Novel vitexin-inspired scaffold against leukemia.

Acute lymphoblastic leukemia (ALL) is the most common type of leukemia in children. Up to a quarter of ALL patients relapse and face poor prognosis. To identify new compound leads, we conducted a phenotypic screen using terrestrial natural product (NP) fractions against immortalized ALL cellular models. We identified vitexin, a flavonoid, as a promising hit with biological activity (EC50  = 30 μM) in pre-B cell ALL models with no toxicity against normal human tissue (BJ cells) at the tested concentrations. To develop more potent compounds against ALL and elucidate its potential mode of action, a vitexin-inspired compound library was synthesized. Thus, we developed an improved and scalable protocol for the direct synthesis of 4-quinolone core heterocycles containing an N-sulfonamide using a one-pot condensation reaction protocol. The newly generated compounds represent a novel molecular scaffold against ALL as exemplified by compounds 13 and 15, which demonstrated EC50 values in the low micromolar range (0.3-10 μM) with little to no toxicity in normal cellular models. Computational studies support the hypothesis that these compounds are potential CDK inhibitors. The compounds induced apoptosis, caused cell arrest at G0/G1 and G2/M, and induced ROS in cancer cells.