- THE ABSOLUTE CONFIGURATION OF BERBERASTINE AND THALIDASTINE
-
Optical resolution of (+/-)-tetrahydrojatrorrhizine using (-)-O,O-di-p-toluoyl-d-tartaric acid gave rise to (+)-tetrahydrojatrorrhizine (6) of high optical purity and of known absolute configuration.Oxidation of this enantiomer with lead tetraacetate, followed by acid hydrolysis, furnished alcohols 10 and ll in a 2:1 ratio, whose relative stereochemistry was established from their nmr spectra.Iodine oxidation of the major alcohol 10 led to protoberberinium salt 14 which was found to be dextrorotatory.Since berberastine (1) and thalidastine (2) are also dextrorotatory, they must possess the same absolute configuration as 14.
- Zarga, Musa H. Abu,Shamma, Maurice
-
-
Read Online
- UNUSUAL METHYL TRANSFER IN THE BIOSYNTHESIS OF APORPHINE AND PROTOBERBERINE ALKALOIDS
-
(S)-Reticuline was triply-labelled with 13C and administrered to cell cultures of Peumus boldus and Berberis stolonifera, which are sources of aporphines and protoberberines, respectively.During incorporation of the labelled precursor into alkaloids of both groups, unexpected transmethylations of the methyl groups were observed by 13C NMR spectroscopy which seem to proceed via demethylation, flux of 13C through the C-1 pool, and remethylation. Key Word Index: Peumus boldus; Berberis stolonifera; Berberidaceae; cell suspension cultures; 13C NMR; reticuline; aporphines; protoberberines; alkaloids; biosynthesis
- Schneider, Bernd,Zenk, Meinhart H.
-
-
Read Online
- Asymmetric total synthesis of tetrahydroprotoberberine derivatives and evaluation of their binding affinities at dopamine receptors
-
Cocaine addiction remains a serious challenge for clinical and medical research because there is no effective pharmacological treatment. L-THP, a natural product isolated from Corydalis yanhusuo W.T. Wang, is one of the most frequently used traditional herbs to treat drug addiction in China. Our laboratory first reported that its demethylated metabolites L-ICP, L-CD, and L-CP had high affinity at dopamine D1, D2, and D5 receptors. Here we report the chemical synthesis of these metabolites and other derivatives and their binding affinities at dopamine receptors. The synthesis of these bioactive metabolites will allow further in vivo study of their potential in treating cocaine addiction.
- Lee, David Y.W.,Liu, Jing,Zhang, Shuzhen,Huang, Peng,Liu-Chen, Lee-Yuan
-
p. 1437 - 1440
(2017/03/08)
-
- Asymmetric total synthesis and identification of tetrahydroprotoberberine derivatives as new antipsychotic agents possessing a dopamine D1, D2 and serotonin 5-HT1A multi-action profile
-
An effective and rapid method for the microwave-assisted preparation of the key intermediate for the total synthesis of tetrahydroprotoberberines (THPBs) including l-stepholidine (l-SPD) was developed. Thirty-one THPB derivatives with diverse substituents on A and D ring were synthesized, and their binding affinity to dopamine D1, D2 and serotonin 5-HT 1A and 5-HT2A receptors were determined. Compounds 18k and 18m were identified as partial agonists at the D1 receptor with Ki values of 50 and 6.3 nM, while both compounds act as D2 receptor antagonists (Ki = 305 and 145 nM, respectively) and 5-HT1A receptor full agonists (Ki = 149 and 908 nM, respectively). These two THPBs compounds exerted antipsychotic actions in animal models. Further electrophysiological studies employing single-unit recording in intact animals demonstrated that 18k-excited dopaminergic (DA) neurons are associated with its 5-HT1A receptor agonistic activity. These results suggest that these two compounds targeted to multiple neurotransmitter receptors may present novel lead drugs with new pharmacological profiles for the treatment of schizophrenia.
- Sun, Haifeng,Zhu, Liyuan,Yang, Huicui,Qian, Wangke,Guo, Lin,Zhou, Shengbin,Gao, Bo,Li, Zeng,Zhou, Yu,Jiang, Hualiang,Chen, Kaixian,Zhen, Xuechu,Liu, Hong
-
p. 856 - 868
(2013/03/13)
-
- Phenolic Berbine Alkaloids: An Improved Total Synthesis of (+/-)-Corypalmine
-
An improved total synthesis of (+/-)-corypalmine (5) starting from 7,8-dimethoxyisochroman-3-one (1) is described.
- Mali, R. S.,Yeola, Suresh N.
-
-