Aloeresin I, an Anti-Inflammatory 5-Methylchromone from Cape Aloe

Abstract

A new diglucoside having a 5-methylchromone moiety was isolated from a commercial sample of Cape aloe, the dried exudate from Aloe ferox Miller, and named aloeresin I. Its structure was established as 1 on the basis of spectral and chemical evidence. Aloeresin I (1) (1 μmol/cm²) reduces in vivo the oedematous response (39 %) induced by Croton oil in the mouse ear with the same potency as aloesin, one of the most abundant Cape aloe constituents, and to a higher extent than aloeresin H (2). Indomethacin (0.3 μmol/cm²), the reference anti-inflammatory compound, provokes 61 % oedema inhibition.

References

• 1 Dagne E, Bisrat D, Viljoen A, Van Wyk B -E. Chemistry of Aloe species.  Curr Org Chem. 2000;  4 1055-78
• 2 Hutter J A, Salman M, Stavinoha W B, Satsangi N, Williams R F, Streeper R T, Weintraub S T. Anti-inflammatory C-glucosyl chromone from Aloe barbadensis .  J Nat Prod. 1996;  59 541-3
• 3 Yagi A, Kabash A, Okamura N, Haraguchi H, Moustafa S M, Khalifa T I. Antioxidant, free radical scavenging and anti-inflammatory effects of aloesin derivatives in Aloe vera .  Planta Med. 2002;  68 957-60
• 4 Lee K Y, Weintraub S T, Yu B P. Isolation and identification of a phenolic antioxidant from Aloe barbadensis .  Free Rad Biol & Med. 2000;  28 261-5
• 5 Manitto P, Speranza G, De Tommasi N, Ortoleva E, Morelli C F. Aloeresin H, a new polyketide constituent of Cape aloe.  Tetrahedron. 2003;  59 401-8
• 6 Tyler V E, Brady L R, Robbers J. Pharmacognosy. Philadelphia; Lee and Fabiger 1988: pp 62-3
• 7 Speranza G, Gramatica P, Dadà G, Manitto P. Aloeresin C, a bitter C,O-diglucoside from Cape aloe.  Phytochemistry. 1985;  24 1571-3
• 8 Manitto P, Monti D, Speranza G. Conformational studies of natural products. III. Conformation of natural 8-C-glucosyl-7-hydroxy-5-methylchromones and their derivatives.  Gazz Chim Ital. 1990;  120 641-6
• 9 Tubaro A, Dri P, Delbello G, Zilli C, Della Loggia R. The Croton oil ear test revisited.  Agents Actions. 1985;  19 347-9
• 10 Haynes L J, Holdsworth D K, Russell R. C-Glycosyl compounds. Part VI. Aloesin, a C-glucosylchromone from Aloe sp. J Chem Soc (C) 1970: 2581-6
• 11 Speranza G, Corti S, Manitto P. Isolation and chemical characterization of a new constituent of Cape aloe having the 1,1-diphenylethane skeleton.  J Agric Food Chem. 1994;  42 2002-6