Unraveling the interaction mechanism between enantiomers of lactone compounds (γ-octalactone and γ-undecalactone) in Longjing tea and OR1A1 olfactory receptor using molecular docking and molecular dynamics simulation

The interactions of key lactone chiral compounds (gamma-octalactone and gamma-undecalactone) in Longjing tea with olfactory receptors (taking OR1A1 as an example) were elucidated through molecular docking and molecular dynamics. The results showed that the thresholds for gamma-octalactone, (R)-(+)-gamma-octalactone, and (S)(- )-gamma-octalactone were 82 mu g/L, 300 mu g/L, and 125 mu g/L, respectively. The thresholds for gamma-undecalactone, (R)(+)-gamma-undecalactone and (S)-(- )-gamma-undecalactone are 6 mu g/L, 4 mu g/L, and 10 mu g/L, respectively. The binding of (S)-(- )-gamma-octalactone (-18.389 kJ/mol) to the olfactory receptor OR1A1 is more stable than that of the (R)(+)-gamma-octalactone (-17.280 kJ/mol). On the contrary, (R)-(+)-gamma-undecalactone (-19.146 kJ/mol) is binding stability than (S)-(- )-gamma-undecalactone (-19.115 kJ/mol). Molecular dynamics simulations imply that the binding of (S)-(- )-gamma-octalactone and (R)-(+)-gamma-undecalactone to OR1A1 are primarily through polar and hydrogen bonding interactions, whereas (R)-(+)-gamma-octalactone and (S)-(- )-gamma-undecalactone are relies on hydrophobic interactions. These findings provide scientific support for improving the quality of Longjing tea.