China 
Africa 
Explore chapters and articles related to this topic
Synthetic Nanoparticles for Anticancer Drugs
Published in Harishkumar Madhyastha, Durgesh Nandini Chauhan, Nanopharmaceuticals in Regenerative Medicine, 2022
To synthesise gold NPs, fucoside monomer-glycopolymer is first prepared using fucoside monomers (2-methacrylamidoethyl-2,3,4-tri-O-acetyl-a-L-fucopyranoside). The monomer is polymerised in dioxane via the classical method with 2-trimethylsilyl-ethanethiol as a chain transfer compound. Glycopolymer is produced by precipitating the per-acetylation polymer with ether. Pellets are collected through filtration and deprotected in NaOCH3/CH3OH (Jain & Das 2011). The second glycopolymer will partially sulphate in the presence of sulphur trioxide in the pyridine complex and dimethylformamide. They are converted to sodium bicarbonate to complete the sodium–sodium salt product (Shukla et al. 2005). A dialysis process using deionised water is performed to purify the obtained product. After synthesising the FM-glycopolymer, gold NPs are synthesise dusing NaBH4, which acts as a reducing agent.
Fe Complexes as Photosensitizers for Dye-Sensitized Solar Cells
Published in Carlito S. Ponseca, Emerging Photovoltaic Technologies, 2019
The RuII bis(terpyridine) complex 16 (Scheme 5.5) is well-known for its much shorter-lived 3MLCT ES compared to the tris(bipyridine) complex 3. This is mainly ascribed to a larger deviation of the coordination sphere from a perfect octahedral geometry as imposed by the rigid tridentate ligand featuring five-membered chelate rings. The thus attenuated overlap between the σ-lone electron pairs of the N-donor and the eg* orbitals of the metal center leads to decreased ligand field strength, resulting in low-lying 3MC state that deactivates the 3MLCT state at a higher rate [18, 89]. This issue has been addressed in a prominent example by Hammarström et al., the RuII bis(dqp) (dqp = 2,6-di(quinolin-8-yl) pyridine) complex 17 (Scheme 5.5), with expanded chelate ring size and thus a close-to-perfect octahedral geometry [90]. Thanks to the significantly enhanced ligand field strength due to the now optimal M–L orbital overlap, and the extended π-conjugation of the ligand, the MLCT energy is beneficially stabilized relative to the 3MC state. This gives rise to a tremendously retarded 3MLCT deactivation, yielding a RT 3MLCT ES lifetime of 3 µs [90–92]. In a similar strategy, combining the expansion of the chelate ring and the extension of the π-conjugation of the ligand, the resulting RuII bis(dcpp) (dcpp = 2,6-bis(2-carboxypyridyl)pyridine) complex 18 (Scheme 5.5) displayed a RT 3MLCT ES lifetime of 1.36 µs [93].
Emerging Trends in Nanotechnology for Diagnosis and Therapy of Lung Cancer
Published in Alok Dhawan, Sanjay Singh, Ashutosh Kumar, Rishi Shanker, Nanobiotechnology, 2018
Nanda Rohra, Manish Gore, Sathish Dyawanapelly, Mahesh Tambe, Ankit Gautam, Meghna Suvarna, Ratnesh Jain, Prajakta Dandekar
The use of nanofibers in drug delivery for lung cancer has been reported by Sridhar et al. For fabrication of biodegradable polycaprolactone nanofibers, the authors have made use of natural extracts like curcumin, neem, and aloe vera and their combinations owing to their anticancer activities. Different combinations of nanofibers such as PCL, 1% aloe vera-loaded PCL, 1% neem loaded-PCL, 1% cisplatin loaded PCL, 5% curcumin-loaded PCL, and combinations of neem with curcumin and aloe vera with curcumin in their respective concentrations. The evaluation of these nanofibers in vitro on human breast cancer (MCF7) and lung cancer (A459) cell lines showed maximum cytotoxicity when curcumin combinations with neem and aloe vera were employed. The combination of curcumin with aloe vera and that of curcumin with neem showed 23% and 18% cell viability in A549 cells, and 38% and 35% in MCF-7 cells, respectively. The amine functional groups of aloe vera were observed to inhibit cancer cell viability by forming a cyclic pyridine complex with curcumin. Inhibition of cancer cell growth after 24 h of incubation was 15% higher with these natural extract combination-loaded PCL nanofibers as compared to 1% commercial cisplatin-loaded PCL nanofibers. Through this study, the potential of these nanofibers in fabricating biocompatible drug-eluting medical devices against lung and breast cancers was demonstrated. However, studies demonstrating in vivo cell viability and therapeutic efficacy would be required to ensure their applicability in fabricating these devices for lung cancer treatment (Sridhar et al. 2014).
Coordination chemistry and magnetic properties of copper(II) halide complexes of quinoline
Published in Journal of Coordination Chemistry, 2022
Christopher P. Landee, Firas F. Awwadi, Brendan Twamley, Mark M. Turnbull
Compound 2 is isostructural with 1. The molecular unit is shown in Figure 4 while figures of the corresponding π-stacking, bromide…bromide short contact chain and crystal packing may be found in the Supplementary Information (Figures S1, S2 and S3, respectively). The Cu-Br1 bond (2.3814(8) Å) is longer than the corresponding Cu-Cl1 bond in 1, as expected, but the Cu-N11 bond (1.997(6) Å) is slightly shorter. Both are shorter than the corresponding Cu-Br (2.451 Å) and Cu-N (2.013 Å) bonds in the pyridine complex Cu(py)2Br2 [3]. The Cl1-Cu-N11 bond angle is 89.6(16)°, the same as observed in 1 within error. The quinoline ring is comparably planar (mean deviation of constituent atoms = 0.009 Å) and again lies almost perpendicular (84.9°) to the copper coordination plane. The molecules are linked into chains parallel to the c-axis via short Br…Br interactions [dBr1…Br1A = 3.676 Å, ∠Cu1-CBr1…Br1A = ∠Br1…Br1A-Cu1A = 158.4°; ∠Cu1-Br1…Br1A-Cu1A = 52.1°] similar to the structure of 1. The differences relative to the pyridine complex, both here and with 1, are likely due to the difference in crystal packing caused by the increased steric demands of the quinoline ring. The pyridine compounds crystallize as bihalide bridged chains, rather than molecules where the intermolecular contacts are formed via the two-halide pathway.
Iron-promoted sulfur sequestration for the substituent-dependent regioselective synthesis of tetrazoles and guanidines
Published in Journal of Sulfur Chemistry, 2021
Venkata Bhavanarushi Pendem, Ramana Tamminana, Madhavi Nannapaneni
However, a high yield of tetrazole was observed when using Et3N and pyridine instead of inorganic bases (NaOAc, NaOH, and Na2HPO4). Organic bases like Et3N and Pyridine complex with iron salts that increase their solubility, which leads to an increase in the yield of tetrazole product. Among the inorganic bases, sodium acetate is better than others. It might be reasoned that NaOAc may produce Fe(OAc)2, which is more soluble than other iron sources. To confirm, we have performed the control experiment with an organo-soluble iron source like Fe(acac)2, and it gave tetrazole product in good yield (Scheme 1). In the case of disodium phosphate and sodium hydroxide, we could observe tetrazole product along with some other undetermined spots, which are in TLC (bond might be broken in the presence of strong bases).
Main group element-mediated phosphaalkyne by combined insertion and oligomerization reactions
Published in Journal of Coordination Chemistry, 2020
A solution of boron(III) halides reacts with tert-butyl-1λ3-phosphaalkyne in hydrocarbon solvents to give the corresponding 1-halo-2-dihaloboranyl-1λ3-phosphaalkene (18) as the E-isomer with yields above 90% [65–67]. Low-field NMR shifts from both the phosphorus (270.2/262.0/237.0) and the sp2-hybridized carbons (215.0/218.0/220.6 ppm) indicate the presence of a P = C double bond. X-ray structure determination of the bromine derivative (18) shows the planes of the trigonal-planar boranyl group and the π(P = C) system to be orthogonal [65–67]. As the Lewis acidity of the boron is still maintained, the chloro compound forms a pyridine complex (18•py) [67], of which the structure has been determined (Scheme 27).