Synthesis, structure and in vitro anticancer, DNA binding and cleavage activity of palladium (II) complexes based on isatin thiosemicarbazone derivatives

Abstract

Six novel palladium(II) complexes of a thiosemicarbazone Schiff base with isatin moiety (PdL1 to PdL6) were synthesized by the reaction of palladium(II) with the following: (Z)‐2‐(2‐oxoindolin‐3‐ylidene)‐N‐phenylhydrazinecarbothioamide (L1H), (Z)‐2‐(5‐methyl‐2‐oxoindolin‐3‐ylidene)‐N‐phenylhydrazinecarbothioamide (L2H), (Z)‐2‐(5‐fluoro‐2‐oxoindolin‐3‐ylidene)‐N‐phenylhydrazinecarbothioamide (L3H), (Z)‐N‐methyl‐2‐(5‐nitro‐2‐oxoindolin‐3‐ylidene)hydrazinecarbothioamide (L4H), (Z)‐N‐methyl‐2‐(5‐methyl‐2‐oxoindolin‐3‐ylidene)hydrazinecarbothioamide (L5H) and (Z)‐N‐ethyl‐2‐(5‐methyl‐2‐oxoindolin‐3‐ylidene)hydrazinecarbothioamide (L6H). The structures of these complexes were characterized using elemental analysis and infrared, UV–visible, 1H NMR and mass spectroscopies. The structure of PdL5 was further characterized using single‐crystal X‐ray diffraction. The interaction of these complexes with calf thymus DNA was characterized with a high intrinsic binding constant (Kb = 5.78 × 104 to 1.79 × 106 M−1), which reflected the intercalative activity of these complexes towards calf thymus DNA. This result was also confirmed from viscosity data. Electrophoresis studies revealed that complexes PdL1 to PdL6 could cleave DNA via an oxidative pathway in the presence of an external agent. Data obtained from an in vitro anti‐proliferative study clearly established the anticancer potency of these compounds against the human colorectal carcinoma cell line HCT 116.

Structure and cytotoxicity of zinc (II) and cobalt (II) complexes based on 1,3,5‐tris(1‐imidazolyl) benzene

“…Hypochromism and bathchromism are shown in the UV absorption spectroscopy when a complex binds to DNA through intercalation, due to the coupling π orbital is partially filled by electrons resulting in hypochromism . It seems that the degree of color reduction in the ultraviolet band is generally consistent with the intensity of the intercalation interaction . The absorption spectra of the complex in the absence and presence of FS‐DNA are illustrated in Figure .…”

A protocatechuic acid-based deep eutectic solvent: a novel and versatile catalyst for the green synthesis of pyranopyrimidines

“…The appropriate methods for preparation of new heterocycles that can be used in various elds are the use of multi-component reactions, which increase the e ciency of these products and create appropriate economic bene ts for preparation of these compounds. [12][13][14][15][16][17][18][19][20][21][22] Among N-heterocycles, pyranopyrimidine moiety widely exists in the structure of various natural products and have been shown to have various pharmacological activities such as antibronchitis, 23 antimicrobial, 24 anti-tumor, 25,26 antihypertensive, anticoagulant, antitumor, cardiac, liver protection, and antibronchitis activities, [27][28][29][30][31][32][33] and several methods reported for their syntheses. [34][35][36][37][38][39][40] Also, chromenes have many important biological properties such as anti-anaphylactic, anti-cancer, anticoagulant, spasmolytic, diuretic, etc., and have received a lot of attention.…”