Maria Nowak

Synthesis, structure and cytotoxic activity of new acetylenic derivatives of betulin.

A new series of betulin derivatives containing one or two pharmacophores bearing an acetylenic and carbonyl function at the C-3 and/or C-28 positions has been synthesized and characterized by 1H- and 13C-NMR, IR, MS and elemental analyses. The crystal structure of 28-O-propynoylbetulin was determined by X-ray structural analysis. All new compounds, as well as betulin, were tested in vitro for their antiproliferative activity against human SW707 colorectal, CCRF/CEM leukemia, T47D breast cancer, and against murine P388 leukemia and Balb3T3 normal fibroblasts cell lines. Most of the compounds showed better cytotoxicity than betulin and cisplatin used as reference agent. 28-O-Propynoylbetulin was the most potent derivative, being over 500 times more potent than betulin and about 100 times more cytotoxic than cisplatin against the human leukemia (CCRF/CEM) cell line, with an ID50 value of 0.02 μg/mL.

Synthesis, spectroscopy and computational studies of selected hydroxyquinolines and their analogues

Synthetic, spectroscopy and mechanistic aspects of preparation of selected hydroxyquinolines and their analogues or derivatives contained methoxy, fluoro, chloro, carboxylic, carbodithioic and phosphinate or dioxaphosphinane groups were elaborated. The multinuclear NMR and five single crystal X-ray characteristics of the series of quinolines have been determined. The molecular orbitals of the selected hydroxyquinolines have been calculated by density functional theory. The X-ray and NMR studies of 8-[(5,5-dimethyl-2-oxido-1,3,2-dioxaphosphinan-2-yl)oxy]-5,7-dibromo-2-methylquinoline and 8-[(5,5-dimethyl-2-oxido-1,3,2-dioxaphosphinan-2-yl)oxy]-5-fluoro-2-methylquinoline indicate the appearance of anomeric effect.

Two polymorphs of anhydrous 4-pyridone at 100 K.

Two polymorphs of the title compound, C(5)H(5)NO, (I), have been obtained from ethanol. One polymorph crystallizes in the monoclinic space group C2/c [henceforth (I)-M], while the other crystallizes in the orthorhombic space group Pbca [henceforth (I)-O]. In the two forms, the lattice parameters, cell volume and packing motifs are very similar. There are also two independent molecules of 4-pyridone in each asymmetric unit. The molecules are linked by N-H...O hydrogen bonds into one-dimensional zigzag chains extending along the b axis in the (I)-M polymorph and along the a axis in the (I)-O polymorph, with the graph set C(2)(2)(12). The structures are stabilized by weak C-H...O hydrogen bonds linking adjacent chains, thus forming a ring with the graph set R(6)(5)(28). The significance of this study lies in the analysis of the hydrogen-bond interactions occurring in these structures. Analyses of the crystal structures of the two polymorphs of 4-pyridone are helpful in elucidating the mechanism of the generation of spectroscopic effects observed in the IR spectra of these polymorphs in the frequency range of the N-H stretching vibration band.

Quinoline-2-sulfonamide

In the title compound, C9H8N2O2S, the sulfamoyl –NH2 group is involved in intermolecular hydrogen bonding with the sulfonamide O and quinoline N atoms. In the crystal, molecules are linked into dimers via pairs of N—H⋯N hydrogen bonds, forming an R 2 2(10) motif. The dimers are further assembled into chains parallel to the b axis through N—H⋯O hydrogen bonds, generating a C(4) motif. The crystal packing is additionally stabilized by intermolecular C—H⋯O interactions. The crystal studied was a non-merohedral twin with a domain ratio of 0.938 (2):0.062 (2). Density functional theory (DFT) calculations, at the B3LYP/6–31 G(d,p) level of theory, were used to optimize the molecular structure and to determine interaction energies for the title compound. The resulting interaction energy is ∼4.4 kcal mol−1 per bridge for the C(4) chain and ∼5.9 kcal mol−1 per bridge for the R 2 2(10) motif.

Quinoline-8-sulfonamide

In the title compound, C9H8N2O2S, the sulfamoyl NH2 group is involved in intramolecular N—H⋯N and intermolecular N—H⋯O hydrogen bonding. In the crystal, molecules are linked via pairs of N—H⋯O hydrogen bonds, forming inversion dimers, which are further associated through π–π stacking interactions between the quinoline benzene rings [centroid–centroid distance = 3.649 (1) Å] into a one-dimensional polymeric structure extending along the a axis.

Synthesis, X-ray structure and antiproliferative activity of 3-benzylthio-4-propargylselenoquinoline

Synthesis, antiproliferative activity and the X-ray single-crystal structure of the 3-benzylthio-4-propargylselenoquinoline are described. The title compound belongs to the group of the acetylenic derivatives of thioquinolines, which have been intensively investigated as a source of new anticancer agents. The comparative study regarding the X-ray structure, the molecular electrostatic potential analysis, and structure-activity relationship for the title compound and the 3-methylthio-4-propargylthioquinoline and 3-methylthio-4-propargylselenoquinoline are presented.

Synthesis, crystal structure, spectroscopic, and magnetic properties of a manganese(II) methoxyacetate complex [Mn(C6O6H10)(H2O)] n

A metal-organic coordination polymer, [Mn(C6O6H10)(H2O)] n (1), has been synthesized and characterized by elemental analysis, FT-IR spectroscopy, and single-crystal X-ray diffraction. Thermogravimetric analysis and EPR spectrum of the compound have also been studied. Light pink crystals of the complex are monoclinic, space group P21 /c, with a = 7.9444(16) Å, b = 9.0802(18) Å, c = 13.142(3) Å, β = 93.53(3)°, V = 946.2(3) Å3, Z = 4, and R 1 = 0.0212. The compound is mononuclear and contains six-coordinate ions bound to bi- and tridentate methoxyacetate molecules and water. Each manganese ion is connected with the neighboring manganese via carboxylate bridges forming a polymeric chain of [Mn(C6O6H10)] n and water. The 1-D manganese polymer chains are further hydrogen-bonded via the carboxyl groups and water to produce a 3-D extended network. The FT-IR spectrum from 4000 to 400 cm−1 region confirms the bonding of water. Decomposition reaction takes place in the temperature range 25–900°C in nitrogen. The temperature dependence of magnetic susceptibility reveals weak antiferromagnetic coupling interaction (J = −0.74 cm−1) between the Mn(II) sites.

Diaquadichloridobis(1H-imidazole)manganese(II) at 100 K.

The mononuclear title complex, [MnCl(2)(C(3)H(4)N(2))(2)(H(2)O)(2)], is located on a crystallographic inversion center. The Mn(II) ion is coordinated by two imidazole ligands [Mn-N = 2.2080 (9) A], two Cl atoms [Mn-Cl = 2.5747 (3) A] and two water molecules [Mn-O = 2.2064 (8) A]. These six monodentate ligands define an octahedron with almost ideal angles: the adjacent N-Mn-O, N-Mn-Cl and O-Mn-Cl angles are 90.56 (3), 92.04 (2) and 90.21 (2) degrees , respectively. Hydrogen bonds between the coordinated water molecules and Cl atoms form a two-dimensional network parallel to (100) involving R(4)(2)(8) rings. The two-dimensional networks link into a three-dimensional framework through weaker N-H...Cl interactions. Thermogravimetric analysis results are in accordance with the water-coordinated character of the substance and its dehydration in two successive steps.

Thioacetanilide at 120 K.

The title compound, C(8)H(9)NS, has four symmetry-independent molecules in the asymmetric unit. These molecules link into two independent infinite N-H...S hydrogen-bonded chains in the a-axis direction with graph-set notation C(2)(2)(8). The NH-CS group adopts a trans conformation and forms a dihedral angle of about 50 degrees with the phenyl ring. The intermolecular hydrogen-bond energy calculated by the density functional theory (DFT) method is -14.95 kJ mol(-1). The correlation between the IR spectrum of this compound and the hydrogen-bond energy is also discussed. This molecular system is of interest because of its biological function.

Low-temperature study of 3-acetylindole at 110 K

The title compound, C(10)H(9)NO, contains an acetyl group that is nearly coplanar with the indole ring system, with an angle between the planes of the heterocyclic ring and the acetyl group of 1.75 (17) degrees . The planes of the benzene and pyrrole rings in the indole system make a dihedral angle of 2.05 (11) degrees . Each molecule in the unit cell is linked through N-H...O hydrogen bonds to two other molecules, forming hydrogen-bonded chains in the [101] direction with graph set C(6). The significance of this study lies in the analysis of the interactions occurring via hydrogen bonds in this structure, as well as in the comparison drawn between the molecular structure of the title compound and those of several other indole derivatives possessing a 3-carbonyl group. The correlation between the IR spectrum of this compound and the structural data is also discussed.