Large‐scale separation of antipsychotic alkaloids from Rauwolfia tetraphylla L. by pH‐zone‐refining fast centrifugal partition chromatography1. Issue 2 (29th November 2012)

• Record Type: Journal Article
• Authors: Maurya, Anupam; Gupta, Shikha; Srivastava, Santosh K.
• Is Part Of: Journal of separation science. Volume 36:Issue 2(2013:Jan.)
• Page Start: 407
• Page End: 413
• Publication Date: 2012-11-29
• Subjects: Separation (Technology) -- Periodicals; Chromatographic analysis -- Periodicals; 543.089
• DOI: 10.1002/jssc.201200273
• Languages: English
• ISSNs: 1615-9306

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>pH‐zone‐refining centrifugal partition chromatography was successively applied in the large‐scale separation of close R<italic><sub>f</sub></italic> antipsychotic indole alkaloids directly from CHCl<sub>3</sub> fraction of <italic>Rauwolfia tetraphylla</italic> leaves. Two experiments with increasing mass from 500 mg to 3 g of crude alkaloid extracts (<bold>1</bold>C) of <italic>R. tetraphylla</italic> were carried out in normal‐displacement mode using a two‐phase solvent system composed of methyl tert‐butyl ether/ACN/water (4:1:5, v/v/v) where HCl (12 mM) was added to the lower aqueous stationary phase as a retainer and triethylamine (5 mM) to the organic mobile phase as an eluter. The two centrifugal partition chromatography separations afforded a total of 162.6 mg of 10‐methoxytetrahydroalstonine (<bold>1</bold>) and 296.5 mg of isoreserpiline (<bold>2</bold>) in 97% and 95.5% purity, respectively, along with a 400.9 mg mixture of α‐yohimbine and reserpiline (<bold>3</bold> and <bold>4</bold>). Further, this mixture was resolved over medium pressure LC using TLC grade silica gel H (average particle size 10 μm), which afforded 160.4 mg of α‐yohimbine (<bold>3)</bold> and 150.2 mg of reserpiline (<bold>4)</bold> in >95% purities. The purity of the isolated antipsychotic alkaloids was analyzed by high‐performance LC and their structures were characterized on the basis of their 1D, 2D NMR and electrospray ionization‐mass spectroscopic data.</p> </abstract>