Synthesis of N-Substituted Benzamide Derivatives and their Evaluation as Antitumor Agents

Design, synthesis and spectroscopic and structural characterization of novel N-(2-hydroxy-5-methylphenyl)-2,3-dimethoxybenzamide: DFT, Hirshfeld surface analysis, antimicrobial activity, molecular docking and toxicology

The novel compound N-(2-hydroxy-5-methylphenyl)-2,3-dimethoxybenzamide, C16H17NO4, I, was prepared by a two-step reaction and then characterized by elemental analysis and X-ray diffraction (XRD) methods. Moreover, its spectroscopic properties were investigated by FT–IR and 1H and 13C NMR. Compound I crystallized in the monoclinic space group P21/c and the molecular geometry is not planar, being divided into three planar regions. Supramolecular structures are formed by connecting units via hydrogen bonds. The ground-state molecular structure of I was optimized by the DFT-B3LYP/6-31G(d,p) method and the theoretical structure was compared with that obtained by X-ray diffraction. Intermolecular interactions in the crystal network were studied by two-dimensional (2D) and three-dimensional (3D) Hirshfeld analyses. The calculated electronic transition results were examined and the molecular electrostatic potentials (MEPs) were also determined. The in vitro antimicrobial activities of I against three Gram-positive bacteria, three Gram-negative bacteria and two fungi were determined. The compound was compared with several control drugs and showed better activity than the amoxicillin standard against Gram-positive bacteria B. subtilis, S. aureus and E. faecalis, and Gram-negative bacteria E. coli, K. pneumoniae and P. aeruginosa. The density functional theory (DFT)-optimized structure of the small molecule was used to perform molecular docking studies with proteins from experimentally studied bacterial and fungal organisms using AutoDock to determine the most preferred binding mode of the ligand within the protein cavity. A druglikeness assay and ADME (absorption, distribution, metabolism and excretion) and toxicology studies were carried out and predict a good drug-like character.

Discovery of Indole-Containing Benzamide Derivatives as HDAC1 Inhibitors with In Vitro and In Vivo Antitumor Activities

Targeting histone deacetylases (HDACs) has become an important focus in cancer inhibition. The pharmacophore of HDAC inhibitors (HDACis) reported so far is composed of three parts: a zinc-binding group (ZBG), a hydrophobic cavity-binding linker, and a surface-recognition cap interacting with HDAC surface located at the rim of active site cavity. This study aims to discover novel HDAC1 inhibitors with potent antitumor activities through modifying the cap and ZBG based on the structures of two marketed oral HDACis: chidamide and entinostat (MS-275). In this work, a series of benzamide derivatives were designed, synthesized, and evaluated for their antitumor activity. The structures of novel compounds were confirmed by 1H NMR (nuclear magnetic resonance) and ESI-MS (electrospray ionization mass spectrometry), and all target compounds were tested in both HDAC1 enzymatic inhibitory activity and cellular antiproliferative activity. Our data showed that the potent compound 3j exhibited good HDAC1 enzyme inhibitory activity and high antitumor cell proliferation activity against a selected set of cancer cells (PC-3, HCT-116, HUT-78, Jurkat E6–1, A549, Colo205, and MCF-7 cells) with no observed effects on human normal cells. In particular, compound 3j inhibited HDAC1 over the other tested HDAC isoforms (HDAC2, HDAC6, and HDAC8). Encouraged by this, the safety characteristics, molecular docking, preliminary pharmacokinetic characteristics, and antitumor effect in vivo of compound 3j were further investigated. Our data showed that compound 3j demonstrated acceptable safety profiles and favorable oral pharmacokinetic properties. Moreover, compound 3j could bind well with HDAC1 and showed significant antitumor activity in a PC-3 tumor xenograft model in vivo, though not as potent as positive control entinostat (MS-275). In summary, 3j might have therapeutic potential for the treatment of human cancers.

Discovery of quinazolinyl-containing benzamides derivatives as novel HDAC1 inhibitors with in vitro and in vivo antitumor activities

A series of quinazolinyl-containing benzamide derivatives were designed, synthesized and evaluated for their in vitro histone deacetylase 1 (HDAC1) inhibitory activities. Compounds 11a surpassed the known class I selective HDAC inhibitor MS-275 in both HDAC1 enzymatic inhibitory activity and cellular anti-proliferative activity against a selected set of cancer cell types (Hut78, K562, Hep3B and HCT116 cells) with no observed effects on human normal cells. In particular, compound 11a inhibited HDAC1 over the other tested HDACs isoforms (HDAC2, HDAC6 and HDAC8) with acceptable safety profiles. Moreover, compound 11a displayed favorable oral pharmacokinetic properties and showed significant antitumor activity in the A549 tumor xenograft model in vivo.

The crystal structure of 4-amino-N′-(4-aminobenzoyl)benzohydrazide monohydrate, C14H16N4O3

C14H16N4O3, orthorhombic, P21212 (no. 18), a = 8.0968(7) Å, b = 16.6829(17) Å, c = 5.3097(5) Å, V = 717.22(12) Å3, Z = 2, R gt (F) = 0.0420, wRref (F 2) = 0.0816, T = 293(2) K.