SYNTHESIS AND BIOCHEMICAL EVALUATION OF A SERIES OF AMINOFLAVONES AS POTENTIAL INHIBITORS OF PROTEIN-TYROSINE KINASES P56(LCK), EGFR, AND P60(V-SRC)

A series of nitroflavones, 8a-p, and their corresponding aminoflavone hydrochloride salts, 10a-p, was synthesized. The preparation of nitroflavones 8b-i,o,p began with commercially available o-hydroxyacetophenones 2b-f which were converted to o-hydroxynitroacetophenones 3a-h via a variety of nitration methods, followed by condensation with nitrobenzoyl chlorides and cyclization under acidic condition. The nitroflavones 8aj-n were prepared by nitration of the corresponding flavones 7a-e. These new compounds were evaluated for their abilities to inhibit the in. vitro protein-tyrosine kinase activities of p56(1ck), EGFr, and p60(v-src), and all of the active compounds were amino-substituted flavones. None of the nitroflavones inhibited the enzymes. The most active substance in this series against p56(lck) was compound 10j, which had an IC50 of is mu M. When tested versus EGFr, compounds 10a,m displayed IC50's of 8.7 and 7.8 mu M, respectively. Against p60(v-src), 10a,m showed IC50 values of 28.8 and 38.4 mu M, respectively.