[A new quinoline alkaloid from Scolopendra subspinipes mutilans].

Three compounds, including scolosprine C(1), uracil(2) and hypoxanthine(3), were isolated and purified from the ethyl acetate fraction of centipede by silica gel normal-phase column chromatography, reversed-phase medium pressure preparation chromatography, and high-pressure semi-preparative HPLC. The structure was elucidated through a combination of spectroscopic analyses [such as nuclear magnetic resonance(NMR) and mass spectrometry(MS)] and literature review. Among them, compound 1 was a new quinoline alkaloid. In previous reports, we have described the isolation and structure elucidation of one new and two known quinoline alkaloids. In this paper, we would report the isolation and structure elucidation of scolosprine C in detail.

[Simultaneous determination of eight iridoid glycosides in Gardeniae fructus by HPLC].

OBJECTIVE: To establish an HPLC method for simultaneous determination of eight iridiods in Gardeniae Fructus. METHOD: Kromasil C18 column (4. 6 mm x 250 mm, 5 microm) was adopted, with acetonitrile-water-trifluoroacetic acid (6:94: 0.05) as the mobile phase at the flow rate of 1.0 mL x min(-1). The detection wavelength was set at 238 nm, and the column temperature was 40 degrees C. RESULT: The linear ranges of geniposide, gardoside, shanzhiside, geniposidic acid, deacetyl asperulosidic acid methyl ester, gardenoside, scandoside methyl ester, and genipin gentiobioside were 1.5036 - 15.036, 0.04256 - 0.4256, 0.1038 - 1.038, 0.00992 - 0.0992, 0.02332 - 0.2332, 0.4128 - 4.128, 0.02040 - 0.2040 and 0.4656 - 4.656 microg, respectively. Their average recoveries were 99.6% , 100.6% , 101.2%, 99.5%, 100.3% , 98.7%, 99.8% and 100.1%, respectively. CONCLUSION: The method shows good separation and it is so simple, accurate and highly repeatable that it can be used for providing basis for quality control of Gardeniae Fructus.

Markedly controllable adhesion of superhydrophobic spongelike nanostructure TiO2 films.

A simple electrochemical and self-assembly method was adopted for the fabrication of superhydrophobic spongelike nanostructured TiO2 surfaces with markedly controllable adhesion. Water adhesion ranging from ultralow (5.0 microN) to very high (76.6 microN) can be tuned through adjusting the nitro cellulose dosage concentrations. The detailed experiments and analyses have indicated that the significant increase of adhesion by introducing nitrocellulose is ascribed to the combination of hydrogen bonding between the nitro groups and the hydroxyl groups at the solid/liquid interfaces and the disruption of the densely packed hydrophobic 1H,1H,2H,2H-perfluorooctyltriethoxysilane (PTES) molecule. A mechanism has been proposed to explain the formation of superhydrophobic TiO2 films with distinct adhesion.

Some critical structure factors of titanium oxide nanotube array in its photocatalytic activity.

A highly ordered TiO2 nanotube array on Ti substrate was fabricated by using an electrochemical anodic oxidation method. The morphology, crystalline phase, and photoelectrochemical property of the nanotube array were characterized. The photocatalytic activity of the nanotube array was evaluated by the decolorization of methyl orange in aqueous solution using the different light sources. The effects of structure and morphology of the nanotube array on its photocatalytic activity were investigated. It was found that the photoabsorption behavior of the TiO2 nanotube film depended on the structures of the nanotube array. The nanotube array films exhibited a drastically enhanced photocurrent, and a higher photocatalytic activity compared with the TiO2 nanoparticle film prepared by the regular sol-gel method. The experimental results indicated that the film thickness markedly influenced the photocatalytic activity of nanotube array film, and the 2.5 microm-thick TiO2 nanotube array film appeared a maximum photodegradation efficiency to methyl orange. However, for a given nanotube length, the tube diameter was only very slightly affected the photocatalytic efficiency in this work. The explanation for some critical structure factors of TiO2 nanotube array in the photocatalytic activity was discussed as well.