J. Ashaks

Cytotoxic di(8-quinolyl) disulfides

It has been shown that the nature of the substituent and its position in the quinoline ring markedly affects the antitumor activity and toxicity of di(8-quinolyl) disulfides. The greatest cytotoxicity in the series of methyl derivatives was shown by the 7-, 6-, and 3-isomers towards HT-1080 (human fibrosarcoma) and MG-22A (mouse hepatoma) tumor cells while the 2-methyl derivatives generally have no effect on these cells. High cytotoxicity was also shown (LC50 <1 µg/ml) by other 7-substituted compounds (Cl, PhO, PhS) but they also appear to be highly toxic towards normal NIH 3Y3 mouse embryonic fibroblasts. A similar trend was observed in the series of 5-substituted compounds (NH2, Cl, OMe, NO2) which were highly active towards tumor cells but were toxic to normal cells. The best selectivity was found for the 6-substituted quinolines, the 6-methoxy derivative at low concentration brought about the death of tumor cells but appeared much less toxic towards normal fibroblasts (LC50 100 µg/ml with a corresponding LD50 of 874 mg/kg ).

Tris(2-methyl­quinoline-8-seleno­lato-κ2N,Se)antimony(III)

The title complex, [Sb(C10H8NSe)3], has a 3Se+3N distorted octaxadhedral geometry at the Sb atom. The structure is stabilized by weak interxadmolecular C—H⋯π(arene) interxadactions.

Synthesis and cytotoxicity of complex compounds of tin, vanadium, and molybdenum with quinolinethiol and its methyl and methoxy derivatives

A series of 8-quinolinethiolates, and 3-methyl-, 4-methyl-, 5-methyl-, 6-methyl-, 7-methyl-, and 6-methoxy-8-quinolinethiolates of tin(II), vanadium(IV), and molybdenum(VI) has been synthesized. Their cytotoxicity on HT-1080 tumor cells (human fibrosarcoma) and MG-22A (mouse hepatoma) cells has been studied. It was established that all of the investigated complexes of 8-quinolinethiol and majority of the complexes of 8-quinolinethiol derivatives possessed very high cytotoxicity towards both cell lines. Their toxicity in relation to mouse embryo fibroblasts NIH 3T3 depended on the position of the substituent in the quinoline ring. Complexes of tin and vanadium with 4-methyl-, 5-methyl-, and 6-methoxy-8-quinolinethiol derivatives were less toxic. 4-Methyl-, 5-methyl-, and 6-methoxy-8-quinolinethiolates of vanadium demonstrated the highest selectivity of cytotoxic action.

Synthesis and crystal structure of a solvate of arsenic 4,6-dimethyl-8-quinolinethiolate

A crystallosolvate of arsenic 4,6-dimethyl-8-quinolinethiolate, As[4,6-Me2C9H4NS]3⋅CHCl3 has been synthesized. The molecular and crystalline structures of the compound have been determined by X-ray structural analysis. The influence of the composition and structure of the ligand on the geometry of the coordination environment of the central arsenic atom in the investigated crystal structures of intracomplex compounds of 8-quinolinethiols is discussed.

Crystal structure of catena-poly[bis(8-mercaptoquinolinato-N,S)disilver(I)], Ag2(C9H6NS)2

C18H12Ag2N2S2, monoclinic, P21/n (no. 14), a = 8.8508(3) Å, b = 18.5170(8) Å, c = 10.1176(4) Å, ) = 97.770(3)°, V = 1643.0 Å, Z = 4, Rgt(F) = 0.039, wRref(F ) = 0.087, T = 293 K. Source of material Sodium salt of 8-mercaptoquinoline (12.8 mmol) is dissolved in the mixture of 50 ml of water and 10 ml of ethanol upon heating and silver nitrate solution (11.8 mmol of AgNO3 in 20 ml of water) was added. The resulting amorphous yellow precipitate was filtered off, washed with water and dried in air (yield 0.25 g, 93 %). Single crystals of the title compound were grown from a solution in benzonitrile. Elemental analysis — found: C, 40.56 %; H, 2.15.%; N, 5.23 %; S, 11.98 %; calculated for C18H12Ag2N2S2: C, 40.80 %; H, 2.24 %; N, 5.22 %; S, 11.94 %. Discussion The present work is the continuation of the systematic investigations of structure of internal complexes of 8-mercaptoquinoline and its derivatives containing the ions of different valency and coordination possibilities. The silver atom is known to be the soft metallic center, its coordination number and environment geometry can differ considerably depending on the nature of the ligands. In the crystal structure of silver 2-phenyl-8-mercaptoquinolinate [1] the 2-C6H5(8-Sq) ligands possess the bidentatic (N,S) and bridging (S) function simultaneously, the Ag atoms are coordinated in bent linear (2S) and “swings” (2S+2N) environment. The coordination of Ag atoms with square-planar (2S+2N), distorted tetrahedral (2S+2N), tetrahedrally distorted square-planar (2S+2N) and square trigonal bipyramidal (3S+2N) manner in the silver complexes with 8-mercaptoquinoline based flexible multidentate ligands have been reported [2-4]. The title compound consists of the independent units (AgC9H6NS)2. Each silver atom is bonded bidentatically (N,S) with one 8-mercaptoquinoline ligand, five membered metalcontaining ring being formed, and monodentatically (S) with the neighbouring ligands, so forming the chain. The covalent bond lengths Ag—S in the metal-containing rings differ practically (2.488(1), 2.492(1) Å). The bridge bond Ag1—S1 in the dimer occurs to be the shortest (2.404(1) Å). This phenomenon evidently determines the planarity of the dimer. The Ag—N bond distances vary from 2.343(3) to 2.429(3) Å. The chelate rings are of different planarity. The translation-identical symmetrically independent parts (AgC9H6NS)2 are united in polymers along [100] by the undulating chain of the altering atoms –S2–Ag1– S1–Ag2–. The 8-mercaptoquinoline ligands are situated in the trans position in relation to the chain, their planes are almost coplanar. The dihedral angle between those planes is 4.2°. The chain is characterized by the insignificantly different lengths of the Ag—S bonds (2.404(1) 2.492(1) Å). The torsion angle –172.41(5)° around the shortest central Ag1—S1 bond of the dimer shows the total planarity of the symmetrically independent part of the structure. The coordination number of silver atoms Ag1 and Ag2 in the chain equals to 3 (2S+N): the surroundings of the atoms are the pyramidally distorted extremely irregular triangle. The chain symmetrical to the base chain is formed by means of symmetry centers. The formed chain is characterized by the reverse order of disposition of atoms Ag and S. The strong interaction between Ag2 and S2 (1–x,–y,2–z, 2.815(1) Å) can be described as the additional covalent bond for Ag2 atom. Thus, in the crystal structure the double polymer chain forms along [100]. Weak interactions Ag1···Ag2 (1–x,–y,2–z), 3.097(1) Å and Ag1···S1 (1–x,–y,2–z), 3.192(1) Å long between the both chains strengthen double chain. The direction of these contacts Z. Kristallogr. NCS 225 (2010) 211-212 / DOI 10.1524/ncrs.2010.0091 211