保康白竹磷矿构造控矿特征

本文从地质力学观点阐述白竹磷矿的构造控矿特征,分析保康磷矿的古构造、古地理环境,以及构造的复合关系,预测隐伏矿体的存在远景。     

Supercritical carbon dioxide extraction of Baizhu: Experiments and modeling

In this work, supercritical CO₂ extraction has been carried out on a traditional Chinese herb of Baizhu under pressure of 15-45 MPa, temperature of 40-60 °C, mean powder size of 0.167-0.675 mm, and extraction time of up to 180 min. The maximum extraction yield obtained in 5 h is about 6.76 × 10⁻² g per gram raw materials at 60 °C and 45 MPa. The extraction process is correlated by means of five different mathematical models. The evaluation of these models against experimental data shows that among these models the Sovová model performs the best with an overall average absolute relative deviation of 1.62%, followed by Crank and Naik models, finally the Barton and Martínez models. From the Sovová model, the mass transfer coefficient in solid or fluid are obtained and they are varying in the ranges of 4.02-6.14 × 10⁻⁸ m/s and 0.88-2.87 × 10⁻⁹ m/s, respectively. These results suggest that solute diffusion in solid matrices and solute mass transfer in fluid are both important in affecting the supercritical CO₂ extraction process of Baizhu.     

祁白术多酚提取工艺及抗氧化、抑菌活性研究

为研究表面活性剂十二烷基苯磺酸钠(sodium dodecyl sulfonate,SDS)协同超声波提取祁白术多酚的工艺参数,以多酚含量为指标,在单因素试验的基础上,采用响应面法优化提取工艺条件,并对祁白术多酚的体外抗氧化、抑菌活性进行研究。结果表明,祁白术多酚的最优工艺条件为:SDS添加量0.47%,超声波功率150 W,超声温度48℃,乙醇浓度64%,超声时间15 min,料液比1:25(g/mL),该条件下提取的多酚含量高达(38.53±0.51)mg/g。祁白术多酚具有显著的抗氧化活性,其对DPPH、ABTS自由基清除作用的半数抑制浓度(IC_(50))分别为0.056,0.050mg/mL。祁白术多酚对4种受试菌均有显著的抑制作用,多酚的质量浓度与抑制作用呈量效关系,其对大肠杆菌、金黄色葡萄球菌、绿脓杆菌的最低抑制浓度(MIC)为0.25mg/mL,对枯草芽孢杆菌的MIC为0.50mg/mL。     

祁白术生物活性物质及其抗氧化、抑菌能力研究

研究祁白术甲醇粗提物及其不同极性萃取相的总酚、总黄酮含量及抗氧化、抑菌活性,考察总酚、总黄酮含量与抗氧化活性的相关性,并采用气相色谱-质谱联用(GC-MS)分析醇提物中的主要化学成分。结果表明,祁白术不同极性萃取相(正己烷相、二氯甲烷相、乙酸乙酯相、正丁醇相和水相)的总酚、总黄酮含量及其抗氧化、抑菌能力存在显著差异(P0.05)。乙酸乙酯相的总酚和总黄酮含量最高,分别为(139.45±0.19)mg TA/g和(21.28±2.28)mg QE/g。乙酸乙酯相表现出最强的还原能力[(38.95±1.66)mg VC/g]、ABTS自由基清除能力[(302.42±7.51)mg VC/g]、DPPH自由基清除能力[(51.61±2.59)mg VC/g]。祁白术的总酚、总黄酮含量均与还原能力、ABTS自由基清除能力及DPPH自由基清除能力呈显著正相关(P0.05)。甲醇粗提物及正己烷相、二氯甲烷相对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌和绿脓杆菌均具有不同程度的抑制作用,其中正己烷相的抑菌活性最为显著,其对4种受试菌的最小抑菌浓度均为1mg/mL。GC-MS分析了醇提物的主要化学成分,共鉴定出18种化合物,以酚、醇、烯、酮类化合物为主,主要成分有3,3'-二氨基-4,4'-二羟基联苯(33.47%)、β-桉叶醇(28.33%)、β-愈创木烯(5.91%)、3,3,5,6,7-五甲基-1-茚满酮(4.70%)等。