CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
409
20 ml of phosphate buffer (7.5 mm), and 140 ml of AAPH soln. (12.8 mm). The reaction was started by the
addition of 20 ml of fluorescein (63 nm) to the test soln. The fluorescence intensity was measured with
Genios multi-detection microplate reader (Tecan; ex. 485 nm, em. 538 nm) every 2 min until the
fluorescence was close to zero. The well-known antioxidant vitamin C and the solvent DMSO were used
as the positive control and the blank, resp. The ORAC value is calculated by dividing the area under the
sample curve by the area under the Trolox curve, with both areas being corrected by subtracting the area
under the blank curve. One ORAC unit is defined as the net area of protection provided by Trolox at a
final concentration 1 mmol lꢀ1. The area under the curve for the sample is compared to the area under the
curve for Trolox, and the antioxidative value is expressed in mmol of Trolox equiv. per l. The experiments
were carried out in triplicate and repeated for three times.
REFERENCES
[1] S. J. Wakil, J. K. Stoops, V. C. Joshi, Annu. Rev. Biochem. 1983, 52, 537.
[2] S. J. Wakil, Biochemistry 1989, 28, 4523.
[3] A. Jayakumar, M.-H. Tai, W.-Y. Huang, W. Al-Feel, M. Hsu, L. Abu-Elheiga, S. S. Chirala, S. J.
Wakil, Proc. Natl. Acad. Sci. U.S.A. 1995, 92, 8695.
[4] T. M. Loftus, D. E. Jaworsky, G. L. Frehywot, C. A. Townsend, G. V. Ronnett, M. D. Lane, P. K.
Francis, Science (Washington, DC) 2000, 288, 2379.
[5] J. V. Swinnen, T. Roskams, S. Joniau, H. Van Poppel, R. Oyen, L. Baert, W. Heyns, G. Verhoeven,
Int. J. Cancer 2002, 98, 19.
[6] Y. Wang, F. P. Kuhajda, J. N. Li, E. S. Pizer, W. F. Han, L. J. Sokoll, D. W. Chan, Cancer Lett. 2001,
167, 99.
[7] L. D. Vlad, C. A. Axiotis, M. J. Merino, W. Green, Mod. Pathol. 1999, 12, 70A.
[8] C. J. Piyathilake, A. R. Frost, U. Manne, W. C. Bell, H. Weiss, D. C. Heimburger, W. E. Grizzle,
Hum. Pathol. 2000, 31, 1068.
`
[9] D. Innocenzi, P. L. Alo, A. Balzani, V. Sebastiani, V. Silipo, G. La Torre, G. Ricciardi, C. Bosman, S.
Calvieri, J. Cutan. Pathol. 2003, 30, 23.
`
[10] P. Visca, V. Sebastiani, E. S. Pizer, C. Botti, P. De Carli, S. Filippi, S. Monaco, P. L. Alo, Anticancer
Res. 2003, 23, 335.
[11] F. P. Kuhajda, E. S. Pizer, J. N. Li, N. S. Mani, G. L. Frehywot, C. A. Townsend, Proc. Natl. Acad. Sci.
U.S.A. 2000, 97, 3450.
[12] E. S. Pizer, F. D. Wood, H. S. Heine, F. E. Romantsev, G. R. Pasternack, F. P. Kuhajda, Cancer Res.
1996, 56, 1189.
[13] E. S. Pizer, F. J. Chrest, J. A. Digiuseppe, W. F. Han, Cancer Res. 1998, 58, 4611.
[14] F. P. Kuhajda, Nutrition 2000, 16, 202.
[15] E. W. Gabrielson, M. L. Pinn, J. R. Testa, F. P. Kuhajda, Clin. Cancer Res. 2001, 7, 153.
[16] X. Wang, W. Tian, Biochem. Biophys. Res. Commun. 2001, 288, 1200.
[17] Jiangsu New Medical College, ꢂDictionary of Chinese Herb Medicinesꢃ, Shanghai Scientific and
Technologic Press, Shanghai, 1986, pp. 586.
[18] G. N. Li, ꢂDictionary of Chinese Herb Medicines in Yunnanꢃ, Yunnan Scientific and Technologic
Press, Yunnan, 1990, pp. 153.
[19] J. K. Li, H. W. Liu, N. L. Wang, M. Li, X. S. Yao, J. Shenyang Pharm. Univ. 2006, 23, 694.
[20] T. Yoshida, T. Okuda, J. Chem. Soc., Perkin Trans. I 1985, 315.
[21] T. Okuda, T. Yoshida, M. Ashida, K. Yazaki, J. Chem. Soc., Perkin Trans. I 1983, 1765.
[22] S.-H. Lee, T. Tanaka, G.-i. Nonaka, I. Nishioka, Phytochemistry 1990, 29, 3621.
[23] T. Okuda, T. Yoshida, T. Hatano, T. Koga, N. Toh, K. Kuriyama, Tetrahedron Lett. 1982, 23, 3937.
[24] X. Wang, K.-S. Song, Q.-X. Guo, W.-X. Tian, Biochem. Pharmacol. 2003, 66, 2039.
[25] W. Bors, C. Michel, Ann. N.Y. Acad. Sci. 2002, 957, 57.
[26] S. Kinoshita, Y. Inoue, S. Nakama, T. Ichiba, Y. Aniya, Phytomedicine 2007, 14, 755.
[27] K. S. Feldman, Phytochemistry 2005, 66, 1984.