Gene duplication significantly contributes to the diversification of biosynthetic potential and increases the structural diversity of secondary metabolites. Here, we report the second alkyl salicylaldehyde derivative biosynthetic gene cluster in Penicillium roqueforti, being responsible for the formation of ethanolamine-containing derivatives. Heterologous expression and feeding experiments provided evidence for their formation via collaboration and modification with one cytochrome P450 and two flavin-containing monooxygenases in a highly ordered manner before and after ethanolamine incorporation.