Biomedical subjects

Jaromír Marek

Publications and source records attributed to Jaromír Marek.

15 recordsLinked to original sources

PubMed2005

Racemic monoperoxovanadium(V) complexes with achiral OO and ON donor set heteroligands: synthesis, crystal structure and stereochemistry of [NH3(CH2)2NH3][VO(O2)(ox)(pic)].2H2O and [NH3(CH2)2NH3][VO(O2)(ox)(pca)].

Monoperoxovanadium(V) complexes, [NH3(CH2)2NH3][VO(O2)(ox)(pic)].2H2O (1) and [NH3(CH2)2NH3][VO(O2)(ox)(pca)] (2) [NH3(CH2)2NH3 = ethane-1,2-diammonium(2+), ox=oxalate(2-), pic=pyridine-2-carboxylate(1-), pca=pyrazine-2-carboxylate(1-)], were synthesized and characterized by X-ray analysis, IR and Raman spectroscopies. The five equatorial positions of the pentagonal bipyramid around the vanadium atoms are occupied by the eta2-peroxo ligand, two oxygen atoms of the ox, and the nitrogen atom of the pic or pca ligands, respectively. The oxo ligand and the oxygen atom of pic or pca are in the axial positions. Networks of X-HO (X=C, N or O) hydrogen bonds, and pi-pi interactions between aromatic rings in and anion-pi interactions in , determine the molecular packings and build up the supramolecular architecture. Three stereochemical rules for occupation of the donor sites in two-heteroligand [VO(O2)(L1)(L2)] complexes (L1, L2 are bidentate neutral or differently charged anionic heteroligands providing an OO, NN or ON donor set) are discussed. and crystallize as racemic compounds. The 51V NMR spectra proved that the parent complex anions of and partially decompose on dissolution in water to the monoperoxo-ox, -pic or -pca complexes.

Ammonia↗

PubMed2005

2',4'-Dihydroxy-3-methoxy-alpha,beta-dihydrochalcone and 2',4-dihydroxy-alpha,beta-dihydrochalcone: supramolecular structures formed by O-H...O, C-H...O and stacking interactions.

The crystal structures of 2',4'-dihydroxy-3-methoxy-alpha,beta-dihydrochalcone, C16H16O4, and 2',4-dihydroxy-alpha,beta-dihydrochalcone, C15H14O3, have been determined. In both compounds, the structure consists of two nearly planar six-membered aromatic rings connected by a propanal chain, which is bent in the methoxy compound and almost straight in the other compound. In the crystal structures, the molecular units of both compounds are linked by O-H...O hydrogen bonds to form infinite one-dimensional chains. Hydrogen bonds and C-H...O contacts in the crystal structures were studied by topological analysis of charge density based on Hartree-Fock calculations. Almost all of the investigated C-H...O contacts should be characterized as weak hydrogen bonds.

Chalcones↗

PubMed2004

Molecular, supramolecular and solution structures of peroxovanadium complexes with ON and O3N donor set ligands: two new types of cationic-anionic peroxovanadium(V) peroxovanadates(V).

The complexes, [VO(O(2))(pa)(2)]ClO(4).3H(2)O (1), [VO(O(2))(pa)(2)][VO(O(2))(2)(pa)].3H(2)O (2), [VO(O(2))(pa)(2)][VO(O(2))(ada)].2H(2)O (3) and [VO(O(2))(pa)(pca)].H(2)O (4)[pa = picolinamide, ada = carbamoylmethyliminodiacetate(2-) and pca = 2-pyrazinecarboxylate(1-)], were synthesized. 2 and 3 are new types of peroxovanadium complexes: monoperoxovanadium diperoxovanadate (2) and monoperoxovanadium monoperoxovanadate (3). The complexes were characterized by chemical analysis and IR spectroscopy, and 1, 3 and 4 also by X-ray analysis. The structure of 1 is disordered, with alternating positions of the oxo and peroxo ligands. The peroxo oxygen atoms, O(p), in 1 are involved in weak hydrogen bonds with water molecules and close intramolecular C-HO...(p) bonds [d(HO(p)) approximately 2.0 A]. The supramolecular structure of 1 is formed by a network of hydrogen bonds and strong attractive intermolecular pi-pi interactions between the pyridine rings. The supramolecular architecture in 4 is constructed by (N,O)-H...O hydrogen bonds between the neutral complex molecules and water of crystallization. The peroxo oxygen atoms in 4 form intramolecular C-H...O(p) bonds [d(H...O(p))= 2.303 A]. The pa and pca ligands are ON coordinated via the oxygen atoms of the C(NH(2))=O and COO(-) groups, respectively, and nitrogen atoms of the heterocyclic rings, and ada as a tetradentate O(3)N ligand. The thermal analysis of 4 showed that the loss of water of crystallization and the active oxygen release (T(min)/ degrees C 82, T(max)/degrees C 165) are, under given conditions, individual processes separated by the temperature interval 90-132 degrees C. The solution structures and stability were studied by UV-VIS and (51)V NMR spectroscopies.

Journal Article↗

PubMed2004

(R)-4-(4-fluorophenyl)-1-[2-hydroxy-2-(3-methyl-1-benzofuran-2-yl)ethyl]piperazinium chloride propan-1-ol solvate.

The title compound, C21H24FN2O2+.Cl-.C3H8O, is a potential drug designed as a hybrid compound with antihypertensive, antioxidant and beta-adrenolytic activity. The cation contains nearly planar benzofuran and fluorophenyl ring systems, as well as a piperazine ring adopting an almost perfect chair conformation. The benzofuran and piperazine moieties are connected by an ethyl chain, the moieties forming a dihedral angle of 163.12 (13) degrees. In the crystal structure, ions and propanol solvent molecules are linked via N-H...Cl and O-H...Cl bonds into linear (010) chains.

Antihypertensive Agents↗

PubMed2004

Di-mu-aqua-bis[(N-salicylidene-beta-alaninato-kappa3O,N,O')copper(II)] urea disolvate.

Crystals of the title compound, [Cu(2)(C(10)H(9)NO(3))(2)(H(2)O)(2)].2CH(4)N(2)O, consist of two (N-salicylidene-beta-alaninato-kappa(3)O,N,O')copper(II) coordination units bridged by two water moieties to form a dimer residing on a crystallographic inversion center, along with two uncoordinated urea molecules. The Cu(II) atom has square-pyramidal coordination, with three donor atoms of the tridentate Schiff base and an O atom of the bridging aqua ligand in the basal plane. The axial position is occupied by the second bridging water ligand at a distance of 2.5941 (18) A. Hydrogen bonds between molecules of urea and the neighboring dimer units lead to the formation of a two-dimensional grid of molecules parallel to [101]. The superposition of the normals of the pyramidal base planes in the direction [100] indicates possible pi-pi interactions between the neighboring units.

Copper↗

PubMed2003

[N,N'-Bis(3-aminopropyl)ethylenediamine-kappa4N,N',N",N"'](trithiocyanurato-kappa2N,S)zinc(II) ethanol solvate.

In the crystal structure of the title compound, [N,N'-bis(3-aminopropyl)ethylenediamine-kappa(4)N,N',N",N"'][1,3,5-triazine-2,4,6(1H,3H,5H)-trithionato(2-)-kappa(2)N,S]zinc(II) ethanol solvate, [Zn(C(8)H(22)N(4))(2)(C(3)HN(3)S(3))].C(2)H(6)O, the Zn(II) atom is octahedrally coordinated by four N atoms [Zn-N = 2.104 (2)-2.203 (2) A] of a tetradentate N-donor N,N'-bis(3-aminopropyl)ethylenediamine (bapen) ligand and by two S and N atoms [Zn-S = 2.5700 (7) A and Zn-N = 2.313 (2) A] of a trithiocyanurate(2-) (ttcH(2-)) dianion bonded as a bidentate ligand in a cis configuration. The crystal structure of the compound is stabilized by a network of hydrogen bonds.

Journal Article↗

PubMed2003

catena-Poly[potassium [copper(II)-mu-isothiocyanato-mu-N-salicylidene-beta-alaninato2-]].

The title polymeric compound, catena-poly[dipotassium [bis[mu-N-salicylidene-beta-alaninato(2-)]-kappa(4)O,N,O':O";kappa(4)O":O,N,O'-dicopper(II)]-di-mu-isothiocyanato-kappa(2)N:S;kappa(2)S:N], [K[Cu(NCS)(C(10)H(9)NO(3))]](n), consists of [isothiocyanato(N-salicylidene-beta-alaninato)copper(II)](-) anions connected through the two three-atom thiocyanate (mu-NCS) and the two anti,anti-mu-carboxylate bridges into infinite one-dimensional polymeric anions, with coulombically interacting K(+) counter-ions with coordination number 7 constrained between the chains. The Cu(II) atoms adopt a distorted tetragonal-bipyramidal coordination, with three donor atoms of the tridentate Schiff base and one N atom of the bridging mu-NCS ligand in the basal plane. The first axial position is occupied by a thiocyanate S atom of a symmetry-related mu-NCS ligand at an apical distance of 2.9770 (8) A, and the second position is occupied by an O atom of a bridging carboxylate group from an adjacent coordination unit at a distance of 2.639 (2) A.

Anions↗

PubMed2003

Diaquabis(1,10-phenanthroline-kappa(2)N,N')manganese(II) thiodiglycolate bis(1,10-phenanthroline-kappa(2)N,N')(thiodiglycolato-kappa(2)O,O')manganese(II) tridecahydrate.

The title compound, [Mn(C(12)H(8)N(2))(2)(H(2)O)(2)](C(4)H(4)O(4)S).[Mn(C(4)H(4)O(4)S)(C(12)H(8)N(2))(2)].13H(2)O, contains one dianion of thiodiglycolic acid (tdga(2-)) and two independent manganese(II) moieties, viz. [Mn(phen)(2)(H(2)O)(2)](2+) and [Mn(tdga)(phen)(2)], where phen is 1,10-phenanthroline. The Mn(II) atoms are octahedrally coordinated by four N atoms of two bidentate phen ligands [Mn-N = 2.240 (2)-2.3222 (19) A] and either two water O atoms or two tdga carboxyl O atoms [Mn-O = 2.1214 (17)-2.1512 (17) A]. The tdga ligand chelates as an O,O'-bidentate ligand, forming an eight-membered ring with one Mn atom. The free tdga(2-) dianion is hydrogen bonded to an [Mn(phen)(2)(H(2)O)(2)](2+) ion, with O.O distances of 2.606 (2) and 2.649 (2) A. The crystal structure is further stabilized by an extensive network of hydrogen bonds involving 13 water molecules.

Journal Article↗

PubMed2003

Berberine formate-succinic acid (1/1).

The title compound [systematic name: 9,10-dimethoxy-2,3-methylenedioxy-5,6-dihydrodibenzo[a,g]quinolizinium formate-succinic acid (1/1)], C(20)H(18)NO(4)(+).CHO(2)(-).C(4)H(6)O(4), contains centrosymmetric pairs of almost planar berberine cations, and hydrogen-bonded (C(4)H(6)O(4).HCOO(-))(2) rings of succinic acid with formate anions, bonded by O-H...O hydrogen bonds with O...O distances of 2.4886 (15) and 2.5652 (16) A. Pairs of cations and molecules of succinic acid are connected by non-conventional weak C-H.O hydrogen bonds, with C...O distances of 3.082 (2) and 3.178 (2) A.

Berberine↗

PubMed2003

Tris(1,10-phenanthroline)sodium 2,4,6-trimercapto-1,3,5-triazin-1-ide.

The title compound, [Na(C(12)H(8)N(2))(3)](C(3)H(2)N(3)S(3)), contains an Na(+) centre which is ionicly bonded to three 1,10-phenanthroline (phen) ligands and one trithiocyanurate(1-) (ttcH(2)) anion. In the crystal structure, the anions are linked via hydrogen bonds to form linear chains. The S and H atoms of the ttcH(2) anion participate in intermolecular N-H.S hydrogen bonding, with N.S distances of 3.298 (2) and 3.336 (2) A. The phen ligands are almost parallel, with dihedral angles of 3.92 (5), 11.75 (5) and 15.45 (5) degrees; moreover, they are nearly perpendicular to the ttcH(2) chains, with angles of 81.94 (7), 85.86 (7) and 85.96 (7) degrees.

Journal Article↗

PubMed2003

Dipotassium di-mu-isothiocyanato-kappa4N:S-bis[(N-salicylidene-DL-valinato-kappa3O,N,O')cuprate(II)].

The title compound, K(2)[Cu(2)(NCS)(2)(C(12)H(13)NO(3))(2)], consists of two K(+) cations and (N-salicylidene-D-valinato)copper(II) and (N-salicylidene-L-valinato)copper(II) coordination units connected through three-atom thiocyanate (mu-NCS) bridges into a centrosymmetric dianion. The Cu(II) atom adopts a square-pyramidal coordination, with three donor atoms of the tridentate Schiff base and one N atom of the bridging ligand (mu-NCS) in the basal plane. The axial position is occupied by the thiocyanate S atom of a symmetry-related ligand at an apical distance of 2.9332 (10) A. Coulombic interactions between six-coordinated K(+) ions and the heteroatoms of neighbouring dimeric anions leads to the formation of one-dimensional chains of molecules parallel to [010]. The superposition of the normals of the pyramidal base planes in a direction close to [001] indicates possible pi-pi interactions between neighbouring units.

Journal Article↗

PubMed2003

[N-(Carboxylatomethyl)aspartato(3-)](ethylenediamine)cobalt(III) trihydrate.

The mononuclear title complex, [Co(C(6)H(6)NO(6))(C(2)H(8)N(2))].3H(2)O, contains an octahedrally coordinated Co(III) atom. The N-(carboxymethyl)aspartate moiety is coordinated as a tetradentate ligand, providing an OONO-donor set and forming two trans five-membered chelate rings and one six-membered chelate ring. A seven-membered chelate ring is also formed, which consists of part of the six-membered chelate ring and part of one of the five-membered chelate rings. The crystal structure of the complex is stabilized by hydrogen bonds with three water molecules.

Journal Article↗

PubMed2003

Mixed ligand complexes of platinum(II) and palladium(II) with cytokinin-derived compounds Bohemine and Olomoucine: X-ray structure of [Pt(BohH+-N7)Cl(3)].9/5H2O [Boh=6-(benzylamino)-2-[(3-(hydroxypropyl)-amino]-9-isopropylpurine, Bohemine].

The new square-planar Pt(II) and Pd(II) complexes with cytokinin-derived compounds Bohemine and Olomoucine, having the formulae [Pt(BohH(+))Cl(3)].H(2)O (1), [Pt(Boh)(2)Cl(2)].3H(2)O (2), [Pt(Boh-H)Cl(H(2)O)(2)].H(2)O (3), [Pt(OloH(+))Cl(3)].H(2)O (4), [Pd(BohH(+))Cl(3)].H(2)O (5), [Pd(Boh)Cl(2)(H(2)O)] (6), [Pd(Boh-H)Cl(H(2)O)].EtOH (7) and [Pd(OloH(+))Cl(3)].H(2)O (8), where Boh=6-(benzylamino)-2-[(3-(hydroxypropyl)amino]-9-isopropylpurine and Olo=6-(benzylamino)-2-[(2-(hydroxyethyl)amino]-9-methylpurine, have been synthesized. The complexes have been characterized by elemental analyses, IR, FAB+ mass, 1H, 13C and 195Pt NMR spectra, and conductivity data. The molecular structure of the complex [Pt(BohH(+)-N7)Cl(3)].9/5H(2)O has been determined by an X-ray diffraction study. Results from physical studies show that both Bohemine and Olomoucine are coordinated to transition metals through the N(7) atom of purine ring in all the complexes. The prepared compounds have been tested in vitro for their possible cytotoxic activity against G-361 (human malignant melanoma), HOS (human osteogenic sarcoma), K-562 (human chronic myelogenous leukemia) and MCF-7 (human breast adenocarcinoma) cell lines and IC(50) values have been also determined for all the complexes. IC(50) values estimated for the Pt(II)-Bohemine complexes (2.1-16 microM) allow us to conclude that they could find utilization in antineoplastic therapy. Thus, from a pharmacological point of view, Pt(II) complexes of Bohemine may represent compounds for a new class of antitumor drugs.

Antineoplastic Agents↗

PubMed2003

Pomiferin.

The crystal structure of pomiferin, 3-(3,4-dihydroxyphenyl)-5-hydroxy-8,8-dimethyl-6-(3-methylbut-2-enyl)-4H,8H-pyrano[2,3-h]chromen-4-one, C(25)H(24)O(6), has been determined. The benzopyranone ring system is nearly planar and the dihedral angle between the phenyl ring and the benzopyranone moiety is 40.85 (4) degrees. The crystal structure is stabilized by a one-dimensional chain of inter- and intramolecular O-H...O hydrogen bonds, with O...O distances in the range 2.5546 (15)-2.7999 (16) A.

Anti-Infective Agents↗

PubMed2003

Palmatine and berberine isolation artifacts.

Some 8-substituted derivatives of the protoberberine alkaloids palmatine (1a) and berberine (1b) have been prepared and investigated by 1D and 2D NMR spectroscopy (H-1, C-13, N-15). Complete NMR data for the 8-hydroxy (2), 8-methoxy (3), 8-ethoxy (4), and 8-trichloromethyl (5) 7,8-dihydro derivatives of 1a and 1b, as well as X-ray data for 8-methoxydihydroberberine (3b), 8-trichloromethyldihydropalmatine (5a), and 8-trichloromethyldihydroberberine (5b), are presented. The physicochemical data for all of these compounds are reviewed and compared with previously published values.

Alkaloids↗