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1.
A new norlabdane diterpenoid, named vitrifolin A, was isolated from the fruits of Vitex trifolia Linn. var. simplicifolia Cham. Its structure was elucidated by mean of spectroscopic methods, including HRESIMS, IR, 1D and 2D NMR. The inhibitory effect of vitrifolin A on nitric oxide production in lipopolysaccarideactivated mouse macrophages was also evaluated.  相似文献   
2.
Equisetum arvense supercritical CO2 extracts (EAE) contained an initial antioxidant activity of 10.3 mM TEAC that suffered a sharp first order kinetics decay characterized by half-life time (t1/2) of 1.05 ± 0.03 and 0.86 ± 0.03 weeks at 25 and 4°C, respectively. The aim of the present work was to develop a nanoemulsion formulation for providing EAE protection against deleterious environmental factors and extending its shelf-life functionality. The nanoemulsion area was identified by constructing pseudoternary phase diagrams and response surface methodology was used to optimize the preparation conditions. The best formulation achieved an EAE encapsulation efficiency of 97.5 ± 0.5% and antioxidant activity half-life time (t1/2) was extended to 12.32 ± 0.40 and 14.56 ± 0.60 weeks at 25 and 4°C, respectively.   相似文献   
3.
Jatropa curcas Linn. (JcL) capsule husk was not recommended as biogas feedstocks. However for biorefinery purpose, several technologies have been conducting to solve this problem. This research reported quantity and quality comparison of Dry Husk Jcl (DH-JcL) in one phase system of batch digester compare with semi continuous digester. HDPE drum of 80 L working volume used as digester with 40 days hydraulic retention time. Feeding of DH-Jcl and solvent water was mixed on concentration of 1: 8. Research conclusion showed that semi continuous digester was better than batch digester. Biogas quality showed that methane content can reach 66.61% to 83.15% and biogas quantity in semi continuous digester can reach 0.016 m3 · kg–1 DH JcL. The result was not in optimize condition yet because ratio number of volatile fatty acids/ alkalinity showed 0.5, it was indicated unstable anaerobic degradation process of DH-JcL.  相似文献   
4.
Phorbol is a tetracyclic diterpenoid found in Euphorbia tirucalliCroton tiglium, and Rehmannia glutinosa, and is nuclear of various phorbol esters. The rapid obtaining of phorbol with high purity highly contributes to its application, such as synthesizing phorbol esters with designable side chains and particular therapeutic efficacy. This study introduced a biphasic alcoholysis method for obtaining phorbol from croton oil by using polarity imparity organic solvents in both phases and established a high-speed countercurrent chromatography method for simultaneous separation and purification of phorbol. The optimized operation conditions of biphasic alcoholysis were a reaction time of 91 min, a temperature of 14°C, and a croton oil-methanol ratio of 1:30 (g:ml). The phorbol during the biphasic alcoholysis was 3.2-fold higher in content than that obtained in conventional monophasic alcoholysis. The optimized high-speed countercurrent chromatography method was using the ethyl acetate/n-butyl alcohol/water at 4.7:0.3:5 (v:v:v) with Na2SO4 at 0.36 g/10 ml as the solvent system, using the mobile phase flow rate of 2 ml/min, the revolution of 800 r/min, under which the retention of the stationary phase was achieved at 72.83%. The crystallized phorbol following high-speed countercurrent chromatography was obtained as high purity of 94%.  相似文献   
5.
为了探究常见沉水植物对水体底泥中重金属污染的富集效果,选取浙江水域较为常见的3种沉水植物苦草(Vallisneria natans (Lour.) Hara)、黑藻(Hydrilla verticillata(Linn.f.) Royle)、金鱼藻(Ceratophyllum demersum L.),在模拟天然水体环境中,将3种沉水植物培养在含有重金属Cd、Zn的底泥中生长一个生活周期.依据沉水植物对重金属Cd、Zn的富集量和生物-沉积物生物富集因子(biota-sediment accumulation factor,BSAF)等指标,筛选出对2种重金属元素富集效果较好的沉水植物,为受重金属污染底泥生态修复的植物选择提供一定的参考.结果表明:3种沉水植物对重金属Cd、Zn的耐受性均较强,同时对重金属Cd、Zn都有较高的富集能力,生物富集因子大于1,对底泥中的Cd、Zn均具有较好的祛除效果;由相关分析可知,3种沉水植物体中的Cd、Zn的质量分数与其根部底泥中Cd、Zn的质量分数呈极显著的负相关(p<0.01),因此这3种植物均可作为重金属Cd、Zn污染的修复物种.苦草对重金属Cd、Zn的富集量及BSAF均大于黑藻和金鱼藻,对重金属Cd的富集量分别达到了黑藻和金鱼藻的1.90和3.02倍.因此可考虑苦草作为水体底泥Cd、Zn复合污染生态修复的先锋物种.  相似文献   
6.
姬晓灵  汪岭  丁莉 《光谱实验室》2012,29(1):128-131
用传统煎煮法对宁夏产决明子中钾、钙、锰、铁、铜和锌6种元素进行提取,采用火焰原子吸收光谱法对决明子各种形态中的6种元素进行测定。结果显示,决明子中6种元素在原药、渣和煎汁中总含量特征:K>Ca>Fe>Zn>Mn>Cu。方法的回收率在80.8%—115.1%之间,各元素分析方法的RSD小于3.8%。  相似文献   
7.
RP-HPLC/二极管阵列检测器同时测定飞机草中3种黄酮   总被引:1,自引:0,他引:1  
应用高效液相色谱法/二极管阵列检测器同时测定了飞机草中木犀草素、槲皮素和山柰酚的含量。色谱柱HiQ sil C18W柱(4.6 mm×25 cm,5μm),流动相V(甲醇)∶V(水)∶V(磷酸)=50∶49.8∶0.2,检测波长槲皮素254 nm,木犀草素和山柰酚360 nm,温度30℃,流速1 mL/min,进样量10μL。确定了以超声波提取法制备飞机草分析样品的方法:溶剂为体积分数85%的乙醇,液固比为10∶1(mL/g),提取时间为1 h。结果表明,3种黄酮在0.01×10-3~0.10×10-3g/mL范围内呈现良好线性关系(R2>0.999 0),平均加样回收率分别为99.601 7%、99.032 6%和99.450 8%,RSD<2%。该方法操作简便、准确度高,可快速测定飞机草中木犀草素、槲皮素和山柰酚3种物质的含量。  相似文献   
8.
青蒿挥发性化学成分分析   总被引:8,自引:0,他引:8  
用同时蒸馏-萃取装置(SDE)提取了青蒿的挥发性物质,用GC-MS法分析鉴定出50种化合物,其中主要成分为醛类(18.16%)、酮类(8.24%)、醇类(17.36%)、酯类(11.02%)、酸类(7.31%)、烃及萜类(25.58%)、杂环类(10.38%),占总检出量的98.05%。  相似文献   
9.
分子烙印技术在沙棘功效成分提取中的应用   总被引:21,自引:0,他引:21  
槲皮素和异鼠李素为黄酮类物质,是中药沙棘治疗和预防多种心血管疾病的主要功效成分.作者制备了以槲皮素为模板的分子烙印聚合物(MIP),从沙棘粗提物中分离提取这两种黄酮,得到良好的效果.  相似文献   
10.
A new compound 1 was isolated from the methanolic extract of the stems of the Caesalpinia pulcherrima Linn. along with a reported compound (2) 3-O-β-D-glucopyranosyl-(1→4)-β-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl hederagenin 28-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester. The new compound 1 has m.p. 272–274°C, m.f. C46H74O17, [M]+ m/z 898. It was characterised as 3-O-β-D-glucopyranosyl-(1→4)-α-L-arabinopyranosyl hederagenin 28-O-β-D- xylopyranosyl ester by various colour reactions, chemical degradations and spectral analyses. Antibacterial activity of compound 1 was screened against various Gram-positive and Gram-negative bacteria and showed significant results.  相似文献   
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