Abstract:
Human  DNA  Topoisomérase  I  (topo  I)  is  the  tar
get  of  several  drugs  commonly  used  in 
cancer  chemotherapy.  These  drugs  induce  topo-DNA  co
mplexes  that  eventually  trigger  cell 
death.  Several  flavonoides  have  been  shown  as  inhib
itors  of    topo  I,  having  an  anticancer 
activity. 
      Using the methods of molecular modeling in pa
rticularl the docking by the Surflex program, 
we  theoretically  evaluated  the  affinity  of  four  fla
vonoids:  myricetin,  fisetin,  quercetin  and 
apigenin,  presented  in  recent  studies  as  inhibitors
  of  topo  I.  Myricetin  with  the  lowest  IC
50        
(11.1  ±  2.0  μ M)  gave  the  best  affinity  (7.01  M
-1
).  For  the  development 
in  silico
  of  novel 
molecules most powerful myricetin, we have made sev
eral substitutions. Replacing the hydroxyl 
group  carried  by  the  carbone  C3 ́  of  the  myricetin  b
y  an  alcoholic  group  CH
2
OH  significantly 
improves the affinity increases from 7.01 M
-1
 to 8.79 M
-1
.  
     The application of the rule of Lipinski inform
s in a positive way about the ADME properties 
of this new molecule that is as an inhibitor potent
ially more active than myricetin.