Flavonoid-bearing probes have been designed and synthesized to explore their ability to selectively capture target proteins or biosynthetic enzymes under oxidative activation.
HIV-1 nucleocapsid protein (NC) is a nucleic acid chaperone implicated in several steps of the virus replication cycle and an attractive new target for drug development. In reverse transcription, NC destabilizes nucleic acid secondary structures and catalyzes the annealing of HIV-1 TAR RNA to its DNA copy (cTAR) to form the heteroduplex TAR/cTAR. A screening program led to the identification of the plant polyphenols acutissimins A and B as potent inhibitors of NC in different assays. These two flavano-ellagitannins, which are found in wine aged in oak barrels, exhibited different mechanisms of protein inhibition and higher potency relatively to their epimers, epiacutissimins A and B, and to simpler structures notably representing hydrolytic fragments and metabolites therefrom
A series of 78 synthetic 7-chloro-(4-thioalkylquinoline) derivatives were investigated for cytotoxic activity against eight human cancer as well as 4 non-tumor cell lines. The results showed, with some exceptions, that sulfanyl 5–40 and sulfinyl 41–62 derivatives exhibited lower cytotoxicity for cancer cell lines than those of well-described sulfonyl N-oxide derivatives 63–82. As for compound 81, the most pronounced selectivity (compared against BJ and MRC-5 cells) was observed for human cancer cells from HCT116 (human colorectal cancer with wild-type p53) and HCT116p53−/− (human colorectal cancer with deleted p53), as well as leukemia cell lines (CCRF-CEM, CEM-DNR, K562, and K562-TAX), lung (A549), and osteosarcoma cells (U2OS). A good selectivity was also detected for compounds 73 and 74 for leukemic and colorectal (with and without p53 deletion) cancer cells (compared to MRC-5). At higher concentrations (5 × IC50) against the CCRF-CEM cancer cell line, we observe the accumulation of the cells in the G0/G1 cell phase, inhibition of DNA and RNA synthesis, and induction of apoptosis. In addition, X-ray data for compound 15 is being reported. These results provide useful scientific data for the development of 4-thioalkylquinoline derivatives as a new class of anticancer candidates.