3-Desoxyanthocyanidins from Arrabidaea chica

The new 3-desoxyanthocyanidins 6,7,3'-trihydroxy-5,4'-dimethoxy-flavylium and 6,7,3',4'-tetrahydroxy-5-methoxy-flavylium and the known 6,7-dihydroxy-5,4'-dimethoxy- transcription factor NF-kappaB as target. The structure of Carajurone was revised to be 6,7,4'-trihydroxy-5-methoxy-flavylium. Additionally, the flavone acaetin was found. All structures were mainly established on the basis of MS- and NMR data (H-1, H-1-H-1 COSY and partly C-13, GHMQCR and GHSQCR). Carajurin, which failed to give a positive result in the DPPH TLC assay completely inhibited NF-kappaB, but not NF-AT at a 500 muM concentration. (C) 2001 Elsevier Science Ltd. All rights reserved.