Sensitive and selective detection of uracil-DNA glycosylase activity with a new pyridinium luminescent switch-on molecular probe.

Uracil-deoxyribonucleic acid glycosylase (UDG) is known to function as an important base-excision repair enzyme and eliminate uracil from DNA molecules to maintain genomic integrity. A new small organic molecule (DID-VP) with interesting structural properties was synthesized as a G-quadruplex selective ligand and was demonstrated to be a sensitive luminescent switch-on probe in a convenient luminescent assay specifically for UDG detection in fetal bovine serum samples under rapid and simple conditions. This newly developed analytical method is based on the UDG enzymatic activity to unwind a duplex DNA substrate, and comprises a G-quadruplex-forming sequence (ON1) and uracil-containing DNA strand (ON2) to generate a remarkable fluorescence signal through the specific interaction of DID-VP with ON1. This luminescent switch-on assay is able to achieve high sensitivity and specificity for UDG over other enzymes. The application range of the present analytical system is found to be 0.05 to 1.00 U mL(-1) UDG with a very low detection limit of 0.005 U mL(-1). The recovery study of UDG in real samples gave a very good performance with 75.05%-102.7% recovery. In addition, an extended application of the assay in screening of UDG inhibitors is demonstrated. A good dose-dependence of the luminescence response with respect to the concentration of UDG inhibitors in samples was observed.

1,4-Bis[4-(meth-oxy-carbon-yl)benz-yl]-1H-1,2,4-triazol-4-ium bromide.

In the title salt, C(20)H(20)N(3)O(4) (+)·Br(-), the dihedral angle between the benzene rings is 8.69 (16)°, and those between the benzene rings and the triazole ring are 69.98 (18) and 72.17 (18)°. In the crystal, C-H⋯Br hydrogen bonds link the cations and anions into chains along the c axis.

New 3',8''-linked biflavonoids from Selaginella uncinata displaying protective effect against anoxia.

Seven 3',8''-linked bioflavonoids, including one new compound, (2''S)-2'', 3''-dihydroamentoflavone-4'-methyl ether and six known compounds: (2S)-2,3- dihydroamentoflavone-4'-methyl ether, (2S,2''S)-2,3,2'',3''-tetrahydroamento- flavone-4'-methyl ether, (2S,2''S)-tetrahydroamentoflavone, (2S)-2,3-dihydro- amentoflavone and (2''S)-2'',3''-dihydroamentoflavone (6) and amentoflavone, were isolated from the 60% ethanolic extract of Selaginella uncinata (Desv.) Spring. The structures of these compounds were elucidated mainly by analysis of their 1D and 2D NMR spectroscopic data, and their absolute configurations were determined by circular-dichroism (CD) spectroscopy. All the seven compounds showed protective effect against anoxia in the anoxic PC12 cells assay, in which compound 6 displayed particularly potent activity.

1,3-Bis[4-(meth-oxy-carbon-yl)benz-yl]benzimidazolium bromide monohydrate.

In the title compound, C(25)H(23)N(2)O(4) (+)·Br(-)·H(2)O, the dihedral angles between the benzimidazole ring system and the two benzene rings are 87.77 (11) and 63.05 (11)°; the dihedral angle between the two benzene rings is 66.25 (13)°. The crystal structure exhibits C-H⋯O and O-H⋯Br inter-actions; it is also stabilized by π-π stacking inter-actions, with a face-to-face separation of 3.456 Šbetween parallel benzimidazole ring systems.

(3E,5E)-3,5-Bis(4-hy-droxy-3,5-di-methoxy-benzyl-idene)oxan-4-one monohydrate.

In the title compound, C(23)H(24)O(8)·H(2)O, the six-membered ring of the oxan-4-one (tetra-hydro-pyran-4-one) ring displays an envelope conformation with the heterocyclic O atom at the flap position. The dihedral angles between the terminal benzene rings is 37.23 (10)°. Classical intermolecular O-H⋯O and weak C-H⋯O hydrogen bonds are present in the crystal structure.

Methyl 4-bromo-3-hy-droxy-benzoate.

In the title compound, C(8)H(7)BrO(3), the meth-oxy-carbonyl group is twisted at a dihedral angle of 8.06 (4)° with respect to the benzene ring. In the crystal, mol-ecules are connected by O-H⋯O hydrogen bonds into helical chains running along the b axis.

(3E,5E)-3,5-Bis(4-hy-droxy-benzyl-idene)oxan-4-one.

In the title compound, C(19)H(16)O(4), there are two 4-hy-droxy-benzyl substituents on the oxan-4-one (tetra-hydro-pyran-4-one) ring, which exhibits an envelope conformation. The dihedral angles between pyran-one ring and the two benzene rings are 26.69 (9) and 36.01 (9)° while the benzene rings make a dihedral angle of 20.88 (10)°. In the crystal, mol-ecules are linked by inter-molecular O-H⋯O hydrogen bonds into a supra-molecular three-dimensional twofold inter-penetrating hydrogen-bonded network.

[The determination of three effective constituents in wild and cultivated Gastrodia elata from Bomi].

OBJECTIVE: To determine the contents of gastrodin, amino acids and total flavonoids in wild and cultivated Gastrodia elata, in order to choose the best method for its cultivation. The Gastrodia elata was picked at Guxiang town Bomi county Linzhi Region in Tibet. METHODS: HPLC was used to determine the content of gastrodin. The autoanalyzer was used to determine the content of amino acid. The ultraviolet spectrophotometer was adopted to measure the content of total flavonoids. RESULTS: The Gastrodin in wild Gastrodia elata was the highest. The contents of amino acids and total flavonoids in organic cultivated Gastrodia elata were higher than those in common cultivated and wild Gastrodia elata. CONCLUSION: The organic cultivated Gastrodia elata has better quality.

3-[(R)-3,3-Dichloro-2-hydroxy-prop-yl]-8-hydr-oxy-6-meth-oxy-1H-isochromen-1-one.

The title compound, C(13)H(12)Cl(2)O(5), is an isocoumarin compound which has been isolated from the ethyl acetate extract of the fermentation broth of actinomycete Streptomyces sp. (V(4)) from the South China Sea. There are intra- and inter-molecular hydrogen bonds and halogen bonds [Cl⋯Cl = 3.434 (2) Å; C-Cl⋯Cl = 121.6°]. The intermolecular O-H⋯O hydrogen bonds link mol-ecules into chains along the b axis.

5-Hydr-oxy-1-methyl-3,4-dihydro-2H-pyrrolium hydrogensulfate.

The title compound, C(5)H(10)NO(+)·HSO(4) (-), has been synthesized by reaction of 1-methyl-pyrrolidin-2-one with H(2)SO(4) in a 1:1 molar ratio. The substituted pyrrolium ring adopts an envelope conformation. The hydrogensulfate anions form infinite helical chains parallel to the a axis via strong O-H⋯O hydrogen bonds. The pyrrolium cations are pendant from the chains. These cations are the hydrogen donors in the strong O-H⋯O hydrogen bonds to the hydrogensulfates. In addition, there are weak C-H⋯O hydrogen bonds in the structure.

[Inhibition of extracts from Synotis erythropappa on tyrosinase].

OBJECTIVE: To study the inhibition of extracts from Synotis erythropappa on tyrosinase. METHODS: The 70% ethanol extracts were extracted by petroleum benzine, ethyl acetate and n-butanol, and the inhibitory activities against tyrosinase of every fraction were determined in vitro and the inhibitory kinetics of ethyl acetate and n-butanol fractions were investigated. RESULTS: The four fractions extracted all had inhibitory activities on tyrosinase, inhibitory activities of ethyl acetate and n-butanol fraction were higher. Their IC50 were 57.8, 140 microg/ml for monophenol oxidase activity and 41.2, 59.6 microg/ml for diphenol oxidase activity, respectively. The inhibition kinetics analyzed by Hnewaver-Burk plots showed that ethyl acetate fraction was a competitive type inhibitor, and its Ki was determined to be 19.7 microg/ml. n-butanol fraction was an uncompetitive type inhibitor, and its Ki was determined to be 60.7 microg/ml. CONCLUSION: Ethyl acetate and n-butanol fractions of extracts from Synotis erythropappa show potential inhibitory activity on tyrosinase.

Aromatic-turmerone ameliorates imiquimod-induced psoriasis-like inflammation of BALB/c mice.

Psoriasis is a usual immune-mediated inflammatory skin disease with undefined pathogenesis. Aromatic-turmerone (ATM) is a mainly constituent of essential oil from Curcuma longa L. It has been shown to exhibit strong anti-oxidant, anti-tumor activities and anti-inflammatory effects. In this study, we investigated the effects of ATM on imiquimod (IMQ)-induced psoriasis-like BALB/c mice and its molecular mechanisms for anti-inflammatory effect. ATM showed inhibition of the transfer of CD8+ T cells in epidermis, and reduced expression of NF-κB and COX-2 as well as phosphorylation of p38 MAPK. It also decreased the level of TNF-α and IL-6, and down-regulates IL-17 IL-22 and IL-23 mRNA synthesis. Notably, we demonstrated that topically applied ATM alleviated skin inflammation in IMQ-induced mice. These results indicate that ATM, a natural active compound exhibits anti-inflammatory activity and is a promising candidate molecule to treat inflammatory skin diseases, such as psoriasis.

[Extraction and anti-tumor activity study of polysaccharide in several traditional Chinese medicine].

Polysaccharides in Several traditional Chinese medicine compounds of Dioscorea bulbifera L, Dioscorea bulbifera L and Chinese Angelica compounds (3: 2 by mass ratio), Hedyotis diffusa Willd and Scutellrla barbata D. Don compounds (3: 2 by mass ratio) were extracted by ultrasound and the content of polysaccharides were determined by the colorimetry. Dioscorea bulbifera L and Chinese Angelica compounds contained the biggest polysaccharide, 16. 509%. All of these three kinds of polysaccharide had anti-tumor activity. The anti-tumor activity was Dioscorea bulbifera L and Chinese Angelica compounds > Hedyotis diffusa Willd and Scutellrla barbata D. Don compounds > Dioscorea bubifera L.

A molecular fluorescent dye for specific staining and imaging of RNA in live cells: a novel ligand integration from classical thiazole orange and styryl compounds.

A new RNA-selective fluorescent dye integrated with a thiazole orange and a p-(methylthio)styryl moiety shows better nucleolus RNA staining and imaging performance in live cells than the commercial stains. It also exhibits excellent photostability, cell tolerance, and counterstain compatibility with 4',6-diamidino-2-phenylindole for specific RNA-DNA colocalization in bioassays.

[Study on the synthesis and spectra of 2-thenoyl-2-carbazolyl-N-butyltrifluoroacetone].

In phene-50% NaOH medium, 1,4-dibromobutane reacts with carbazole (CZ) to form N-bromobutylcarbaole (BCZ) at 70-80 degrees C. The 2-thenoyl-2-carbazolyl-N-butyltrifluoroacetone (TCBTA) was synthesized by reaction of BCZ with 2-thenoyltrifluoroacetone (TTA) in acetone-K2CO3 medium at 50 degrees C. The TCBTA is a light brown crystal with m.p. of 211-214 degrees C. The structure of the synthesized TCBTA was characterized by UV, IR and GC/MS, and the UV and IR spectra of CZ, BCZ and TTA have been studied. In chloroform, TCBTA has three maximum absorptions at 241, 265 and 295 nm whose molar absorptivity is 1.88 x 10(5), 1.25 x 10(5) and 1.08 x 10(5) L x mol(-1) x cm(-1), respectively. Extraction rate of iron(III) and neodymium(III) by TCBTA in chloroform rises by 3 and 1.6 times compared with TTA. The fluorescence of TCBTA-Nd(III) complex is 5 times higher than TTA-Nd(III) complex. It was shown that TCBTA has excellent photosensitivity.

[Studies on the chemical constituents of Chinese herb Melastoma dodecandrum].

OBJECTIVE: To investigate the chemical constituents of Chinese herb Melastoma dodecandrum. METHOD: The chemical constituents were isolated by solvent extraction and chromatography. Their structure were identified on the basis of physic-chemical constants and specral data. RESULT: Five compounds were isolated and identified as hexacosanoic acid (I), quercetin(II), avicularin(III), gallic acid (IV), kaempferol(V). CONCLUSION: The above-mentioned compounds were separated from the plant for the first time.