Straightforward synthesis and biological evaluation as topoisomerase I inhibitors and antiproliferative agents of hybrid Chromeno[4,3-b][1,5]Naphthyridines and Chromeno[4,3-b][1,5]Naphthyridin-6-ones

1. Martín-Encinas, E.
2. Rubiales, G.
3. Knudssen, B.R.
4. Palacios, F.
5. Alonso, C.