Akanksha Dixit

BODIPY appended copper(II) complexes of curcumin showing mitochondria targeted remarkable photocytotoxicity in visible light

Copper(II) complexes of BODIPY (borondipyrromethene) derivatives (L-1, L-2) and curcumin (Hcur), viz. Cu(L-1)(cur)]Cl (1) and Cu(L-2)(cur)]Cl (2), where L-1 and L-2 are the non-iodinated and diiodinated BODIPY appended dipicolylamine ligands, are prepared and characterized and their photocytotoxic activity in visible light studied. Binding to copper(II) has rendered stability to curcumin from its hydrolytic degradation in buffer medium. The complexes show mitochondrial localization in HeLa cells emphasizing the findings that both 1 and 2 are mitochondria-targeting complexes and induce cancer cell death. Complex 1 with a fluorophoric BODIPY moiety in L-1 gave IC50 values of 7.9(+/- 0.3) mu M in visible light (400-700 nm) and 29.1(+/- 0.5) mu M in the dark. Complex 2 having a diiodo BODIPY moiety in L-2 as a photosensitizer gave IC50 values of 3.8(+/- 0.2) mu M in visible light and 32.1(+/- 0.4) mu M in the dark. The PDT effect of 2 is comparable to that of Photofrin (R), an FDA approved PDT drug. Cell death follows an apoptotic pathway with the formation of reactive oxygen species (ROS).

BODIPY appended copper(II) complexes for cellular imaging and singlet oxygen mediated anticancer activity in visible light

Copper(II) complexes of N,N,N-donor dipicolylamine ligands, viz. [Cu(L1)Cl2] (1), [Cu(L2)Cl2] (2) and [Cu(L3)Cl2] (3) with L2 and L3 having BODIPY (borondipyrromethene) moieties were synthesized, characterized and their photocytotoxicity studied. Complex 1 was structurally characterized by X-ray crystallography. It has copper(II) in a distorted square-pyramidal geometry (τ = 0.11) with two chloride ligands in axial-equatorial cis-disposition. The one-electron paramagnetic and redox active complexes are non-electrolytic in DMF. They behave as 1 : 1 and 1 : 2 electrolytes in 1 : 1 and 1 : 9 (v/v) DMF–H2O. The BODIPY complexes 2 and 3 show respective visible bands at 501 nm and 535 nm in DMF. Complex 2 displays an emission band at 515 nm in DMF (λex = 465 nm) with a quantum yield (ΦF) value of 0.14. This complex, as a fluorogenic probe for cellular imaging, shows cytosolic localisation of the complex in HeLa and MCF-7 cancer cells. Complex 3 having a diiodo BODIPY unit in L3 is non-emissive but acts as an efficient photosensitizer showing a significant PDT effect with apoptotic cell death forming singlet oxygen as ROS (ϕΔ = 0.53) and giving respective IC50 values of 0.15 ± 0.02 and 0.17 ± 0.03 μM in HeLa and MCF-7 cancer cells in visible light of 400–700 nm, while being less toxic in the dark.

Photocytotoxic ternary copper(II) complexes of histamine Schiff base and pyridyl ligands

AbstractTernary copper(II) complexes of salicylaldehyde-histamine Schiff base (HL) and pyridyl ligands, viz. [Cu(bpy)(L)](ClO4) (1) and [Cu(dppz)(L)](ClO4) (2), where bpy is 2,2′

Cellular imaging and mitochondria targeted photo-cytotoxicity in visible light by singlet oxygen using a BODIPY-appended oxovanadium(IV) DNA crosslinking agent

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Terpyridyl oxovanadium(IV) complexes for DNA crosslinking and mito-targeted photocytotoxicity

-bipyridine (in 1) and dppz is dipyrido[3,2-a:2′

Endoplasmic reticulum targeted chemotherapeutics: the remarkable photo-cytotoxicity of an oxovanadium(IV) vitamin-B6 complex in visible light

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Remarkable Selectivity and Photo-Cytotoxicity of an Oxidovanadium(IV) Complex of Curcumin in Visible Light

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Endoplasmic reticulum targeting tumour selective photocytotoxic oxovanadium(IV) complexes having vitamin-B6 and acridinyl moieties

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Photoinduced DNA Crosslink Formation by Dichloridooxidovanadium(IV) Complexes of Polypyridyl Bases

-c]phenazine (in 2), were synthesized, characterized and their DNA binding, photo-activated DNA cleavage activity and photocytotoxicity studied. The 1:1 electrolytic one-electron paramagnetic complexes showed a d-d band near 670 nm in aqueous DMF (1:1 v/v). The crystal structure of complex 1 showed the metal in CuN4O distorted square-pyramidal geometry. Complex 2 intercalatively binds to calf-thymus (ct) DNA with a binding constant (Kb) of ∼10 5 M−1. It exhibited moderate chemical nuclease activity but excellent DNA photocleavage activity in red light of 647 nm forming •OH radicals. It showed remarkable photocytotoxicity in human cervical cancer cells (HeLa) giving IC50 of 1.6 μM in visible light (400-700 nm) with low dark toxicity. The photo-induced cell death is via generation of oxidative stress by reactive oxygen species. Graphical AbstractSchiff base copper(II) complex of dipyridophenazine shows remarkable photocytotoxic effect in HeLa cells in visible light (400-700 nm) with reduced dark toxicity via apoptotic pathway. The complex intercalatively binds to ct-DNA, exhibits moderate chemical nuclease activity but excellent DNA photocleavage activity in red light of 705 nm forming •OH radicals.

Glycodelin A and galectin-1: Role in foetal tolerance

Oxovanadium(IV) complexes VO(L-1)Cl-2] (1) and VO(L-2)Cl-2] (2), where L-1 is N,N,N-donor benzyldipicolylamine and L-2 is the BODIPY-appended N,N,N-donor base, viz., (8-{bis(2-pyridylmethyl)amino]methylphenyl}-4,4-difluoro-1,3,5,7-te tramethyl-4-bora-3a,4a-diaza-s-indacene), were synthesized, characterized and their photo-induced DNA crosslinking activity and photocytotoxicity were studied. Single crystal X-ray diffraction analysis of 1 reveals two chloride ligands in the cis disposition to the VO2+ moiety. The complexes are 1 : 1 electrolytes in aqueous media, and the loss of the second chloride takes place on irradiation with visible light. The DNA melting and alkaline agarose gel electrophoresis studies on complex 2, treated with ct-DNA in light, suggest the formation of DNA crosslinks. Complex 2 selectively localizes in the mitochondria of the HeLa and MCF-7 cancer cells and shows remarkable photocytotoxicity via an apoptotic pathway (IC50 < 3 mu M) in visible light (400-700 nm) with low dark toxicity. The complex is remarkable in showing dual activity: (i) light-activated VO2+-DNA crosslink formation and (ii) singlet oxygen (O-1(2)) induced mitochondria-targeted PDT involving the BODIPY moiety.