Molecular and solid-state structure of methyl [2-(acridin-9-ylimino)-3-(tert-butylamino)-4-oxothiazolidin-5-ylidene]acetate

4-({(Z)-5-[(Z)-3-Eth-oxy-4-hy-droxy-benzyl-idene]-3-methyl-4-oxo-1,3-thia-zolidin-2-yl-idene}amino)-benzoic acid dimethyl-formamide monosolvate

The mol-ecular structure of the title compound, C20H18N2O5S·C3H7NO, represents an essentially planar 5-benzyl-idene-thia-zolidine moiety (r.m.s. deviation from planarity without ring substituents = 0.095 Å) to which the 4-amino-benzoic acid fragment is inclined at 76.23 (1)°. In the crystal, the benzoic acid mol-ecules are arranged in layers parallel to [001] which are built up from inversion dimers held together by head-to-tail phenol-carb-oxy O-H⋯O hydrogen bonds and head-to-tail π-π stacking inter-actions between the 5-benzyl-idene-thia-zolidine moieties (ring centroid distance = 3.579 Å). These layers are separated by the dimethyl-formamide solvent mol-ecules which are firmly anchored via a short O-H⋯O hydrogen bond [O⋯O = 2.5529 (10) Å] donated by the -COOH group.

DNA binding acridine-thiazolidinone agents affecting intracellular glutathione

Three new acridine-thiazolidinone derivatives (2a-2c) have been synthesized and their interactions with calf thymus DNA and a number of cell lines (leukemic cells HL-60 and L1210 and human epithelial ovarian cancer cell lines A2780) were studied. The compounds 2a-2c possessed high affinity to calf thymus DNA and their binding constants determined by spectrofluorimetry were in the range of 1.37 × 10(6)-5.89 × 10(6) M(-1). All of the tested derivatives displayed strong cytotoxic activity in vitro, the highest activity in cytotoxic tests was found for 2c with IC(50) = 1.3 ± 0.2 μM (HL-60), 3.1 ± 0.4 μM (L1210), and 7.7 ± 0.5 μM (A2780) after 72 h incubation. The cancer cells accumulated acridine derivatives very fast and the changes of the glutathione level were confirmed. The compounds inhibited proliferation of the cells and induced an arrest of the cell cycle and cell death. Their influence upon cells was associated with their reactivity towards thiols and DNA binding activity.

4-(9,10-Dihydroacridin-9-ylidene)thiosemicarbazide and its five-membered thiazole and six-membered thiazine derivatives

Two methyl derivatives, five-membered methyl 2-{2-[2-(9,10-dihydroacridin-9-ylidene)-1-methylhydrazinyl]-4-oxo-4,5-dihydro-1,3-thiazol-5-ylidene}acetate, C(20)H(16)N(4)O(3)S, (I), and six-membered 2-[2-(9,10-dihydroacridin-9-ylidene)-1-methylhydrazinyl]-4H-1,3-thiazin-4-one, C(18)H(14)N(4)OS, (II), were prepared by the reaction of the N-methyl derivative of 4-(9,10-dihydroacridin-9-ylidene)thiosemicarbazide, C(14)H(12)N(4)S, (III), with dimethyl acetylenedicarboxylate and methyl propiolate, respectively. The crystal structures of (I), (II) and (III) are molecular and can be considered in two parts: (i) the nearly planar acridine moiety and (ii) the singular heterocyclic ring portion [thiazolidine for (I) and thiazine for (II)] including the linking amine and imine N atoms and the methyl C atom, or the full side chain in the case of (III). The structures of (I) and (II) are stabilized by N-H...O hydrogen bonds and different pi-pi interactions between acridine moieties and thiazolidine and thiazine rings, respectively.