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HPLC enantioseparation of alkaloid malacitanine using fluorimetric/polarimetric detection
Author(s) -
Sánchez Francisco García,
Navas Díaz Aurora,
Aguilar Alfonso,
Medina Lama Ignacio,
Algarra Manuel
Publication year - 2012
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.201200275
Subject(s) - chemistry , enantiomer , chromatography , high performance liquid chromatography , trifluoroacetic acid , cyclohexane , resolution (logic) , analytical chemistry (journal) , stereochemistry , organic chemistry , artificial intelligence , computer science
This work reports two methods developed for the separation and determination of the enantiomers of the new alkaloid malacitanine ( MLC ) and the determination of the enantiomeric purity in mixtures. First, the isomers were separated using a C hirex 3020 (250 mm × 4.6 mm, 5 μm) chiral column with a mobile phase of cyclohexane–1,2‐dichloroethane–ethanol–trifluoroacetic acid (64:30:6:0.6, v/v/v/v) at a flow rate of 1 mL/min and fluorimetric detection. Obtained retention times were 12.4 and 15.9 min (+ and −) with a resolution Rs of 1.13. Relative standard deviations ( RSD s) were 2.5 and 2.4% at the 0.5‐μg level (four determinations). Second, a nonenantioselective procedure for the determination of enantiomeric purity of MLC using a L ichrospher ® Si‐60 (250 mm × 5 mm, 5 μm) normal phase with a mobile phase of 100% ethanol at a flow rate of 0.9 mL/min coupled to two detectors in series, fluorimetric and polarimetric. RSD of 3.3% was obtained. Calculated enantiomeric purity by chiral chromatography gave 48.6% (−)‐ MLC in the near racemic product. Using polarimetric signal of the nonseparated enantiomers and comparing the slopes of the calibration curves (enantiomers) from the racemic product gave 47.8% (−)‐ MLC content. A study of accuracy of (−)‐ MLC gave recoveries from 98.3 to 100.7%.