Synthesis and spectral characterization of zinc(II) and cadmium(II) complexes of acetone-N(4)-phenylsemicarbazone: Crystal structures of acetone-N(4)-phenylsemicarbazone and a cadmium(II) complex

Synthesis, spectral characterization, molecular structure and pharmacological studies of N'-(1, 4-naphtho-quinone-2yl) isonicotinohydrazide

A simple and efficient procedure was employed for the synthesis of N'-(1,4-naphtho-quinone-2-yl) isonicotinohydrazide (NIH) by the reaction of 2-hydroxy-1,4-naphthaquinone (lawsone) and isonicotinoyl hydrazine in methanol using ultrasonic irradiation. Lawsone is the principal dye, isolated from the leaves of henna (Lawsonia inermis). Structural modification was done on the molecule aiming to get a more active derivative. The structure of the parent compound and the derivative was characterized by elemental analyses, infrared, electronic, (1)H, (13)C NMR and GC-MS spectra. The fluorescence spectral investigation of the compound was studied in DMSO and ethanol. Single crystal X-ray diffraction studies reveal that NIH crystallizes in monoclinic space group. The DNA cleavage study was monitored by gel electrophoresis method. The synthesized compound was found to have significant antioxidant activity against DPPH radical (IC50=58 μM). The in vitro cytotoxic studies of the derivative against two human cancer cell lines MCF-7 (human breast cancer) and HCT-15 (human colon carcinoma cells) using MTT assay revealed that the compound exhibited higher cytotoxic activity with a lower IC50 value indicating its efficiency in killing the cancer cells even at low concentrations. These results suggest that the structural modifications performed on lawsone could be considered a good strategy to obtain a more active drug.

(2E)-2-[1-(2-Hy-droxy-4-meth-oxy-phenyl)ethyl-idene]-N-phenyl-hydrazine-carbox-amide monohydrate

The title compound, C(16)H(17)N(3)O(3)·H(2)O, exists in the E conformation with respect to the azomethine C=N double bond. While the phenyl ring is almost coplanar with the central hydrazinecarboxamide group [dihedral angle = 14.18 (11)°], it is twisted slightly with respect to the other aromatic ring in the mol-ecule, with a dihedral angle of 22.88 (13)°. The packing is dominated by O-H⋯O, N-H⋯O and C-H⋯O hydrogen-bond inter-actions, forming a three-dimensional supra-molecular structure which is augmented by two types of C-H⋯π inter-actions. An intramolecular O-H⋯N interaction is also present in the molecule.

(2E)-2-[(2-Hy-droxy-4-meth-oxy-phen-yl)(phen-yl)methyl-idene]-N-phenyl-hydrazinecarboxamide dimethyl-formamide monosolvate

The title compound, C₂₁H₁₉N₃O₃·C₃H₇NO, adopts an E conformation with respect to the azomethine bond and crystallizes in the amide form. The dihedral angle between the rings lined to the C=N bond is 88.60 (12)°. The dimethyl­formamide solvent mol­ecule is disordered over two orientations with site occupancies of 0.684 (3) and 0.316 (3). The two N atoms of the hydrazinecarboxamide group are involved in inter­molecular N—H⋯O hydrogen bonds in which the dimethyl­formamide O atom acts as acceptor. The structure also features π–π inter­actions, with a centroid–centroid distance of 3.6561 (13) Å. Classical and non-classical intra­molecular O—H⋯N and C—H⋯O hydrogen bonds are also present.