Conformational interpretation of vescalagin and castalagin physicochemical properties.
Vescalagin and castalagin are two diastereoisomers. The variability of their principal physicochemical properties, compared with their small structural differences, suggests important conformational variations. This study shows, experimentally, that vescalagin has a greater effect on polarity, oxidizability in solution, and thermodegradability than castalagin. Conformational analysis by molecular mechanics demonstrated that vescalagin was more hydrophilic and was more reactive to electrophilic reagents than castalagin. Experimental results were thus explained and demonstrated the distinct behaviors of vescalagin and castalagin. These results were attributed to the C1 position of the two compounds because vescalin and castalin have comparable characteristics. Experimental data were confirmed and interpreted by molecular mechanics. This work represents one of the first attempts to correlate conformation and the properties of phenolic compounds. This step constitutes a predictive method for the pharmacology or chemistry of new compounds.
Vivas
Nicolas
N
Tonnellerie Demptos seconded to the CESAMO (Centre d'Etudes Structurales et d'Analyses des Molécules Organiques)--Université Bordeaux I, 351 Cours de la Libération, F-33405 Talence, France.
Laguerre
Michel
M
Pianet de Boissel
Isabelle
I
Vivas de Gaulejac
Nathalie
N
Nonier
Marie-Françoise
MF
D001713:Biphenyl Compounds; D002396:Catechols / Q000737:chemistry*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D047348:Hydrolyzable Tannins; D008968:Molecular Conformation; D015394:Molecular Structure; D010084:Oxidation-Reduction; D012996:Solutions; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
D001713:Biphenyl Compounds; D002396:Catechols; D047348:Hydrolyzable Tannins; D012996:Solutions; C084709:vescalagin