Three-dimensional networks in the 1:2 organic salts 2,2'-biimidazolium bis(3-carboxy-4-hydroxybenzenesulfonate) and 2,2'-bibenzimidazolium bis(3-carboxy-4-hydroxybenzenesulfonate) trihydrate.

The two title compounds of 2,2'-biimidazole (Bim) with 5-sulfosalicylic acid (5-H(2)SSA) and 2,2'-bibenzimidazole (Bbim) with 5-H(2)SSA are 1:2 organic salts, viz. C(6)H(8)N(4)(2+).2C(7)H(5)O(6)S(-), (I), and C(14)H(12)N(4)(2+).2C(7)H(5)O(6)S(-).3H(2)O, (II). The cation of compound (I) lies on a centre of inversion, whereas that of (II) lies on a twofold axis. Whilst compound (I) is anhydrous, three water molecules are incorporated into the crystal structure of (II). The substitution of imidazole H atoms by other chemical groups may favour the incorporation of water molecules into the crystal structure. In both compounds, the component cations and anions adopt a homogeneous arrangement, forming alternating cation and anion layers which run parallel to the (001) plane in (I) and to the (100) plane in (II). By a combination of N-H...O, O-H...O and C-H...O hydrogen bonds, the ions in both compounds are linked into three-dimensional networks. In addition, pi-pi interactions are observed between symmetry-related benzene rings of Bbim(2+) cations in (II).

Hydrogen-bonded layers in the 1:2 cocrystal of 2,2'-dithiodibenzoic acid with isonicotinohydrazide.

Cocrystallization of 2,2'-dithiodibenzoic acid with isonicotinohydrazide from methanol solution yields the 1:2 cocrystal 2,2'-dithiodibenzoic acid-isonicotinohydrazide (1/2), C(14)H(10)O(4)S(2) x 2 C(6)H(7)N(3)O. The component molecules are linked by intermolecular O-H...N, N-H...O, N-H...N and C-H...O hydrogen bonds into layers running parallel to the (010) plane, and these layers are further linked into a three-dimensional framework structure by means of weak aromatic pi-pi stacking interactions. As a potential cocrystallization agent, isonicotinohydrazide may be used for effective and versatile synthetic supramolecular strategies utilizing hydrogen bonding of specific molecular building blocks.

2,2'-(Imino-dimethyl-ene)dibenz-imid-azol-ium bis-(perchlorate) methanol solvate.

In the title compound, C(16)H(17)N(5) (2+)·2ClO(4) (-)·CH(3)OH, the dihedral angle between the two benzimidazolium ring systems is 34.6 (1)°. The anions and solvent mol-ecules are linked to the cation by N-H⋯O hydrogen bonds. In the crystal structure, the combination of N-H⋯O and O-H⋯O hydrogen bonds results in two-dimensional layers running parallel to the (010) plane; these are in turn linked by π-π inter-actions, forming a three-dimensional network.

[Effect of podophyllotoxin on human gastric cancer cell line SGC 7901].

OBJECTIVE: To investigate the effect of podophyllotoxin on human gastric cancer cell line SGC 7901 cells in vitro and in vivo, and to provide evidence for treatment of gastric cancer with podophyllotoxin. METHODS: SGC 7901 cells were treated with podophyllotoxin at various concentrations for different time. MTT assay, colony formation assay, and flow cytometry were performed to determine the effect of podophyllotoxin on the growth and apoptosis of SGC 7901 cells in vitro. Furthermore, xenograft experiment was performed to detect the effect of podophyllotoxin on the in vivo tumorigenicity of SGC 7901 cells. RESULTS: Podophyllotoxin inhibited the growth of SGC 7901 cells in a concentration- and time-dependent manner, decreased the colony formation rate of the cells, induced SGC 7901 cell apoptosis, arrested SGC 7901 cells at G2/M phases of cell cycle, and decreased the volume and weight of SGC 7901 cell xenografts in nude mice. CONCLUSION: Podophyllotoxin inhibits the growth of human gastric cancer SGC 7901 cells, induce the apoptosis of SGC 7901 cells in vitro, and inhibit the in vivo tumorigenicity of SGC 7901 cells, which provides evidence for treatment of gastric cancer using podophyllotoxin.

Two salts of 5-sulfosalicylic acid and 3-aminopyridine.

5-Sulfosalicylic acid (5-SSA) and 3-aminopyridine (3-APy) crystallize in the same solvent system, resulting in two kinds of 1:1 proton-transfer organic adduct, namely 3-aminopyridinium 3-carboxy-4-hydroxybenzenesulfonate monohydrate, C(5)H(7)N(2)(+).C(7)H(5)O(6)S(-).H(2)O or 3-APy.5-SSA.H(2)O, (I), and the anhydrous adduct, C(5)H(7)N(2)(+).C(7)H(5)O(6)S(-) or 3-APy.5-SSA, (II). Both compounds have extensively hydrogen-bonded three-dimensional layered polymer structures, with interlayer homo- and heterogeneous pi-pi interactions in (I) and (II), respectively.

[Study on adsorption of tea polyphenol and caffine with polyamide resin].

The performance of adsorption of tea polyphenol and caffine with polyamide resin was investigated. The results obtained by spectrophotometry and HPLC show that the ability of adsorption of tea polyphenol with polyamide is stronger than that of caffine, in which hydrogen bond plays a very important role. The adsorption amount of caffine is 2.65 mg.g-1 with 7.5% adsorption ratio when 100 mL of 0.71 g.L-1 caffine is adsorbed on polyamide resine, but the adsorption amount of tea polyphenol is up to 148.13 mg.g-1 with 85% adsorption ratio when 700 mL of 1.98 g.L-1 tea polyphenol is adsorbed on polyamide resine. The dilution ratios of caffine and tea polyphenol are 74% and 90%, respectively, when they are diluted by 85% alcohol. The static adsorptions of caffine and tea polyphenol on polyamide resine reach equilibrium quickly in 80 min, and the plots of adsorption kinetics are nearly linear. Tea polyphenol and caffine are successfully separated on polyamide resine, and the obtained product contains more than 96% of tea polyphenol and 80% of EGCC with caffine less than 2.8%.

[Study on optimizing the analysis condition for active compound in Eucommia olive].

The absorption spectroscopic determination of aucubin by condensation with p-dimethylaminobenzaldehyde was optimized in this paper. A high sensitive method was established and the linearity range of the method was from 4.5 to 45 microg x mL(-1). The influences of the factors, such as the dosage of coloring agent, reaction time, heating temperature and the dose of acid etc., on the system were studied. And the result indicated that all of the factors had obvious effects on the system. The method has been applied to determining the content of aucubin in the extract of Eucommia olive with satisfactory results.

[Pharmacognostic identification of Cryptolepis buchanaii].

OBJECTIVE: To supply basis for the establishment of quality standard of Cryptolepis buchanaii. METHOD: Characters of crude drugs, microscopic characteristic as well as UV spectrum of the herb were studied. RESULT: Laticifers were found in the cortex and pith of the stem; much papillary non-glandular hair was found covering the stomata in the sub-cuticle of the leaf. CONCLUSION: The results can be employed as the basis for identifying the herb.

[Study on technology of extracting geniposidic acid from Eucommia ulmiodes and its application].

OBJECTIVE: To study the optimum technology of extracting bioactive component named geniposidic acid in Eucommia Ulmiodes by orthogonal test. METHOD: An orthogonal test table L16(4(5)) was used with the factors of extracting time, temperature, times, ethanol consistency and the ratio of solid to liquid. The content of geniposideic acid was determined by RP-HPLC. RESULT: The optimum technology was: temperature 50 degrees C, time 1 h, once, consistency 80%, and the ratio of solid and liquid 1:12. Under the condition, the best material of Eucommia Ulmiodes for extracting geniposidic acid was chosen. CONCLUSION: The technology can provide some theoretic advice for industry.