ANYL 176 |
| Black raspberries have been found to be chemopreventive with respect to oral, esophageal and colon cancers. To identify probable bioactive components, NMR experiments on several cultivars were conducted using a 750 MHz spectrometer equipped with a cryoprobe, permitting a significant improvement in sensitivity. Integrated areas of the proton NMR spectra at 3Hz (0.004 ppm) intervals were used to compute the principal components. Black raspberry samples that were influential for each principal component were determined. Correlations between the principal components and variables, such as anthocyanin content, antioxidant activity, total phenolics and bioactivity as measured by inhibition of colon cancer HT-29 lines, were computed by regression analysis. Areas in the proton NMR spectrum that were important to each principal component were identified according to the magnitude of their eigenvalues. Results from multidimensional NMR experiments such as DQCOSY, HSQC, HMBC, HSQCTOCSY and TNDQCOSY aided spectral interpretation. Thus, even minor bioactive components in black raspberries could be examined to determine additive and/or synergistic effects. |
|
General Papers
7:00 PM-9:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster
Division of Analytical Chemistry |