Abstract:
Flavonoids have been recognized as promising compounds with various bioactivities. Certain flavonoid derivatives exhibited more potent activities than their parent compounds. Recently, halogenated flavonoids have been addressed for their anti-dengue activity. In this research, a series of twenty-two brominated and iodinated flavonoid derivatives were synthesized and explored for dengue infection inhibition. Seventeen derivatives have been investigated for the first time. 8-Bromobaicalein, 6,8-dibromopinocembrin, 6,8-dibromopinostrobin, 6,8-diiodopinostrobin were disclosed as effective and non-toxic anti-dengue agents. These compounds displayed remarkably low EC50 as well as high CC50, which could be considered as potent therapeutic agents. Moreover, the preliminary screening on brominated O7-ether chrysins discovered some noticeable compounds, for example, 6,8-dibromo-O7-butylchrysin and 6,8-dibromo-O7-hexylchrysin; nonetheless, some synthesized brominated O7-ether chrysins were insoluble under tested conditions. Though the relationship between the length of side chain and bioactivity were inconsistent, there was a gradually increasing in percentage of plaque inhibition from ethyl to hexyl in case of 6,8-dibromo O7-ether chrysins.
