三白草不同部位及鱼腥草挥发油成分的GC-MS比较分析

采用水蒸气蒸馏法提取,气相色谱-质谱联用技术(GC-MS)对三白草不同部位及鱼腥草挥发油化学成分进行定性和定量分析。共分离鉴定出88个化合物,从三白草地上部分鉴定出36个,根茎中鉴定出31个,分别占挥发油总量的73.38%和95.53%,其中仅13个共有成分;从鱼腥草中鉴定出50个化合物,占挥发油总量的74.59%。三白草地上部分与根茎挥发油中化学成分含量和组成有明显差异,且均不含有甲基正壬酮。     

蚤休、重楼和王孙

经过历史考证,作者确认:首载于《神农本草经》的蚤休为重楼属的Paris polyphyllaSmith var. chinensis (Fr.)Hara;首载于《滇南本草》中的重楼为重楼属的Paris polyphyllaSmith var. yunnanensis (Fr.) Hand. -Mazz.;《植物名实图考》中的王孙则是三白草科的三白草Saururus chinensis (Lour.) Bail.     

Saururus cernuus lignans--potent small molecule inhibitors of hypoxia-inducible factor-1

Hypoxia-inducible factor-1 (HIF-1) represents an important tumor-selective therapeutic target for solid tumors. In search of novel small molecule HIF-1 inhibitors, 5400 natural product-rich extracts from plants, marine organisms, and microbes were examined for HIF-1 inhibitory activities using a cell-based reporter assay. Bioassay-guided fractionation and isolation, followed by structure elucidation, yielded three potent natural product-derived HIF-1 inhibitors and two structurally related inactive compounds. In a T47D cell-based reporter assay, manassantin B1, manassantin A, and 4-O-methylsaucerneol inhibited hypoxia-induced HIF-1 activation with IC50 values of 3, 3, and 20 nM, respectively. All three compounds are relatively hypoxia-specific inhibitors of HIF-1 activation, in comparison to other stimuli. The hypoxic induction of HIF-1 target genes CDKN1A, VEGF, and GLUT-1 were also inhibited. These compounds inhibit HIF-1 by blocking hypoxia-induced nuclear HIF-1alpha protein accumulation without affecting HIF-1alpha mRNA levels. In addition, preliminary structure-activity studies suggest specific structural requirements for this class of HIF-1 inhibitors.     

The history of Dryas octopetala L. in eastern Fennoscandia

The information available concerning the Late-Quaternary history of Dryas octopetala L. in eastern Fennoscandia is surveyed. It is evident that Dryas has been an important component of the treeless periglacial vegetation which existed along most of the perimeter of the Weichselian glacier c. 10,000 B.P., marked by the Salpausselkä-Kuittijärvi-Tromsø-Lyngen end moraine arc. Dryas has not been as common in the archipelago of southern Finland, west of about 28°E long. Disjunctive recent localities inside the area still glaciated during the early Flandrian (Pre-boreal period) are relics of an immigration contemporaneous with the advance of light birch forests.     

三白草花、叶和茎挥发性成分的比较分析

采用顶空固相微萃取提取三白草花、叶和茎中的挥发性成分,利用GC-MS对比分析三者中的挥发性成分.从三白草花、叶和茎分别鉴定出的31、22和22个成分,分别占总挥发性成分的95.64％、98.75％和98.54％.三者共有18个化学成分,其主要化合物类型是萜类(单萜和倍半萜,其中单萜含量最高),分别占总挥发性成分的92.18％、98.19％和97.74％,还含有两个芳香族化合物:枯茗醇和姜黄烯,此外,4-(1,5-二甲基己基-4-烯)环己烯-2-酮和二十一烷两个脂肪族化合物仅存在于花中,三者的主要化合物均为柠檬烯、柠檬醛(含顺式柠檬醛)、蒎烯(含α和β构型)和β-月桂烯,另外大根香叶烯D、姜黄烯、1-b-红没药烯和β-倍半水芹烯在花中的含量均高于叶和茎.叶茎中化合物种类和含量差别均不大,但与花有较大的差别.     

三白草中ATG4B抑制剂的发现及活性测定

验证从三白草中提取的两个化合物XGN56和XGN59对自噬关键蛋白ATG4B酶活性的影响及对自噬的调节作用。分子对接的方法验证化合物与游离ATG4B及ATG4B-LC3复合体的氢键结合作用;SDS-PAGE法及荧光共振能量转移法(FRET)测定化合物(10μmol/L)抑制ATG4B的IC50值;LC3融合GFP荧光标签检测化合物(10μmol/L)对LC3荧光聚集的影响,并设置正常组、给药组和药物联用Baf(0.5μmol/L)组;过表达GFP-LC3的WT-MEF及ATG5-/--MEF细胞检测化合物诱导LC3荧光点的情况。结果显示,XGN56和XGN59能分别与游离ATG4B和ATG4B-LC3复合体形成氢键作用,且两者均能剂量依赖地抑制ATG4B的酶切活性,体外IC50分别为7.74μmol/L和8.00μmol/L,同时能够ATG5依赖地促进GFP标记的自噬体的生成(P<0.001)。结果表明,两个化合物可能是通过一定程度地抑制ATG4B的酶活性从而促进细胞自噬水平。     

Lignans from Saururus chinensis inhibiting the transcription factor NF-kappaB

The sesquineolignans, saucerneol D and saucerneol E were isolated from the roots of Saururus chinensis together with four known lignans, manassantin A, manassantin B, (-)-saucerneol methyl ether, and (+)-saucernetin. Structure elucidation was based on the analysis of spectroscopic data and anti-inflammatory activity was studied using HeLa cells transfected with NF-kappaB reporter construct. All compounds except for (+)-saucernetin inhibited NF-kappaB dependent reporter gene expression with IC50 values of 2.5-16.9 microM.     

Population Structure and Reproductive Biology of Saururus cernuus L. (Saururaceae)

Abstract The population structure and reproductive biology of Saururus cernuus (Lizard's Tail; Saururaceae; Piperales), is documented in five sites in southern Louisiana (Mississippi Delta). The species is common throughout the southeastern United States in marshes, along streams, edges of lakes, and in the understory of moist forests. The clonal species exhibits sexual and vegetative reproduction. Wind and insects both play important roles in pollination. Pollen may be borne by insects directly. Alternatively, the pollen may be borne by wind after its release is triggered from pendulous floral spikes (the “Lizard's Tail”) by either wind or insect landings (insect-mediated wind pollination). The plants are self-incompatible and seed set results from a combination of pollination modes with wind pollination being the primary mode (rare in the Magnoliidae). Inflorescence and floral structure exhibit adaptive features that facilitate the various modes of pollen transfer, viz., numerous, small scented, protogynous flowers with no perianth, ultraviolet patterns produced by stamen filaments, small pollen grains, curved inflorescences, and exerted stamens, etc. Fruit production and seed germination are documented and plant growth and densities are compared in sunny versus forest sites.     

A methylene chloride fraction of Saururus chinensis induces apoptosis through the activation of caspase-3 in prostate and breast cancer cells

The aerial parts of Saururus chinensis (SC) have been used for the treatment of edema, fever, jaundice, and inflammatory diseases in Korean folk medicine for centuries. However, the mechanism by which SC exerts these anti-tumorigenic activities in human prostate and breast cancer cells has not yet been fully understood. In this study, we report on the methylene chloride fraction from SC exerting cytotoxicity against prostate and breast cancer cells in a dose-dependent manner. Specifically, SC exerted the most potent cytotoxicity in LNCaP and MCF-7 cells. SC was shown to down-regulate various angiogenetic (VEGF), proliferative (Cyclin D₁), anti-apoptotic (Bcl-2) gene products in these cells. SC also increased the number of annexin V-positive apoptotic bodies and the sub-G1 DNA contents of the cell cycle undergoing apoptosis through caspase-3 activation in both LNCaP and MCF-7 cells. We further confirmed that caspase-3 plays an important role in SC-induced apoptosis in LNCaP and MCF-7 cells through the use of the caspase-3 inhibitor. Moreover, we observed that SC potentiated paclitaxel-induced apoptosis in MCF-7 cells and sauchinone is a major active constituent of SC, which could induce apoptosis in the cells. Taken together, our data provide the evidence that SC induces apoptosis depending on caspase-3 activation and overcomes the natural biological resistance to chemotherapy found in human prostate and breast cancer cells.