Investigation on PAHs in agricultural soils in Dongguan, South China were conducted. A total of 59 agricultural soil samples were collected from sites representative of the region for analysis of contents of 16 PAHs. Results show that 13 PAHs were detected with detectable ratios above 90%, Fie, Phe, Chr and Bbf were detected in all 59 samples, the detectable ratio of Ant was the lowest (13.56%). Sigma PAHs in soil samples is ranged from 29 to 2184 mug/kg, and 44.07%, 8.47% and 3.39% soil samples were slightly, moderately and heavily polluted by PAHs, respectively. Compared with other regions, Dongguan city is higher in soil PAHs contents, which can be confirmed that the increase of PAHs in agricultural soils is connected with human activities closely. Principal component analvsis demonstrate that the above-said 16 PAHs in agricultural soils may have three major contributors, corresponding to biomass burning, volatilization of oil production, and coal burning respectively. It is found that environmental factors (temperature, humidity), soil characters (pH, organic materials) and other pollutants (heavy metals) can affect environmental behaviors of PAHs. By means of ordinary Kriging interpolation, spatial distribution of 16 PAHs were studied. The results indicate that 16 PAHs vary greatly in spatial distribution between types, PAHs contents in west-north soils are much higher than that in south-east soils, and the highest PAHs contents area is in Wangniudun town, which hint that there are some pollutant sources connected with poisonous wastes combustion.
Ursolic acid(UA,3beta-hydroxy-urs-12-en-28-oic acid),a pentacyclic triterpene compound, exists abundantly in the plant kingdom as the major constituent of medicinal herbs. UA has been reported to display a remarkable spectrum of biochemical activities to influence processes capable of controlling cancer development. The pleuripotent anti-tumor activities of UA have stimulated the experts to research actively in this field. This paper summarizes the modification and pharmacological activity of ursolic acid derivatives according to literature and reports both at home and abroad熊果酸(UA,3beta-羟基-乌苏烷型-12-烯-28-羧酸),五环三萜化合物,作为药草的主要成分,存在于丰富的植物王国中.据报道,UA具有广 谱的生物活性,调控和控制肿瘤细胞形成.UA多效性的抗肿瘤活性激发了专家们在这方面的积极研究,现综合国内外文献报道,对熊果酸结构修饰物及其药理活性 进行综述
Persistent organic pollutants (POPs) have been associated with a wide range of adverse health effects. Our case-control study was performed to explore the association between placental levels of selected POPs and risks for neural tube defects (NTDs) in a Chinese population with a high prevalence of NTDs. Cases included 80 fetuses or newborns with NTDs, whereas the controls were 50 healthy, nonmalformed newborn infants. Placental concentrations of polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides, polychlorinated biphenyls, and polybrominated diphenyl ethers were analyzed by gas chromatography-mass spectrometry. The medians of PAHs, o,p'-isomers of dichlorodiphenyltrichloroethane (DDT) and metabolites, alpha- and gamma-hexachlorocyclohexane (HCH), and alpha-endosulfan were significantly higher in case placentas than in controls. PAH concentrations above the median were associated with a 4.52-fold (95% confidence interval (CI), 2.10-9.74) increased risk for any NTDs, and 5.84-(95% CI, 2.28-14.96) and 3.71-fold (95% CI, 1.57-8.79) increased risks for anencephaly and spina bifida, respectively. A dose-response relationship was observed between PAH levels and the risk of NTDs, with odds ratios for the second, third, and fourth quartiles, compared with the first, of 1.77-(95% CI, 0.66-4.76), 3.83-(95% CI, 1.37-10.75), and 11.67-fold (95% CI, 3.28-41.49), respectively. A dose-response relationship was observed for anencephaly and spina bifida subtypes. Similar results were observed for o,p'-DDT and metabolites, alpha-HCH, gamma-HCH, and alpha-endosulfan, whereas no dose-response relationship was observed for the last two pollutants. Elevated placental concentrations of PAHs, o,p'-DDT and metabolites, and alpha-HCH were associated with increased risks of NTDs in this population.