Monodispersed Fe3O4 magnetic nanoparticles (MNPs) having size of 7 nm have been prepared from iron oleate and made water dispersible by functionalization for biomedical applications. Three different reactions employing thioglycolic acid, aspartic acid and aminophosphonate were performed on oleic acid coated Fe3O4. In order to achieve a control on particle size, the pristine nanoparticles were heated in presence of ferric oleate which led to increase in size from 7 to 11 nm. Reaction parameters such as rate of heating, reaction temperature and duration of heating have been studied. Shape of particles was found to change from spherical to cuboid. The cuboid shape in turn enhances magneto-crystalline anisotropy (Ku). Heating efficacy of these nanoparticles for hyperthermia was also evaluated for different shapes and sizes. We demonstrate heat generation from these MNPs for hyperthermia application under alternating current (AC) magnetic field and optimized heating efficiency by controlling morphology of particles. We have also studied intra-cellular uptake and localization of nanoparticles and cytotoxicity under AC magnetic field in human breast carcinoma cell line.

An efficient catalytic asymmetric 1,3-dipolar cycloaddition of N-benzylidineiminoglycinate-derived azomethine ylides to β-silylmethylene malonates catalyzed by a Ag(I)-Fesulphos complex has been developed, affording fully substituted 3silylproline derivatives with an all carbon quaternary center. The silylproline derivatives were obtained in moderate-to-good yields (up to 81%) in high diastereoselectivities and enantioselectivities (dr up to 95:5; er up to 96:4). Tamao−Fleming oxidation of selected 3-silylproline derivatives provided not only an efficient route but also the shortest route to 3hydroxyproline derivatives, which are not accessible by direct 1,3-dipolar cycloadditions of azomethine ylide with frequently used arylidene/alkylidene malonates.

Exclusively red-emitting upconversion nanoparticles (UCNPs) with the composition NaErF4:0.5%Tm as a core and NaYF4 as a shell were synthesized for performing photodynamic therapy (PDT). A possible mechanism was proposed for core–shell UCNPs formation. For loading a maximum amount of 5-aminolevulinic acid (5-ALA), mesoporous silica coating was performed on UCNPs. Studies under dark conditions confirmed the biocompatibility of 5-ALA-loaded UCNPs formulation (UCNPs-5-ALA) with MCF-7 cells. Meanwhile, studies under light-exposed conditions exhibited effective cytotoxicity against MCF-7 cells. Studies employing D2O-based cell cultured media and addition of DABCO in cell culture established that the cell death was due to oxidation of cellular components by reactive oxygen species (ROS) triggering the apoptosis. The formation of ROS was confirmed by DCF­(H)­DA-based ROS analysis via fluorescence microscopy to demonstrate the ROS production, which mediates the programmed cell death. Additionally, we have validated the apoptosis in MCF-7 cells with flow cytometry analyses. This was further confirmed by an electrophoretic mobility shift assay on nuclear extract and measurement of mitochondrial membrane potential. In the case of animal model studies, the formulation UCNPs-5-ALA without irradiation (980 nm) did not possess any in vivo cytotoxicity on tumor-induced SCID mice and there was a minimum migration of UCNPs-5-ALA to the vital organs but maximum retention at the tumor site only. Meanwhile, only the mice treated with UCNPs-5-ALA and irradiated on the tumor region with 980 nm laser (500 mW) for 20 min possessed a tumor with a size reduced to about 75% as compared with the corresponding control groups. To the best of our knowledge, this type of study was conducted for the first time employing exclusively red-emitting phosphors for effective PDT.

Cinchona-alkaloid derived bifunctional thiourea catalyzed conjugate addition reaction of nitroalkanes to -silylmethylene malonates is reported for direct access of densely functionalized enantioenriched organosilanes in good yields (up to 86 %) with excellent stereoselectivities (up to 98:2 dr and 90 % ee). Using pseudoenantiomeric catalyst, both the enantiomers of the conjugate addition products were easily accessible. Preparative scale synthesis of two conjugate addition products [a] Dr. Scheme 1. Selected state-of-the-art strategies for the synthesis of chiral organosilanes under organocatalytic conditions and present work.nitromethane to aryl/alkylidene malonates took place with moderate yields and long reaction time (3-5 days) in presence of 10 mol-% catalyst and nitromethane as a solvent. In addition, bifunctional iminophosphorane catalysed Michael addition of nitroalkanes to enone diesters is also reported. [19] However, to the best of our knowledge, organocatalytic asymmetric conjugate addition reaction of nitroalkanes to -silylmethylene malonates has not been studied so far. In this paper, we disclose the first catalytic conjugate addition of nitroalkanes including nitromethane to -silylmethylene malonates for the diastereoand enantioselective synthesis of chiral organosilanes (Scheme 1 E). The important feature of these conjugate addition products is the presence of different functional groups which could be useful for downstream synthetic transformation. Results and DiscussionInitially, we started the optimization studies by screening readily available bifunctional hydrogen-bonding organocatalysts [20] I-XII (Figure 2) for the Michael addition reaction betweensilylmethylene malonate1a and nitromethane 2a in toluene as a solvent. To our delight, quinidine derived thiourea catalyst I Eur. 2964 and good enantioselectivities (80-90 % ee) ( Table 2). Thesilylmethylene malonate 1e with the bulky tert-butyldiphenylsilyl group also participated in the conjugate addition reaction in presence of 20 mol-% of catalyst VI at room temperature and

An enantioselective 1,4-conjugate addition of nitromethane to β-silyl α,β-unsaturated carbonyl compounds catalyzed by bifunctional squaramide catalysts has been developed. This methodology offers both enantiomers of β-silyl nitroalkanes in good to excellent yields (up to 92%) and enantioselectivities (up to 97.5% ee) under solvent-free conditions at room temperature. Control experiments reveal that the presence of a β-silyl group in the enones is crucial for high reactivity under the optimized reaction conditions.

Herein, we report a Michael addition reaction of pyrazolin-5-ones with β-silylmethylene malonates using a squaramide catalyst derived from quinidine under mild reaction conditions. This protocol delivered chiral organosilanes appendage with pyrazole moiety in high yields (up to 90%) and good to excellent enantioselectivities (up to 98 : 2 er). A quinine derived thiourea catalyst deliver corresponding antipode for enantiomers with almost similar level of yields (up to 93%) and good to excellent enantioselectivities (up to 2 : 98 er). The scale-up reaction for synthesis of two chiral organosilanes confirmed the practical reliability of this protocol.

On the basis of the boron neutron capture therapy (BNCT) modality, we have designed and synthesized a zinc gallate (ZnGa2O4)-based nanoformulation for developing an innovative theranostic approach for cancer treatment. Initially, the (ZnGa1.995Cr0.005O4 or ZnGa2O4:(0.5%)­Cr persistent luminescence nanoparticles (PLNPs) embedded on silica matrix were synthesized. Their surface functionalization was performed using organic synthesis strategies to attach the amine functional moieties which were further coupled with poly­(vicinal diol). These diols were helpful for conjugation with 10B­(OH)3, which subsequently served to couple with an in-house-synthesized variant of pH-(low)-insertion peptide (pHLIP) finally giving a tumor-targeting nanoformulation. Most importantly, the polymeric diols helped in conjugation of a substantial number of 10B to provide the therapeutic dose required for effective BNCT. This nanoformulation internalized substantially (∼80%) to WEHI-164 cancer cells within 6 h. Tumor homing studies indicated that the accumulation of this formulation at the acidic tumor site was within 2 h. The in vitro evaluation of the formulation against WEHI-164 cancer cells followed by neutron irradiation revealed its potent cytotoxicity with IC50 ∼ 25 μM. In the case of studies on animal models, the melanoma-induced C57BL/6 and fibrosarcoma-induced BALB/c mice were treated with formulations through intratumoral and intravenous injections, respectively, followed by neutron irradiation, leading to a significant killing of the cancer cells, which was evidenced by a reduction in tumor volume (75–80%) as compared with a control tumor. Furthermore, the histopathological studies confirmed a damaging effect only on tumor cells, while there was no sign of damage to the vital organs in treated mice as well as in controls.

Water soluble Pt(IV) prodrug of cisplatin was synthesized by oxidation of cisplatin followed by treatment with succinic anhydride to achieve easily reducible ester linkage at axial positions which was...