Preparation and Antiviral Activity of Some New C3- and CS-Symmetrical Tri-Substituted Triazine Derivatives Having Benzylamine Substituents

C3-Symmetric ligands in drug design: An overview of the challenges and opportunities ahead

C3-symmetry is a type of star-shaped molecule consisting of a central core and three symmetrically attached chains. These molecules are used in drug discovery due to their unique three-fold rotational symmetry, which allows for specific binding interactions and improved molecular recognition. In this text, we provide an overview of synthetic approaches with C3-symmetry as a pharmaceutical tool: progress, challenges, and opportunities. C3-symmetric ligands offer both challenges and opportunities in drug design. Their unique symmetry can enhance binding interactions, but careful consideration of rigidity, synthetic complexity, and target compatibility is crucial. Further research and advancements in synthetic methods and modeling tools will likely drive their exploration in drug discovery, leading to the discovery of potent C3-symmetric ligands.

Synthetic and pharmacological developments in the hybrid s-triazine moiety: A review

This article summarizes the most recent advancements in the synthetic and pharmacological approaches along with the structure activity relationship towards the s-triazine and its derivatives. Much attention has been given to s-triazine core due to its facile synthesis, interesting pharmacology, high reactivity, and binding characteristics towards various enzymes. An array of biological applications has been demonstrated by s-triazines including antimalarial, anti-HIV, anti-viral, antimicrobial, anti-tuberculosis to name a few. In the present investigation s-triazine based molecular structures have been assembled in respect to their synthesis and medicinal properties. Further, the competence of s-triazine has been correlated and compared with the other heterocyclic moieties to substantiates-triazine a privileged scaffold. From the literature it is revealed that nucleophilic substitution at 2, 4, and 6 positions is significant for various biological applications. This article would help in assisting the chemists in designing novel molecular entities with high medicinal value.

C3-Symmetric Ligands in Drug Design: When the Target Controls the Aesthetics of the Drug

A number of proteins are able to adopt a homotrimeric spatial conformation. Among these structures, this feature appears as crucial for biologic targets, since it facilitates the design of C3-symmetric ligands that are especially suitable for displaying optimized ligand-target interactions and therapeutic benefits. Additionally, DNA as a therapeutic target, even if its conformation into a superhelix does not correspond to a C3-symmetry, can also take advantage of these C3-symmetric ligands for better interactions and therapeutic effects. For the moment, this opportunity appears to be under-exploited, but should become more frequent with the discovery of new homotrimeric targets such as the SARS-CoV2 spike protein. Besides their potential therapeutic interest, the synthetic access to these C3-symmetric ligands often leads to chemical challenges, although drug candidates with an aesthetic structure are generally obtained.

Multicomponent Molecular Systems Based on Porphyrins, 1,3,5-Triazine and Carboranes: Synthesis and Characterization

2,4,6-Trichloro-1,3,5-triazine (cyanuric chloride) is an excellent coupling reagent for the preparation of highly structured multifunctional molecules. Three component systems based on porphyrin, cyanuric chloride and carborane clusters were prepared by a one-pot stepwise amination of cyanuric chloride with 5-(4-aminophenyl)-10,15,20-triphenylporphyrin, followed by replacement of the remaining chlorine atoms with carborane S- or N-nucleophiles. Some variants of 1,3,5-triazine derivatives containing porphyrin, carborane and residues of biologically active compounds such as maleimide, glycine methyl ester as well as thioglycolic acid, mercaptoethanol and hexafluoroisopropanol were also prepared. A careful control of the reaction temperature during the substitution reactions will allow the synthesis of desired compounds in a good to high yields. The structures of synthesized compounds were determined with UV-vis, IR, ¹H NMR, ¹¹B NMR, MALDI-TOF or LC-MS spectroscopic data. The dark and photocytotoxicity as well as intracellular localization and photoinduced cell death for compounds 8, 9, 17, 18 and 24 were evaluated.

Free Amine-Directed Ru(II)-Catalyzed Redox-Neutral [4 + 2] C-H Activation/Annulation of Benzylamines with Sulfoxonium Ylides

An external oxidant free Ru(II)-catalyzed C-H functionalization/annulation of primary benzylamines with sulfoxonium ylides has been developed for the synthesis of isoquinolines. The reaction utilizes free amine as a directing group, which is generally considered to be a poor directing group. This work presents the first example of Ru-catalyzed C-H functionalization of benzylamines under redox-neutral conditions. The detection of the amine-directed ruthenacyclic intermediate using high-resolution mass spectrometry corroborated the involvement of free amine as a directing group.

Triazine based chemical entities for anticancer activity

Triazine is a six-membered aromatic nitrogen heterocyclic moiety that was extensively investigated because of its biological properties and, in particular anticancer potentials. Kinases play a crucial role in cancer cell proliferation and metabolism. Triazine derivatives show anticancer activity by inhibiting the lipid kinases like phosphoinositide 3-kinases, mammalian target of rapamycin, receptor tyrosine kinases, like focal adhesion kinase, cyclin-dependent kinases, Rho-associated protein kinases, p21-activated kinases, carbonic anhydrases, enolase inhibitors, microtubules inhibitors, and histone deacetylases. The present chapter highlights the synthesis of triazine-based derivatives, their characterization, evaluation of anticancer properties, and their journey towards possible medicine for cancer.

Rh(I)-catalysed imine-directed C-H functionalization via the oxidative [3 + 2] cycloaddition of benzylamine derivatives with maleimides

The Rh(I)-catalysed imine-directed oxidative [3 + 2] cycloaddition of benzylamines with maleimides is reported. A wide range of both benzylamines and maleimides is applicable to the reaction. A one-pot three component strategy using benzylamines, 2-pyridinecarboxaldehyde, and maleimides is successfully achieved. Mechanistic studies including deuterium labelling experiments suggest that a zwitterionic intermediate is formed and is a key intermediate through the Rh-catalysed activation of a benzylic C(sp³)-H bond of the imine.

In Silico Molecular Docking and Molecular Dynamic Simulation Analysis of Phytochemicals From Indian Foods as Potential Inhibitors of SARS-CoV-2 RdRp and 3CLpro

With the current pandemic of the novel coronavirus disease 2019 (COVID-19) in hand, researchers around the globe are dexterously working to find the best suitable drug candidates and overcome vaccination-related challenges, to achieve efficient control over the second surge of COVID-19. The medical consultants time and again have been reiterating the need to abide by the precautionary steps to prevent the spread of the coronavirus by maintaining social distancing when outside, sanitizing hands regularly, and wearing masks and gloves. They also suggest taking a good and hygienic meal so as to boost immunity. Indians have an inborn nature of using natural spices, food, and medicines in their daily lives. Indian researchers have paid heed to deploy compounds from natural sources to explore potential antiviral agents against COVID-19 as the chances of acquiring side effects are perceived as less, and the efficacy of phytochemicals from medicinal plants is sometimes greater when compared to their synthetic counterparts. In the present study, we performed an in silico molecular docking and molecular dynamic simulation analysis of screened phytochemicals from a comprehensive list of Ayurvedic herbs/functional foods that are present in natural food products against key receptor proteins of severe acute respiratory syndrome coronavirus 2. We found that Aegle marmelos, Vetiveria zizanoides, Moringaolifera, and Punica granatum have antiviral potential to prevent coronavirus infection in the populace.

Rh(II)-Catalyzed C-H Alkylation of Benzylamines with Unactivated Alkenes: The Influence of Acid on Linear and Branch Selectivity

The Rh-catalyzed C-H alkylation of benzylamine derivatives with unactivated 1-alkenes that proceeds via a picolinamide directing group is reported. The crucial role of an acid additive in this transformation is confirmed. Aromatic acids showed high linear selectivity, and aliphatic acids provided branched alkylation products as the major product. The reaction has a broad scope for benzylamines and alkenes. Deuterium labeling experiments suggest that a Rh-carbene intermediate is involved in the case of linear product formation. A different reaction pathway, however, appears to be involved in the case of branched alkylation products, and this pathway also appeared to be a minor pathway in linear-selective reactions.

Rh(i)- and Rh(ii)-catalyzed C-H alkylation of benzylamines with alkenes and its application in flow chemistry

The Rh-catalyzed C–H alkylation of benzylamines with alkenes using a picolinamide derivative as a directing group is reported. Both Rh(i) and Rh(ii) complexes can be used as active catalysts for this transformation. In addition, a flow set up was designed to successfully mimic this process under flow conditions. Several examples are presented under flow conditions and it was confirmed that a flow process is advantageous over a batch process. Deuterium labelling experiments were performed to elucidate the mechanism of the reaction, and the results indicated a possible carbene mechanism for this C–H alkylation process.

Rh(i)- and Rh(ii)-catalyzed C–H alkylation of benzylamines with alkenes using a picolinamide derivative as a directing group is reported under both batch and flow.

[Synthetic Studies on Developments for Bioactive New Leads of Oligovalent Symmetrical Molecules]

Interactions between carbohydrate-containing glycoproteins, proteoglycans, and glycolipids on the cell surface are important biological stages for the processes of bacterial or viral infection and tumor metastasis. Moreover, supramolecular interaction by macromolecules with two-fold (C₂) or three-fold (C₃) geometry is one of the common interactions in many important biological responses. To develop new multivalent symmetrical bioactive compounds or leads, we designed and synthesized several new molecules with these geometries and evaluated their bioactivities in an attempt to find new types of bioactive leads that may interfere with the sugar recognition process. We evaluated bioactivities including antibacterial, antiviral, and anticancer activities of targeted molecules in vitro using biological assay systems. Among the synthesized target derivatives examined, some bivalent symmetrical derivatives showed high levels of bioactivities. In this review, the author describes the results of synthesis of oligovalent symmetrical target compounds and some interesting guiding results of evaluation of their biological activities and structure-activity relationships.

Anti-proliferative Activities of Some Bivalent Symmetrical 5-Substituted Hydantoin Derivatives towards Human Brain Glioma U251 Cells (U251) and Human Carcinoma Cells (KB3-1)

Novel bivalent twin-drug type hydantoin derivatives were evaluated in vitro using a human brain glioma cell line (U251) and a human carcinoma cell line (KB3-1). Among the 5-substituted hydantoin derivatives (1a-b and 2a-d) examined in this study, bivalent symmetrical 5-substituted hydantoin derivative 1b showed the highest anti-proliferative activity towards both U251 and KB3-1 cells. The values of anti-proliferative activity (IC₅₀) of this hydantoin derivative against the two cell lines (U251 and KB3-1) were 0.46 and 5.21 µM, respectively. The anti-proliferative activity of all of the compounds except for compounds 2a and 2d against U251 cells was higher than that of cisplatin. Bivalent symmetrical compound 1b had a biphenylmethane linker in the molecule. All of the tested bivalent hydantoin derivatives showed higher activity against U251 cells than against KB3-1 cells. For twin-drug type hydantoin derivatives 2a-d, which have a linear methylene linker in the molecules, it was found that methylene linker length in these molecules have an effect on the anti-proliferative activity against U251 and KB3-1 cells.

Anti-proliferative Activities towards Human Brain Glioma U251 Cells and Human Carcinoma Cells (KB3-1) of Some Twin-Drug Type Bivalent C2-Symmetrical Phenylboronic Acid Derivatives

Derivatives of C₂-symmetrical bivalent phenylboronic acid exhibit several remarkable biological activities such as anti-herpes simplex virus (HSV)-1 and cytotoxic activities against Vero cells and they can reverse the effect of anticancer drugs. Novel symmetrical bivalent molecules were synthesized and their biological activities were evaluated in vitro using a human brain glioma cell line (U251) and a human carcinoma cell line (KB3-1). Among the tested compounds (1a-i), bivalent C₂-symmetrical phenylboronic acid derivative 1g showed the highest anti-proliferative activity towards both U251 and KB3-1 cells. The values of 50% anti-proliferative activity (IC₅₀) of this compound against the two cell lines (U251 and KB3-1) were 19.0 and 3.78 µM, respectively. The anti-proliferative activity of compound 1g towards KB3-1 cells was higher than that of cisplatin. The bivalent C₂-symmetrical compound 1g had a linear methylene linker in the molecule.