Three new antioxidant C-glucosylanthrones from Aloe nobilis

Abstract

Three new C-glucosylanthrones, 3′-O-acetyl-5-hydroxylaloin A (2), 2′,6′-O-diacetyl-5-hydroxylaloin A (4), and 4′,6′-O-diacetyl-5-hydroxylaloin A (5), along with three known compounds, 5-hydroxyaloin A (1), 6′-acetyl-5-hydroxylaloin A (3), and 4-methoxy-6-(2′,4′-dihydroxy-6′-methylphenyl)-pyran-2-one (6), were isolated from the leaves of Aloe nobilis, and their structures were elucidated on the basis of spectroscopic evidences. Compounds 1, 2, 4 and 5 showed antioxidant activity with inhibitory rates of 31.0, 34.0, 34.0, and 42.0%, respectively, at 10^− 5 M.

Keywords:

• Aloe nobilis
• Liliaceae
• C-glucosylanthrones
• aloin A
• antioxidant activity

Acknowledgements

The authors acknowledge the financial support from the NSFC (Grant Nos. 20432030, 30500647). We thank the Department of Pharmacology of our institute for measuring antioxidant activity and the Department of Instrumental Analysis of our institute for the measurement of spectral data.