N-苄氧羰基甘氨酰-L-脯氨酸-鬼臼毒素衍生物的合成及其抗肿瘤活性

以鬼臼毒素（podophyllotoxin）、N-苄氧羰基甘氨酰-L-脯氨酸为原料,首次合成了10个新型鬼臼毒素衍生物（Ⅲa～Ⅲi、Ⅳ）,目标化合物结构经1H NMR、13C NMR和MS确认。采用MTT法测试化合物Ⅲa～Ⅲi和Ⅳ对HepG2、THP-1、HeLa、MCF-7细胞的抑制活性。结果表明：所有目标化合物均具有不同程度的抑制活性,其中化合物Ⅲa对HepG2细胞的活性最突出,IC50达0.58 nmol/L。通过分子对接模拟技术进一步研究了化合物Ⅲa和FAPα酶的结合模式,Ⅲa可以与FAPα酶的多个位点产生相互作用,值得进一步研究其抗肿瘤机制。     

地形因子对桃儿七鬼臼毒素含量的影响与生态适宜度研究

该研究从四川、青海、甘肃、西藏、云南和陕西六省桃儿七分布较多的区域进行实地采样116份桃儿七样品,并测定鬼臼毒素含量,再利用测得的鬼臼毒素数据和桃儿七地形因子(海拔、坡度、坡向)对桃儿七进行中药区划研究.采用偏相关分析和最大信息熵模型2种方法对鬼臼毒素含量和桃儿七生境适宜度进行综合分析,选择出最适宜桃儿七生长的地形因子.研究结果如下:桃儿七鬼臼毒素含量与海拔相关性最大(偏相关系数为-0.120),与坡度、坡向联系不大(偏相关系数-0.094,-0.039).桃儿七在海拔为2 800～3 600 m,坡向为北、东北、西北,坡度在12° ～65°的地区时,桃儿七生境适宜度较高,较适合桃儿七的野生引种和人工栽培.研究表明,桃儿七地形因子对桃儿七适生区域有一定影响,与鬼臼毒素含量影响不.该文分析结果对桃儿七区划布局和生产发展提供了重要科学依据,但由于该文只是从桃儿七的地形因子对桃儿七的生境适宜度进行分析,而影响桃儿七生境适宜度和鬼臼毒素含量的生态因子较多,因此在对桃儿七资源进行实际开发与保护时,应结合其他气候、土壤因子等综合考虑.     

Podophyllum hexandrum Offers Radioprotection by Modulating Free Radical Flux: Role of Aryl-Tetralin Lignans

We have evaluated the effect of variation in aryl-tetralin lignans on the radioprotective properties of Podophyllum hexandrum. Two fractionated fractions of P. hexandrum [methanolic (S1) and chloroform fractions (S2)], with varying aryl-tetralin lignan content were utilized for the present study. The peroxyl ion scavenging potentials of S1 and S2 were found to be comparable [i.e. 45.88% (S1) and 41% (S2)] after a 48 h interval in a time-dependent study, whereas in a 2 h study, S2 exhibited significant (P < 0.05) antioxidant activity in different metal ion + flux states. In the aqueous phase, S2 exhibited non-site-specific reactive oxygen species scavenging activity, i.e. 73.12% inhibition at 500 mug ml(-1). S1 exhibited 58.40 +/- 0.8% inhibition (at 0.025 mug ml(-1)) of the formation of reactive nitrite radicals, comparable to S2 (52.45 +/- 0.825%), and also showed 45.01% site-specific activity (1000 mug ml(-1)), along with significant (P < 0.05) electron donation potential (50-2000 mug ml(-1)) compared to S2. Such activities of S1 could be attributed to the significantly (P < 0.05) higher levels of podophyllotoxin beta-d-glucopyranoside (16.5 times) and demethyl podophyllotoxin glucoside (2.9 times) compared with S2. Together, these findings clearly prove that aryl-tetralin lignan content influences the radiation protective potential of the Podophyllum fractions to a great extent.     

Mucor fragilis as a novel source of the key pharmaceutical agents podophyllotoxin and kaempferol

Context: Podophyllotoxin, a pharmaceutically important bioactive compound of Podophyllum sps. (Berberidaceae), is in great demand worldwide as an anticancer and antivirus drug precursor. However, the source of podophyllotoxin is very limited due to the endangered status of the Podophyllum plant.

Objective: The aim of this study was to isolate podophyllotoxin-producing endophytic fungi from Sinopodophyllum hexandrum (Royle) Ying (1979) (Berberidaceae) plants of the Taibai Mountains of China in order to obtain bioactive compounds.

Materials and methods: The strains producing kaempferol and podophyllotoxin were screened by thin-layer chromatography (TLC) analysis. The presence of kaempferol and podophyllotoxin in extracts of these strains was further confirmed by high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR) analyses.

Results: Among six endophytic fungi isolated from the rhizomes of S. hexandrum, one strain was able to produce kaempferol. Another strain, named TW5, was able to produce both kaempferol and podophyllotoxin simultaneously according to the TLC, HPLC, and NMR results. The podophyllotoxin yield of TW5 was calculated to be 49.3?μg/g of mycelial dry weight after 7-d fermentation. Strain TW5 was identified morphologically and phylogenetically to be Mucor fragilis Fresen. (Mucoraceae). These results suggest that the podophyllotoxin-synthesizing ability is obtained by uptaking genes involved in the podophyllotoxin synthesis from the host plant into endophytic fungal genomes.

Conclusion: Our results showed, for the first time, that the endophytic fungus M. fragilis is able to produce simultaneously the same two bioactive metabolites, podophyllotoxin and kaempferol, as its host plant. Furthermore, the relatively high podophyllotoxin yield obtained may improve the industrial production of podophyllotoxin, which may help protect this endangered plant.     

鬼臼毒素固体脂质纳米粒的制备及对人表皮细胞体外增殖的影响

目的研究鬼臼毒素固体脂质纳米粒(POD-SLN)对人表皮细胞增殖的影响。方法采用超声乳化法制备POD-SLN混悬液,采用扫描电镜观察其粒径大小和形态,粒径分析仪测定其粒径和电位,高效液相法测定其包封率,并观察其稳定性。用POD-SLN作用于体外培养的人表皮细胞,并于6、12、24、48h检测细胞的生长情况。实验设POD-SLN组、鬼臼毒素普通脂质体组、鬼臼毒素(POD)组、空白固体脂质纳米粒(SLN)组、空白对照组,MTT法测定各组对人表皮细胞增殖的抑制作用。结果制备的POD-SLN呈圆球形或椭圆形,稳定性好,粒径为87.2±10.3nm,电位25.3±0.8mV,包封率为83.2%±2.5%。POD-SLN对人表皮细胞增殖的抑制作用呈浓度和时间依赖性。POD-SLN、POD普通脂质体及POD作用48h对人表皮细胞的抑制率最高分别为91.05%、77.02h.46%,IC50分别为2.11、16.65、101.42μg/L。空白SLN对人表皮细胞增殖无影响。结论该制备工艺可行,所制备的POD-SLN在体外能有效抑制人表皮细胞增殖,且作用强于POD及普通POD脂质体。     

鬼臼毒素衍生物的合成及其体外抗肿瘤活性

目的 获得更高活性且具有抗多药耐药活性的抗肿瘤新化合物。方法 将4β-氨基-4-脱氧鬼臼毒素与醇类化合物以丁二酸为桥连接合成了7个鬼臼毒素衍生物,其结构经1H-NMR、TOF-MS证实。用K562和K562/AO2细胞经MTT法筛选了这些衍生物的体外抗肿瘤活性。结果 7个化合物均为新化合物,其中5b、5d的抗肿瘤活性显著高于VP-16, 并且5b、5c、5d、5e的抗多药耐药活性显著高于VP-16。结论 这些鬼臼毒素衍生物可提高抗肿瘤活性。     

鬼臼毒素水溶液稳定性研究

目的考察鬼臼毒素水溶液的稳定性,为鬼臼毒素新型给药系统的研究奠定基础。方法在室温下将鬼臼毒素水溶液分别用1 mol/L的NaOH或HCL调节pH至设定值,放置60 h,考察pH对鬼臼毒素水溶液稳定性的影响;采用经典恒温法预测鬼臼毒素水溶液在室温下和4℃条件下的稳定性。结果鬼臼毒素降解的pH-速率曲线呈V型,最稳定的pH(pHm)为5。鬼臼毒素的水溶液在室温下有效期(t90)为24.86 d,4℃下为478.34 d。结论鬼臼毒素水溶液不稳定,其降解反应速率受溶液pH的影响。     

一株产鬼臼毒素内生真菌的分离及其代谢产物抗小鼠S180肉瘤的研究

目的从秦岭濒危药用桃儿七(Sinopodophyllum hexandrum)植株内分离出产鬼臼毒素(podophyllotoxin)的内生真菌,研究其发酵液的抑瘤活性。方法采用组织分离法分离、纯化桃儿七植株根、茎部位的内生真菌,逐一鉴定其代谢产物,筛选出能够产鬼臼毒素的内生真菌。采用动物体内抑瘤实验研究内生真菌发酵液对小鼠S180肉瘤的抑制作用,并对荷瘤小鼠眼眶取血进行白细胞及淋巴细胞计数。结果分离出一株产鬼臼毒素的内生真菌T8,鉴定为Cephalosporium sp.。T8发酵液实验动物组的肿瘤质量低于模型组,大于环磷酰胺组(P<0.05),且其抑制率低于环磷酰胺(P<0.05)。T8发酵液能够促进白细胞和淋巴细胞的增殖。结论 T8发酵液具有一定的抑制肿瘤生长的作用,经减毒处理后可以作为肿瘤治疗的辅助药物。     

Cytotoxic constituents from the roots ofAnthriscus sylvestris

Activity-guided fractionation of the roots of Anthriscus sylvestris resulted in the isolation and characterization of five cytotoxic compounds, deoxypodophyllotoxin (1), falcarindiol (2), and angeloyl podophyllotoxin (5) from the hexane soluble fraction and morelensin (3), bursehernin (4) from the chloroform soluble fraction. It is the first report of the occurrence of compound 5 in nature.     

鬼臼毒素衍生物的合成及细胞毒活性研究

目的基于鬼臼毒素进行结构修饰,并对得到的衍生物进行体外抗肿瘤活性评价。方法以鬼臼毒素和醛类化合物为起始原料,经多步反应合成目标化合物,并采用MTT法测试所有的目标化合物对人宫颈癌He La细胞、人慢性髓性白血病急变期K562细胞及其阿霉素耐药株K562/A02的体外抗肿瘤活性。结果合成了11个文献未报道的鬼臼毒素衍生物,其结构经1H-NMR、13C-NMR、HR-ESI-MS及熔点测定分析确证。抗肿瘤活性筛选结果表明所有目标化合物均具有不同程度的体外细胞毒活性,大部分化合物对耐药的K562细胞具有较好的细胞毒活性。结论通过对鬼臼毒素进行结构修饰,能够增强其抗肿瘤活性。