甘草酸的提取与纯化

甘草具有悠久的使用历史,它的主要成分是甘草酸。由于其在药理上能够治疗和预防一系列疾病,因此具有广泛的应用价值。本文通过查阅国内外文献资料,综述了甘草酸的提取及纯化的方法。

Methodological Studies on Genomic DNA Extraction and Purification from Plant Drug Materials

This paper reports the rationale and methods of DNA extraction and purification from nine species of Compositae and four commercial drugs of corresponding plant Elephantopus scaber. The comparison of three methods: CsCl gradient, CTAB/CsCl gradient and CTAB miniprep extraction by yield, purity and factors affecting PCR was carried out. In conclusion, CTAB miniprep method provides a rapid, effective, economic approach for isolating genomic DNA for Chinese drug identification by genomic fingerprints.

泽泻总三萜提取纯化工艺的实验室试验及中试验证

以泽泻提取物中总三萜(1)和23-乙酰泽泻醇B(2)含量为评价指标;优化泽泻前处理、提取和纯化方法。所得最优工艺为:取过10目筛的泽泻粉末,用10倍量85%乙醇回流提取2次,每次1 h。所得提取液浓缩至每1 ml含0.5 g生药的溶液,取100 ml以2 BV/h(60 ml/h)的速度上D101大孔吸附树脂柱,上样完成后用水4 BV洗脱,再用6 BV 40%乙醇以4 BV/h的速度除杂,8 BV 80%乙醇以2 BV/h的流速富集1。实验室小试至50 kg规模的中试试验表明,该工艺稳定可行,所得提取物中1含量大于50%,得率约77%,2的含量约为8%。

Purification and Characterization of Plant Peroxidase from Coccinia Grandis （Ivy Gourd）

Plant peroxidase extracted from Coccinia grandis Lin. （Ivy gourd） was purified from crude extract by ammonium sulfate precipitation, ion-exchange chromatography, and size exclusion chromatography. The purified enzyme preparation exhibited a specific activity of 6106.63 p.mol.minl.mg protein1, while purification fold and yield were 17.45 and 34.70%, respectively. The purified peroxidase was homogenous as judged by native and sodium dodecyl sulfate （SDS） polyacrylamide gel electrophoresis. The molecular weight as determined by gel filtration and SDS-polyacrylamide gel electrophoresis was 45 kD, which suggested that the purified peroxidase contained only one subunit. The apparent Km and Vmax values of the enzyme against phenol were 93 p.M and 561 μmol.min^-1.mg protein^-1, respectively. The temperature and pH optimum for purified peroxidase were 45℃ and pH 6.0, respective. However, it was stable at 30-60℃ and pH 4.0-8.0. The presence of metal ions such as Cu2＋ and Ca2＋ enhanced peroxidase activity. On the other hand, Cr3＋ and Hg2＋ strongly inhibited the enzyme activity at 500 p.M. Sodium dodecyl sulfate reduced a half of peroxidase activity at approximately 3 mM. Ivy gourd was stability in the presence of each urea concentrations. The affinity of the enzyme with different substrates showed as the highest relative activities on gallic acid followed by catechin, ascorbic acid and caffeic acid, respectively.

An Efficient Procedure for DNA Isolation and Profiling of the Hyper Variable MtDNA Sequences

Present study describes the results of an efficient protocol for the isolation of good quality DNA from human saliva. The protocol includes collection of saliva in sterile specimen tubes, followed by the cell lysis. After formation of cell lysate, proteins wereextracted by phenol chloroform treatment for purification of DNA. The purified DNA was precipitated by adding equal volume of isopropanol to the treated supernatant. After isolation DNA pellet was washed with 70% ethanol, air-dried and was suspended in 30 pL of double distilled water. Best quality of DNA was extracted from the saliva samples and the PCR product was amplified for hyper-variable regions （HVI＆ HV2） of the mitochondrial DNA. The genes were cleaned with GeneAll gel elution kit （Gel SV） （Cat. No. 102-10） and sequenced accordingly. The DNA isolation protocol presented here is recommended for the isolation, best quality and yield of DNA from the human saliva.

Improvements on environmental DNA extraction and purification procedures for matagenomic analysis

Our previously described environmental DNA extraction method has been widely used in environmental microbial community analysis. However, residual humic substances may remain with obtained environmental DNA, which interferes downstream molecular analyses. To remedy this situation, two DNA extraction buffers （PIPES and Tris-HCl） and four purification strategies including our new modified low melting point gel purification method and three commercial kits from QIAEX, Omega and Promega were evaluated with diverse soil samples. The PIPES buffer （pH 6.5） is found to be more effective for removing the humic substances, but it leads to lower DNA yield and causes more severe DNA shearing than using the Tris-HC1 buffer （pH 8.0）. Gel purification and the Promega purification kit achieve much higher DNA recoveries than QIAEX or Omega kit, and higher purity of DNA is obtained by gel purification than by the Promega kit with both DNA extraction buffers mentioned above. Considering all results together, two alternative methods for DNA extraction and purification are proposed： one uses Tris-HCl buffer extraction and gel purification as the primary approach when the amount of soil or biomass is not a major concern, and the other uses PIPES buffer extraction and the Promega kit purification when severe DNA shearing and/or limited biomass occurs. Purified DNA samples by both methods are amenable for use as templates for whole community genome amplifications and PCR amplifications of bacterial 16S rRNA genes. It is demonstrated that these two alternative methods could be applied to a wide variety of environmental samples.

Antiviral activities against influenza virus(FM1) of bioactive fractions and representative compounds extracted from Banlangen(Radix Isatidis)

OBJECTIVE: To study the antiviral activities of clemastanin B(CB), epigoitrin, phenylpropanoids portion(PEP) and the mixture of phenylpropanoids, alkaloids and organic acid fractions(PEP+ALK+OA)from Banlangen(Radix Isatidis).METHODS: The experiment consisted of four parts:therapeutic action, prophylaxsis action, inhibition of virus attachment, and direct virucidal action. Cytopathic effect(CPE) and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium(MTT) were used to assess antiviral activity.RESULTS: CB, epigoitrin, PEP and PEP + ALK + OA fractions from Banlangen(Radix Isatidis) extract significantly increased the viability of MDCK cells pre-infected with the virus compared with the virus control group in all the dilutions(P < 0.01). Pretreated with either pure compounds or chemical frac-tions of Banlangen(Radix Isatidis) extract in all the dilutions significantly improved the viability of MDCK cells(P < 0.01). The inhibition of virus absorption to the host cells by CB, epigoitrin and PEP was in a dose dependent manner.CONCLUSION: CB, epigoitrin, PEP and PEP+ALK+OA exert their anti-influenza activity by inhibiting the virus multiplication, prophylaxsis and blocking the virus attachment. The primary mode of action of PEP and PEP + ALK + OA is the inhibition of virus replication. The inhibitory effects on virus attachment and multiplication are the main modes for epigoitrin.