Separating and Identifying the Four Stereoisomers of Methyl Jasmonate by RP‐HPLC and using Cyclodextrins in a Novel Way

Abstract Introduction Several authors have reported on the different bioactivities of methyl jasmonate (MeJA) stereoisomers. However, no simple, precise and cheap method for separating and identifying them using reversed‐phase high performance liquid chromatography (RP‐HPLC) has been developed. Objective (1) To create a simple, precise and cheap method for separating and identifying the four stereoisomers present in commercial racemic mixtures of MeJA and (2) to identify the four stereoisomers using molecular docking techniques and coinjection. Materials and Methods – RP‐HPLC using a 250 mm C18 column and different proportions of cyclodextrins (CDs) and organic solvents was applied to a commercial sample of racemic MeJA. Results The results show that the best conditions for separating the MeJA stereoisomers are: 20% methanol in the mobile phase, a temperature of 45 °C and a 16 mM concentration of methyl‐ β ‐cyclodextrin (M‐β‐CD). A simple C18 250 mm column and a flow rate of 1.25 mL/min were used. The reduction in the retention time of MeJA observed when M‐β‐CD is added to the mobile phases was used to determine the complexation constants of the guest/CD complex and compared with the obtained when other CDs were used. The K F for M‐β‐CD (117.49 ± 5.9 1/M) was obtained with a 1:1 stoichiometry. The four stereoisomers were identified by molecular docking techniques and coinjection of a commercially available rosemary essential oil. Conclusion The new method identified and classified the four stereoisomers of MeJA in the following ordination: (−)epiMeJA, (−)MeJA; (+)MeJA and (+)epiMeJA. These results could be used to improve the elicitation of cell cultures with only the best isomer. Copyright © 2016 John Wiley & Sons, Ltd.