Model‐Based Nanoengineered Pharmacokinetics of Iron‐Doped Copper Oxide for Nanomedical Applications

The progress in nanomedicine (NM) using nanoparticles (NPs) is mainly based on drug carriers for the delivery of classical chemotherapeutics. As low NM delivery rates limit therapeutic efficacy, an entirely different approach was investigated. A homologous series of engineered CuO NPs was designed for dual purposes (carrier and drug) with a direct chemical composition–biological functionality relationship. Model‐based dissolution kinetics of CuO NPs in the cellular interior at post‐exposure conditions were controlled through Fe‐doping for intra/extra cellular Cu²⁺ and biological outcome. Through controlled ion release and reactions taking place in the cellular interior, tumors could be treated selectively, in vitro and in vivo. Locally administered NPs enabled tumor cells apoptosis and stimulated systemic anti‐cancer immune responses. We clearly show therapeutic effects without tumor cells relapse post‐treatment with 6 % Fe‐doped CuO NPs combined with myeloid‐derived suppressor cell silencing.     

Mechanochemical Synthesis of Functionalized Quinolines by Iodine Mediated Oxidative Annulation

An iodine‐mediated environmentally benign synthesis of multi‐substituted quinoline derivatives is developed using a solvent‐free mechanochemical process. Appropriately designed and easily accessible protecting group‐free aniline derivatives were used for the oxidative annulation reaction, and a series of quinoline derivatives with variable functionalities were synthesized up to 89 % isolated yield. Importantly, the activator iodine remains in the quinoline molecule and promotes further functionalizations. The present methodology is beneficial with regard to operational simplicity and mild reaction conditions.     

A triad of rhenium-mediated transformations

The title transformations are oxygen atom transfer, twin isomerization and regiospecific imine oxidation.Bispyridyldiazole ligands have furnished new oxygen atom transfer reagents of coordination type Re^VOCl₃(NN) which undergo a slower transfer to PPh₃ than the corresponding azole reagents. The rate of twin isomerization (linkage and geometrical) of meridional azole complexes of coordination type Re^III(OPnP)Cl₃(NN) to facial Re^III(PnPO)Cl₃(NN) decreases rapidly asn increases in the interval 1–4 (PnP is Ph₂P(CH₂)_nPPh₂). An α-diimine chelate of type Re^V(NPh)Cl₃(NN) is shown to undergo facile oxidation to the corresponding iminoamide complex Re_VI(NPh)Cl₃(NN) upon treating with dilute nitric acid. The reaction proceeds via regiospecific nucleophilic addition of waterto the more polarized imine function. Dedicated to Professor C N R Rao on his 70th birthday     

Electrokinetic separation of charged macromolecules in nanochannels within the continuum regime: effects of wall interactions and hydrodynamic confinements

In this paper, a detailed continuum-based theoretical model is proposed to investigate the effects of near-wall potentials and hydrodynamic confinement on separation of charged macromolecules in channels of nanoscale dimensions. These wall effects are primarily confined within a few nanometers from the channel wall, and hence have negligible influences in the conventional electrokinetic separation methods that are routinely performed in microchannels. However, in nanochannels, their zone of influence becomes significant in comparison to the channel height, thereby inducing certain nontrivial effects on the resultant separation characteristics. By executing a regular perturbation analysis, it is established that depending on the macromolecular size relative to the channel height and the extent of electrical double layer (EDL) interactions, the wall forces decide the speed of traverse and the extent of spreading (dispersion) of the macromolecular bands. These factors combine together to finally decide the separation characteristics (quantified by the resolution of separation) of the charged macromolecules in nanochannels. It is demonstrated that because of the near-wall effects, macromolecular pairs with less disparities in sizes give rise to higher values of resolution. Moreover, the wall-induced influences are shown to magnify the resolution for any given pair of macromolecules in the nanofluidic systems, thereby signifying greater separation efficiency.     

Expression of tropane alkaloids in the hairy root culture of Atropa acuminata substantiated by DART mass spectrometric technique

Agrobacterium rhizogenes-mediated 'hairy root' cultures were established in Atropa acuminata. The chemical profiling of the hairy roots was carried out by a new mass spectrometric technique, direct analysis in real time (DART). The intact hairy roots were directly analyzed by holding them in the gap between the DART ion source and mass spectrometer. Two alkaloids, atropine and scopolamine, were characterized. The structural confirmation of the two alkaloids was made through their accurate molecular formula determinations. This is the first report of establishing hairy roots in A. acuminata as well as application of the DART technique for the chemical profiling of its hairy roots.     

Formation of superoxide anion on aerial oxidation of Cu(II)-porphyrinogen in the synthesis of tetrakis(cyclohexyl)porphyrinogenCu(III) anion

Tetraethylammonium-tetrakis(cyclohexyl)porphyrinogenCu(II) (1) is spontaneously oxidized by aerial oxygen to the corresponding Cu(III) (2) species, producing 1 equiv of O2(-). Steric crowding of the peripheral hydrogens in 1 prevented any direct Cu-O2 bond formation in the oxidation process, which suggests an outer-sphere electron transfer reaction.     

Pt(II)-promoted [2 + 3] cycloaddition of azide to cyanopyridines: convenient tool toward heterometallic structures

The [2 + 3] cycloaddition reactions (which are greatly accelerated by microwave irradiation) of the di(azido)platinum(II) compounds cis-[Pt(N(3))(2)(PPh(3))(2)] (1) with cyanopyridines NCR (2) (R = 4-, 3-, and 2-NC(5)H(4)) give the corresponding bis(pyridyltetrazolato) complexes trans-[Pt(N(4)CR)(2)(PPh(3))(2)] (3) [R = 4-NC(5)H(4) (3a), 3-NC(5)H(4) (3b), and 2-NC(5)H(4) (3c)]. Compound 3c has been characterized as the N(1)N(2)-bonded isomer in the solid state by X-ray crystallography and represents the first bis(tetrazolato) complex of this kind. Complexes 3a and 3b have been used as metallaligands to generate heteronuclear coordination polymers in the presence of copper nitrate. A one-dimensional supramolecular architecture was obtained as the exclusive product, {trans-[Pt(2)(N(4)CR)(4)(PPh(3))(4)Cu](n)(NO(3))(2n).nH(2)O (4.nH(2)O) (R = 4-NC(5)H(4)), when 3a was employed, whereas with 3b the heteronuclear square complex trans-[Pt(N(4)CR)(2)(PPh(3))(2)Cu(NO(3))(2)(H(2)O)](2) (5) (R = 3-NC(5)H(4)), composed of Pt/Cu ions, was obtained. All the isolated complexes were characterized by IR, elemental, and (for 3b, 3c, 4, and 5) X-ray structural analyses. Complexes 3 were additionally characterized by (1)H, (13)C, and (31)P {(1)H} NMR spectroscopies.