The effect of solvent composition on the acidity of substituted phenols in DMSO-H 2 O systems was examined. It is shown that in DMSO-H 2 O mixtures with up to 35 mol% DMSO there is a linear relationship between the pK a values of monosubstituted phenols in the binary solvent mixtures of different co
Solvent effects in the structure dereplication of caffeoyl quinic acids
β Scribed by Guido F. Pauli; Ulrich Kuczkowiak; Adolf Nahrstedt
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 153 KB
- Volume
- 37
- Category
- Article
- ISSN
- 0749-1581
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β¦ Synopsis
The choice of solvent is an important but often neglected cofactor in the structure determination and compound dereplication of caffeoyl quinic acid derivatives (CQAD). Both unforeseeable shift effects and substantial influences on molecular conformation caused by the various solvents lead to marked changes in the shifts and the coupling pattern. Therefore, the assignment of the relative stereochemistry of the cyclohexane ring substituents is complicated and can be misleading, especially when relying on literature data. Both 1 H and 13 C shift values were determined for prominent CQAD. Furthermore, the proton spin systems were fully analyzed in order to establish changes in molecular geometry that are due to solvent effects.
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