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Developing multifunctional nanomaterials with distinct photochemical properties, such as high quantum yield, improved photostability, and good biocompatibility is critical for a wide range of biomedical applications. Motivated by this, we designed and synthesized a dansyl-tagged xanthate-based capping agent (DX) for the synthesis of fluorescent silver nanoparticles (AgNPs). The capping agent DX was characterized by 1 H and 13 C-NMR, LC-MS, and FT-IR. The synthesized DX-capped fluorescent AgNPs were thoroughly characterized by UV-visible spectroscopy, fluorescence spectroscopy, field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), dynamic light scattering (DLS), and zeta potential. The fluorescent AgNPs showed distinct surface plasmon resonance absorption at λ max  = 414 nm, fluorescence at λ max  = 498 nm, quantum yield = 0.24, zeta potential = +18.6 mV, average size = 18.2 nm. Furthermore, the biological activity of the fluorescent AgNPs was validated by its interaction with the most abundant protein in the blood, that is, BSA (Bovine serum albumin) and HSA (Human serum albumin) with binding constant of 2.34 × 10 4  M -1 and 2.14 × 10 4  M -1 respectively. Interestingly, fluorescence resonance energy transfer (FRET) was observed between the fluorescent AgNPs and BSA/HSA with a FRET efficiency of 77.23% and 56.36%, respectively, indicating strong interaction between fluorescent AgNPs and BSA/HSA., (© 2024 American Society for Photobiology.)

Molecules with tuneable properties are well known for their applications in the material and bio-medical fields; nevertheless, the structural and functional tunability makes them more significant in diverse applications. Herein, we designed and synthesized a novel class of star-shaped molecules via incorporating two important functional groups, i.e., triazole and dithiocarbamate (DTC). The rationale behind selecting these two key functional groups is their diverse applications, e.g., DTC having applications for therapeutics, pesticides, and vulcanizing agents, and triazole having applications for anti-cancer, fungicides, anti-microbials, inhibitors, etc. The structure of the molecules was strategically designed in such a way that their overall structures are the same (central tertiary-amine and peripheral hydroxy groups), except the key functional group (DTC and triazole) in the respective molecules was different. Following synthesis and characterization, the influence of DTC and triazole groups on their bioactivity was compared via interacting with the most abundant proteins present in the blood, including serum albumin, trypsin, haemoglobin, and ribonuclease. From both the experimental and molecular docking studies, it was confirmed that the triazole molecule has a higher binding affinity towards these proteins as compared to the DTC molecule. In summary, two star-shaped DTC- and triazole-based molecules were synthesized and their bioactivity was compared via binding with blood plasma proteins. [ABSTRACT FROM AUTHOR]

The architecture of molecules plays a significant role in their effective binding with another moiety. Direct comparison of a linear dithiocarbamate and its macrocyclic analogue was carried out, to explore the magnitude of these architectural effects for different biological and material science applications. Linear and macrocyclic compounds with the same functional groups, such as amide, dithiocarbamic ester, naphthyl, and propyl, were designed, synthesized, and compared through their spectral, physicochemical, and thermal properties. Utilizing dithiocarbamates, the compounds were used for the detoxification of water by removal of toxic heavy metals, including Hg2+, Cu2+, Cd2+, Pb2+, Zn2+, and Ni2+ by precipitation. In addition, comparable interactions with various important proteins, such as bovine serum albumin, human serum albumin, haemoglobin, lysozyme, proteinase, ribonuclease, and trypsin, were performed. The observation of better performance for the macrocycle towards protein interaction, and of the linear compound for removal of heavy metals is remarkable, and proves that the compound architecture is important. [ABSTRACT FROM AUTHOR]

A modular platform for the synthesis of tunable aza-oxa-based macrocycles was established. Modulations in the backbone and the side-chain functional groups have been rendered to achieve the tunable property. These aza-oxa-based macrocycles can also differ in the number of heteroatoms in the backbone and the ring size of the macrocycles. For the proof of concept, a library of macrocycles was synthesized with various hanging functional groups, different combinations of heteroatoms, and ring sizes in the range of 17–27 atoms and was characterized by NMR and mass spectrometry. In light of the importance of the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction and the significance of triazole groups for various applications, we employed the click-reaction-based macrocyclization. The competence of the synthesized macrocycles in various biomedical applications was proven by studying the interactions with the serum albumin proteins; bovine serum albumin and human serum albumin. It was observed that some candidates, based on their hanging functional groups and specific backbone atoms, could interact well with the protein, thus improving the bioactive properties. On the whole, this work is a proof-of-concept to explore the backbone- and side-chain-tunable macrocycle for different properties and applications. [ABSTRACT FROM AUTHOR]

The design and synthesis of a versatile class of macrocycles with tunable functional groups and ring size are unfolded. Herein, a synthetic strategy is reported to furnish a new class of macrocycles in multi-gram scale in a two-step reaction. The total time taken for synthesizing a macrocycle is 1.5 h. Dithiocarbamates, an important functional group in biomedical and material sciences, is strategically incorporated in the macrocyclic backbone without metal for the first time. It is noteworthy that when state-of-the-art macrocycle synthesis is in millimolar concentration, this work employs the reaction in molar concentration (0.2–0.4 M). As proof-of-principle, a library of macrocycles was synthesized, varying the functional groups and ring size. The physicochemical properties of macrocycles revealed their druggable nature and are affirmed by protein (serum albumin) interaction study theoretically and experimentally. Diverse functional groups and ring sizes of macrocycles brought about twenty-five-fold difference in binding constant with the model protein. [ABSTRACT FROM AUTHOR]

[Display omitted] • Structurally and functionally tuneable dansyl appended sequence-defined oligomers (SDOs) were synthesised. • Structure of the dansyl attached SDOs were tuned to modify (a) the number and type of functional groups (Dithiocarbamate, ester and amide) (b) architectures-Linear and Branched and (c) hydrophobic/hydrophilic character. • The interaction of these SDOs with serum proteins (BSA and HSA) were studied experimentally via FRET and theoretically via molecular docking. • The binding constant, number of binding sites and FRET efficiency values were obtained and this indicats that an optimum hydrophobic character, chain length, functional groups and architecture are essential for a favourable interaction with BSA/HSA. • In-silico results support all the experimental findings. In this work, a library of functionally and structurally tuneable macromolecules were synthesised and their interaction with serum proteins were studied experimentally and theoretically, with an aim to identify the driving factors that influence protein-drug interaction. The parameters taken for assessment were (a) the number and type of functional groups (dithiocarbamate, ester and amide) present in the backbone and sidechain, (b) different architectures including linear and branched, and (c) hydrophobic/hydrophilic character. Dansyl moiety was attached to make these macromolecules a suitable acceptor for FRET with serum proteins. The binding constant values calculated from the fluorescence titrations indicated that an optimum hydrophobic character, chain length and architecture are essential for a favourable interaction with BSA/HSA. By changing the above mentioned three factors, we were able to achieve a wide range of binding constant values in the range of (2.99–7.91) × 104 M−1 for BSA and (1.64–11.7) × 104 M−1 for HSA. The number of binding sites varied from 1.13 to 1.69 for BSA and 0.89 to 1.35 for HSA. Also, the energy transfer efficiency was calculated and it falls in the range of 63.9–88.7% and 52.0–84.2% respectively for BSA and HSA. The quenching mechanism for serum protein-drug complex was found to involve both static and dynamic quenching. Moreover, this structure–activity relationship was also backed by molecular docking studies. [ABSTRACT FROM AUTHOR]

• Design of a novel class of Pd-complexes: Pd3 shows unique monodentate-coordination. • Interaction of Pd3 with DNA/BSA was confirmed by experimental and docking study. • Pd3 exhibited anticancer activity with superior selectivity towards cancer cells. • Pd3 induced ROS dependent MOMP decrease leading to cancer cell death. • Cellular uptake of Pd3 was confirmed with fluorescent-based cellular imaging. A novel class of Pd(II) pyrene aroylhydrazone complexes (Pd1–Pd4) of general formula [Pd(L)(PPh 3)Cl] (L = pyrene aroylhydrazones) was synthesized and their solid-state structures were determined by single-crystal XRD study. In vitro cytotoxicity of Pd1 – Pd4 were examined against two cancer cell lines, HeLa and MCF-7 and two non-cancerous cell line, HEK 293T and 3T3-L1 to assess their selectivity. Among these, Pd2 and Pd3 had the most significant cytotoxic effects in comparison to cisplatin, a traditional anticancer medication featuring undesirable side effects, in tested cancer cell lines. Moreover, they showed noticeably less toxicity towards non-cancerous cell lines. Their interactions with serum albumin were confirmed experimentally as well as with molecular docking. Pd3 was also found to effectively interact with DNA as revealed by DNA interactions studies. Pd3 -treated HeLa cells exhibited nuclear apoptotic features such as chromatin condensation and nuclear fragmentation and was also found to induce ROS which further led to decrease in mitochondrial membrane potential in cancer cells. Further, Pd3 was efficiently internalized by HeLa cells as evident from cellular imaging using confocal microscopy. Taken together, we report a novel class of Pd(II) pyrene aroylhydrazone complexes displaying strong protein/DNA binding and anti-cancer activity via ROS generation under in vitro circumstances. Author Statement A.V and M.P conceived the molecular design, synthesis, and characterization. N.S.P.B conceived the single-crystal X-ray diffraction. A.B and S.S carried out the anticancer activity assay. A.V and A.B analyzed the data and wrote the manuscript. S.S and M.P edited the manuscript. [Display omitted] [ABSTRACT FROM AUTHOR]