HPLC analyses of the enzymatic reactions involved in the HBC tailoring pathway. HbcF-catalyzed reaction with (i) 6 or (iii) 9 as the substrate. (v) HbcH-mediated reaction with 9 as the substrate. (vii) HbcG-catalyzed reaction with 8 as the substrate. (ii, iv, vi, and viii) Control reactions. (ix) Authentic standards. The results obtained with the Her enzymes are shown in Figures S83, S84, S86, and S87.