Two new antioxidant bergenin derivatives from the stem of Rivea hypocrateriformis.

@article{Zamarrud2011TwoNA,
  title={Two new antioxidant bergenin derivatives from the stem of Rivea hypocrateriformis.},
  author={Zamarrud and Iftikhar Ali and Hidayat Hussain and Viqar Uddin Ahmad and M. S. Qaiser and Afroze Amyn and Faryal Vali Mohammad},
  journal={Fitoterapia},
  year={2011},
  volume={82 4},
  pages={
          722-5
        }
}
Two new bergenin derivatives, named rivebergenin A and B (1, and 2), together with two known compounds, bergenin (3) and norbergenin (4) were isolated from the stem of Rivea hypocrateriformis (Desr.) Choisy. The structures of the new compound have been assigned from (1)H and (13)C NMR spectra, DEPT, and by 2D COSY, HMQC, and HMBC experiments. Compounds 1-4 showed the strong antioxidant activity. 
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