抗癌药VP16—213合成工艺的改进

鬼臼脂素经脱甲基化、酰化、缩合、脱酰制得抗癌药足叶乙甙（ＶＰ１６－２１３），总产率１７．２％，校老工艺有明显的改进。     

A pH‐controllable imprinted composite membrane for selective separation of podophyllotoxin and its analog

A molecularly imprinted composite membrane (MICM) with pH‐controllability and selectivity to podophyllotoxin (PPT) was prepared using a polyvinylidene fluoride (PVDF) microfiltration membrane as the support. The functional monomer is 1‐phenyl‐3‐methyl‐4‐methacryloyl‐5‐pyrazolone (PMMP), which is a new β‐diketone compound with enol/ketol tautomerization. In this study, imprinting parameters, including the amounts of functional monomer and cross‐linker, and immersion time of membrane in the imprinting solution, were optimized by equilibrium adsorption experiments. Pore structure and surface morphology of the optimal MICM (MICM₂) was characterized. Finally, competitive permeability of PPT in the presence of its analog 4′‐demethylpodophyllotoxin (DMEP) was measured under the drive of concentration difference. The results reveal that the surface morphology and pore structure of MICM₂ are structurally different from those of the control nonimprinted membrane. As a result, MICM₂ could efficiently recognize PPT in a complex system due to a better structural matching and the interaction between the functional groups of MICM₂ and PPT. However, the most interesting finding is its pH‐controllability. The membrane could switch the preference to either PPT or DMEP with the change of pH values in the sample solution. At pH values smaller than 8.4, it led to a faster transportation of PPT, while the situation reversed to DMEP at pH values greater than 8.4. This peculiar property would lead this imprinted membrane to have potential application in the separation and enrichment of PPT, and the new functional monomer PMMP exhibited an attractive application prospect in the functional material fields. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

高纯鬼臼毒素制备新工艺

以桃儿七为原料 ,甲醇作溶剂 ,70℃回流提取 3次 ,每次 2h。所得浸膏 ,用苯在 80℃加热回流溶解 ,过滤、浓缩、放置结晶 ,得浅黄色粗品。用无水乙醇溶解粗品 ,经活性炭脱色后 ,浓缩成树脂状 ,用苯悬浮溶解 ,弃去不溶物。采用二步结晶法 ,先用苯作溶剂 ,除去绝大部分杂质后 ,再用苯 乙醇〔V(苯 )∶V(乙醇 ) =2∶1〕为溶剂 ,重结晶 ,得白色针状溶剂加合物结晶 (熔点 92～ 93℃ ) ,12 5℃烘干 2h ,脱去溶剂分子后 ,即得精品鬼臼毒素 ,其质量分数 >96 % ,产率为 1 7%     

Improving the Enantioselectivity of CHMOBrevi1 for Asymmetric Synthesis of Podophyllotoxin Precursor

(R)-β-piperonyl-γ-butyrolactones are key building blocks for the synthesis of podophyllotoxin, which have demonstrated remarkable potential in cancer treatment. Baeyer-Villiger monooxygenases (BVMOs)-mediated asymmetric oxidation is a green approach to produce chiral lactones. While several BVMOs were able to oxidize the corresponding cyclobutanone, most BVMOs gave the (S) enantiomer while Cyclohexanone monooxygenase (CHMO) from Brevibacterium sp. HCU1 gave (R) enantiomer, but with a low enantioselectivity (75 % ee). In this study, we use a strategy called “focused rational iterative site-specific mutagenesis” (FRISM) at residues ranging from 6 Å from substrate. The mutations by using a restricted set of rationally chosen amino acids allow the formation of a small mutant library. By generating and screening less than 60 variants, we achieved a high ee of 96.8 %. Coupled with the cofactor regeneration system, 9.3 mM substrate was converted completely in a 100-mL scale reaction. Therefore, our work reveals a promising synthetic method for (R)-β-piperonyl-γ-butyrolactone with the highest enantioselectivity, and provides a new opportunity for the chem-enzymatic synthesis of podophyllotoxin.     

ELISA法测定尿液中鬼臼毒素的含量

本文建立了一种利用IC-ELISA法测定尿液中的鬼臼毒素的方法。尿液样经离心沉淀,采用间接竞争酶联免疫吸附法(IC-ELISA)测定。鬼臼毒素的添加浓度在0.5 mg/L-10 mg/L时,回收率范围为78.3%-99.3%,相对标准偏差(RSD)在4.3%-11.5%之间。方法最低检测浓度为0.012μg/mL,检测范围为0.025-19.59μg/mL。方法的准确度和精密度符合残留分析要求。方法操作简捷,结果可靠稳定,比仪器方法检测成本低。     

濒危植物桃儿七中鬼臼毒素的提取分离及分析

目的:研究桃儿七中提取分离鬼臼毒素及其TLC、HPLC分析的简便方法。方法:采用Sephadex LH-20和正相硅胶柱色谱法进行分离,运用核磁共振波谱学分析鉴定所得化合物结构,并用TLC、HPLC进行纯度检测。结果:所得化合物经鉴定为鬼臼毒素,纯度不低于98%。结论:所建方法简便快捷,结果可靠,适合大规模生产。     

高速逆流色谱分离鬼臼中六个鬼臼毒素类化合物及其结构鉴定

采用制备型高速逆流色谱对鬼臼中鬼臼毒素类成分进行分离纯化。实验经优化获得的分离条件为：先用正己烷-乙酸乙酯-甲醇-水（2∶3.5∶2∶3.5,V/V）上相为固定相,下相为流动相洗脱48分钟后,换用正己烷-乙酸乙酯-甲醇-水（4∶5∶4∶5,V/V）下相进行洗脱;转速为1200r/min;流速为50mL/min;进样体积50mL;进样浓度20mg/mL;共收集到六种高纯度化合物,经鉴定为鬼臼毒素、山荷叶素、4’-去甲基鬼臼毒素、异苦鬼臼毒酮、4’-去甲基去氢鬼臼毒素和去氢鬼臼毒素。     

Germinating seeds of the mung bean, <i>Vigna radiata</i> (Fabaceae), as a model for the preliminary evaluation of cytotoxic effects of drugs

Cytotoxic properties of plant extracts and drugs being developed for cancer treatment are usually evaluated by a variety of in vivo and in vitro tests carried out in animal or plant based models. In the present study we have evaluated the possibility of using the germinating mung beans (Vigna radiata), for rapid and inexpensive screening of drugs exhibiting cytotoxic properties. Mung beans were allowed to germinate either in tap water or in different drug solutions, and parameters like percent germination, increase in radicle length, change in seedling weight and mitotic index of apical root meristems were determined at two time intervals coinciding with the time at which the radicle length in control group was 1.0 to 1.5 cm (time 0, T0) and 48 h later (T48). Methanol extract of Calotropis procera latex as well as drugs like podophyllotoxin, cyclophosphamide, cyproheptadine and aspirin produced a dose-dependent inhibitory effect on seed germination, seed weight gain, radicle growth and mitotic index in the radicle meristems. The inhibitory effect of some of the drugs tested was associated with reduction in water imbibition. Some of the drugs at higher concentrations allowed seed germination to take place but produced radicle decay and seedling weight loss. Our study shows that germinating V. radiata beans could be used as a convenient model for the preliminary screening of drugs exhibiting cytotoxic properties.     

桃儿七内生真菌产鬼臼毒素发酵条件研究

对鬼臼毒素(Podophyllotoxin)产生菌Ty的发酵培养基及发酵条件进行优化研究。结果表明。优化的半合成培养基组成为:可溶性淀粉2%,蔗糖2%.蛋白胨0.1%,酵母膏0.1%,K_2HPO_4 0.1%.NaCl 0.1%,pH 6.5,装液量80 mL/250 mL三角瓶,接种量2.5%,发酵培养6d,细胞干重为8.5g/L,鬼臼毒素产量达2.418μg/L.