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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
2010-5-3
pubmed:abstractText
In this study, the racemization kinetic parameters of R-(-)-synephrine, the active phenethylamine alkaloid of Citrus aurantium L., were determined by means of an off-column HPLC method. Enantioseparation was carried out in different buffer solutions and solvents on a chiral stationary phase (CSP) with cellobiohydrolase as the chiral selector (Chiral-CBH, 100 mm x 4.0 mm i.d., 5 microm). The mobile phase was 10 mM sodium phosphate buffer (pH 6.0)-2-propanol (95:5, w/w), with 50 microM disodium EDTA, at 0.8 mL/min. The column was thermostatted at 20 degrees C and detection was set at 225 nm. The influence of pH value, ionic strength, temperature and addition of organic modifier on the rate constant, the half-life of racemization and the free energy barrier of racemization of R-(-)-synephrine were determined. Among the different chemical and physical parameters evaluated as affecting the racemization of naturally occurring R-(-)-synephrine, pH, temperature and addition of an organic co-solvent appear to have the strongest effect, while ionic strength does not exert a significant influence on the racemization rate. The results of the present study indicated that synephrine racemization is possible at high temperature at both acidic and basic pH values; therefore, the extraction procedure of R-(-)-synephrine from the plant material should be carried out under specific conditions to preserve the stereochemical integrity and the biological activity of this secondary metabolite.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1873-3778
pubmed:author
pubmed:copyrightInfo
2010 Elsevier B.V. All rights reserved.
pubmed:issnType
Electronic
pubmed:day
21
pubmed:volume
1217
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3503-10
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Study on the racemization of synephrine by off-column chiral high-performance liquid chromatography.
pubmed:affiliation
Department of Pharmaceutical Sciences, University of Modena and Reggio Emilia, Via G. Campi 183, 41100 Modena, Italy. federica.pellati@unimore.it
pubmed:publicationType
Journal Article