ABSTRACT
Two new indole alkaloids, naucleactonin A and B, along with two known compounds, naucleficine and nauclefidine, were isolated from the bark and wood of Naucleaofficinalis, which has been used as an anti-inflammatory and anti-bacterial agent in folk medicine. Their chemical structures were elucidated by the spectral data, especially 1D and 2D NMR experiments.
Subject(s)
Indole Alkaloids/chemistry , Plant Components, Aerial/chemistry , Plants, Medicinal/chemistry , Rubiaceae/chemistry , China , Chromatography , Indole Alkaloids/isolation & purification , Magnetic Resonance Spectroscopy , Molecular StructureABSTRACT
Piperbetol, methylpiperbetol, piperol A, and piperol B, isolated from Piper betle, selectively inhibited the washed rabbit platelet aggregation induced by platelet activating factor (PAF) in a concentration-dependent manner. The IC50 values of piperbetol, methylpiperbetol, piperol A, piperol B, and ginkgolide B were about 18.2, 10.6, 114.2, 11.8, and 4.8 mumol/l, respectively. The inhibitory potency of ginkgolide B was about 2.8, 1.2, 22.8, and 1.4 times higher than those of piperbetol, methylpiperbetol, piperol A, and piperol B. The concentration-response curve of PAF-induced platelet aggregation was shifted to the right by 50 mumol/l of piperbetol, methylpiperbetol, piperol A, piperol B, and ginkgolide B. The EC50 of PAF was increased by these compounds from 1.5 nmol/l to 14.3, 23.1, 2.4, 20.6, and 47.2 nmol/l, respectively. The compounds also inhibited the binding of [3H]-PAF to washed rabbit platelets with IC50 values of 8.7, 5.3, 88, 6.2, and 1.8 mumol/l. Correlating with the inhibitory potency for platelet aggregation, the inhibitory potency of ginkgolide B for binding of PAF was about 3.8, 1.9, 48, and 2.4 times higher than those of piperbetol, methylpiperbetol, piperol A, and piperol B. However, the aggregation of washed rabbit platelets induced by threshold ADP and arachidonic acid were unaffected by piperbetol, methylpiperbetol, piperol A, and piperol B. Furthermore, piperbetol, methylpiperbetol, piperol A, and piperol B had no effects on the cAMP contents in rest washed rabbit platelets. In conclusion, these data indicate that piperbetol, methylpiperbetol, piperol A, and piperol B are effective PAF receptor antagonists in vitro.
Subject(s)
Lignans/isolation & purification , Plants, Medicinal/chemistry , Platelet Aggregation Inhibitors/isolation & purification , Platelet Membrane Glycoproteins/antagonists & inhibitors , Receptors, Cell Surface , Receptors, G-Protein-Coupled , Animals , Lignans/chemistry , Lignans/pharmacology , Medicine, Chinese Traditional , Molecular Structure , Platelet Aggregation Inhibitors/chemistry , Platelet Aggregation Inhibitors/pharmacology , RabbitsSubject(s)
Drugs, Chinese Herbal/pharmacology , Heart/drug effects , Animals , Anura , Electroencephalography , Guinea Pigs , Mice , Phagocytosis/drug effects , RabbitsABSTRACT
Counter-current chromatography is a new liquid-liquid partition chromatography without using solid support. Recently, the technique has been remarkably improved in both partition efficiency and separation time. In this paper the capability of this high-speed counter-current chromatography was demonstrated on separation of two sets of samples obtained from medicinal herbs: a synthetic mixture of 3'-hydroxygenkwanin, luteolin and apigenin was separated on a two-phase solvent system composed of chloroform-methanol-water (4:3:2, v/v/v) and a crude ethanol extract from Anisodus tangulicus (Maxin) Pasch on chloroform-0.07 M sodium phosphate (pH 6.4) (1:1, v/v). In the light of chromatograms obtained from these samples, advantages of high-speed counter-current chromatography over other chromatographic methods were discussed in terms of partition efficiency, peak resolution, separation time, sample loading capacity, etc.