Abstract This review article summarizes the role of heterocyclic compounds as anticancer drugs used against various human cancers, including doxorubicin, cisplatin, paclitaxel, and resveratrol, which are among the most effective therapeutic agents. Chemotherapy, a treatment modality, exerts its effects on tumor cell DNA and often involves the use of low-molecular-weight medicines to selectively target and destroy cancer cells. However, systemic chemotherapy is associated with several side effects, such as nausea, vomiting, myelosuppression, and cardiotoxicity. Cancer remains one of the most prevalent and lethal diseases, characterized by uncontrolled cell division and abnormal cell growth driven by multiple genetic mutations. The etiopathogenesis of cancer is complex, but significant advancements have been made in treatment, particularly with the discovery of anticancer drugs, including cytotoxic chemotherapy, hormonal agents, and targeted therapies. Anticancer drugs are widely employed for the treatment of various cancers, such as breast, cervical, uterine, and kidney cancers. These drugs are classified into several categories, including alkylating agents, antimetabolites, antibiotics, and topoisomerase inhibitors. Among these, numerous heterocyclic compounds have shown promising anticancer properties. The goal of this review is to compile information on heterocyclic compounds used as anticancer drugs, highlighting their positive effects and therapeutic targets in cancer treatment and chemoprevention.

Abstract A novel water-soluble substituted pyridine dicarboxylate containing a quaternary ammonium ion with potential applications in fluorescence cell imaging was synthesized and characterized. Remarkably, this compound exhibited water solubility in the absence of additional solubilizers, enabling direct dissolution in phosphate-buffered saline for cell studies. No obvious cytotoxicity was observed in 4T1 cells (mouse breast cancer cells) within the concentration range of 0.2–25 μmol L−1, with a cell survival rate above 89%. Furthermore, the compound exhibited a maximum two-photon absorption cross-section of 86 GM at an excitation wavelength of 780 nm, demonstrating high cell permeability, effective distribution in the cytoplasm, and preferential targeting of organelles. Single- and two-photon fluorescence imaging of cells revealed a distinctive blue emission and strong bright green emission, respectively. The newly synthesized substituted pyridine dicarboxylate exhibited low cytotoxicity and strong fluorescence imaging properties, demonstrating its potential in cell imaging applications.

Abstract As part of our ongoing antileishmanial structure–activity relationship study, a structural simplification of the 3‐nitroimidazo[1,2‐a]pyridine ring to a 5-nitroimidazole moiety was conducted. A series of novel 2,4-disubsituted 5-nitroimidazole derivatives, including the 5-nitroimidazole analog of Hit A and the 4-phenylsulfonylmethyl analog of fexinidazole, were obtained by using the vicarious nucleophilic substitution of hydrogen (VNS) reaction, to substitute position 4, and by using the tetrakis(dimethylamino)ethylene methodology to modulate position 2. The molecular structures of eight novel 5-nitroimidazoles were characterized by 1H NMR, 13C NMR, LC/MS, and HRMS. The in vitro antileishmanial activity of these compounds was evaluated against the promastigote form of Leishmania infantum and their influence on cell viability was assessed on the human hepatocyte HepG2 cell line. The 4-phenylsulfonylmethyl analog of fexinidazole showed the best selectivity index of the series, displaying good activity against both the promastigote form of L. infantum (EC50 = 0.8 µM, SI > 78.1) and the promastigote form of Leishmania donovani (EC50 = 4.6 µM, SI > 13.6), and exhibiting low cytotoxicity on the HepG2 cell line (CC50 > 62.5 µM).

Abstract Research on gold catalysis has flourished over the last 20 years, and gold catalysts are now acknowledged as the “best choice” for a range of organic transformations. Gold complexes have emerged as promising candidates for this use in recent years because of their high reactivity, which enables them to induce a broad range of transformations under mild conditions. Extensive demonstrations have showcased the extraordinary efficiency of synthesizing complex organic compounds from the basic starting components. In addition to its traditional applications in catalysis, gold catalysis has expanded to include the total synthesis of natural compounds, which is a complex and demanding undertaking. The class of molecules known as carbo- and heterocycles, which is arguably the most important, has a significant impact on the synthesis of agrochemicals and pharmaceuticals among the numerous additional products made possible by the novel procedures pioneered. The main topic of this review is how to use Au salts in homogeneous catalysis to create cyclization processes for small heterocyclic and carbocyclic systems. This study gives an overview of most of the books and articles written after 2013 that discuss making three- and four-membered carbo- and heterocyclic rings with gold as a catalyst. We have made every effort to include all outstanding reports on this subject; nonetheless, we apologize for any omissions.

Abstract A series of novel 1,2,4-triazole-chalcone compounds 10a–10s were designed by molecular hybridization strategy and synthesized. The molecular structures of the novel chalcones were characterized by 1H-NMR, 13C-NMR, and HRMS. The anti-proliferative activities of the novel chalcones against four cancer cell lines in vitro were examined by MTT, four tumor cell lines including human colon cancer cell SW620, human non-small cell lung cancer cell A549, human cervical cancer cell HeLa, and human breast cancer cell MCF-7. Compound 10o showed certain selectivity to SW620 cell line, and its IC50 value was 21.55 μM. 10q had good anti-proliferative activity against A549 cells with an IC50 value of 25.58 μM.

Abstract In the drug chemistry industry, synthesizing a talented exclusive series of aza-polyheterocyclic compounds was crucial. Aminopyrimidine nucleus reacted with two equivalents of benzaldehyde in the presence of KOH as a starting material to bring about imidazopyrimidine derivative, which experienced intermolecular cyclization using carbon disulfide, Br2/AcOH, and/or HNO2 to produce thiazole, thieno, and/or nitro pyrimidine derivative, respectively. Accordingly, the nucleus of Aminopyrimidine was prepared and used to develop the novel polyheterocyclic systems acylated with two moles of succinic anhydride to furnish the imidazolopyrimidine derivative. Benzylidene ethyl cyanoacetate and aminopyrimidine undergo (3 + 4) intermolecular cycloaddition 1,3 H shift followed by hydrolysis and after CO2 evolution provided diazepine derivative. The diazepine derivative was attained due to the cyclo-condensation of the starting material and acetylacetone. Moreover, the structure of the novel synthesized compound series was exploited and verified via spectroscopic approaches. The synthesized series were tested for antimicrobial activity against gram-positive and gram-negative bacterial strains and antifungal activity. The thienopyrimidine derivatives and diazepine exhibited unusual antimicrobial activity. Furthermore, the molecular docking studies confirmed the biological studies with Molecular Operating Environment and petro orisis molinspiration studies, which proved the activity of compounds 4, 5, 7, 10, 13, and 16.

Abstract The present work describes the synthesis, characterization, and evaluation of the antibacterial activity of a new poly azo compound resulting from the coupling of a previously reported N-arylsuccinimid precursor 5 with the diazonium ion of aniline. This azo compound was characterized using its physical, elemental, and 1D and 2D spectroscopic data. The novel azo compound 7 (minimum inhibitory concentration [MIC] = 16–32 μg/mL) showed higher antibacterial activity than its precursor 5 (MIC = 32–64 μg/mL), although it was low compared to the reference drug ciprofloxacin (MIC = 0.5–4 μg/mL).

Abstract A series of benzo (dibenzo)dioxadiaza and triazamacrocyclic ether compounds carrying 1,2,4-oxadiazole group has been successfully synthesized through N-substitution with 3-p-phenylsubstituted-5-chloromethyl-1,2,4-oxadiazoles. The structures of all the novel macrocycles were confirmed by spectral/physical data including HRMS measurements.

Abstract In this study, quantum chemical calculations of phenazine-based organic molecules applied in organic dye-sensitized solar cells (DSSCs) have been made and interpreted. Since DSSC molecules work with the electron push–pull system, the sequence of other compounds (2–8) from compound 1 is designed as a donor–π bridge (weak acceptor)–acceptor (D–π–A). Later, the studied molecules were expanded from 2a to 8c by lengthening the conjugation with phenyl, thiophene, and furan to the acceptor parts. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations are practiced to investigate all structures and absorption spectra of molecules, respectively. It has been observed that the phenazine-based molecule series are good candidates for DSSCs, both with their band gap and their absorption spectrum results. It can be assumed that changing the HOMO and LUMO energy values of all designed structures according to compound 1 can absorb light in the organic dye-sensitized solar cells and transfer electrons to the conductivity band of TiO 2 . As a result, it has been resolved that various dyes can be designed for dye-sensitizing solar cells by calculating electronic energies, HOMO–LUMO energies, and absorption wavelengths.

Abstract New Schiff bases and azo dyes derivatives have been synthesized via appropriate conventional methods using pyranoquinolinone as a starting material. The compounds obtained were characterized by spectral analysis and evaluated for anticancer activity in several human tumor cell lines: MCF-7 breast cancer, HepG2 liver cancer and HCT-116 colon carcinoma. 5-fluorouracil was used as a reference drug. The in vitro cytotoxicity screening results revealed that all tested compounds showed promising activity against MCF-7 cells. In particular, compounds 6a, 6b , and 7b showed excellent activity against the three human tumor cell lines. Structure-activity relationship studies indicated that the azo derivative with a trifluoromethoxy group (compound 7b ) was the most potent candidate against the three human tumor cell lines (IC 50 , 1.82-8.06 μg/mL). Our findings highlight pyranoquinolinone analogues as a promising class of compounds for new anticancer therapies.