoic acid.