Study on bioactivity of extracts from marine sponges in Chinese Sea

The bioactivity screening of fractions from two inter-tidal sponges collected from the north of China Yellow Sea and one sponge collected from the South Chinese Sea was reported in this study. In sponge Hymeniacidon perleve there were 9 fractions out of 15 from CHCl3 extract with anti Staphylococcus aureus activity, 9 fractions out of 19 from BuOH extract with anti Escherichia coli activity, and three fractions from CHCl3 extract which had moderate to strong activity in inhibiting Bacillus subtilis, Candida albicans, and Aspergilus niger. The fractions of Reniochalina sp. showed bioactivity against bacteria and fungi. The fractions of Acanthella acuta Schmidt showed bioactivity against S. aureus and fungi. One compound from H. perleve obtained by the bioactively directing isolation was tested for bioactivity against the human hepatoma cell line Qgy7701 (IC50 10.1 mug/ml), Burkitt's lymphoma cell line Raji (IC50 9.76 mug/ml) and chronic myelogenous leukemia K562 (IC50 1.90 mug/ml). (C) 2003 Elsevier B.V. All rights reserved.

Utilizing a CdTe quantum dots-enzyme hybrid system for the determination of both phenolic compounds and hydrogen peroxide

In this paper, we attempt to construct a simple and sensitive detection method for both phenolic compounds and hydrogen peroxide, with the successful combination of the unique property of quantum dots and the specificity of enzymatic reactions. In the presence Of H2O2 and horseradish peroxidase, phenolic compounds can quench quantum dots' photoluminescence efficiently, and the extent of quenching is severalfold to more than 100-fold increase. Quinone intermediates produced from the enzymatic catalyzed oxidation of phenolic compounds were believed to play the main role in the photoluminescence quenching.

Characterization of saccharides and phenolic acids in the Chinese herb Tanshen by ESI-FT-ICR-MS and HPLC

This study sought to determine the main components (saccharides and phenolic acids) in crude extract of the Chinese herb Tanshen by electrospray ionization Fourier transform ion cyclotron resonant mass spectrometry (ESI-FT-ICR-MS) in negative-ion mode. Eleven compounds were identified as phenolic acids by exact mass measurement and further confirmed by sustained off-resonance irradiation (SORI) CID data. In addition, monosaccharicles and oligosaccharides (n = 2 similar to 5) and a serial of corresponding anionic adducts of saccharide were observed without adding any anions additionally to the extract solution, and the anionic components were unambiguously identified as H2O, HCl, HCOOH, HNO3, C3H6O2, H2SO4 and C5H7NO3 according to the exact mass measurement results.

Analysis on Iridoid Glycosides in Crude and Processed Extracts from Cornus Officinals by Liquid Chromatography-electrospray Ionization Mass Spectrometry

The iridoid glycosides in crude and processed extracts from cornus officinals have been analyzed by high performance liquid chromatography-electrospray ionization mass spectrometry. Samples were analyzed by a reversed-phase C18 column using a binary eluent under gradient conditions. Seven iridoid glycosides could be separated and detected. The [M-H](-) ions of iridoid glycosides in the negative ion mode were observed, which reflect their molecule mass information. An in-source collision induced dissociation (in-source CID) experiment was carried out in order to identify the structures and to measure the contents of iridoid glycosides. The epimers were discovered in the experiment for the first time, namely 7 alpha-O-ethyl-morroniside and 7 beta-O-ethylmorroniside.

Characterization of triterpenoidic saponin mixture in crude extracts from leaves of Acanthopanax senticosus Harms by saponin structural correlation and mass spectrometry

Eighteen triterpenoidic saponins in crude extracts from leaves of Acanthopanax senticous Harms have been investigated by electrospray ionization multi-stage tandem mass spectrometry and high-resolution mass spectrometry. In ESI-MS spectra, predominant [M + Na](+) ions in the positive ion mode have been observed for molecular mass information. Meanwhile, specific structural correlations between these ions are firstly found. The 18 peaks (ions) can be classified into three groups (group D, E, and F with mass increase) with each group including six peaks. There is a mass difference of 132 Da between group D and E for each corresponding peak in turn (for example peak 1 to peak 7), indicating one more pentose residue was attached to saponins in group E than those corresponding in group D. The mass difference of 146 Da between group E and F implies one more deoxy-hexose attached to saponins in group F than those corresponding in group E. The structural correlations of the corresponding ions are confirmed by tandem mass spectrometry and high-re solution mass spectrometry. These structural features can not only facilitate the rapid characterization of the native known saponins in crude plant extracts, thus avoiding tedious derivation and separation of saponins, but also help find novel compounds of the same type in a specific medicinal plant.

The preparation of phenolic resin/montmorillonite nanocomposites by suspension condensation polymerization and their morphology

Phenolic resin/clay nanocomposites were prepared using a suspension condensation polymerization method that was suitable to both novolac and resole. Natural montmorillonite and two kinds of organic modified montmorillonite were adopted to investigate the effect of modification on the final morphology of the nanocomposites. X-ray diffraction (XRD) measurements and Transmission Electron Microscope (TEM) observations showed that clay platelets were easier to be exfoliated or intercalated in novolac than in resole because novolac usually has a linear structure. The modifier with a phenyl ring was more compatible with novolac (or resole) than the aliphatic type modifier. The influence of curing on the morphology was studied as well. An exfoliation-adsorption and in situ condensation mechanism was proposed on the formation of the nanocomposites.