Two New Phenolic Glycosides from the Roots of Rhododendron molle

Two new phenolic glycosides,everninic acid methyl ester-2-O-β-O-xylopyran-osyl-(1→6)-β-D-glucopyranoside 1 and 7-hydroxyl-5-methoxyphthalide-7-β-D-xylopyranosyl-(1→6)-β-D-glucopyranoside 2 were isolated from the roots of Rhododendron molle G.Don. Their structures were determined by spectral evidence including 2D NMR techniques.     

沙菜属经济藻类氨基酸与微量元素研究

首次报道了沙菜属Ｈｙｐｅｎａ３种经济藻类的１６种氨基酸和１２种元素的住房及其测定方法，还报道了沙菜属藻类无机元素和氨基酸的特征谱，以显示本属藻类的特片和属间种间的区别。     

A New Steroidal Saponin from Dioscorea deltoidea Wall var. orbiculata

Bioactivity-guided fractionation led to the isolation of a new steroidal saponin, orbiculatoside B, together with a pair of furostanol saponins, protobioside and methyl protobioside, from the fresh rhizomes of Dioscorea deltoidea Wall var. orbiculate. The new compound was identified to be isonarthogenin 3-O-α-L-thamnopyranosyl(1→2)-[α-L-rhamnopyranosyl-(1→4)]-β-D-glucopyranoside by various NMR techniques in combination with chemical methods. The three saponins showed strong activity against Pyricularia oryzae,and were cytotoxic to cancer cell line K562,HCT-15,A549, and A2780a in vitro.     

Two new C-glycosylflavones from the leaves of Iris lactea var.chinensis

Two new acylated C-glycosylflavones were isolated from the leaves of Iris lactea var. chinensis, and their structures were elucidated on the basis of extensive NMR experiments and mass spectrometry methods and were assigned as 5-hydroxy-4＇- methoxyflavone-7-O-（β-D-2＇＇＇＇4＇＇＇＇-diacetylrhamnopyranosyl）-6-C-[ O-（α-L-6＇＇＇-acetyl-glucpyranosyl）-1→2-β-D-glucopyrano- side] （irislactin A） and 5-hydroxy-4＇,7-dimethoxyflavone-6-C-[O-（α-L-2＇＇＇,3＇＇＇-diacetylrhanmo-pyranosyl）-1→ 2-β-D-glucopyranoside] （irislactin B）.     

Two new benzofuran lignan glycosides from Gelsemium elegans

Two new benzofuran lignan glycosides, gelsemiunoside A and B, were isolated from the whole plant of Gelsemium elegans Benth. Their structures were elucidated on the basis of spectroscopic evidence. Furthermore, gelsemiunoside A and B were shown a potent cytotoxic activity by suppressing the proliferation of A375-S2 cells.     

牛筋果茎中一个新的异戊烯基异黄酮类化合物

综合运用硅胶柱色谱、ODS柱色谱、SephadexLH-20凝胶柱色谱以及制备型高效液相色谱(HPLC)等色谱分离手段,对苦木科牛筋果属植物牛筋果Harrisoniaperforata茎中的化学成分进行了研究,从其茎的95%乙醇提取物中分离得到了8个异戊烯基异黄酮类化合物,采用多种波谱鉴定方法确定了这些分离得到化合物的化学结构,其中化合物1为1个新的异戊烯基异黄酮类化合物,化合物2～8为从牛筋果属植物中分离得到的化合物.化合物1～8体外抑制肿瘤细胞生长的活性评价结果表明,它们对五种肿瘤细胞株(HL-60、A549、SMMC-7721、MCF-7和SW480)均具有较为显著的体外生长抑制活性,抑制肿瘤细胞生长的活性的IC₅₀范围为(0.38±0.03)～(31.68±0.21)μmol/L,抑制肿瘤细胞生长的活性与抗肿瘤阳性对照药顺铂的抑制活性相当.     

大理紫乌头的二萜生物碱成分研究

为了研究大理紫乌头的二萜生物碱成分,采用硅胶柱层析进行化合物的分离纯化,通过NMR方法对其化合物结构进行鉴定。结果表明大理紫乌头含6个二萜生物碱成分,包括5个C_(19)-乌头碱型:塔拉萨敏(1)、14-乙酰塔拉萨敏(2)、黄草乌碱丙(3)、8-去乙酰滇乌碱(4)、印乌碱(5)和1个C_(20)-海替定型宽乌宁(6)。其中化合物3～6为首次从该物种分离得到。     

Exploration of iron-chalcogenide superconductors

Iron-chalcogenide compounds with FeSe（Te, S） layers did not attract much attention until the discovery of high-Tc superconductivity （SC） in the iron-pnictide compounds at the begining of 2008. Compared with FeAs-based superconductors, iron-chalcogenide superconductors have aroused enormous enthusiasm to study the relationship between SC and magnetisms with several distinct features, such as different antiferromagnetic ground states with relatively large moments in the parents, indicating possibly different superconducting mechanisms, the existence of the excess Fe atoms or Fe vacancies in the crystal lattice. Another reason is that the large single crystals are easily grown for the iron-chalcogenide compounds. This review will focus on our exploration for the iron-chalcogenide superconductors and discussion on several issues, including the crystal structure, magnetic properties, superconductivity, and phase separation. Some of them reach a consensus but some important questions still remain to be answered.     

原子吸收光谱法测定女贞属苦丁茶中金属含量

用火焰原子吸收光谱法测定贵州不同产地的女贞属苦丁茶中Cu、Zn、Ca,Mg 4种金属的含量,并比较含量差异.测定结果表明,女贞属苦丁茶中4种金属元素的含量较高,Cu元素含量为11.28-18.15μg·g-1、Zn元素含量为25.92-43.21μg·g-1、Ca元素含量为2371-12091μg·g-1、Mg元素含量...     

贯众多糖提取及其抗氧化作用

采用水提-醇沉法从贯众中提取多糖,脱脂、去蛋白,经冷冻干燥后得到粗多糖。通过比色法研究其体外清除羟基自由基能力。贯众多糖具有较好的清除.OH的能力,且其清除能力与多糖浓度有明显的量效关系。清除50%羟基自由基所需要的多糖浓度为3.9m g/mL。