Related Experiment Video
Updated: Jan 19, 2026

Crystallization of Membrane Proteins in Lipidic Mesophases
Published on: March 28, 2011
Enabling Direct Preferential Crystallization in a Stable Racemic Compound System
Lina C Harfouche1, Clément Brandel1, Yohann Cartigny1
1UFR des Sciences et Techniques, Laboratoire SMS-EA3233 , Universite de Rouen Normandie , Place Emile Blondel , Mont-Saint-Aignan 76821 , France.
Abstract:
The preparative resolution by preferential crystallization (PC) of proxyphylline has been achieved despite the existence of a stable racemic compound. This is enabled through the careful selection of a solvent in which both the racemic compound and the metastable conglomerate possess a low nucleation rate. Induction time measurements in isobutyl alcohol show that a highly supersaturated solution (β = 2.3) remains clear for almost 1 h at 20 mL scale, revealing a slow nucleation rate. Seeding the supersaturated solution with the pure enantiomer triggered its crystallization both isothermal and polythermic modes of PC were successfully implemented. Alongside the reported case of diprophylline, this study opens opportunities to broaden the application of PC toward slowly crystallizing racemic compounds.
More Related Videos
Related Concept Videos
Racemic Mixtures and the Resolution of Enantiomers
Recrystallization: Solid–Solution Equilibria
SN1 Reaction: Stereochemistry
In the first step of an SN1 reaction, the bond between the electrophilic carbon and the leaving group ionizes to generate the carbocation intermediate. The second step of the mechanism is the nucleophilic attack.
In the formed carbocation, the positively charged carbon is sp2 hybridized with a trigonal planar geometry. As all the three substituents lie on the same plane, a plane of symmetry for the...
Stereochemical Effects of Enolization
Prochirality
Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...

