Liquid chromatographic electrospray mass spectrometric study of the phthalides of Angelica sinensis and chemical changes of Z-ligustilide

High-performance liquid chromatography-electrospray ionization-mass spectrometry has been applied to analyze the chemical constituents of Danggui (the rhizome of Angelica sinensis) and to study chemical changes of Z-ligustilide. Twelve phthalides were unambiguously identified as senkyunolide I (3), senkyunolide H (4), sedanenolide (8), butylphthalide (9), E-ligustilide (13), Z-ligustilide (14), Z-butylidenephthalide (15), Z,Z'-6.8',7.3' -diligustilide (16), angelicide (17), levistolide A (18), Z-ligustilide dimer E-232 (19) and Z,Z'-3.3',8.8'-diligustilide (20) in Danggui extract. The existence of 12 other phthalides (2, 5-7, 11, 12, 22-27), ferulic acid (1) and coniferyl ferulate (10) in Danggui extract has also been demonstrated. Phthalides 3, 4, 16-18 and 20 were determined to be the products from chemical change of Z-ligustilide. This is the first report of the existence of 16 compounds (2-8, 10-12, 20, 22-25 and 27) in Danggui extract. (C) 1998 Elsevier Science B.V. All rights reserved.