Development and validation of a simultaneous HPLC with UV detection method for quantifying five bioactive compounds in diverse Lactuca sativa varieties

This study evaluated five bioactive marker compounds—chlorogenic acid, lactucin, quercetin, scutellarin, and lactucopicrin—in three lettuce (Lactuca sativa) cultivars: 'Cheongchima', 'Cheongharang I', and 'Cheongharang II', using HPLC with UV detection. The method showed excellent linearity (R²>0.999), with detection limits of 0.36 to 1.51㎍/mL and quantification limits between 1.09 and 4.56 ㎍/mL. It also exhibited good precision (relative standard deviation, RSD: 0.11- 3.93%) and accuracy (RSD: 0.04-3.50%) with recovery rates of 95.06-104.28%. Among extracts, the 60% ethanol extract of 'Cheongharang I' exhibited the highest levels of chlorogenic acid (745.34㎍/mL) and quercetin (632.08㎍/mL). Lactucin was most abundant in the 0% ethanol extract of 'Cheongharang II', while scutellarin peaked in the 60% ethanol extract of 'Cheongharang I' (1,945.47㎍/mL). Lactucopicrin was highest in the 100% ethanol extract of 'Cheongharang II' (23.49㎍/mL). These findings provide a reliable analytical basis for quality control and bioactive profiling of lettuce cultivars.