Cytotoxicity and structure-activity relationships of four alpha-N-heterocyclic thiosemicarbazone derivatives crystal structure of 2-acetylpyrazine thiosemicarbazone.

A series of thiosemicarbazone ligands, HL(1) (2-acetylpyrazine thiosemicarbazone), HL(2) (2-acetylpyrazine N(4)-methylthiosemicarbazone), HL(3) (2-benzoylpyridine thiosemicarbazone) and HL(4) (2-benzoylpyridine N(4)-methylthiosemicarbazone), have been synthesized. The crystal structure of HL(1) has been determined by single-crystal X-ray diffraction. Hydrogen bonds link the different components to stabilize the crystal structure. The antitumor activity of the four ligands were tested against K562 leucocythemia and BEL7402 liver cancer cell lines. All the thiosemicarbazones showed significant antitumor activity. Different substituents on the ligands show different levels of antitumor activity. By comparison with the other thiosemicarbazone species studied, HL(4) with substitution at N(4) position in thiosemicarbazone along with 2-benzoylpyridine is the most active thiosemicarbazone ligand with IC(50)=0.002microm in the K562 leucocythemia cell line and 0.138microm in the BEL7402 liver cancer cell line, respectively.

3,3'-(1,3,5,7-Tetra-oxo-2,3,6,7-tetra-hydro-1H,5H-pyrrolo[3,4-f]isoindole-2,6-di-yl)dipropanoic acid N,N-dimethyl-formamide disolvate.

In the title compound, C(16)H(12)N(2)O(8)·2C(3)H(7)NO, the complete tricyclic compound is generated by a crystallographic centre of symmetry. In the crystal, the tricycle is linked to two adjacent N,N-dimethyl-formamide solvent mol-ecules by O-H⋯O hydrogen bonds.

[Study on release mechanism of berberine hydrochloride-loaded carboxymethyl konjac glucomannan pellets for colonic delivery].

OBJECTIVE: To study release mechanism of berberine hydrochloride (BH) from carboxymethyl konjac glucomannan pellets for colonic delivery. METHOD: The pellets were prepared by ionotropic gelation technique. The effects of the kinds of enzyme and enzyme concentration of dissolution media on the release of BH and the erosion properties of the pellets were studied. RESULT: Compared with the dissolution media without enzymes, the release of BH and the erosion of the pellets were increased obviously in the media with rat cecal and colonic content or beta-mannase, the degradation of the carrier material of pellets by enzymes was the main factor which result in the erosion of the pellets. With the increased of beta-mannase concentration, the release of BH and the erosion of the pellets increased, the amount relationships of the release of BH and the erosion of the pellets were approximately 1:1. The release of BH exhibit Peppas equation, the n value was more than 1. CONCLUSION: The release mechanism of BH from the pellets was enzymatic erosion-controlled, which indicates the potential of the pellets to serve as a colon-specific drug delivery system.

Tetra-kis[tris-(2,2'-bi-1H-benzimidazole)nickel(II)] bis-(phosphate) sulfate.

The title compound, [Ni(C(14)H(10)N(4))(3)](4)(PO(4))(2)(SO(4)), consists of [Ni(C(14)H(10)N(4))(3)](2+) complex cations (.3. symmetry) and disordered anions ( symmetry) with occupancy factors of two-thirds for PO(4) (3-) and one-third for SO(4) (2-). The Ni(2+) centre is chelated by three bidentate 2,2'-bi-1H-benzimidazole mol-ecules in a distorted octa-hedral coordination. N-H⋯O hydrogen bonds consolidate the building units into a framework structure.

catena-Poly[[bis-(3,5-dicarboxy-benzo-ato)cobalt(II)]-µ-4,4'-bipyridine].

In the title compound, [Co(C(9)H(5)O(6))(2)(C(10)H(8)N(2))](n), the asymmetric unit consists of one Co(2+) ion with site symmetry 2, one mono-deprotonated 1,3,5-benzene-tricarboxylic acid anion and one-half of a 4,4'-bipyridine (4,4'-bipy) mol-ecule, in which two N and two C atoms have site symmetry 2. In the crystal structure, the Co(2+) centre is coordinated by four O atoms from two bidentate carboxyl-ate groups of two anions and two N atoms of two 4,4'-bipy mol-ecules, resulting in infinite chains propagating in [010]. The cobalt coordination is distorted trans-CoO(4)N(2) octa-hedral and inter-chain O-H⋯O hydrogen bonds complete the structure.

8,9-Isopropyl-idenedi-oxy-3-p-tolyl-1,6-dioxa-3-aza-spiro-[4.5]decane-2,10-dione.

In the title compound, C(17)H(19)NO(6), which may serve as a ketone catalyst for the asymmetric epoxidation of olefins, the crystal packing is consolidated by C-H⋯O inter-actions.