麻黄碱的噁唑烷衍生物的合成

近期文献报道了麻黄碱的嗯唑烷衍生物作为前药的研究以及拆分前列脲素中间体的用途;并从麻黄植物中分离出嗯唑烷酮衍生物。本文根据上述资料,从麻黄生物碱出发,合成了2种N-氨基甲酰衍生物,3种席夫碱、8种嗯唑烷和2种(口恶)唑烷酮衍生物。根据元素分析、红外、核磁共振氢谱和质谱,确定了衍生物的结构。经醋酸扭体法和热板法药理试验,衍生物(Ⅳ)有镇痛作用。     

Dyskinesias possibly induced by norpseudoephedrine

We report two case histories of previously healthy patients who both developed persistent dyskinetic syndromes (spasmodic torticollis and cranial dystonia, respectively) following the intake of norpseudoephedrine (NPE) as an appetite suppressant. The symptoms took a chronic course even after NPE intake was discontinued. Similar drug-induced dyskinesias have been described for amphetamine and neuroleptic drugs. This side effect has, however, not yet been reported for NPE, which is pharmacologically related to amphetamine. One of the patients may also have had multiple sclerosis. Structural lesions in the basal ganglia area might predispose the development of such a movement disorder. The potential relationship between NPE intake and the development of dyskinesia is discussed. Appetite suppressants, often taken without the neurologist's knowledge, may be the cause of dyskinetic syndromes.     

Pharmacokinetic comparisons of five ephedrine alkaloids following oral administration of four different Mahuang–Guizhi herb-pair aqueous extracts ratios in rats

Ethnopharmacological relevance

Herba Ephedra (Mahuang in Chinese), is derived from dried Ephedra sinica Stapf stems and has been widely used to treat the common cold, coughs, asthma, and edema for thousands of years. The Mahuang–Guizhi herb-pair is a famous formula composed of Mahuang and Ramulus Cinnamomi (Guizhi in Chinese, the dried twig of Cinnamomum cassia Presl.), used to improve pharmacological effects and reduce toxicity. In order to investigate the influence of Mahuang–Guizhi herb-pair ratios on bioavailability, the plasma pharmacokinetics profiles of five ephedrine alkaloids were compared following oral administration of four different ratios to rats.

Materials and methods

Sprague-Dawley rats were randomly assigned to four groups and orally administered Mahuang–Guizhi (ratios 3:0; 3:1; 3:2; 3:4, w/w). Assays for five ephedrine alkaloids (ephedrine, pseudoephedrine, methylephedrine, norephedrine, and norpseudoephedrine) were developed and validated using ultra-high-performance liquid chromatography tandem mass spectrometry coupled with liquid-liquid extraction.

Results

Key pharmacokinetic parameters of the five ephedrine alkaloids (maximal plasma concentration, mean residence time, and half-life) were significantly different (p<0.05) after oral administration of Mahuang–Guizhi herb-pair ratios, as compared to those of Mahuang.

Conclusion

Ephedrine alkaloid pharmacokinetic differences in rat plasma could help explain previous findings of pharmacological and toxicity differences between Mahuang and Mahuang–Guizhi herb-pair preparations. These results could facilitate future studies to increase the efficacy and decrease the toxicity of Mahuang and Guizhi.     

十二种国产麻黄的品质评价

本文应用高效液相色谱法对我国24个产地所产的12种麻黄生药进行了六种生物碱的定量分析,这六种生物碱是:麻黄碱(ephedrine),伪麻黄碱(pseudoephedrine),去甲基麻黄碱(norephedrine),去甲基伪麻黄碱(norpseudoephedrine),甲基麻黄碱(methylephedrine)和甲基伪麻黄碱(methylpseudoephedrine)。根据分析结果,对这些麻黄生药的品质作出了评价。