Figure 1

RP-HPLC chromatogram (λ = 200 nm) of the reaction of a crude extract of A. niger N402 biomass with 18:2. Indicated are peak 1 (9.2 min; 8,11-diHOD), peak 2 (10,8 min; 5,8-diHOD), peak 2* (10.9 min, λ_max 218 nm; lactonized 5,8-diHOD), and peak 3 (15.1 min; 8-HOD), the major fatty acid metabolites. RP-HPLC analysis and purification of the fatty acid products were carried out on a Cosmosil 5C18-AR (5 μm; 250 × 4.6 mm i.d.; Nacalai Tesque, Kyoto, Japan) reversed-phase column using a gradient system (solvent A: methanol/water/acetic acid (50:50:0.01, v/v/v); solvent B: methanol/water/acetic acid (95:5:0.01, v/v/v)) with the following gradient program: 45% solvent A for 1 min, followed by a linear increase of solvent B up to 100% within 10 min and finally an isocratic post-run at 100% solvent B for 10 min. The flow-rate was 1 mL/min. Reference compounds of dihydroxy fatty acids had a retention time of 9–11 min, whereas monohydroxy fatty acid references eluted between 15–18 min.