Whatever the acyl donor and the acyl acceptor (DHLc, DHLp, Lc, Lp), the main interactions within enzyme/substrates complexes were hydrophobic in nature. More specifically, the residues Ile189, Ile285 and Val154 located on both sides of the cavity entrance interact with cycle B and the methyl groups of the STLs (Figure . and Figure ). Hydrogen bond interactions were also observed between the hydroxy groups of the STLs and the residue Thr40 from the oxyanion hole, as well as with the less buried residue Gln157. When one hydroxy group interacts with Thr40, the other one on the opposite side of the molecule interacts with Gln157, and vice versa. Furthermore, hydrogen bond interactions where also observed between the residue Ala282 and the α,β-unsaturated ketone within cycle A (cyclopentenone) (Figure .).