[Levels distribution and risk assessment of the indicator and dioxin-like polychlorinated biphenyls in ten different species of marine fish of Bohai Bay, China].

Polychlorinated biphenyls (PCBs) are highly lipohilic compounds with high metabolic persistence and toxicity. PCBs tend to accumulate in the aquatic food chain and make fish a source of various environmental toxicants to humans. Industries in the Bohai Bay include iron and steel smelting, cement manufacturing and waste incineration, which are potential emission sources of PCBs. In this study, risks and potential effects of PCBs in the Bohai Bay were assessed. Twelve dioxin-like polychlorinated biphenyls (dl-PCBs) and seven indicator PCBs in marine fish samples were analyzed by High Resolution Gas Chromatography/High Resolution Mass Spectrometry (HRGC/HRMS). The concentrations of dl-PCBs in marine fishes ranged from 28.9 pg x g(-1) to 1067.6 pg x g(-1) wet weight. The concentrations of indicator PCBs were between 185.5 pg x g(-1) and 8 371.7 pg x g(-1) wet weight. PCB-118 and PCB-105 were the major congeners of the dl-PCBs congeners, which contributed 41% - 56% and 15% - 21%, respectively. The predominant indicator PCBs were PCB-153 and PCB-138, which contributed 27% and 22%, respectively. The concentrations of dl-PCBs and indicator PCBs were relatively low as compared with those in other studies.

Polyphenolic content and physiological activities of Chinese hawthorn extracts.

Hawthorn polyphenol (HP) was prepared by ethyl acetate treatment of the ethanol extract (HE) of Chinese hawthorn fruit. The concentrations of 15 polyphenols in the HP, HE, extraction residue (HJ), and a hawthorn leaf extract (HF) were determined by HPLC. For HP, the total content of the 15 polyphenols was 21.4%, comprised of 19.7% of procyanidins, 1.21% of chlorogenic acid, and 0.48% of flavonoids, compared to 2.55% for the HE. The yields of procyanidin monomer, dimer, trimer, tetramer, and pentamer were 50.5%, 30.3%, 23.0%, 14.6%, and 12.5% respectively, and the mean degree of polymerization was reduced to 1.39 (HP) from 1.65 (HE). Seven different physiological actions of the four extracts were investigated. The HP showed strong O(2)(-) and (.-)OH scavenging capacities (IC(50) values of 6.3 microg/ml and 1.1 microg/ml respectively), as well as selective prolyl endopeptidase inhibition (IC(50) of 60 microg/ml). The active constituents appeared to be procyanidins.

[Determination of Chinese traditional medicine activity eliminating superoxide anion radical by kinetics spectrophotometry].

A new method to determine Chinese traditional medicine activity eliminating superoxide anion radical by kinetic spectrophotometry was developed. It is shown that the optimum determination condition may be obtained when wavelength is 520 nm, the concentration of enzyme is 4 x 10(-3) microg x mL(-1), the reaction time is between 2-7 min. Vitamin C activity eliminating superoxide anion radical was determined under the condition, and the results were identical with literature. The method is used to determine IC50 of Cortex Magnoliae Officinalis and Cortex Eucommia, and they are 7.580 and 323.800 mg x L(-1) respectively.

[Determination of eliminating ratio of Chinese traditional medicine for hydroxyl radical by fluorescent spectrophotometry].

Benzoic acid with weak fluorescence may react on .OH, and products with intense fluorescence are made. Extractives of Chinese traditional medicine may eliminate .OH in solution, and make amounts of the products to reduce. Then, increase level of fluorescence of products in solution will be lowered. Based on this principle, a new method is developed to determine eliminating ratio of Chinese traditional medicine for .OH. It is shown that productivity of .OH tends to saturation when H2O2 is shown more than 20 min by 280 nm UV light; .OH may react on benzoic acid completely when molar ratio of H2O2 and benzoic acid is 30:1; linear response range of products fluorescence is 2.2-80 mmol.L-1 with concentration of H2O2. IC50 of elimination .OH with magnoliae and eucommia are 1.025 and 515.3 mg.L-1 respectively. There are no remarkable difference between these results and that of spectrophotometry.