Objective Huanghuacai (Hemerocallis citrina) is a traditional vegetable with anti-inflammatory and anti-depressant effects. Its leaves are widely used in Taiwan and other regions to promote sleep, however, there are few reports on its chemical composition. This article aims to analyze the characteristic components of H. citrina leaves by fingerprint spectrum and to further determine the content of the index components, including chlorogenic acid, rutin, quercetin-3-O-glucoside, quercitrin, and quercetin, providing a basis for better utilization and quality evaluation of H. citrina leaves. Methods Firstly, the ethanol extraction method was used to prepare H. citrina leaves extract. Chromatographic separation was performed by DIKMA spursil C₁₈ column (250 mm × 4.6 mm, 5 mm) maintained at 30 ℃ and the mobile phase was acetonitrile-0.5% acetic acid water. The injection volume was 10 mL, the detection wavelength was 190—400 nm and the flow rate was 1 mL/min. Based on the principle of maximum absorption wavelength, the wavelengths of 258 nm was selected in two periods of 0—5.5 and 23—48 min, the wavelengths of 300 and 370 nm were selected in two periods of 5.5—23 and 48—80 min respectively, and a three-wavelength switching fingerprint was constructed. Secondly,a quantitative analysis of multi-components by single marker (QAMS) was used to determine the contents of chlorogenic acid, rutin, quercetin-3-O-glucoside, quercetin, and quercetin in ethanol extract of H. citrina leaves. Results The similarity of fingerprint spectrums of 10 batches of H. citrina leaves was above 0.90, and the three-wavelength switching fingerprint spectrums included 42 common peaks (accounting for more than 90% of the total peak area), of which 11, 25, and 26, 32 and 37 were identified as chlorogenic acid, rutin, quercetin-3-O-glucoside, quercitrin, and quercetin. With quercetin (S) as the internal reference, the relative correction factors of chlorogenic acid, rutin, quercetin-3-O-glucoside, and quercitrin were obtained by the QAMS as 1.402, 1.896, 1.268, 1.221. The average contents of the above five components in 10 batches of H. citrina leaves are 0.079, 0.086, 0.374, 0.325, 0.037 mg/g. There was no significant difference between the external standard method and QAMS. Conclusion The three-wavelength switching fingerprint spectrum constructed in this study has significantly increased the number of chromatographic peaks contained in any single wavelength fingerprint spectrum and can be used to characterize the chemical composition of H. citrina leaves. The QAMS further constructed can be used to determine the content of chlorogenic acid, rutin, quercetin-3-O-glucoside, quercitrin, and quercetin at one time. This study provides a methodological basis and reference for the comprehensive evaluation of H. citrina leaves quality.

Hemerocallis citrina Baroni. leaves  /  HPLC fingerprint spectrum  /  multi-wavelength switching  /  quantitative analysis of multi-components  /  QAMS  /  chlorogenic acid  /  rutin  /  quercetin-3-O-glucoside  /  quercitrin