Antioxidant homoisoflavonoids from Chionodoxa forbesii Baker

Chionodoxa is a genus within the Hyacinthaceae, which species are high in homoisoflavonoids (HFs) [1]. Antibacterial, anti-mutagenic and anti-inflammatory effects have been described for some HFs, especially for those from Eucomis and Scilla [2]. A detailed examination of HFs from Chionodoxa forbesii Baker (syn. Ch. gigantea Whittall) is missing in literature, thus the aim of this work was to determine its compounds. A mixture of substances yielded by extraction with ethanol and ether was separated by column chromatography on silica gel and polyamide. The compounds were identified using FT-IR, ESI-MS and ¹H- NMR and ¹³C-NMR. Thereby, HFs of the 3-benzyl-4-chromone-, 3-benzyl-3-hydroxy-4-chromanone and the scillascillin-type were determined. The pattern of substances was found to be in strong relation to this of Ch. luciliae Boiss. [3]. For measuring the antioxidant potentials the ABTS radical decolourization assay following the method described by Re et al. [4] and the DPPH free radical scavenging method were used. Ascorbic acid and trolox served as references. Scillascillin-type HFs showed low activity, whereas 3-benzyl-4-chromone-type HF had a high potential. Cytotoxic effects of HFs on human cells were tested using trypan blue vital stain on HEK-293 cells. It was found, that the tested HFs do not show any adverse cytotoxic effects.

References: 1. Heller, W., Tamm, C. (1981) Fortschr. Chem. Org. Naturst. Vol. 40. Springer. Wien.

2. Du Toit, K. et al. (2007) South African J. Bot. 73: 236–241.

3. Corsaro, M.M. et al. (1992) Phytochemistry 31: 1395–1397.

4. Re, R. et al. (1999) Free Radical Biol. Med. 26: 1231–1237.