Chiral separation of amide conjugates of jasmonic acid by liquid chromatography

Synthetic amide conjugates of (-)-jasmonic acid and its (+)-enantiomer were resolved by means of chiral liquid chromatography. The diastereomeric pairs prepared by chemical reaction of (+)-jasmonic acid with a series of (S)- or (R)-amino acids and with some (S)-amino acid alcohols were completely separated on Chiralpak AS using a mixture of n-hexane/2-propanol as mobile phase. The retention data indicate that the (-)-jasmonic acid conjugates eluted faster than those of the (+)-enantiomer, independent on the configuration of the bound amino acid. Likewise, enantiomeric derivatives of (+/-)-jasmonic acid and non-chiral amino acids were completely separated on the chiral stationary phase and showed the same elution sequence. The resolution factors, Rs,were found to range between 1.13 and 6.64. The separated compounds were chiroptically analyzed by measurement of the circular dichroism.