Chemical properties and antioxidant activity of a water-soluble polysaccharide from Dendrobium officinale.

In this report, a water-soluble polysaccharide was obtained from the dried stems of Dendrobium officinale Kimura et Migo by hot-water (70-75°C) extraction and 85% ethanol precipitation, and successively purification by DEAE-cellulose anion-exchange chromatography and gel-permeation chromatography. The D. officinale polysaccharide (DOP) has a molecular weight of 8500Da. Monosaccharide composition analysis reveals that DOP is composed of mannose, glucose, and arabinose with a trace of galacturonic acid in a molar ratio of 6.2:2.3:2.1:0.1. Periodate oxidation-smith degradation and 1D and 2D NMR spectroscopy analysis suggest the predominance of mannose and glucose, and it contains a 2-O-acetylglucomannan and (1→4)-linked-ß-d-mannopyranosyl and (1→4)-linked-ß-d-glucopyranosyl residues. Atomic force microscope shows that DOP mainly exists as rod-shaped chains, supporting high degrees of polymerization. The antioxidant activities of the polysaccharide in vitro assay indicate that DOP has good scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, higher scavenging activity of hydroxyl radical, and metal chelating activities.

Effect of a novel synthesized sulfonamido-based gallate-SZNTC on chondrocytes metabolism in vitro.

The ideal therapeutic agent for treatment of osteoarthritis (OA) should have not only potent anti-inflammatory effect but also favorable biological properties to restore cartilage function. Gallic acid (GA) and its derivatives are anti-inflammatory agents reported to have an effect on OA (Singh et al., 2003) [1]. However, GA has much weaker antioxidant effects and inferior bioactivity compared with its derivatives. We modified GA with the introduction of sulfonamide to synthesize a novel sulfonamido-based gallate named sodium salt of 3,4,5-trihydroxy-N-[4-(thiazol-2-ylsulfamoyl)-phenyl]-benzamide (SZNTC) and analyzed its chondro-protective and pharmacological effects. Comparison of SZNTC with GA and sulfathiazole sodium (ST-Na) was also performed. Results showed that SZNTC could effectively inhibit the Interleukin-1 (IL-1)-mediated induction of metalloproteinase-1 (MMP-1) and MMP-3 and could induce the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1), which demonstrated ability to reduce the progression of OA. SZNTC can also exert chondro-protective effects by promoting cell proliferation and maintaining the phenotype of articular chondrocytes, as evidenced by improved cell growth, enhanced synthesis of cartilage specific markers such as aggrecan, collagen II and Sox9. Expression of the collagen I gene was effectively down-regulated, revealing the inhibition of chondrocytes dedifferentiation by SZNTC. Hypertrophy that may lead to chondrocyte ossification was also undetectable in SZNTC groups. The recommended dose of SZNTC ranges from 3.91µg/ml to 15.64µg/ml, among which the most profound response was observed with 7.82µg/ml. In contrast, its source products of GA and ST-Na have a weak effect in the bioactivity of chondrocytes, which indicated the significance of this modification. This study revealed SZNTC as a promising novel agent in the treatment of chondral and osteochondral lesions.

Novel function of N,N-bis(2-chloroethyl)docos-13-enamide for reversal of multidrug resistance in tongue cancer.

Multidrug resistance (MDR) is a key element in the failure of chemotherapies, and development of agents to overcome MDR is crucial to improving cancer treatments. The overexpression of glutathione-S-transferases (GSTs) is one of the major mechanisms of MDR. Because some agents used in traditional Chinese medicine have strong antitumor effects coupled with low toxicity; we investigated the ability of N,N-bis(2-chloroethyl)docos-13-enamide (compound J), the synthesized analog of a highly unsaturated fatty acid from Isatis tinctoria L., to reverse the MDR induced by adriamycin (ADM) in TCA8113/ADM cells. We found that compound J significantly increased the cytotoxicity of ADM in TCA8113/ADM cells, with a reversal fold of 2.461. Analysis of the mechanisms through which compound J reversed MDR indicated that compound J significantly decreased the activity of GSTs and enhanced the depletion of GSH in TCA8113/ADM cells, but did not affect the P-glycoprotein (P-gp) efflux. Taken together, our data suggested that compound J was an excellent candidate for reversing MDR in cancer therapy.

Synthesis and interaction of bovine serum albumin with p-hydroxybenzoic acid derivatives.

Three novel p-hydroxybenzoic acid derivatives (HSOP, HSOX, HSCP) were synthesized from p-hydroxybenzoic acid and sulfonamides (sulfamonomethoxine sodium, sulfamethoxazole and sulfachloropyridazine sodium) and characterized by elemental analysis, HNMR and MS. Interactions between derivatives and bovine serum albumin (BSA) were studied by fluorescence quenching spectra, UV-vis absorption spectra and time-resolved fluorescence spectra. Based on fluorescence quenching calculation and Förster's non-radioactive energy transfer theory, the values of the binding constants, basic thermodynamic parameters and binding distances were obtained. Experimental results indicated that the three derivatives had a strong ability to quench fluorescence from BSA and that the binding reactions of the derivatives with BSA were a static quenching process. Thermodynamic parameters showed that binding reactions were spontaneous and exothermic and hydrogen bond and van der Waals force were predominant intermolecular forces between the derivatives and BSA. Synchronous fluorescence spectra suggested that HSOX and HSCP had little effect on the microenvironment and conformation of BSA in the binding reactions but the microenvironments around tyrosine residues were disturbed and polarity around tyrosine residues increased in the presence of HSOP.

4-Hy-droxy-3,5-dimeth-oxy-N-{4-[(5-methyl-1,2-oxazol-3-yl)sulfamo-yl]phen-yl}benzamide methanol monosolvate.

The title compound, C(19)H(19)N(3)O(7)S·CH(3)OH, was synthesized from syringic acid and sulfamethoxazole. The benzene rings make a dihedral angle of 41.8 (1)° and the isoxazole ring is twisted by 74.3 (1)° from the central benzene ring. The crystal packing features O-H⋯O and O-H⋯N hydrogen bonds in which the hy-droxy groups from the main mol-ecule and methanol solvent mol-ecules serve as donor groups.

(E)-Methyl 3-(3,4-dihy-droxy-phen-yl)acrylate.

The benzene ring in the title compound, C(10)H(10)O(4), makes an angle of 4.4 (1)° with the C-C-C-O linker. The hy-droxy groups are involved in both intra- and inter-molecular O-H⋯O hydrogen bonds. The crystal packing is stabilized by O-H⋯O hydrogen-bonding inter-actions. The mol-ecules of the caffeic acid ester form a dimeric structure in a head-to-head manner along the a axis through O-H⋯O hydrogen bonds. The dimers inter-act with one another through O-H⋯O hydrogen bonds, forming supermolecular chains. These chains are further extended through C-H⋯O hydrogen bonds as well as van der Waals inter-actions into the final three-dimensional architecture.

catena-Poly[[[diaqua-sodium]-di-µ-aqua] 2-(2-pyrid-yl)quinoline-4-carboxyl-ate].

In the title compound, [Na(H(2)O)(4)](C(15)H(9)N(2)O(2)), the Na(+) ion is coordinated by six water mol-ecules in an octa-hedral geometry. The NaO(6) octa-hedra are connected by sharing edges, forming a cationic chain along the b-axis direction. O-H⋯O and O-H⋯N hydrogen bonds link the chains and the 2-(2-pyrid-yl)quinoline-4-carboxyl-ate anions into a two-dimensional network parallel to (100).

[Orthogonal experiment of the extraction of triterpenoids from stems of Hyptis suaveolens with microwave].

OBJECTIVE: To study the best technology of the extraction of triterpenoids from the stems of Hyptis suaveolens with microwave. METHODS: Orthogonal experiment was carried out to investigate 4 influential factors as follows: the time (A), the temperature (B), the solid fluid compared to (C), the NaOH density (D). RESULTS: The optimal conditions for microwave extraction were A1 B2 C3 D2. CONCLUSION: The microwave extraction can extract more triterpenoids from the stems of Hyptis suaveolens in shorter time with less energy. It also shows a promising prospect for leaching the effective constituents from Chinese herbal medicine by using microwave extraction.

Bis[3-chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinato-κO,N,N']copper(II) tetra-hydrate.

In the title complex, [Cu(C(11)H(9)ClN(3)O(2))(2)]·4H(2)O, the Cu(II) atom is in a distorted octa-hedral coordination environment, coordinated by four N atoms and two O atoms from two tridentate 3-chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinate ligands. The mol-ecules are linked via inter-molecular O-H⋯O hydrogen bonds involving water mol-ecules to form extended chains along [010], and there are short Cl⋯Cl contacts [3.153 (4) Å].

Nitrato(1,10-phenanthroline)(1H-1,2,4-triazole-3-carboxyl-ato)copper(II).

In the title complex, [Cu(C(3)H(2)N(3)O(2))(NO(3))(C(12)H(8)N(2))], the Cu(II) ion is coordinated by an N and an O atom from a bidentate 1H-1,2,4-triazole-3-carboxyl-ate (TRIA) ligand, two N atoms from a 1,10-phenanthroline (phen) ligand, and an O atom from a nitrate ligand in a slightly distorted square-pyramidal environment. In the crystal structure, inter-molecular N-H⋯O hydrogen bonds link mol-ecules into one-dimensional chains propagating along the b axis direction.

Tris[6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinato]gadolinium(III) methanol hemisolvate 2.5-hydrate.

In the title complex, [Gd(C(11)H(10)N(3)O(2))(3)]·0.5CH(4)O·2.5H(2)O, the Gd atom is coordinated by six N atoms and three O atoms derived from three tridentate monoanionic 6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinate ligands. The mol-ecules are linked together via hydrogen bonds involving the solvent water and methanol mol-ecules.

Diaqua-bis[6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinato-κN,N',O](nitrato-κO,O')lanthanum(III) monohydrate.

In the title complex, [La(C(11)H(10)N(3)O(2))(2)(NO(3))(H(2)O)(2)]·H(2)O, the La atom is coordinated by four N atoms and six O atoms derived from two 6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinate ligands, one nitrate anion and two water mol-ecules. The mol-ecules are linked together via hydrogen bonds involving the water mol-ecules, forming a three-dimensional network.

Aqua-tris[6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinato]-κN,N',O;κO-dysprosium(III) trihydrate.

In the title complex, [Dy(C(11)H(10)N(3)O(2))(3)(H(2)O)]·3H(2)O, the Dy(III) atom is coordinated by four N atoms and four O atoms derived from three tridentate deprotonated 6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinate ligands and one water mol-ecule. The complex and solvent water mol-ecules are linked together via O-H⋯O, O-H⋯N, C-H⋯O and C-H⋯π hydrogen-bonding inter-actions, forming a three-dimensional network structure.

Bis[6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinato-κN,O]cadmium(II) 1.75-hydrate.

In the title complex, [Cd(C(11)H(10)N(3)O(2))(2)]·1.75H(2)O, the Cd atom is coordinated by four N atoms and two O atoms from two tridentate 6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinate ligands in a distorted cis-N(4)O(2) octa-hedral geometry. Three water mol-ecules, with occupancies of 1.0, 0.5 and 0.25, complete the asymmetric unit. The components of the crystal structure are linked via hydrogen bonds, forming a three-dimensional network.

3,6-Dichloro-N-(4,6-dichloro-pyrimidin-2-yl)picolinamide.

In the title compound, C(10)H(4)Cl(4)N(4)O, the pyridine and pyrimidine rings are nearly perpendicular to each other, the dihedral angle between them being 86.60 (10)°. In the crystal structure, the N and O atoms in the amide group are involved in inter-molecular hydrogen bonds, forming a one-dimensional chain along the c axis.

3ß-Hydroxy-friedelan-17ß-carboxylic acid.

The title compound, C(30)H(50)O(3), which was isolated from a marine endophytic fungus, is a new friedelan derivative. The mol-ecule contains five six-membered rings, which exhibit boat (ring A), distorted boat (ring B) and chair (rings C-E) conformations. The crystal structure is stabilized by inter-molecular O-H⋯O hydrogen bonds, which link neighbouring mol-ecules into 12-membered rings.

[6-(3,5-Dimethyl-1H-pyrazol-1-yl)picolinato](pyridine-2,6-dicarboxyl-ato)copper(II) dihydrate.

In the title complex, [Cu(C(7)H(4)NO(4))(C(11)H(10)N(3)O(2))]·2H(2)O, the Cu(II) atom is in a distorted octa-hedral geometry. The equatorial plane is formed by two N atoms and one O atom from 6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinate and by one N atom from pyridine-2,6-dicarboxyl-ate (pdc). Two pdc O atoms occupy the axial positions. Water mol-ecules are hydrogen bonded to the complex mol-ecules, forming a two-dimensional sheet structure.

Bis[6-(3,5-dimethyl-1H-pyrazol-1-yl-κN)picolinato-κN,O]manganese(II) bis-(3,5-dinitro-benzoic acid) solvate.

In the title complex, [Mn(C(11)H(10)N(3)O(2))(2)]·2C(7)H(4)N(2)O(6), the Mn(II) atom has a disorted octa-hedral coordination formed by four N and two O atoms of two mer-6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinate ligands (DMPP). Each of the two symmetry-independent 3,5-dinitro-benzoic acid mol-ecules is linked to the mol-ecule of the complex via a hydrogen bond involving its carboxylic H atom and one of the DMPP ligands of the complex. However, in one of the DMPP ligands, the non-coordinated carbonyl O atom serves as the hydrogen-bond acceptor, whereas in the second ligand it is the Mn-coordinated O atom which is involved in the hydrogen bonding.

(3,6-Dichloro-pyridin-2-yl)(3,5-dimethyl-1H-pyrazol-1-yl)methanone.

In the crystal structure of the title compound, C(11)H(9)Cl(2)N(3)O, mol-ecules are held together by short inter-molecular Cl⋯Cl contacts [3.319 (1) Å] and C-H⋯N hydrogen bonds, forming two-dimensional networks parallel to (01).