鸦胆子抗肿瘤活性成分的化学研究

从苦木科植物鸦胆子[Brucea javanica(L.)Merr]干躁果实的硅胶干柱柱层析所得的活性部位中经层析分离得到7个四环三萜苦木内酯成份(A,B,C,D,E,F,G),经UV,IR,~1H-NMR,~(13)C-NMR等方法鉴定分别为鸦胆苦醇(Brusatol A),双氢鸦胆苦醇(Dihydrobrusatol,B),鸦胆因B(Bruceine B,C),鸦胆因D(Bruceine D,D),鸦胆因H(Bruceine H,E),鸦胆子甙A(Bruceoside A,F)和双氢鸦胆子甙A(Yadanzioside A,G)。据报道,鸦胆苦醇和鸦胆子甙A具有较强的抗肿瘤活性。     

RP-HPLC分离制备桔梗皂苷

在对桔梗总皂苷粗分的基础上,利用制备高效液相色谱分离制备桔梗单体皂苷,共分离得到四个化合物,经波谱法分别鉴定为platycodinD（1）,platycoside E（2）,deapio-platycoside E（3）,未知化合物（4,鉴定中）,经HPLC分析,纯度均大于98％．对比以前的分离手段,该方法分离制备桔梗单体皂苷工艺简单,效率高,为在桔梗中寻找新的天然活性物质提供了新方法。     

制备型高效液相色谱法分离蛋白质的研究

生物工程的发展,特别是生化制品下游处理技术的兴起,对现代分离科学提出了更高的要求,研究和开发各类生化物质特别是活性生物大分子的分离纯化技术,已成为一项十分重要的研究课题。在现有的分离技术中,液相色谱,尤其是80年代在分析型高效液相色谱(HPLC)基础上兴起的制备型HPLC,在大规模分离纯化生物活性物质特别是蛋白质方面已显示出巨大的应用潜力,引起了各国研究者的高度重视^[1-5].本文利用自行设计的制备型HPLC分离装置,对牛血清白蛋白(BAS)和牛血清红蛋白(HG)的制备分离过程进行了实验研究,着重考虑了流动流速、柱超载方式、柱长等因素对BAS和HG分离度的影响。     

银杏叶中银杏内酯B及白果内酯的分离鉴定

前文中作者已报道从我国特有植物银杏(Ginkgo biloba L.)的叶子中分到银杏内酯A及C(ginkgolide A,C),本文报道从银杏叶中分到的另外二个结晶,经理化性质、薄层层析、红外光谱及质谱分析,鉴定结晶Ⅲ为银杏内酯B(ginkgolide B),结晶Ⅳ为白果内酯(bilobalide),后者为国内首次分离。     

分散蓝102标准品的制备研究

将商品化的分散蓝102以二甲基甲酰胺溶解,运用制备高效液相色谱制备分散蓝102标准品,纯度大于99%。制备型色谱柱为Waters Xbridge C18柱(5μm,30 mm×150 mm);流动相为10 mmol.L-1碳酸氢铵水溶液和乙腈;流速为30 ml.min-1;检测波长为254 nm;柱温为室温。该方法所得分散蓝102纯度高,可用作分析方法的对照品。     

柴达木栽培和野生枸杞子中东莨菪内酯含量的测定

建立测定枸杞子中东莨菪内酯的HPLC方法,并进行方法学考察。利用所建立的方法对柴达木栽培和野生枸杞子的东莨菪内酯含量进行测定。以Diamonsil C18柱为分析柱,甲醇-0.05%磷酸溶液(35∶65)为流动相,流速:1 m L/min,柱温:30℃,检测波长:344 nm;研究发现,枸杞子中东莨菪内酯在0.026~1.040μg(R2=0.9996)范围内成良好的线性关系;平均加样回收率(n=6)为96.1%,RSD=2.0%。该方法准确、可靠、重现性好,适用于枸杞子中东莨菪内酯的含量测定。测定结果表明,柴达木栽培枸杞子具有很整齐的品质优良性,而野生枸杞子品质差异很大,适宜于选择性的开发。     

当归中藁本内酯在大鼠体内的药代动力学研究

采用超高效液相色谱(UPLC-PDA)法测定大鼠灌胃当归石油醚萃取物后藁本内酯的血药浓度。色谱条件:色谱柱BEH C18(2.1 mm×100 mm,1.7μm);流动相:乙腈-水(0.03%三氟乙酸)(45∶55,v/v);流速:0.5mL/min;检测波长:320 nm。并运用DAS 3.0药动学软件计算药动学参数,研究当归石油醚萃取物中藁本内酯在大鼠体内的药代动力学。结果显示藁本内酯在大鼠体内较符合二室模型,主要的药动参数:高、中剂量组的Cmax分别为0.38±0.04、0.33±0.02(μg/mL);t1/2β分别为4.08±0.25、3.06±0.82(h),低剂量组含量过低,无法进行定量。实验结果表明UPLC-PDA法能够较准确、灵敏的测定藁本内酯在大鼠体内的血药浓度,经比较高、中剂量组的药动参数得知,该物质呈非剂量依赖型。     

高效液相色谱分析银杏萜内酯的含量

用高效液相色谱法测定银杏叶及提取物中银杏内酯Ａ、Ｂ、Ｃ和白果内酯的含量。采用Ｃ１８分离柱,示差检测器,甲醇：水（３３：６７）为流动相,方法回收率平均达９７％以上,变异系数（ＣＶ）为２．１％。     

柴达木栽培和野生枸杞子中东莨菪内酯含量的测定北大核心CSCD

建立测定枸杞子中东莨菪内酯的HPLC方法,并进行方法学考察。利用所建立的方法对柴达木栽培和野生枸杞子的东莨菪内酯含量进行测定。以Diamonsil C18柱为分析柱,甲醇-0.05%磷酸溶液（35∶65）为流动相,流速：1 m L/min,柱温：30℃,检测波长：344 nm;研究发现,枸杞子中东莨菪内酯在0.026-1.040μg（R2=0.9996）范围内成良好的线性关系;平均加样回收率（n=6）为96.1%,RSD=2.0%。该方法准确、可靠、重现性好,适用于枸杞子中东莨菪内酯的含量测定。测定结果表明,柴达木栽培枸杞子具有很整齐的品质优良性,而野生枸杞子品质差异很大,适宜于选择性的开发。     

高速逆流色谱法(HSCCC)分离制备香水莲花中的柚皮素

采用高速逆流色谱法对香水莲花中的黄酮类化合物进行了分离,溶剂系统为正己烷-醋酸乙酯-甲醇-水(体积比1∶1.2∶2∶1),上层为固定相,下层为流动相,流速2.0 mL/min,转速830 r/min,检测波长280 nm,进样量300 mg,分离出80 mg化合物C,经HPLC测定纯度98.6%,根据UV光谱、MS分析及1H-NMR、13C-NMR图谱分析结果,化合物C鉴定为柚皮素,该化合物为首次从该植物中分离得到,为香水莲花的开发应用提供了理论依据。     

Brucin,an antibacterial peptide derived from fruit protein of Fructus Bruceae,Brucea javanica (L.) Merr

A novel antibacterial peptide specific to Streptococcus pyogenes was produced from dried fruit protein of Brucea javanica (L.) Merr. A mixture of active peptides from the fruit protein was produced in vitro by pepsin hydrolysis. The hydrolysate was purified by reverse‐phase HPLC, and antimicrobial peptides active against Gram‐negative and Gram‐positive bacteria were analysed using SDS‐PAGE and nanoLC‐MS/MS. Here, four possible peptides were obtained and chemically synthesized for comparative study of the growth inhibition of Strep. pyogenes. One chemically synthesized peptide with a molecular mass of 1168·31 Da, His‐Thr‐Leu‐Cys‐Met‐Asp‐Gly‐Gly‐Ala‐Thr‐Tyr, showed the most potent antibacterial activity against Strep. pyogenes. This 11‐amino acid peptide was named Brucin. Its bacterial inhibitory activity was 16‐fold and 12·5‐fold higher than penicillin G and chloramphenicol, respectively, with a MIC value of 20 μmol l^?1. The results suggest that Brucin, a potent antibiotic peptide, may be developed as an alternative drug for the treatment of the disease caused by Strep. pyogenes.

Significance and Impact of the Study

An antibacterial peptide, named Brucin with specificity for Streptococcus pyogenes, was produced in vitro from dried fruit protein of Brucea javanica (L.) Merr. by pepsin‐catalysed hydrolysis. Its inhibitory activity towards the Gram‐positive bacteria was higher than penicillin G and chloramphenicol. The result suggested that Brucin may be applied for the treatment of the disease caused by Strep. pyogenes^*.     

蕨菜黄酮分离鉴定

采用75%的乙醇提取经乙醚脱脂的蕨菜粉末,提取液回收乙醇后以石油醚、氯仿、乙酸乙酯、正丁醇依次萃取粗分段,硅胶柱层析、乙酸乙酯-甲醇系统对乙酸乙酯部位梯度洗脱,对其乙酸乙酯洗脱部分反复凝胶柱层析获得2个黄酮单体,分别鉴定为紫云英苷(1)、芦丁(2),其中化合物1为首次从蕨菜中分离得到。     

Production of canthin-6-one alkaloids by cell suspension cultures of Brucea javanica (L.) Merr.

Cell suspension cultures of Brucea javanica (L.) Merr. were used to determine culture growth characteristics and production of canthin-6-one alkaloids. The major alkaloids produced were canthin-6-one, 11-hydroxycanthin-6-one, 5-methoxycanthin-6-one and 11-methoxycanthin-6-one. Alkaloids were synthesised throughout the 36 day growth cycle of the cells with maximum amounts within the cells occurring between days 20 to 28; approximately 10% of the alkaloids were in the medium at day 24 rising to 45% at day 32.     

Synchronization of protoplasts from Glycine max (L.) Merr. and Brassica napus (L.)

Cells of Glycine max originating in a suspension culture and cells of Brassica napus prepared from hypocotyls were synchronized. Synchronization was achieved by preparing protoplasts in the usual way and subsequently letting the protoplasts regenerate into cells by removing the cell-wall-digesting enzymes. More than 70% of the cells had divided synchronously at the end of the first cycle as determined by the mitotic index. The high frequency of mitosis critically depended on the osmolality of the medium. The duration of the S-phase was estimated by measuring the activity of thymidylate kinase as well as incorporation of [³H]deoxythymidine into acid-insoluble material. The data indicate that synchronization is induced by resetting the cell cycle.Abbreviations dTMP deoxythymidine 5-monophosphate - TCA trichloroacetic acid     

Isolation and Identification of a Senescence-promoting Substance from Wormwood (Artemisia absinthium L.)

The senescence-promoting substance of wormwood (Artemisia absinthium L.) as detected by the oat (Avena sativa L. cv “Victory”) leaf assay has been identified as (−)-methyl jasmonate, methyl (1S, 2R)-3-oxo-2-(2′-cis-pentenyl)-cyclopentane-1-acetate, by gas-liquid chromatography-mass spectrometry and optical rotatory dispersion. Its senescence-promoting effect was much stronger than that of abscisic acid, and even at such a low concentration as 1 to 2.5 micrograms per milliliter, it could completely eliminate the anti-senescence action of 2 micrograms per milliliter kinetin. Comparing the biological activity of the (−)- with the (±)-forms of methyl jasmonate, it seemed that only the (−)-form was biologically active.     

Regeneration of transformed shoots from electroporated soybean (Glycine max (L.) Merr.) protoplasts

Stable transformation of soybean (Glycine max (L.) Merr.) protoplasts isolated from immature cotyledons was achieved following electroporation with plasmid DNA carrying chimeric genes encoding ß-glucuronidase (GUS) and hygromycin phosphotransferase (HPT) under the control of the cauliflower mosaic virus (CaMV) 35S promoter. Transformed colonies were stringently selected by growing 15-day-old protoplast-derived cells in the presence of 40 g/ml of hygromycin-B for 6 weeks. Over 93% of the resistant cells and colonies exhibited GUS activity, indicating that the two marker genes borne on a single plasmid were co-introduced and co-expressed at a very high freguency. This transformation procedure reproducibly yields transformants at frequencies of 2.9–6.8 × 10^–4 (based on the number of protoplasts electroporated) or 23.0% (based on the number of control microcalli formed) counted after 6 weeks of selection. After repeated subculturing on regeneration medium, shoots were induced from 8.0% of the transformed calli. Southern hybridization confirmed the presence of both the GUS and hygromycin genes in the transformed calli and shoots.     

锦鲤中吉氏库特菌的分离与鉴定

对从患病锦鲤(Cyprinus carpio L.)肝组织中分离的1株纯培养菌(HC050630C-1)进行了形态特征、主要理化特性、对健康鲤鱼的致病作用、药物敏感性等方面的检验;同时测定了该株菌的16S rRNA基因序列,构建了系统发育树。结果表明,被检菌为吉氏库特菌(Kurthia gibsonll),对健康鲤鱼未显示明显的致病作用;所测菌株的16S rRNA基因序列长度1459bp,在GenBank中登录号为EF611423;该菌株16SrRNA基因序列与GenBank数据库中吉氏库特菌的16S rRNA基因序列同源性在99%;药敏试验结果显示,对供试的氨苄青霉素等27种药物呈现高度敏感或敏感,对头孢吡肟等6种呈低度敏感,对苯唑青霉素等4种耐药。     

Isolation and Identification of Two 2,3-Unsubstituted Chromones from Glasswort (Salicornia europaea L.)

Two 2,3-unsubstituted chromones were isolated from the reddish leaves and stems of glasswort (Salicornia europaea L.) and, on the basis of chemical and spectral evidences and syntheses of both of the compounds, they were identified to be 6,7-methylenedioxychromone and 6,7-dimethoxychromone, respectively. This is the first report which shows the natural occurrence of these two chromones.     

Identification of QTL underlying somatic embryogenesis capacity of immature embryos in soybean (Glycine max (L.) Merr.)

High embryogenesis capacity of soybean (Glycine max (L.) Merr.) in vitro possessed potential for effective genetic engineering and tissue culture. The objects of this study were to identify quantitative trait loci (QTL) underlying embryogenesis traits and to identify genotypes with higher somatic embryogenesis capacity. A mapping population, consisting of 126 F_5:6 recombinant inbred lines, was advanced by single-seed-descent from cross between Peking (higher primary and secondary embryogenesis) and Keburi (lower primary and secondary embryogenesis). This population was evaluated for primary embryogenesis capacity from immature embryo cultures by measuring the frequency of somatic embryogenesis (FSE), the somatic embryo number per explant (EPE) and the efficiency of somatic embryogenesis (ESE). A total of 89 simple sequence repeat markers were used to construct a genetic linkage map. Six QTL were associated with somatic embryogenesis. Two QTL for FSE were found, QFSE-1 (Satt307) and QFSE-2 (Satt286), and both were located on linkage group C2 that explained 45.21 and 25.97% of the phenotypic variation, respectively. Four QTL for EPE (QEPE-1 on MLG H, QEPE-2 on MLG G and QEPE-3 on MLG G) were found, which explained 7.11, 7.56 and 6.12% of phenotypic variation, respectively. One QTL for ESE, QESE-1 (Satt427), was found on linkage group G that explained 6.99% of the phenotypic variation. QEPE-2 and QESE-1 were located in the similar region of MLG G. These QTL provide potential for marker assistant selection of genotypes with higher embryogenesis.