Luminescent anticancer ruthenium(ii)-p-cymene complexes of extended imidazophenanthroline ligands: synthesis, structure, reactivity, biomolecular interactions and live cell imaging.

Of late, cancer has become a terrible disease affecting people throughout the world. Keeping this in mind, we tried to design drugs that are more lipophilic, target-specific, water-soluble, cytoselective and fluorescent. In this regard, we reported novel ruthenium(ii)-p-cymene imidazophenanthroline scaffolds as effective DNA targeting agents. The planarity of imidazophenanthroline ligands caused the Ru(ii) complex to be a good intercalator. An extended π-electronic conjugation was introduced in the imidazophenanthroline moieties through the Suzuki and Sonogashira coupling reactions. Here, we synthesized nine Ru(ii) complexes (16a-b, 17a-d, and 19a-c). Among these, [(η6-p-cymene)RuCl(K2-N,N-2-(4'-methyl-[1,1'-BIphenyl]-4-yl)-1H-imidazo[4,5-f][1,10]phenanthroline)]·PF6 (16b) exhibited the best potency and selectivity with excellent cellular uptake; [(η6-p-cymene)RuCl(K2-N,N-2-(4-(phenylethynyl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline)]·PF6 (17a) acted as a cytoselective probe for live cell imaging.

Water-mediated green synthesis of PbS quantum dot and its glutathione and biotin conjugates for non-invasive live cell imaging.

This study addresses the cellular uptake of nanomaterials in the field of bio-applications. In the present study, we have synthesized water-soluble lead sulfide quantum dot (PbS QD) with glutathione and 3-MPA (mercaptopropionic acid) as the stabilizing ligand using a green approach. 3-MPA-capped QDs were further modified with streptavidin and then bound to biotin because of its high conjugation efficiency. Labelling and bio-imaging of cells with these bio-conjugated QDs were evaluated. The bright red fluorescence from these types of QDs in HeLa cells makes these materials suitable for deep tissue imaging.

Discovery of benzothiazolylquinoline conjugates as novel human A3 receptor antagonists: biological evaluations and molecular docking studies.

Adenosine is known as an endogenous purine nucleoside and it modulates a wide variety of physiological responses by interacting with adenosine receptors. Among the four adenosine receptor subtypes, the A3 receptor is of major interest in this study as it is overexpressed in some cancer cell lines. Herein, we have highlighted the strategy of designing the hA3 receptor targeted novel benzothiazolylquinoline scaffolds. The radioligand binding data of the reported compounds are rationalized with the molecular docking results. Compound 6a showed best potency and selectivity at hA3 among other adenosine receptors.

Amberlite IR-120 (H) mediated "on water" synthesis of fluorescent Ruthenium(II)-arene 8-hydroxyquinoline complexes for cancer therapy and live cell imaging.

A series of Ruthenium-Quinolinol complexes (3a-d &4a-d) has been synthesized by employing a simple, efficient and environmental friendly condition. Catalytic role of Amberlite IRA-120(H) has been demonstrated. The structures of the new compounds were elucidated by the analysis of spectroscopic data. The stability of these complexes was measured by UV spectroscopy & time dependent NMR spectroscopy. These newly developed complexes were represented as potential anticancer agent against human breast carcinoma cell line (MCF-7), human Epitheloid Cervix Carcinoma (HeLa), human lung adenocarcinoma epithelial cell line (A549) and human colon cancer cell line (Caco-2). Most of the ruthenium complexes showed higher anticancer activity in MCF-7, HeLa and Caco-2 cell lines than cisplatin. A high selectivity (9-28 folds) was observed with these newly developed organoruthenium compounds in human cancer cell lines (MCF-7, HeLa and Caco-2) with respect to normal fibroblast cell line (MRC-5). Complex [(η6-hexamethylbenzene)RuCl(κ2-O,N-5-chloro-HyQ)]·Cl (4b), [(η6-hexamethylbenzene)RuCl(κ2-O,N-5,7-dibromo-HyQ)]·Cl (4c) and [(η6-hexamethylbenzene)RuCl(κ2-O,N-5-chloro-7-iodo-HyQ)]·Cl (4d) exhibited best cytotoxicity profiles in three reported human cancer cell lines (MCF-7, HeLa, Caco-2). Cellular imaging study was also performed with these newly developed organoruthenium compounds. Compound 4c might be utilized for cancer theranostic agents because of its significant quantum yield in water, high potency, selectivity and high cellular uptake in cancer cell lines.

Theranostic Aspects: Treatment of Cancer by Nanotechnology.

Theranostic agents or theranostic imaging as its name suggests is a combination of two terms-'diagnosis' & 'therapy'. Efforts are being made to combine both the terms into clinical formulations. This theranostic imaging is found to be very much significant to complex diseases like cancer and proliferative tumors especially because accurate photocopy for every tumor can be obtained by genomic and proteomic profiling and using such informations in theranostic agents can be constructed or modeled in such a way that it is specific in its action and selective towards the cancer cells only, without causing any adverse effects on the normal tissue cells. By means of nanoplatforms, we can conveniently deliver cancer cell specific targeting ligand or peptide inside the human body. Primary delivery approach comprises of nanoparticles, liposomes, dendrimers, prodrugs, polymersomes, carbon nanotubes and polymeric micelles. Theranostic agents, i.e., therapeutic and diagnostic agents can be physically bound or else they can be bound with polymers which are exclusively designed and this together forms nanocarriers. Hence, the review highlights the advances of nanotechnology that has given us a platform for cancer detection and treatment.

Pyridine Based Fluorescence Probe: Simultaneous Detection and Removal of Arsenate from Real Samples with Living Cell Imaging Properties.

Pyridine based fluorescence probe, DFPPIC and its functionalized Merrifield polymer has been synthesized, characterized and used as an arsenate selective fluorescence sensor. Arsenate induced fluorescence enhancement is attributed to inter-molecular H-bonding assisted CHEF process. The detection limit for arsenate is 0.001 µM, much below the WHO recommended tolerance level in drinking water. DFPPIC can detect intracellular arsenate in drinking water of Purbasthali, West Bengal, India efficiently. Graphical Abstract DFPPIC and its Merrifield conjugate polymer are used for selective determination and removal of arsenate from real drinking water samples of Purbasthali, a highly arsenic contaminated region of West Bengal, India. DFPPIC is very promising to imaging arsenate in living cells.

An INHIBIT logic gate from a thiophene derivative using iron and zinc ions as the input: tuning the efficiency on moving from naphthalene to anthracene to pyrene for the green luminescent detection of the intracellular iron.

A pyrene-thiophene conjugate has been used for the efficient detection of intracellular irons through the generation of bright green luminescence. Amongst three different probes being reported, it is observed that the efficiency for the naked eye green luminescent detection of iron increases on moving from naphthalene to anthracene to pyrene. The developed technique may be very useful to monitor iron and zinc supplementation as single micronutrients in living systems through the construction of an INHIBIT logic gate.

Selective sensing of Hg²âº using rhodamine-thiophene conjugate: red light emission and visual detection of intracellular Hg²âº at nanomolar level.

Rhodamine-thiophene conjugate (L) has been synthesized and characterized by (1)H NMR, FTIR and mass spectra. L shows a large enhancement in emission intensity in presence of Hg(2+). Moreover, naked eye color of L becomes intense red in presence of Hg(2+). The lowest detection limit for Hg(2+) is 1 × 10(-9)M in HEPES buffer (0.1M in EtOH/water, 1/1, v/v, pH 7.4). Hg(2+) induced chelation enhanced fluorescence (CHEF) is associated with spirolacram ring opening of the rhodamine unit. Trace level intracellular Hg(2+) is visualized under fluorescence microscope.

Rhodamine-based fluorescent probe for Al3+ through time-dependent PET-CHEF-FRET processes and its cell staining application.

Rhodamine-diformyl p-cresol conjugate (L) has been developed as a novel Al(3+)-selective fluorometric and colorimetric sensor based on the FRET mechanism for the first time. L can selectively detect Al(3+) through time-dependent PET-CHEF and FRET processes. This phenomenon is nicely reflected from (1)H NMR, fluorescence lifetime, and fluorescence cell imaging studies. The probe can detect Al(3+) as low as 5 × 10(-9) M in HEPES-buffered EtOH:water (0.1 M, 4:1, v/v, pH 7.4). The probe shows pH-dependent emission properties viz. an intense red emission (585 nm) at acidic pH and an intense green fluorescence (535 nm) at basic pH. Thus, L can also be used as a pH sensor via tunable wavelength.

A naphthalene exciplex based Al3+ selective on-type fluorescent probe for living cells at the physiological pH range: experimental and computational studies.

2-((Naphthalen-6-yl)methylthio)ethanol (HL) was prepared by one pot synthesis using 2-mercaptoethanol and 2-bromomethylnaphthalene. It was found to be a highly selective fluorescent sensor for Al(3+) in the physiological pH (pH 7.0-8.0). It could sense Al(3+) bound to cells through fluorescence microscopy. Metal ions like Mn(2+), Fe(3+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Ag(+), Cd(2+), Hg(2+), Cr(3+) and Pb(2+) did not interfere. No interference was also observed with anions like Cl(-), Br(-), F(-), SO(4)(2-), NO(3)(-), CO(3)(2-), HPO(4)(2-) and SCN(-). Experimentally observed structural and spectroscopic features of HL and its Al(3+) complex have been substantiated by computational calculations using density functional theory (DFT) and time dependent density functional theory (TDDFT).

A naphthalene-based Al3+ selective fluorescent sensor for living cell imaging.

An efficient fluorescent Al(3+) receptor, N-(2-hydroxy-1-naphthalene)-N'-(2-(2-hydroxy-1-naphthalene)amino-ethyl)-ethane-1,2-diamine (L) has been synthesized by the condensation reaction between 2-hydroxy naphthaldehyde and diethylenetriamine. High selectivity and affinity of L towards Al(3+) in ethanol (EtOH) as well as in HEPES buffer at pH 7.4, makes it suitable to detect intracellular Al(3+) with fluorescence microscopy. Metal ions, viz. Li(+), Na(+), K(+), Mg(2+), Ca(2+), Mn(2+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Ag(+), Cd(2+), Hg(2+) and Pb(2+) do not interfere. The lowest detection limit for Al(3+) is 3.0 × 10(-7) M and 1.0 × 10(-7) M in EtOH and HEPES buffer respectively.