Neglschisandrins C-D: two new dibenzocyclooctadiene lignans from Schisandra neglecta

Two new dibenzocyclooctadiene lignans, neglschisandrins C-D (1-2), were isolated from the stems of Schisandra neglecta. Their structures and stereochemistries were elucidated by spectroscopic methods, including 1D- and 2D-NMR and HR-ESI-MS techniques.     

Five New Nortriterpenoids from the Stems of Schisandra neglecta

Five new nortriterpenoids, schicagenins D–F ( 1 – 3 , resp.) and negleschidilactones A and B ( 4 and 5 , resp.), together with eleven known ones, were isolated from the stems of Schisandra neglecta. Their structures were established on the basis of extensive spectroscopic analyses. All the compounds were evaluated for their activities regarding insulin sensitivity in 3T3‐L1 differentiated adipocytes. None of them showed a significant bioactivity at 10 μM concentration.     

A new triterpene and dibenzocyclooctadiene lignans from Schisandra propinqua (WALL.) BAILL

A new triterpene and two new natural dibenzocyclooctadiene lignans were isolated from the stems of Schisandra propinqua. In addition, three known lignans, octadecanoic acid, 2,3-dihydroxypropyl ester and beta-sitosterol were isolated. The structures of the new triterpene and new natural products were elucidated base on spectral analysis, including 1D and 2D NMR experiments. The isolates were tested for their cytotoxic effects against several tumor cell lines by MTT assay.     

Nortriterpenoids and lignans from the fruit of Schisandra chinensis

Phytochemical investigation of the fruit of Schisandra chinensis led to the isolation of a schisanartane nortriterpenoid, schindilactone H (1); an 18-norschiartane bisnortriterpenoid, wuweizidilactone I (2); two tetrahydrofuran-type lignans, schinlignins A and B (18 and 19); and three dibenzyl butane-type lignans, schineolignins A-C (20-22), together with 16 known compounds. The structures of these new compounds were elucidated on the basis of extensive analysis of spectroscopic data.     

Triterpenoids and lignans from the stems of Schisandra glaucescens

Two new triterpenoids, 24(E)-3α,12α-dihydroxyl-lanost-9(11),24-dien-26-oid acid (1) and 3,4-seco-24(Z)-6α,7β-dihydroxyl-cycloart-4(28),24-dien-3,26-dioic-3-methyl ester (2), and ten known ones (3–12), together with eight lignans (13–20), were isolated from the stems of Schisandra glaucescens. Their structures were established on the basis of extensive spectroscopic analyses. Compounds 1–3, 5–7, 9, 11–13 and 15–18 were isolated from this species for the first time. 1 and 2 were evaluated for their in vitro cytotoxicities against the mouse cancer B16 cell line, human cancer HepG2 and MCF7 cell lines by MTT assay.     

Micranoic acids A and B: two new octanortriterpenoids from Schisandra micrantha

Two novel octanortriterpenoids, micranoic acids A (1) and B (2), along with three known compounds, kadsuric acid (3), 3beta-hydroxy-lanost-9(11),24(25)-dien-26-oic acid (4) and schizandronic acid (5), were isolated from the leaves and stems of Schisandra micrantha. The structures of 1 and 2 were determined by 1D and 2D NMR spectroscopic analysis. Micranoic acids A and B represent a new group of triterpenes in which the entire C-17 side chain has lost. This is the first report of octanortriterpenoids isolated from the family Schisandraceae.     

二维反相液相色谱制备五味子中的木脂素

应用自主研发的具有分离-富集模式的制备色谱工厂,建立了分离制备五味子木脂素有效部位及其单体化合物的方法。该方法首先以C₁₈（250 mm×4.6 mm,5 μm）为色谱柱,水和甲醇为流动相,分离度和保留时间为考察指标,采集4个不同梯度的色谱信息,通过XTool色谱专家系统软件模拟,确定五味子木脂素第一、二维色谱条件;然后采用线性放大的方法,以C₁₈（250 mm×30 mm,10 μm）为第一、二维分离柱,C₁₈（80 mm×30 mm,10 μm）为富集柱,水为富集稀释液,对五味子木脂素进行二维色谱分离纯化;最后第一维分离得到9个可重复组分,第二维分离得到20个高纯度化合物,其中有6个单体化合物。结果表明该法重现性良好,可以实现五味子木脂素的系统性分离,对五味子化学成分的研究具有重要意义。     

Two new lignans from Horsfieldia kingii

Two new dibenzylbutyrolactol lignans and three known dibenzylbutyrolactone lignans were isolated from the twigs and leaves of Horsfieldia kingii. Their structures were elucidated by spectroscopic analysis. Cytotoxicity evaluation of these compounds against five human tumour lines showed no inhibitory effects.     

Two new lignans from Dipteronia dyeriana

A new sesquilignan, 7＇,8＇-didehydroherpetotriol （1）, and a new lignan glycoside, （＋）-isolariciresinol-9＇-O-α-L-rhamnopyra- nosy1-（1→6）-[3-D-glucopyranoside （2）, were isolated from the branches of Dipteronia dyeriana. Their structures were elucidated by spectroscopic methods and chemical evidence. Compound 1 possessed inhibitory activity against human leukaemia K562 cells with an IC50 value of 39 μmol/L.     

Cyphostemmins A-B, two new antifungal oligostilbenes from Cyphostemma crotalarioides (Vitaceae)

Two new antifungal resveratrol dimers, cyphostemmins A-B (1–2), have isolated from the roots of Cyphostemma crotalarioides planch (Vitaceae) together with resveratrol 3 and previously known reseveratrol dimers (4–7). Structures of these new compounds have been established on the basis of their MS and ¹H and ¹³C NMR spectroscopic data.     

Henrischinins A-C: three new triterpenoids from Schisandra henryi

Three novel triterpenoids, henrischinins A-C (1-3), featuring the unique motif of a 3-one-2-oxabicyclo[3.2.1]-octane, were isolated from the leaves and stems of Schisandra henryi. Their structures were elucidated by spectroscopic methods, and the absolute configuration of 2 was confirmed by a single crystal X-ray diffraction. Compounds 1 and 2 showed weak cytotoxicity against HL-60 cell lines.     

Two new eupodienone lignans from Gymnotheca chinensis

Two new eupodienone lignans, named gymnothelignan T(1) and gymnothelignan U(2) were isolated from the whole plants of endemicmedicinal plant of Gymnotheca chinensis(Saururaceae). The structures of the new compounds were elucidated by means of HRMS, 1D and 2D NMR. Compound 1 was tested for cytotoxic activity in HCT15, HCT116, A549, MCF-7 and HepG2 cells and exhibited no appreciable activity against these tested cell lines with IC50 values above 50 mmol/L.     

Airlanggins A-B,two new isoprenylated benzofuran-3-ones from the stem bark of Calophyllum soulattri

Two new isoprenylated benzofuran 3-ones, airlanggin A (1) and B (2) along with two known xanthones, ananixanthone (3) and trapezifolixanthone (4) were isolated from the stem bark of Calophyllum soulattri. Structures of all the compounds were elucidated using extensive spectroscopic methods, including UV, IR, HRESIMS, 1D and 2D NMR. Compounds 1–4 were evaluated for their cytotoxicity against P-388 cells, showing that compound 3 was the most active with IC₅₀ 0.68 μg/mL and compound 1 showed moderate activity with IC₅₀ 5.80 μg/mL.     

基质固相分散萃取-高效液相色谱法同时测定五味子中5种木脂素类化合物北大核心CSCD

研究建立了基质固相分散萃取-高效液相色谱(MSPD-HPLC)分析五味子中5种木脂素类化合物(五味子醇甲、五味子醇乙、五味子甲素、五味子乙素、五味子丙素)的方法。采用反相C_(18)色谱柱进行分离,以0.1%(v/v)甲酸水溶液和乙腈为流动相进行梯度洗脱,在波长250 nm下检测。考察了包括硅胶、酸性氧化铝、中性氧化铝、碱性氧化铝、佛罗里硅土、Diol、XAmide、Xion和C_(18)、C_(18)-ME、C_(18)-G_(1)、C_(18)-HC等在内的12种吸附剂以及吸附剂的质量、洗脱剂的种类、洗脱剂体积对五味子木脂素类化合物得率的影响。选定Xion作为MSPD-HPLC分析五味子中木脂素类化合物的吸附剂;基于吸附剂Xion的萃取参数优化结果表明:以0.25 g五味子粉末为固定值,Xion(0.75 g)为吸附剂,甲醇(15 mL)为洗脱剂,MSPD对五味子中木脂素类化合物具有较高的得率。建立的五味子中5种木脂素类化合物的分析方法,各目标分析物具有良好的线性关系(相关系数R^(2)≥0.9999),检出限与定量限分别介于0.0089~0.0294μg/mL和0.0267~0.0882μg/mL之间。对五味子木脂素类化合物进行低、中、高3个水平的加标回收试验,平均回收率为92.2%~111.2%,相对标准偏差为0.23%~3.54%。日内和日间精密度均小于3.6%。与超声辅助提取和热回流提取前处理相比,MSPD具有萃取和净化相结合、耗时少、所需溶剂量少的优点,且MSPD-HPLC获得的结果优于经典方法。所建立的方法成功应用于17批五味子中5种木脂素类化合物含量的分析。     

Ionic liquid-based microwave-assisted extraction of essential oil and biphenyl cyclooctene lignans from Schisandra chinensis Baill fruits

Ionic liquid-based microwave-assisted extraction (ILMAE) has been successfully applied in extracting essential oil and four kinds of biphenyl cyclooctene lignans from Schisandra chinensis Baill. 0.25 M 1-lauryl-3-methylimidazolium bromide ionic liquid is selected as solvent. The optimum parameters of dealing with 25.0 g sample are 385 W irradiation power, 40 min microwave extraction time and 1:12 solid-liquid ratio. The yields of essential oil and lignans are 12.12±0.37 ml/kg and 250.2±38.2 mg/kg under the optimum conditions. The composition of the essential oil extracted by hydro-distillation, steam-distillation and ILMAE is analyzed by GC-MS. With ILMAE method, the energy consumption time has not only been shortened to 40 min (hydro-distillation 3.0 h for extracting essential oil and reflux extraction 4.0 h for extracting lignans, respectively), but also the extraction efficiency has been improved (extraction of lignans and distillation of essential oil at the same time) and reduces the environmental pollution. S. chinensis materials treated by different methods are observed by scanning electronic microscopy. Micrographs provide more evidence to prove that ILMAE is a better and faster method. The experimental results also indicate that ILMAE is a simple and efficient technique for sample preparation.     

Study on ionic liquid-based ultrasonic-assisted extraction of biphenyl cyclooctene lignans from the fruit of Schisandra chinensis Baill

The ionic liquid-based ultrasonic-assisted extraction (ILUAE) has been successfully applied in extracting four biphenyl cyclooctene lignans from the fruit of Schisandra chinensis Baill. Seventeen different types of ionic liquids with different cations and anions have been investigated. 0.8 M 1-lauryl-3-methylimidazolium bromide ([C12mim]Br) solution was selected as solvent. In addition, the ultrasonic parameters including ultrasonic power, time for ultrasonic treatment and solid–liquid ratio have been optimized by Response Surface Method (RSM). Compared with the conventional solvent extraction, the efficiency of the approach proposed in this work is about 3.5 times as much as that of the conventional solvent extraction method. With the proposed extraction method, the extraction time has been reduced to 30 min, whereas the conventional extraction method requires about 6.0 h. The experimental results presented in this work indicate that the ILUAE is a simple and efficient technique for sample preparation. The proposed method is reproducible.     

Structural and spectroscopic characteristics of two new dibenzylbutane type lignans from Taxus baccata L.

Chromatographic separation of chloroform extracts of the heartwood of Taxus baccata L. has yielded two new dibenzylbutane type lignans, together with a known lignan. Their structures were established as 3′-demethylisolariciresinol-9′-hydroxy isopropylether (1) and 3-demethylisolariciresinol (2) and isolariciresinol (3) on the basis of 1D- and 2D-NMR spectroscopic analysis. Compounds 1 and 2 were identified as new lignans of isolariciresinol derivatives. Compound 1 is the first lignan with a hydroxyisopropyl group at C-9′. Molecular mechanic calculations of these compounds were carried out by using mm3 program. Furthermore, the conformations of these three compounds were computed with the semi-empirical molecular orbital methods AM1 and PM3 by using X-ray crystal structure results of similar compounds. So, three-dimensional, the most probable structure of these compounds were obtained, compared and discussed.     

Legonoxamines A-B,two new hydroxamate siderophores from the soil bacterium, Streptomyces sp. MA37

Two new siderophores belonging to the hydroxamate class, Legonoxamine A (1) and B (2) have been isolated from the soil bacterium, Streptomyces sp. MA37, together with one known compound, desferrioxamine B (3). Their structures were elucidated based on spectroscopic methods including 1D, 2D NMR, MS, as well as by comparison with the relevant literatures. To our knowledge, this is the first report describing a siderophore containing the N-hydroxyl phenylacetyl cadaverine (HPAC) moiety in the structure. Based on bioinformatics analysis and previous knowledge of the biosynthesis of the hydroxamate-type siderophore, the biosynthetic gene cluster (lgo) responsible for the production of 1–3 was identified in the annotated genome of the producing strain. The supplementation of phenylacetate and benzoate analogues with meta substitution into the cultures of Streptomyces sp. MA37 resulted in the production of new legonoxamine A derivatives as observed in LC-HR-ESIMS, suggesting that the legonoxamine biosynthetic pathway has a good degree of natural flexibility of accepting unnatural precursors with different functional groups.     

Schinarisanlactone A, a new bisnortriterpenoid from Schisandra arisanensis

A novel triterpenoid, schinarisanlactone A (1), was isolated from the fruits of Schisandra arisanensis. Compound 1 possesses an unprecedented skeleton having a 5/7/7/5/7/5/6/5-fused octacyclic ring system. The structure of 1 was determined by 2D NMR techniques (COSY, HMQC, HMBC, and NOESY) and was confirmed by X-ray crystallographic analysis. Schinarisanlactone A (1) exhibited significant anti-HIV activity.