高良姜多糖提取工艺优化及其抗氧化活性

通过Box-Behnken试验设计,获得了热水浸提高良姜多糖的最佳工艺;以清除1,1-二苯基-2-三硝基苯肼(DPPH)自由基能力、还原力、清除羟自由基能力、螯合铁离子能力为指标,评价了高良姜多糖的抗氧化活性。结果表明,热水浸提高良姜多糖的最佳工艺条件为液料比43∶1(mL/g)、浸提温度95℃、浸提时间3 h,在此条件下多糖得率实测值为11.81%。高良姜多糖具有较好的抗氧化活性,清除自由基能力、还原力和螯合铁离子能力均表现出一定的质量浓度依赖性;高良姜多糖清除DPPH自由基、清除羟自由基和螯合铁离子能力的半数有效质量浓度(EC50)分别为(0.59±0.01)、(0.05±0.003)g/L和(2.75±0.2)g/L。

Evaluation of Soil Quality Indicators in Sugarcane Management in Sandy Loam Soil

An important factor for the sustainability of soils highly susceptible to degradation is the use of monitoring tools that promptly and realistically reflect changes imposed on soil by different cropping systems. To select soil quality indicator variables in sugarcane (Saccharum officinarum L.) production areas that fulfill the criteria of sensitivity to management practices and between-season consistency in the management discrimination, ten composite soil samples (0–10 cm) were collected in July 2005 (rainy season) and again in March 2006 (dry season) from areas under cultivation of organic sugarcane (OS), green sugarcane (GS), burned sugarcane (BS) and from an adjacent native forest (NF) area at Usina Triunfo, Boca da Mata, Alagoas, Brazil. Microbial biomass-C (MBC), total organic C (TOC), soil enzyme activity expressed as the rate of fluorescein diacetate (FDA) hydrolysis, mean weight diameter of water-stable soil aggregates (MWD), and percentage of water-stable macroaggregates (PWSA) were analyzed. Although MBC and TOC were higher in NF than in the cultivated areas, no differences were observed in these C pools between the three sugarcane systems. The response of FDA to the site management was dependent on the sampling time. In the rainy period, the activity followed the order: NF > OS > GS > BS, whereas in the dry season, only NF differed from the other treatments. Irrespective of the sampling time, MWD and PWSA decreased in the order NF > OS = GS > BS. The variables MWD and PWSA are quite sensitive for discriminating between site management histories regardless the sampling season.

不同产地高良姜的质量分析及其抗肿瘤活性部位筛选

目的对来自不同产地的高良姜饮片进行质量分析,确定优质高良姜药材来源,在此基础上,筛选其对6种肿瘤细胞的抗肿瘤活性部位。方法以高良姜素含量为指标,利用HPLC法对不同产地的高良姜进行质量分析,色谱柱为Agilent C_(18)(4.6 mm×250 mm,5μm)柱,检测波长266 nm,柱温25℃,流动相甲醇-0.2%磷酸(55∶45),流速1 mL·min^(-1)。采用石油醚、二氯甲烷、乙酸乙酯、正丁醇依次对高良姜85%乙醇提取物进行萃取,将得到的各提取部位用MTT法评价其体外细胞毒活性,进行抗肿瘤活性筛选。结果广东产高良姜中高良姜素含量高于其他2个产地,为14.17 mg·g^(-1)。高良姜石油醚萃取部位和二氯甲烷萃取部位对6种肿瘤细胞均有明显抑制作用,活性强于乙酸乙酯萃取部位、正丁醇萃取部位与水部位,且呈现时间和浓度依赖关系。对人宫颈癌细胞株Hela抑制效果最好,石油醚萃取部位24 h与48 h的IC_(50)分别为7.88、6.55μg·mL^(-1);二氯甲烷萃取部位24 h与48 h的IC_(50)分别为6.13、4.78μg·mL^(-1)。结论 HPLC法优选方便、高效,高良姜抗肿瘤活性的有效部位为石油醚萃取部位和二氯甲烷萃取部位。