| 總結: | The aim of the project as presented in this thesis concerns on the preparation,
characterization and biological evaluation of Schiff bases derived from 3, 5-
dihyroxybenzohydrazide and their Cu(II) and Zn(II) complexes. The Schiff bases were
synthesized by the condensation of 3, 5-dihyroxybenzohydrazide and
hydroxyacetophenone (BzyHAP-H), 5-bromo hydroxyacetophenone (BzyHAP-Br), 5-
chloro hydroxyacetophenone (BzyHAP-Cl), salicylaldehyde (BzySAL-H), 5-bromo
salicylaldehyde (BzySAL-Br), and 5-chloro salicylaldehyde (BzySAL-Cl). The BzyHAP
series ligands were subsequently reacted with the acetate of Zn(II) whereas the BzySAL
series ligands were reacted with Cu(II) and Zn(II) acetate in a 1:2 metal to ligand ratio. The
chemical structures of the compounds were characterized by means of elemental analyses, ,
and spectroscopy methods including IR, 1H NMR, 13C NMR, and UV-Vis.The
determination of metal content was carried out using atomic absorption spectroscopy.
Single X-ray diffraction data collection is carried out for ligand BzySAL-Br. From the
structural analysis, the ligand is found to be planar with an r.m.s. deviation for the non-H
atoms of 0.16Å. In the crystal structure, the Schiff base molecules and the water molecules
are linked together by intermolecular N-H--O and O-H--O hydrogen bonds, leading to
layers parallel to the bc plane. An intramolecular O-H--N hydrogen bond involving the
imine N atom and a hydroxyl substituent is also observed. The synthesized Schiff base and
their metal complexes are screened for the in vitro cytotoxicity towards prostate cancer cell
line (PC-3), colon cancer cell line (HT-29) lung cancer cell line (A549), and normal cell
line (WRL-68). All Zn (II) complex Schiff bases show relatively low cytotoxicity against
all tested cell line. Complexes labeled as CuBzySAL-H, CuBzySAL-Br, and CuBzySALCl
show encouraging value of EC50 against colon cancer cell line (HT-29), lung cancer cell
line (A549), and normal cell line (WRL-68). On contrary, the cytotoxicity against prostate cancer cell line (PC-3) is recorded negative. The evaluation of antioxidant reveals that all compounds are moderate DPPH inhibitor compared to the standard vitamin C.
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