Isolation, purification, and identification of the main phenolic compounds from leaves of celery (Apium graveolens L. var. dulce Mill./Pers.)

We developed a simple and meaningful preparative method for the separation and purification of the main phenolic compounds from the leaves of celery (Apium graveolens L. var. dulce Mill./Pers.) and we established an accurate and specific analytical method for the identification of the main phenolic compounds from celery leaves. The crude extract from celery leaves was prefractioned by polyamide resin to enrich the phenolic compounds. They were then purified further by preparative high-performance liquid chromatography, and seven main phenolic compounds were obtained: including chlorogenic acid, luteolin 7-O--d-apiofuranosyl(12)--d-glucopyranoside, luteolin 7-O--d-glucopyranoside, apiin, chrysoeriol 7-O--d-apiofuranosyl(12)--d-glucopyranoside, luteolin 7-O-[-d-apiofuranosyl(12)-(6-O-malonyl)]--d-glucopyranoside, and apigenin 7-O-[-d-apiofuranosyl(12)-(6-O-malonyl)]--d-glucopyranoside. Their purities were measured by using high-performance liquid chromatography, and their chemical structures were confirmed using UV spectrophotometry, ultra high performance liquid chromatography with quadrupole time-of-flight tandem mass spectrometry, and NMR spectroscopy. Our studies indicate that preparative high-performance liquid chromatography combined with polyamide resin is a simple and meaningful preparative method for the separation and purification of phenolic compounds from the leaves of celery or other plants, and the use of UV spectrophotometry, ultra high performance liquid chromatography with quadrupole time-of-flight tandem mass spectrometry, and NMR spectroscopy is an accurate and specific analytical method for the identification of phenolic compounds.