From the molecular docking study, there is no common (primary) H-bond for all methylchalcone analogues. With highly rotatable bonds in methylchalcone structure, so there are many different orientations of docked ligand template in ,-tubulin binding site, and hence the patterns of hydrogen bond formations of methylchalcone analogues to amino acid residues can be specifically classified for five models, as illustrated in Figure 5-41. The only eighty-one analogues are considering in these five models, since fifty-one analogues form no H-bond to any residues. The hydrogen bond formations of docked methylchalcone analogues to amino acid residues were represented in Table 4-7.