[3] Virgili F, Pagana G, Bourne L, et al. Free Radic. Biol. Med., 2000, 28(8): 1249.

[4] Packer L, Rimbach G, Virgili F. Pycnogenol. Free Radic. Biol. Med., 1999, 27 (5/6): 704.

[5] Stevenson, D E. Hurst, R D. Cell. Mol. Life Sci., 2007, 64: 2900.

[6] Garcia-Marino M Rivas-Gonnalo J C, Ibanez E, et al. Anal. Chim. Acta, 2006, 563: 44.

[7] Wu W, Sun S Q, Zhou Q, et al. Journal of Pharmaceutical and Biomedical Analysis, 2008, 46: 498.

[9] Zhou Q, Sun S Q, Yu L, et al. Journal of Molecular Structure, 2006, 799: 77.

[10] Xu C H, Sun S Q, Guo C Q, et al. Vibrational Spectrosocopy, 2006, 41: 118.

[11] Noda I. J. Am. Chem. Soc., 1989, 111: 8116.

[12] Noda I. Appl. Spectrosc., 1990, 44: 550.

[13] Noda I. Appl. Spectrosc., 1993, 47: 1329.

[14] L Y Foo. Phytochemistry, 1981, 20(6): 1397.

[15] Lai Yeap Foo, Lawrence J. Porter. Phytochemistry, 1980, 19(8): 1747.