[Residues and Spatial Distribution Characteristics of Organochlorine Pesticides DDTs in Soil of Linyi City, Shandong Province].

Surface soil samples were collected every 36 km2 from Linyi City to study the residues, composition and origin, influencing factors, spatial distribution and environment quality characteristics of soil DDTs. Measurements were taken for DDTs, OrgC, N, etc. for all samples. The results indicated that the detectable rate of DDTs was 71. 75%, and the mean content of DDTs was 0. 035 µg.g-1. p,p'-DDT and p,p'-DDE were the predominant contaminant compounds, with mean concentrations of 0.033 µg.g-1 and 0.010 µg.g-1, and accounted for 60. 99% and 34. 62% of the detectable samples, respectively. The degradation rate of DDTs suggested that 58% surface soils were recently inputted, these newly inputted locations were especially distributed in the middle to south of the study area, meanwhile, p,p'-DDD/p,p'-DDE revealed that the degradation of DDTs was mainly under oxidizing condition, and o,p'-DDT/p,p'-DDT illustrated that 71. 37% DDTs in soils of the study area were concerned with technical DDTs sources. Besides, the correlation, analysis showed that the external factors affecting the distribution of DDTs included OrgC, N, C and pH etc. and the higher the p, p'-DDT proportion of DDTs, the greater the effect. The distribution of DDTs had an obvious point source characteristic, and significant concentration centers were located nearby the cities and counties, typically, the DDTs concentrations of middle to southern area were much higher. However, DDTs environmental quality assessment suggested that the pollution level was relatively low, and the soil was mainly classified into grade I or II, which accounted for 78. 95% and 21. 05% of the whole study area, respectively.

[Correlation between chemical constituents and ecological factors of Astragalus membranaceus var. mongholicus].

Principal component analysis (PCA) and correlation analysis (CA) were applied to analyze the correlation of the main chemical components in Astragalus membranaceus var. mongholicus and ecological factors. The results showed that the contents of astragaloside, campanulin, ononin, kaempferol and astragalus polysaccharides (APS) of A. membranaceus var. mongholicus produced. in Shanxi were significantly higher than in Inner Mongolia and Gansu. The main climatic factors for affecting the contents of chemical ingredients in A. membranaceus var. mongholicus were annual average relative humidity, sunshine hours and average July temperature. Calcium was the main factor in the soil affecting the chemical ingredient contents, and calcium was negatively correlated with the contents of calycosin glycosides, kaempferol, ononin, quercetin and APS in A. membranaceus var. mongholicus within a certain range.

Hypericin: chemical synthesis and biosynthesis.

Hypericin is one of the most important phenanthoperylene quinones extracted mainly from plants of the genus Hypericum belonging to the sections Euhypericum and Campylosporus of Keller's classification. Widespread attention to the antiviral and anti-tumor properties of hypericin has spurred investigations of the chemical synthesis and biosynthesis of this unique compound. However, the synthetic strategies are challenging for organic and biological chemists. In this review, specific significant advances in total synthesis, semi-synthesis, and biosynthesis in the past decades are summarized.

UPLC-QTOF/MS Analysis of Alkaloids in Traditional Processed Coptis chinensis Franch.

The processing technology employed in traditional Chinese medicine (TCM) is significant and distinct. Meanwhile, the processed Coptis chinensis Franch. are significant in clinic based on clinical practice and literature. The current study used ultraperformance liquid chromatography method (UPLC) coupled with quadrupole time of flight mass spectrometry (qTOF/MS) and Marklynx software to analyze the chemical profiles of crude and processed C. chinensis Franch. 13 compounds in these samples are identified, including 3 compounds that are detected in C. chinensis Franch. for the first time. Moreover, the results of the experiment show significant chemical differences between crude and processed C. chinensis Franch. with principal component analysis (PCA). The obvious separation in PCA confirms the traditional processing theory in TCM.

Biocleavable comb-shaped gene carriers from dextran backbones with bioreducible ATRP initiation sites.

It is of crucial importance to design reduction-sensitive polysaccharide-based copolymers for intracellular triggered gene and drug delivery. In this work, a simple two-step method involving the reaction of hydroxyl groups of dextran with cystamine was first developed to introduce reduction-sensitive disulfide linked initiation sites of atom transfer radical polymerization (ATRP) onto dextran. Well-defined biocleavable comb-shaped vectors consisting of nonionic dextran backbones and disulfide-linked cationic P(DMAEMA) side chains were subsequently prepared via ATRP for highly efficient gene delivery. The P(DMAEMA) side chains can be readily cleavable from the dextran backbones under reducible conditions. Moreover, the bioreducible P(DMAEMA) side chains can be functionalized by poly(poly(ethylene glycol)ethyl ether methacrylate) (P(PEGEEMA)) end blocks to reduce the cytotoxicity and further enhance the gene transfection efficiency. This present study demonstrated that properly grafting short bioreducible polycation side chains from a nonionic polysaccharide backbone with biocleavable ATRP initiation sites is an effective means to produce a class of polysaccharide-based gene delivery vectors.

Growth responses of in vitro Fusarium oxysporum f. sp. niveum to external supply of tannic acid.

Allelochemicals released from root exudates or decaying residues of plants play diversified roles in ecological interactions of plant-pathogen. The objective of this work was to evaluate the allelopathic effect of an externally supplied tannic acid on soil-borne in vitro Fusarium oxysporum f. sp. niveum. Results showed that the tannic acid decreased the growth of the fungus up to 9.5% at 800 mg l(-1). Conidial germination was reduced by 52.3% in comparison with the control. However, sporulation and mycotoxin production by the fungus were stimulated. The activity of pectinase and proteinase were initially increased and finally decreased with increase in concentrations of tannic acid. Tannic acid served as an ecological allelochemical, repressing the growth of the pathogen.