Synthesis and Antimicrobial Evaluation of Bis-morpholine Triazine Quaternary Ammonium Salts

Design, synthesis, bioactivity, X-ray crystallography, and molecular docking studies of chrysin-1,3,5-triazine derivatives as anticancer agents

In order to discover new effective anti-cancer drugs, fifteen derivatives of chrysin-1,3,5-triazine were designed and synthesized as potential novel anti-cancer agents. The structure of the target compounds were characterized by 1H NMR, 13C NMR, IR, and HR-MS. The purity of all compounds were detected by HPLC. The structure of compound 4a was subjected to further investigation through single crystal X-ray diffraction, and elaborate discussions were conducted on the Hirshfeld surface and two-dimensional fingerprint diagram to explore the molecular conformation, crystal packing mode and molecular interactions. The antiproliferative activity of these compounds was assessed by the MTT (methylthiazolyl tetrazolium) assay against MDA-MB-231 (breast cancer cells), HeLa (cervical cancer cells), HCCLM3 (liver cancer cells), and HCT116 (colon cancer cells). Positive controls were cisplatin and chrysin. The results show that some chrysin-1,3,5-triazine derivatives have better anti-cancer activity than cisplatin and chrysin. Chrysin-1,3,5-triazine derivatives selectively targets HeLa cervical cancer cells. Compound 4c (7-((4-(Dibutylamino)-1,3,5-triazin-2-yl)oxy)-5-hydroxy-2-phenyl-4H-chromen-4-one) exhibits the strongest antiproliferative activity against HeLa cells (IC50 = 9.86 ± 0.37 μM), superior to cisplatin and chrysin (IC50 values of 28.09 ± 0.47 μM and 29.51 ± 0.51 μM, respectively). Further studies showed that compound 4c not only inhibits the invasion, adhesion, and proliferation of HeLa cells, but also has a strong inhibitory effect on the proliferation of HeLa tumor heterotopic xenografts in vivo. Molecular docking studies suggest that compound 4c can interact with phosphatidylinositol 3-kinase(PI3K)and cysteine aspartic acid proteinase-3 (Caspase-3). Western blot results demonstrated that compound 4c inhibited PI3K expression at the protein level and promoted the degradation of Pro-caspase-3, thereby activating the caspase-3-dependent apoptotic pathway. Furthermore, the absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties of these compounds suggest that they may have pharmacological characteristics and safety. Thus, compound 4c has the potential to be a highly promising candidate for cancer treatment.

Design, synthesis, in silico studies and antiproliferative evaluation of some novel hybrids of pyrimidine-morpholine

Introduction

Cancer is a complex group of diseases characterized by the uncontrolled growth and spread of abnormal cells in the body. These cells can invade nearby tissues and organs, or they may metastasize to other parts of the body through the bloodstream or lymphatic system.

Methods

In this study, eight novel pyrimidine-morpholine hybrides (2a-2h) were designed and synthesized based on molecular hybridization approach to identify potent cytotoxic agents. Spectroscopic methods, including infrared spectroscopy (IR), proton and carbon nuclear magnetic resonance (1HNMR & 13CNMR), and mass spectrometry, were employed to confirm the structures of the compounds. The cytotoxic effects of the derivatives were evaluated against cancerous cell lines, including MCF-7 and SW480, using the MTT assay.

Results and discussion

It was demonstrated that all derivatives had appropriate cytotoxic potential with IC50 in range of 5.12-117.04 μM. Compound 2g was identified as the most potent compound, exhibiting IC50 values of 5.10 ± 2.12 μM and 19.60 ± 1.13 μM toward the SW480 and MCF-7 cell lines, respectively. Cell cycle analysis showed that 2g could induces phase arrest in MCF-7 breast cancer cells. The apoptosis assay demonstrated the induction of apoptosis in the SW480 cell line. The biological activity of the compounds was confirmed by the docking studies. DFT analysis for compounds 2g and 2h was conducted at the B3LYP/6-31+G** level of theory. It was concluded that 2g is both thermodynamically and kinetically more stable than 2h. Moreover, the interpretation of ADME (Absorption, Distribution, Metabolism, and Excretion) indicates that these new series of compounds possess acceptable prognostic physicochemical properties. These synthesized compounds may serve as promising candidates for further investigation as anticancer agents.

Designing Antibacterial-Based Quaternary Ammonium Coatings (Surfaces) or Films for Biomedical Applications: Recent Advances

Antibacterial coatings based on quaternary ammonium compounds (QACs) have been widely investigated in controlled release applications. Quaternary ammonium compounds are low-cost and easily accessible disinfectants that have been extensively used, especially after the COVID-19 outbreak. There has been a growing interest in developing a clearer understanding of various aspects that need to be taken into account for the design of quaternary ammonium compounds to be used in the biomedical field. In this contribution, we outline the mechanism of action of those materials as well as the key design parameters associated with their structure and antibacterial activity. Moreover, emphasis has been placed on the type of antibacterial coatings based on QACs and their applications in the biomedical field. A brief outlook on future research guidelines for the development of dual-function antibacterial coatings is also discussed.

Enhanced Antibacterial Activity of Vancomycin Loaded on Functionalized Polyketones

Today, polymeric drug delivery systems (DDS) appear as an interesting solution against bacterial resistance, having great advantages such as low toxicity, biocompatibility, and biodegradability. In this work, two polyketones (PK) have been post-functionalized with sodium taurinate (PKT) or potassium sulfanilate (PKSK) and employed as carriers for Vancomycin against bacterial infections. Modified PKs were easily prepared by the Paal-Knorr reaction and loaded with Vancomycin at a variable pH. All polymers were characterized by FT-IR, DSC, TGA, SEM, and elemental analysis. Antimicrobial activity was tested against Gram-positive Staphylococcus aureus ATCC 25923 and correlated to the different pHs used for its loading (between 2.3 and 8.8). In particular, the minimum inhibitory concentrations achieved with PKT and PKSK loaded with Vancomycin were similar, at 0.23 μg/mL and 0.24 μg/mL, respectively, i.e., six times lower than that with Vancomycin alone. The use of post-functionalized aliphatic polyketones has thus been demonstrated to be a promising way to obtain very efficient polymeric DDS.

Chitosan as a Bio-Based Ligand for the Production of Hydrogenation Catalysts

Bio-based polymers are attracting increasing interest as alternatives to harmful and environmentally concerning non-biodegradable fossil-based products. In particular, bio-based polymers may be employed as ligands for the preparation of metal nanoparticles (M(0)NPs). In this study, chitosan (CS) was used for the stabilization of Ru(0) and Rh(0) metal nanoparticles (MNPs), prepared by simply mixing RhCl3 × 3H2O or RuCl3 with an aqueous solution of CS, followed by NaBH4 reduction. The formation of M(0)NPs-CS was confirmed by Fourier Transform Infrared Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC), Thermal Gravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Analysis (EDX), Transmission Electron Microscopy (TEM) and X-ray Diffraction (XRD). Their size was estimated to be below 40 nm for Rh(0)-CS and 10nm for Ru(0)-CS by SEM analysis. M(0)NPs-CS were employed for the hydrogenation of (E)-cinnamic aldehyde and levulinic acid. Easy recovery by liquid-liquid extraction made it possible to separate the catalyst from the reaction products. Recycling experiments demonstrated that M(0)NPs-CS were highly efficient up to four times in the best hydrogenation conditions. The data found in this study show that CS is an excellent ligand for the stabilization of Rh(0) and Ru(0) nanoparticles, allowing the production of some of the most efficient, selective and recyclable hydrogenation catalysts known in the literature.

May 1,3,5-Triazine derivatives be the future of leather tanning? A critical review

Leather is produced by a multi-step process among which the tanning phase is the most relevant, transforming animal skin collagen into a stable, non-putrescible material used to produce a variety of different goods, for the footwear, automotive, garments, and sports industry. Most of the leather produced today is tanned with chromium (III) salts or alternatively with aldehydes or synthetic tannins, generating high environmental concern. Over the years, high exhaustion tanning systems have been developed to reduce the environmental impact of chromium salts, which nevertheless do not avoid the use of metals. Chrome-free alternatives such as aldehydes and phenol based synthetic tannins, are suffering from Reach restrictions due to their toxicity. Thus, the need for environmentally benign and economically sustainable tanning agents is increasingly urgent. In this review, the synthesis, use and tanning mechanism of a new class of tanning agents, 1,3,5-triazines derivatives, have been reported together with organoleptic, physical mechanical characteristics of tanned leather produced. Additionally environmental performance and economic data available for 1,3,5-triazines have been compared with those of a standard basic chromium sulphate tanning process, evidencing the high potentiality for sustainable, metal, aldehyde, and phenol free leather manufacturing.

Metal-free synthesis and study of glycine betaine derivatives in water for antimicrobial and anticancer applications

A sustainable synthesis of interesting glycine betaine derivatives from cyclic 3°-amines viz. N-methyl morpholine (NMM), N-methyl piperidine (NMP), and 1,4-diazabicyclo[2.2.2]octane (DABCO) with numerous aryl diazoacetates 1 in water and under blue LED is reported. Generally, 3°-amines and metal carbenoids (from diazoacetates with transition metal catalysts) provide C-H insertion at the α-position of the amines. Computational comparison of the metal carbenoid with the singlet carbene (metal free and generated under blue LED) realized the difference in reactivity. Next, experimental results corroborated the preliminary findings. The products were isolated either by precipitation of the solid or gel-like final products from the aqueous reaction mixture without any chromatographic purification. The reaction mechanism was realized by control experiments. These compounds exhibit selective bactericidal properties against Gram-positive S. aureus, induce lipid droplets (LDs) formation in HePG2 cells and single crystal X-ray diffraction study of their halogenated analogs reveal interesting Hal … Hal contacts.

Design, Synthesis, and Anti-PVY Biological Activity of 1,3,5-Triazine Derivatives Containing Piperazine Structure

In this study, a commercial agent with antivirus activity and moroxydine hydrochloride were employed to perform a lead optimization. A series of 1,3,5-triazine derivatives with piperazine structures were devised and synthesized, and an evaluation of their anti-potato virus Y (PVY) activity revealed that several of the target compounds possessed potent anti-PVY activity. The synthesis of compound C35 was directed by a 3D-quantitative structure-activity relationship that used the compound's structural parameters. The assessment of the anti-PVY activity of compound C35 revealed that its curative, protective, and inactivation activities (53.3 ± 2.5%, 56.9 ± 1.5%, and 85.8 ± 4.4%, respectively) were comparable to the positive control of ningnanmycin (49.1 ± 2.4%, 50.7 ± 4.1%, and 82.3 ± 6.4%) and were superior to moroxydine hydrochloride (36.7 ± 2.7%, 31.4 ± 2.0%, and 57.1 ± 1.8%). In addition, molecular docking demonstrated that C35 can form hydrogen bonds with glutamic acid at position 150 (GLU 150) of PVY CP, providing a partial theoretical basis for the antiviral activity of the target compounds.

Antifouling Systems Based on a Polyhedral Oligomeric Silsesquioxane-Based Hexyl Imidazolium Salt Adsorbed on Copper Nanoparticles Supported on Titania

The reaction of octakis(3-chloropropyl)octasilsesquioxane with four equivalents of 1-hexylimidazole or 1-decylimidazole gave two products labelled as HQ-POSS (hexyl-imidazolium quaternized POSS) and DQ-POSS (decyl-imidazolium quaternized POSS) as regioisomer mixtures. An investigation of the biological activity of these two compounds revealed the higher antimicrobial performances of HQ-POSS against Gram-positive and Gram-negative microorganisms, proving its broad-spectrum activity. Due to its very viscous nature, HQ-POSS was adsorbed in variable amounts on the surface of biologically active oxides to gain advantages regarding the expendability of such formulations from an applicative perspective. Titania and 5 wt% Cu on titania were used as supports. The materials 10HQ-POSS/Ti and 15HQ-POSS/5CuTi strongly inhibited the ability of Pseudomonas PS27 cells-a bacterial strain described for its ability to handle very toxic organic solvents and perfluorinated compounds-to grow as planktonic cells. Moreover, the best formulations (i.e., 10HQ-POSS/Ti and 15HQ-POSS/5CuTi) could prevent Pseudomonas PS27 biofilm formation at a certain concentration (250 μg mL^-1) which greatly impaired bacterial planktonic growth. Specifically, 15HQ-POSS/5CuTi completely impaired cell adhesion, thus successfully prejudicing biofilm formation and proving its suitability as a potential antifouling agent. Considering that most studies deal with quaternary ammonium salts (QASs) with long alkyl chains (>10 carbon atoms), the results reported here on hexylimidazolium-based POSS further deepen the knowledge of QAS formulations which can be used as antifouling compounds.

Quaternary Ammonium Salts: Insights into Synthesis and New Directions in Antibacterial Applications

The overuse of antibiotics has led to the emergence of a large number of antibiotic-resistant genes in bacteria, and increasing evidence indicates that a fungicide with an antibacterial mechanism different from that of antibiotics is needed. Quaternary ammonium salts (QASs) are a biparental substance with good antibacterial properties that kills bacteria through simple electrostatic adsorption and insertion into cell membranes/altering of cell membrane permeability. Therefore, the probability of bacteria developing drug resistance is greatly reduced. In this review, we focus on the synthesis and application of single-chain QASs, double-chain QASs, heterocyclic QASs, and gemini QASs (GQASs). Some possible structure-function relationships of QASs are also summarized. As such, we hope this review will provide insight for researchers to explore more applications of QASs in the field of antimicrobials with the aim of developing systems for clinical applications.

Antibacterial quaternary ammonium agents: Chemical diversity and biological mechanism

Bacterial infections have seriously threatened public health especially with the increasing resistance and the cliff-like decline of the number of newly approved antibacterial agents. Quaternary ammonium compounds (QACs) possess potent medicinal properties with 95 successfully marketed drugs, which also have a long history as antibacterial agents. In this review, we summarize the chemical diversity of antibacterial QACs, divided into chain-like and aromatic ring, reported over the past decade (2012 to mid-2022). Additionally, the structure-activity relationships, mainly covering hydrophobicity, charges and skeleton features, are discussed. In the cases where sufficient information is available, antibacterial mechanisms including biofilm, cell membrane, and intracellular targets are presented. It is hoped that this review will provide sufficient information for medicinal chemists to discover the new generation of antibacterial agents based on QACs.