title: The Generally Useful Estimate of Solvent Systems (GUESS) method enables the rapid purification of methylpyridoxine regioisomers by countercurrent chromatography.
abstract: The TLC-based Generally Useful Estimate of Solvent Systems (GUESS) method was employed for countercurrent chromatography solvent system selection, in order to separate the three synthetic isomers: 3-O-methylpyridoxine, 4'-O-methylpyridoxine (ginkgotoxin), and 5'-O-methylpyridoxine. The Rf values of the three isomers indicated that ChMWat+2 (chloroform-methanol-water 10:5:5, v/v/v) was appropriate for the countercurrent separation. The isomer separation was highly selective and demonstrated that the TLC-based GUESS method can accelerate solvent system selection for countercurrent separation. Accordingly, the study re-emphasizes the practicality of TLC as a tool to facilitate the rapid development of new countercurrent and centrifugal partition chromatography methods for this solvent system. Purity and structure characterization of all samples was performed by quantitative (1)H NMR.
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, USA; Physical Sciences Department, Rosary College of Arts and Sciences, Dominican University, River Forest, IL 60305, USA. Electronic address: jbfriesen@dom.edu.
authors.forename: J Brent
authors.initials: JB
authors.lastname: Friesen
authors.affiliation: Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, USA.
authors.forename: Larry L
authors.initials: LL
authors.lastname: Klein
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, USA; Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, USA.
authors.forename: James B
authors.initials: JB
authors.lastname: McAlpine
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, USA.
authors.forename: David C
authors.initials: DC
authors.lastname: Lankin
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, USA; Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, USA.
authors.forename: Guido F
authors.initials: GF
authors.lastname: Pauli
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, USA. Electronic address: sc4sa@uic.edu.
authors.forename: Shao-Nong
authors.initials: SN
authors.lastname: Chen
mesh_terms: D002725:Chloroform / Q000737:chemistry; D003377:Countercurrent Distribution; D000432:Methanol / Q000737:chemistry; D011736:Pyridoxine / Q000031:analogs & derivatives* / Q000302:isolation & purification; D012997:Solvents / Q000737:chemistry*; D013237:Stereoisomerism; D014867:Water / Q000737:chemistry
chemical_list: C406624:4'-O-methylpyridoxine; D012997:Solvents; D014867:Water; D002725:Chloroform; D011736:Pyridoxine; D000432:Methanol
keywords: Countercurrent separation; Generally useful estimate of solvent systems; Ginkgo biloba; Ginkgotoxin isomers; Quantitative (1)H NMR; Thin layer chromatography