Chemical Constituents of Plants from the Genus Dracocephalum
Download 0.51 Mb.
|
Chemical Constituents of Plants from the Genus Dracocephalum
|
threo-Guaiacylglycerol 3-O-(6-O-p-hydroxybenzoyl)-b-d-glucopyrano- side
D. forrestii [44]
Lignans. Eleven lignans, 222 – 232, were isolated from this genus [13][24] [29] [30][34] [37][44]. 222 – 224 and 227 were isolated from D. moldavica. Compounds 223 and 225 – 229 were isolated from D. heterophyllum. Compound 223 was also found in D. tanguticum. Compounds 230 – 232 were isolated from D. forrestii. Phenols. Eleven phenols, 233 – 243, were found in four plants, D. moldavica, D. ruyschiana, D. heterophyllum, and D. rupestre [6] [23][24][29] [31] [ 34] [45]. Coumarins. Only one coumarin, skimmin (244), was isolated from D. tanguticum [7]. Cyanogenic Glucosides. Two cyanogenic glucosides, peregrinumicin A (245) and prunasin (246), were isolated from D. peregrinum [ 31][ 35]. Others. Besides the above-mentioned compounds, Dracocephalum genus comprise amino acids [46]. Biological Activities. – 3.1. Antioxidant Activity. The D. moldavica extract demonstrated antioxidant activity in various assays. The antioxidant properties assessed include iron(III) reduction, iron(II) chelation, 1,1-diphenyl-2-picrylhydrazyl, 2’-azinobis( 3-ethylbenzthiazoline-6-sulfonate), and superoxide anion free-radical scavenging. In addition, the ability of the extract to protect 2-deoxy-d-ribose and bovine brain-derived phospholipids against HO. radical-mediated degradation was assessed. However, the extract was not as potent as the positive control, except in the phospholipid-based assay where its HO. radical scavenging activity was statistically indistinguishable from that demonstrated by pycnogenol [29]. Abd El-Baky et al. reported that the essential oil of D. moldavica showed a moderate antioxidant activity compared to that of a-tocopherol, BHT, and BHA [47]. Guo et al. used a biochemical assay method to test the reducing effects of D. moldavica polysaccharides (DMP) on free-radical oxygen species. Lycium barbarum polysaccharides were selected as control. The DMP showed significant reducing effects on O. , HO., H O , were concentration dependent, and more active than Lycium 2 2 2 barbarum polysaccharides [48]. In addition, in the in vitro malonyldialdehyde (MDA) test, the essential oil of Tibetan medicine D. heterophyllum Benth also exhibited antioxidant activity with inhibition of lipid peroxidation of 59.3% at the concentration of 0.5 mg/ml [20]. Antihypoxic Activity. Hai et al. reported that the aqueous extracts of D. tanguticum could significantly reduce the oxygen consumption of mice by intra- peritoneal injection of 2.5 g/kg and 5.0 g/kg (P < 0.01). The tissue resistance to hypoxia induced by KCN and NaNO2 was increased and consequently, the survival time of mice extended significantly [49]. In addition, the aqueous extracts could significantly prolong decapitation-induced gasping duration in mice and the survival time of mice after bilateral carotid ligation (P > 0.01) [50]. The whole plant of D. heterophyllum, which was fed directly to rabbits, showed significant hypoxic activity in several experimental models measuring the density data of RBC, Hb, Hct [51], megakaryocytic [52], and the bone marrow s sinusoids (BMS) , the changes of mitochondrials and smooth endoplasmic reticulums in Leydig s cell , content of amine [55], the ultrastructure change in the cerebral cortex [56], and the area CA3 of hippocampus [57]. Immunomodulatory Activity. Kim et al. investigated the anti-allergy effect of aqueous extract of D. argunense (DAAE). They found that DAAE inhibited compound 48/80-induced systemic reactions and serum histamine release in mice, attenuated IgE-mediated skin allergic reaction. The level of cAMP was transiently increased by treatment of DAAE. The extract could also block the phorbol 12- myristate 13-acetate (PMA) plus calcium ionophore A23187-induced p38 mitogen- activated protein kinase (MAPK) activation, decreased the secretion of pro- inflammatory cytokines, such as tumor necrosis factor-a and interleukin-6 in mast cells. These findings provided evidences that DAAE inhibited mast cell-derived allergic reactions, and showed the involvement of cAMP for histamine release and p38 MAPK for pro-inflammatory cytokine secretion [58] [59]. Calycopterin (196), the main active compound of D. kotschyi, inhibited the lymphocyte proliferation in a dose-dependent fashion with an IC50 value of 1.7 mg/ml. The IC50 value of dexamethasone as the positive control was 0.3 mg/ml [40]. Antitumor Activity. Jahaniani et al. reported that the leaf MeOH extract of D. kotschyii inhibited tumor proliferation in mice. Further they reported that the active ingredient in the leaf extract of D. kotschyii, xanthomicrol (171), inhibited the proliferation of a number of malignant cells, including HL60, K562, Saos-2, A2780-cp, A2780-s, and HFFF-P16. Xanthomicrol was more selective towards malignant cells than doxorubicin [ 36]. Antimicrobial Activity. The antimicrobial activity of the essential oil of D. heterophyllum was evaluated against nine bacterial strains, one yeast, and three fungi. The MIC values for bacteria, yeast, and fungi strains were 0.039 – 0.156, 0.156, 0.313 – 2.500 mg/ml, respectively [20]. Sonboli et al. investigated the antimicrobial activity of the essential oil of the flowering parts of D. moldavica. The results showed that all the tested microorganisms were highly inhibited by the essential oil [60]. Download 0.51 Mb. Do'stlaringiz bilan baham: 
|