Cu immobilized on chitosan-modified iron oxide magnetic nanoparticles: Preparation,characterization and investigation of its anti-lung cancer effects

Chitosan is a linear polysaccharide and non-toxic bioactive polymer with a wide variety of applications due to its functional properties such as ease of modification, and biodegradability. In this study, a green protocol for supporting of Cu(II) on chitosan-encapsulated magnetic Fe₃O₄ nanoparticles is described. The morphological and physicochemical features of the material were determined using several advanced techniques like fourier transformed infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), inductively coupled plasma (ICP), vibrating sample magnetometer (VSM) and X-ray photoelectron spectroscopy (XPS). The average diameter of the NPs was approximately 15–25 nm. In addition, the Fe₃O_/CS/Cu(II) nanocomposite was engaged in biological assays like study of anti-oxidant properties by DPPH mediated free radical scavenging test using BHT as a reference molecule. Thereafter, on having a significant IC₅₀ value in radical scavenging assay, we extended the bio-application of the desired nanocomposite in anticancer study of lung well-differentiated bronchogenic adenocarcinoma, lung moderately differentiated adenocarcinoma, and lung poorly differentiated adenocarcinoma of human lung in-vitro conditions. In the cytotoxicity and anti-human lung studies, the nanocomposite was treated to lung cancer lung well-differentiated bronchogenic adenocarcinoma (HLC-1), lung moderately differentiated adenocarcinoma (LC-2/ad), and lung poorly differentiated adenocarcinoma (PC-14) cell line following MTT assay. The cell viability of malignant lung cell line reduced dose-dependently in the presence of Fe₃O_/CS/Cu(II) nanocomposite. The recent results suggest that Fe₃O_/CS/Cu(II) nanocomposite have a suitable anticancer activity against lung cell lines.     

Formulation and characterization of a novel cutaneous wound healing ointment by silver nanoparticles containing Citrus lemon leaf: A chemobiological study

IntroductionFormulating new wound-healing ointments by natural compounds is the first research priority in the developing and developed countries. This study was intended to provide green formulation of Ag-NP ointment containing Citrus lemon leaf aqueous extract and examine its capability of healing cutaneous wounds and its antioxidant and cytotoxicity activities under in vitro and in vivo conditions.Materials and methodsDifferent techniques, including UV–Vis and FT-IR spectroscopy, were used to characterize Ag-NPs. MTT assay was used to investigate cytotoxicity property of Ag-NPs. Antioxidant activity of Ag-NPs were examined by DPPH in the presence of butylated hydroxytoluene as positive control. Parameters of cutaneous wound healing were measured both histopathologically and biochemically.ResultsClear peak at 429 nm shown by UV–Vis spectroscopy indicated formation of Ag-NPs. In FT-IR spectroscopy, presence of many antioxidant compounds provided an excellent condition to reduce silver in Ag-NPs. FE-SEM and TEM images showed spherical Ag-NPs with an average size of 25.1 nm. The synthesized silver nanoparticles had excellent cell viability on the HUVECs line and indicated this method was nontoxic. Application of Ag-NP ointment improved wound healing parameters significantly (P ≤ 0.01). Ag-NPs reduced wound areas, total cells, neutrophils and lymphocytes significantly (P ≤ 0.01) and increased wound contracture, vessels, hexosamines, hydroxyl proline, hexuronic acid, fibrocytes, fibroblasts and fibrocyte/ fibroblast ratios significantly (P ≤ 0.01).ConclusionsOnce our results are verified by clinically experimental studies, Ag-NP ointment can be used as a modern one to treat several types of wounds, especially cutaneous ones, in humans.     

Tetracyclopenta[def,jkl,pqr,vwx]tetraphenylene: A Potential Tetraradicaloid Hydrocarbon

A tetramesityl derivative of hitherto unknown tetracyclopenta[def,jkl,pqr,vwx]tetraphenylene (TCPTP), which is a potential tetraradicaloid hydrocarbon, was synthesized. Theoretical calculations based on spin‐flip time‐dependent density functional theory predict that the closed‐shell D_2h form of TCPTP is more stable than the open‐shell D_4h form with its slightly tetraradical character. The tetramesityl derivative (Mes)₄‐TCPTP exhibits remarkable antiaromaticity as a result of the peripheral 20‐π‐electron circuit, which causes an absorption maximum at a long wavelength and a small HOMO–LUMO gap. In solution, (Mes)₄‐TCPTP most likely adopts rapidly equilibrating D_2h structures that interconvert via the D_4h transition state. X‐ray crystallographic analysis showed (Mes)₄‐TCPTP as an approximate D_2h structure.     

Synthesis and Applications of Hajos–Parrish Ketone Isomers

Numerous natural products possess ring systems and functionality for which Hajos–Parrish ketone isomers with a transposed methyl group (termed “iso‐Hajos–Parrish ketones”) would be of value. However, such building blocks have not been exploited to the same degree as the more typical Hajos–Parrish hydrindane. An efficient three‐step synthesis of such materials was fueled by a simple method for the rapid preparation of highly functionalized cyclopentenones, several of which are new chemical entities that would be challenging to access through other approaches. Furthermore, one iso‐Hajos–Parrish ketone was converted into two distinct natural product analogues and one natural product. As one indication of the value of these new building blocks, that latter target was obtained in 10 steps, having previously been accessed in 18 steps using the Hajos–Parrish ketone.     

Redesign of a Fluorogenic Labeling System To Improve Surface Charge,Brightness, and Binding Kinetics for Imaging the Functional Localization of Bromodomains

Protein labeling with fluorogenic probes is a powerful method for the imaging of cellular proteins. The labeling time and fluorescence contrast of the fluorogenic probes are critical factors for the precise spatiotemporal imaging of protein dynamics in living cells. To address these issues, we took mutational and chemical approaches to increase the labeling kinetics and fluorescence intensity of fluorogenic PYP‐tag probes. Because of charge‐reversal mutations in PYP‐tag and probe redesign, the labeling reaction was accelerated by a factor of 18 in vitro, and intracellular proteins were detected with an incubation period of only 1 min. The brightness of the probe both in vitro and in living cells was enhanced by the mutant tag. Furthermore, we applied this system to the imaging analysis of bromodomains. The labeled mutant tag successfully detected the localization of bromodomains to acetylhistone and the disruption of the bromodomain–acetylhistone interaction by a bromodomain inhibitor.     

Rhenium-Catalyzed Construction of Polycyclic Hydrocarbon Frameworks by a Unique Cyclization of 1,n-Diynes Initiated by 1,1-Difunctionalization with Carbon Nucleophiles

A regioselective cyclization of 1,n-diynes under rhenium catalysis was developed on the basis of a rare type of 1,1-difunctionalization of terminal alkynes with carbon nucleophiles, followed by sequential addition reactions of the resulting alkenylrhenium species. The reaction provides an efficient approach to the synthesis of complex cyclopentane-fused bi- and tricycles and spirocycles, which are useful building blocks for the construction of essential frameworks of biologically active compounds as well as functional materials, from simple starting materials by the formation of up to six new carbon–carbon bonds in a single step. The reaction proceeds under neutral conditions and does not require external ligands or additives. The key to this reactivity is the unique activation mode of the rhenium carbonyl complex, which prefers to interact with heteroatoms in polar carbon–heteroatom bonds as well as nonpolar carbon–carbon unsaturated π bonds.     

Simple abelian quadruple systems

We generalize a construction of simple cyclic 3-designs due to Köhler (1981) to that of simple abelian 3-designs. We prove that for any abelian group A of order , there exists a simple 3-(v,4,3) design with A?Aut(A) as an automorphism group.     

Direct cyanation of heteroaromatic compounds mediated by hypervalent iodine(III) reagents: In situ generation of PhI(III)-CN species and their cyano transfer

Hypervalent iodine(III) reagents mediate the direct cyanating reaction of a wide range of electron-rich heteroaromatic compounds such as pyrroles 1, thiophenes 3, and indoles 5 under mild conditions (ambient temperature), without the need for any prefunctionalization. Commercially available trimethylsilylcyanide is usable as a stable and effective cyanide source, and the reaction proceeds in a homogeneous system. The N-substituent of pyrroles is crucial to avoid the undesired oxidative bipyrrole coupling process, and thus a cyano group was introduced selectively at the 2-position of N-tosylpyrroles 1 in good yields using the combination of phenyliodine bis(trifluoroacetate) (PIFA), TMSCN, and BF3.Et2O at room temperature. In the reaction mechanism, cation radical intermediates of heteroaromatic compounds are involved as a result of single electron oxidation, and the key to successful transformations seems to depend on the oxidation potential of the substrates used. Thus, the reaction was also successfully extended to other heteroaromatic compounds having oxidation potentials similar to that of N-tosylpyrroles such as thiophenes 3 and indoles 5. However, regioisomeric mixtures of the products derived from the reaction at the 2- and 3-positions were obtained in the case of N-tosylindole 5a. Further investigation performed in our laboratory provided insights into the real active iodine(III) species during the reaction; the reaction is induced by an active hypervalent iodine(III) species having a cyano ligand in situ generated by ligand exchange reaction at the iodine(III) center between trifluoroacetoxy group in PIFA and TMSCN, and effective cyanide introduction into heteroaromatic compounds is achieved by means of the high cyano transfer ability of the hypervalent iodine(III)-cyano intermediates. In fact, the reaction of N-tosylpyrrole 1a with a hypervalent iodine(III)-cyano compound (e.g., (dicyano)iodobenzene 8), in the absence of TMSCN, took place to afford the 2-cyanated product 2a in good yield, and an effective preparation of the intermediates is of importance for successful transformation. 1,3,5,7-Tetrakis[4-{bis(trifluoroacetoxy)-iodo}phenyl]adamantane 12, a recyclable hypervalent iodine(III) reagent, was also comparable in the cyanating reactions as a valuable alternative to PIFA, affording a high yield of the heteroaromatic cyanide by facilitating isolation of the cyanated products with a simple workup. Accordingly, after preparing the active hypervalent iodine(III)-CN species by premixing of a recyclable reagent 12, TMSCN, and BF3.Et2O for 30 min in dichloromethane, reaction of a variety of pyrroles 1 and thiophenes 3 provided the desired cyanated products 2 and 4 in high yields. The iodine compound 13, recovered by filtration after replacement of the reaction solvent to MeOH, could be reused without any loss of activity (the oxidant 12 can be obtained nearly quantitatively by reoxidation of 13 using m-CPBA).     

New dimeric compounds of avenanthramide phytoalexin in oats

Avenanthramide B is an oat phytoalexin produced in response to pathogen attack and elicitation. We found the formation of new dimers (1-5) of avenanthramide B in elicited oat leaves. The dimers were synthesized by a reaction of peroxidase and avenanthramide B in the presence of hydrogen peroxide. The structures of 1-5 were determined by spectroscopic analyses, chemical derivatization, and 15N labeling. Compound 1 was a dehydrodimer of avenanthramide B with a bisbutane lactam skeleton, while 2-4 were monohydrated dehydrodimers with butane lactam structures. Compound 5 was also a monohydrated dehydrodimer but with a tetrahydrofuran structure. All the compounds were classified into lignanamides that were formed by an 8'-8' coupling reaction between two avenanthramide B units.