| Systematical study on the chemical constituents of traditional Chinese herbs is one of important routes to discover bioactive compounds. There are about 60 species belong to the genus Dracocephalum, family Labiatae. These plants distribute in alpine and semidry regions mainly in temperate Asia, with a few in Europe, one in North America. There are about 32 species, 7 variations in China. Several species belong to the genus Dracocephalum are used as folk medicine for the treatment of tracheitis and cardiovascular disease in Xinjiang autonomous region. Dracocephalum rupestre Hance and Drcocephalum moldavica L can be applied for the protection of cardiac ischemia. This dissertation mainly focused on the chemical studies of these two herbal plants. Bioactivities including antitumor, protecting cardiac cells and the free radical scavenging were investigated for some flavonoids. Determinations of the dominating flavonoids in Dracocephalum rupestre were achieved by HPLC.Dracocephalum rupestre Hance is a perennial herb distributed in northern China, i.e. Liaoning, Neimeng, Shanxi, Qinghai Province. Its aerial parts were commonly employed in relieving headache, soothing sore throat, subsiding cough, and preventing icterohepatitis in traditional Chinese medicine. By Silica gel chromarography, Sephadex LH-20 chromatography and Chiral HPLC, thirty-eight compounds were isolated from the ethanol extract of this plant. Based on spectroscopy methods, all the compounds were elucidated as: m-hydroxybenzoic acid (1), 3-methoxy-4-hydroxybenzoic acid (2), 3,5-dimethoxy-4-hydroxybenzoic acid (3), 5,7-dihydroxychromone (4), 5,7-dihydroxychromone-7-O-glucoside (5), betulin (6), betulinic acid (7), ursolic acid (8), naringenin (9), naringenin-7-O-glucoside (10), apigenin (11), apigenin-7-O-glucoside (12), eriodityol (13), eriodityol-7-O-glucoside (14), luteolin (15), luteolin-7-O-glucoside (16), 25,65-dracorupesin (17), 2R,6S-dracorupesin (18), 2R,6S-dracorupesin (19), 2S,6R-dracorupesin (20), 2R,5"S-dracocephin A (dracocephin A1, 21), 2S,5"S-dracocephin A (dracocephin A2, 22), 2S,5"S-dracocephin A (dracocephin A3, 23), 2R,5"R-dracocephin A (dracocephin A4, 24), 2S,5"S-dracocephin B (dracocephin B1, 25), 2R,5"S-dracocephin B (dracocephin B2, 26), 2R,5"R-dracocephin B (dracocephin B3, 27), 2S,5"R-dracocephin B (isodracocephin B4, 28), 2R,5"S- dracocephin C (dracocephin C1, 29), 2S,5"S-dracocephin C (dracocephin C2, 30), 2S,5"R- dracocephin C (dracocephin C3, 31), 2R,5"R-dracocephin C (dracocephin C4, 32), 2S',5"S-dracocephin D (dracocephin D1, 33), 2R,5"S-dracocephin D (dracocephin D2, 34), 2R,5"R-dracocephin D (dracocephin D3,35), 2S,5"R-dracocephin D (dracocephin D4, 36), sitosterol (37), daucosterol (38). 17—36 were novel compounds. 17-20 were characterized as two diastereomeric pairs of enantiomers with an unprecedented flavanone fused benzopyran skeleton. Using HPLC-CD, the on-line CD spectra of 17-20 were obtained and the exciton chirality method was used for the determination of the absolute configuration of them. Compounds 21—24,25—28,29—32,33—36 were all conjugates of flavanone with pyrrolidin-2-one and each group were two diastereomeric pairs of enantiomers with the same planar structure. The single stereoisomers of 21-36 were prepared by chiral HPLC using Chiralpak AS-H column.The stereochemical features of 21-24 were elucidated on the basis of measurements of NMR, CD and by combined with X-ray analysis. Investigating the CD behavior of the stereoisomers, the chiroptical contributions of the two stereocenters were found to behave additively. By substraction of their respective contributions, the CD contributions of the chiral carbon in the pyrrolidin-2-one ring were discussed. Based on the deduced CD rules, the stereostructures of compounds 25-36 were assigned unambiguously.Drcocephalum moldavica L, habitually used herb by Weiwuer and Meng nationality, mainly distributed in Heilongjiang, Jilin, Liaoning, Neimenggu, Gansu, Shanxi, Qinghai and Xinjiang in China. It was a annual herb and was cultivated in southern Xinjiang autonomous region. The aerial parts of this herb were employed in soothing the nerves, relieveing a cough and protecting the heart. By MCI gel chromarography, Silica gel chromatography and Sephadex LH-20 chromatography, thirteen compounds were isolated from the ethanol extract of this plant. Based on spectroscopy methods, all the compounds were elucidated as: luteolin (15), gardenin B (39) , scrophulein (40) , salvigenin (41) , isorhamnetin (42) , kaempferol (43) , acacetin (44) , agastachoside (45) , tilianin (46) ,ursolicacid (8) and betulinic acid—28—ethyl ester (47) 。For some flavonoids isolated from the two herbs, DPPH·scavenging test was applied to study the free radical scavenging activity. The cytotoxity to K562 cells (antitumor effect) and protection to cardiac cells was also studied by MTT. 3',4'-dihydroxyl substituted flavonoids possessed preferable DPPH- scavenging ability; flavonoids with multi-methoxyl substitution showed potent anticancer effect; flavanones showed significant protective effects on doxorubicin-mediated cytotoxicity in H9C2 cells.Using RP-HPLC method, the contents of naringenin-7-O-β-D-glucoside, eriodityol-7-O-β-D-glucoside and luteolin-7-O-β-D-glucoside in D. rupestre were determined. The flavonoids contents in different parts of D. rupestre and in the aerial parts collected in different seasons were compared. It indicated that the content of the three flavonoid glucosides was maximum in the leaves, and it was different in different seasons. The HPLC method was suitable for the quality evaluation of the herbs.
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