XK and influenza: In conclusion, 1c ((E)-3-(4-butoxyphenyl)-1-(4-hydroxy-3-methoxyphenyl)prop-2-en-1-one) and 2b ((E)-1-(3-(cyclopentyloxy)phenyl)-3-(4-fluorophenyl)prop-2-en-1-one) have potencies to be developed as anti-influenza drugs by inhibiting H5N1 and H1N1 NA in the non-catalytic site.