Chemical constituents from the fruits of Trichosanthes kirilowii

Two new compounds, 1-deoxy-1-[2′-oxo-1′-pyrrolidinyl]-2-n-butyl-α-fructofuranoside (1) and isoarvenin III (2), were isolated from the fruits of Trichosanthes kirilowii Maxim, and their structures were established on the basis of spectroscopic methods.     

New sesquiterpene and triterpene from the fruits of Cryptomeria fortunei

A new sesquiterpene (1) and a new triterpene (2) along with 25 known compounds were isolated from the fruits of Cryptomeria fortunei (Taxodiaceae). Their structures were elucidated on the basis of spectroscopic analysis.     

Cytotoxic triterpene saponins from Clematis mandshurica

Two new triterpene saponins, mandshunosides A and B (1 and 2), were isolated from the roots and rhizomes of Clematis mandshurica. Their structures were elucidated on the basis of spectroscopic evidence and hydrolysis products. Compounds 1 and 2 showed inhibitory activities against two colorectal human cancer cells HCT 116 (IC₅₀ 2.1 μM for 1 and 2.5 μM for 2) and HT-29 (IC₅₀ 3.7 μM for 1 and 3.3 μM for 2).     

A new ursane-type triterpenoid from Schefflera heptaphylla (L.) Frodin

A new ursane-type triterpenoid (1), together with 15 known compounds (2–16), was isolated from the barks of Schefflera heptaphylla (L.) Frodin. The structure of the new compound was determined on the basis of extensive spectroscopic data including IR, HR-ESI-MS, 1D and 2D NMR, and further confirmed by single-crystal X-ray diffraction. Compounds 2–6 were isolated from Schefflera genus for the first time.     

Bioactive constituents of oleanane-type triterpene saponins from the roots of Glycyrrhiza glabra

Three new oleanane-type triterpene saponins, namely licorice-saponin M3 (1), licorice-saponin N4 (2), and licorice-saponin O4 (3), an artificial product (4), as well as five known triterpene glucuronides (5–9), were isolated from the roots of Glycyrrhiza glabra L. Their structures were established using 1D and 2D NMR spectroscopy, mass spectrometry, and by comparison with spectroscopic data reported in the literature. The inhibitory effects of the selected compounds on neuraminidase were evaluated, and the preliminary structure–activity relationship was also predicted.     

Dual biosynthetic pathways to phytosterol via cycloartenol and lanosterol in Arabidopsis

The differences between the biosynthesis of sterols in higher plants and yeast/mammals are believed to originate at the cyclization step of oxidosqualene, which is cyclized to cycloartenol in higher plants and lanosterol in yeast/mammals. Recently, lanosterol synthase genes were identified from dicotyledonous plant species including Arabidopsis, suggesting that higher plants possess dual biosynthetic pathways to phytosterols via lanosterol, and through cycloartenol. To identify the biosynthetic pathway to phytosterol via lanosterol, and to reveal the contributions to phytosterol biosynthesis via each cycloartenol and lanosterol, we performed feeding experiments by using [6-¹³C²H₃]mevalonate with Arabidopsis seedlings. Applying ¹³C-{¹H}{²H} nuclear magnetic resonance (NMR) techniques, the elucidation of deuterium on C-19 behavior of phytosterol provided evidence that small amounts of phytosterol were biosynthesized via lanosterol. The levels of phytosterol increased on overexpression of LAS1, and phytosterols derived from lanosterol were not observed in a LAS1-knockout plant. This is direct evidence to indicate that the biosynthetic pathway for phytosterol via lanosterol exists in plant cells. We designate the biosynthetic pathway to phytosterols via lanosterol “the lanosterol pathway.” LAS1 expression is reported to be induced by the application of jasmonate and is thought to have evolved from an ancestral cycloartenol synthase to a triterpenoid synthase, such as β-amyrin synthase and lupeol synthase. Considering this background, the lanosterol pathway may contribute to the biosynthesis of not only phytosterols, but also steroids as secondary metabolites.     

四合木化学成分研究

研究了四合木Tetraena mongolica的化学成分。采用硅胶柱色谱,凝胶柱色谱,HPLC制备色谱方法分离纯化得到单体化合物,采用有机波谱方法鉴定化合物结构。从四合木乙酸乙酯提取物中分离得到1个新化合物,命名为olean-11-oxo-12-en-28-ol-3β-yl-caffeate。     

准噶尔大戟的化学成分研究

目的 对准噶尔大戟中的化学成分进行分离鉴定.方法 采用硅胶、Sephadex LH-20及MPLC制备色谱技术,通过理化方法和光谱分析鉴定其结构.结果 从准噶尔大戟的乙醇提取物中得到11个化合物,分别鉴定为香茅二醇(Ⅰ)、白桦脂醇(Ⅱ)、白桦脂酸(Ⅲ)、齐墩果酸(Ⅳ)、7-O-β谷甾醇(Ⅴ)、3-甲氧基-4-羟基反式苯丙烯酸正二十八醇酯(Ⅵ)、二十八酸(Ⅶ)、I-二十八烯(Ⅷ)、24-亚甲基-环阿尔廷醇(Ⅸ)、大戟醇(Ⅹ)、β-谷甾醇(Ⅺ).结论 化合物Ⅰ～Ⅷ均为首次从该植物中分离得到.     

桐花树化学成分研究

目的研究桐花树的化学成分。方法采用硅胶柱色谱法分离纯化,薄层色谱及波谱法进行结构鉴定。结果从桐花树树皮的乙醇提取物的醋酸乙酯萃取部位分得6个化合物,其结构鉴定为16α,28-dihydroxyl-3-oxo-12-oleanene(Ⅰ)、5-O-methylembelin(Ⅱ)、豆甾醇(Ⅲ)、α-菠甾醇(Ⅳ)、岩藻甾醇(Ⅴ)、棕榈酸(Ⅵ)。结论化合物Ⅰ为新三萜化合物,命名为桐花树素(aegicornin),Ⅲ~Ⅵ均为首次从该植物中分离得到。     

兴安升麻的化学成分研究

目的：对兴安升麻（Cimicifuga dahurica根茎的化学成分进行分离、鉴定。方法：采用不同的层析技术进行分离，用IR，MS，^1HNMR,^13CNMR和2DNMR等波谱技术确定化合物的结构。结果：分离鉴定了10个化合物：升麻醇（1），24－表－7，8－去氢升麻醇3－O－β-D－吡喃木糖苷（Ⅱ），7，8－去氢升麻醇3－O－β-D－吡喃木糖苷（Ⅲ），25－O－乙酰基－7，8－去氢升麻醇3－O－β-D－吡喃木糖苷（Ⅳ），3－aradinosyl-24-O-acetylhydroshengmanol 15-glucoside (Ⅴ）；异阿魏酸（Ⅵ），（E）－3－（3‘-甲基－2‘－亚丁烯基）－2－吲哚酮（Ⅶ）、蔗糖（Ⅷ），β－谷甾醇（Ⅸ）和豆甾醇葡萄糖苷（Ⅹ）。结论：化合物Ⅱ，Ⅲ，Ⅳ和Ⅹ为首次从兴安升麻中分离得到。