Search results for "medicinal"

Aqua complex of iron(III) and 5-chloro-3-(2-(4,4-dimethyl-2,6- dioxocyclohexylidene) hydrazinyl)-2-hydroxybenzenesulfonate: Structure and catalytic a…

2013

Abstract A water-soluble iron(III) complex [Fe(H2O)3(L)]·5H2O (1) was prepared by reaction of iron(III) chloride with 5-chloro-3-(2-(4,4-dimethyl-2,6-dioxocyclohexylidene)hydrazinyl)-2-hydroxy-benzenesulfonic acid (H3L). The complex was characterized by IR, 1H NMR and ESI-MS spectroscopies, elemental and X-ray crystal structural analyses. The coordination environment of the central iron(III) is a distorted octahedron, three sites being occupied by L3− ligand, which chelates in O,N,O fashion, while three other sites are filled with the water molecules. The uncoordinated water molecules are held in the channels of the overall 3D supramolecular structure by the carbonyl and sulfonyl groups of …

ChemInform Abstract: Asymmetric Conjugate Addition of Malonate Esters to α,β-Unsaturated N-Sulfonyl Imines: An Expeditious Route to Chiral δ-Aminoest…

2014

The asymmetric conjugate addition of malonate esters to α,β-unsaturated N-sulfonyl imines is catalyzed by PyBOX/La(OTf)3 complexes in the presence of 4 A MS. The reaction gives the corresponding E enamines bearing a stereogenic center at the allylic position with good yields and enantiomeric ratios up to 97:3. This reaction provides a synthetic entry to chiral δ-aminoesters and piperidones.

Methyl [4-methoxy-3-(methylsulfonyloxy)benzoyl]formate

2005

The crystal structure of the title compound, C11H12O7S, confirms an earlier proposal concerning the regioselectivity of electrophilic substitution reactions of mesyl guaiacol.

Polyaza[n](1,4)naphthalenophanes and polyaza[n](9,10)anthracenophanes

2002

Abstract A series of polyaza[n](1,4)naphthalenophanes and polyaza[n](9,10)anthracenophanes have been prepared by using the Fukuyama's protecting group (2- or 4-nitrophenyl sulfonyl) in a one-pot cyclization–deprotection reaction. Global yields for the purified products are comparable with those obtained for other polyazacyclophanes using the tosyl group as the amine protecting group. Their structural study has been carried-out by NMR showing a high rigidity for the smaller cycles and a more dynamic behaviour for the largest member of the series. The free energy barrier for the rotational equilibrium for compound 25 is about 3 kcal/mol lower than that calculated for analogous N-tosylated mac…

N‐Heterocyclic Carbene Catalyzed Asymmetric Synthesis of Pentacyclic Spirooxindoles via [3+3] Annulations of Isatin‐Derived Enals and Cyclic N‐Sulfon…

2019

Discovering Copper for Methane C–H Bond Functionalization

2015

The copper complex Tp(CF3)2,BrCu(NCMe) (1, Tp(CF3)2,Br = hydrotris((3,5-bis(trifluoromethyl)-4-bromo)-pyrazol-1-yl)borate) catalyzes the insertion of the CHCO2Et group (from ethyl diazoacetate N2CHCO2Et, EDA) into the C–H bonds of methane, in a homogeneous process that uses supercritical carbon dioxide (scCO2) as the reaction medium. Other light alkanes such as ethane, propane, and butane have been also functionalized with this copper-based catalyst, in the first example of the derivatization of the series of C1–C4 alkanes with this metal and a soluble catalyst.

Catalytic and anticancer activities of sawhorse-type diruthenium tetracarbonyl complexes derived from fluorinated fatty acids

2013

The reaction of fluorinated fatty acids, perfluorobutyric acid (C3F7CO2H), and perfluorododecanoic acid (C11F23CO2H), with dodecacarbonyltriruthenium (Ru3(CO)12) under reflux in tetrahydrofuran, followed by addition of two-electron donors (L) such as pyridine, 1,3,5-triaza-7-phosphatricyclo[3.3.1.1]decane, or triphenylphosphine, gives stable diruthenium complexes Ru2(CO)4(μ2-η2-O2CC3F7)2(L)2 (1a, L = C5H5N; 1b, L = PTA; 1c, L = PPh3) and Ru2(CO)4(μ2-η2-O2CC11F23)2(L)2 (2a, L = C5H5N; 2b, L = PTA; 2c, L = PPh3). The catalytic activity of the complexes for hydrogenation of styrene under supercritical carbon dioxide has been assessed and compared to the analogous triphenylphosphine complexes w…

Surface and volume non-invasive methods for the structural monitoring of the bass-relief ‘Madonna con Bambino’ (Gorizia, Northern Italy)

2016

Structural analysis of marble statues, carried out by non-invasive and in situ methods, is crucial to define the state of conservation of the artworks and to identify the deterioration phenomena that can affect them. In this work, we combined in situ non-destructive techniques, ultrasonic tomography (US), ultraviolet-induced visible fluorescence (UV-IF) and X-ray fluorescence (XRF) to study the bass-relief ‘Madonna con Bambino’ (Gorizia, Italy). The US revealed the presence of some metallic pivots, associated with areas of high sound velocity; moreover, a more degraded area has been identified in the lower part of the bass-relief. The acquired UV-IF image confirmed the presence of surface d…

Cytotoxicity and inhibition of P-glycoprotein by selected medicinal plants from Thailand.

2014

Abstract Ethnopharmacological relevance Thai medicine has a long tradition of tonifying medicinal plants. In the present investigation, we studied the flower extracts of Jasminum sambac, Mammea siamensis, Mesua ferrea, Michelia alba, Mimusops elengi, and Nelumbo nucifera and speculated that these plants might influence metabolism and substance flow in the body. Materials and methods Isolation of porcine brain capillary endothelial cells (PBCECs) as well as multidrug-resistance CEM/ADR5000 leukemia cells, MDA-M;B-231 breast cancer, U-251 brain tumor, and HCT-116 colon cancer cells were used. The calcein-acetoxymethylester (AM) assay was used to measure inhibition of P-glycoprotein transport.…

Induction of apoptosis in a leukemia cell line by triterpene saponins from Albizia adianthifolia

2004

Abstract Triterpenoid saponins, which are present in plants and some marine animals, exert various important pharmacological effects. The present study examines the effects of adianthifoliosides A, B, and D (AdA, AdB, and AdD) together with two prosapogenins (Pro1 and Pro2) obtained from Albizia adianthifolia (Mimosaceae) on human leukemia T-cells (Jurkat cells) and on splenocytes. AdA, AdB, and AdD were found to exhibit a cytotoxic effect on Jurkat cells, whereas the prosapogenins were found to exert a lymphoproliferative effect on this cell type. Furthermore, all tested compounds were found to exert a synergistic lymphoproliferative activity with concanavalin A (ConA) on splenocytes. The …