[Studies on chemical constituents from herbs of Taraxacum mongolicum].

To investigate the chemical constituents of the herbs of Taraxacum mongolicum.The chemical constituents were isolated by various column chromatographic methods and their structures elucidated mainly by NMR and MS evidences.Forty-four components were obtained and identified were as artemetin (1), quercetin (2), quercetin-3', 4', 7-trime-thyl ether (3), luteolin (4), luteolin-7-O-beta-D-glucopyranoside (5), luteolin-7-O-beta-D-galactopyranoside (6), genkwanin (7), isoetin (8), hesperetin (9), genkwanin-4'-O-beta-D-lutinoside (10), hesperidin (11), quercetin-7-O-[beta-D-glucopyranosyl (1-->6) -beta-D-glucopyranoside (12), quercetin-3, 7-O-beta-D-diglucopyranoside (13), isoetin-7-O-beta-D-glucopyranosyl- 2'-O-alpha-L-arabinopyranoside (14), isoetin-7-O-beta-D-glucopyranosyl-2'-O-alpha-D-glucopyranoside (15), isoetin-7- O-beta-D-glucopyranosyl-2'-O-beta-D-xyloypyranoside (16), caffeic acid (17), furulic acid (18), 3-O-caffeoylquinic acid (19), 3, 5-di-O-caffeoylquinic acid (20), 3, 4-di-O-caffeoylquinic acid (21), 4, 5-di-O-caffeoylquinic acid (22), 1-hydroxymethyl-5-hydroxy-phenyl-2-O-beta-D-glucopyranoside (23), p-hydroxybenzoic acid (24), p-coumaric acid (25), 3, 5-dihydroxylbenzoic acid (26), gallic acid (27), gallicin (28), syringic acid (29), 3, 4-dihydroxybenzoic acid (30), caffeic acid ethyl ester (31), esculetin (32), rufescidride (33), mongolicumin A [6, 9, 10-trihydroxy-benzoxanthene-1, 2-dicarboxylic acid] (34), mongolicumin B [1 l-hydroxy-2-oxo-guaia-1 (10), 3, 5-trien-8, 12-lactone] (35), isodonsesquitin A (36), taraxacin (37), sesquiterpene ketolactone (38), taraxasteryl acetate (39), phi-taraxasteryl acetate (40) and lupenol acetate (41), palmitic acid (42), beta-sitosterol (43), and stigmasterol (44).Four compounds (14, 15, 34 and 35) were new compounds, compounds 1, 3, 6-13, 20-22, 30 and 31 were isolated from this genus for the first time, while compounds 18, 23-29, 32 and 37-42 were obtained from this species for the first time.