蔬毛吴茱萸果实中新化合物吴茱萸塔宁的分离及结构表征

从传统中药蔬毛吴茱萸的干燥未成熟果实中分离得到一个稀有高氧化状态、新的柠檬苦素类化合物吴茱萸塔宁(evolimorutanin),同时还分离得到了已知结构的化合物柠檬苦素(limonin)。根据IR、MS、1DNMR(1HNMR,13C NMR,DEPT)和2D NMR(1H-1HCOSY,HSQC,HMBC)谱学数据确定了它们的结构,两者均归属为降三萜类化合物,A,A′,B,C,D五个环的取代和立体构型完全相同,只有E环氧化状态不同。此外,还分析了从柠檬苦素转化为吴茱萸塔宁的可能过程。     

Extraction and Crystal Structure of Physalin B

The title compound of physalin B(C28H32O9), a main active physalin of Physalis angulata L, was isolated from the whole plant of Physalis angulata L, and characterized by X-ray diffraction analysis. It crystallizes in the monoclinic system, space group P21 with C28H32O9, a = 12.4996(2), b = 14.35620(10), c = 14.75190(10), V = 2607.97(5) 3, Z = 4, Dc = 1.382 mg/cm3, Mr = 542.56, F(000) = 1152, and μ = 0.870 mm-1. The final R = 0.0389 and wR = 0.1037 for 47670 observed reflections(I 2σ(I)). The rigid molecule consists of eight fused rings involving two lactones. There are two C28H32O9 molecules in an symmetric unit, and the title compound is stacked into a 3D layer structure through hydrogen bonds. In the 5~20 μmol/L range, physalin B can significantly inhibit the secretion of inflammatory cytokines TNF-α and IL-6 on RAW264.7 cells. The results suggest that physalin B has anti-inflammatory activity in vitro.     

鸦胆子化学成分的研究 Ⅰ.鸦胆子酮酸等五个苦木素的分离和鉴定

鸦胆子系我国常用中药,从中分得五个苦木素类化合物.其中四种依次鉴定为已知的鸦胆子苦醇(1),鸦胆子苦素D(2),去氢鸦胆子苦素B(3),鸦胆子苦素E(4).另一种为新化合物,经光谱及化学方法推定其结构为5,命名为鸦胆子酮酸.1对S₁₈₀瘤株有边缘活性.2和4有抗疟作用.     

长苞铁杉中两个新的重排羊毛甾烷型三萜

从中国特有植物长苞铁杉树枝的甲醇提物中分离得到2个新的重排羊毛甾烷型三萜,命名为铁杉内酯素A(1)和铁杉内酯素B(2),其结构通过HR-ESIMS,1D和2D NMR等光谱技术确定,铁杉内酯素A(1)的构型进一步通过X单晶衍射确认.     

大孔树脂法精制酸浆宿萼色素的研究

研究了大孔树脂法精制酸浆宿萼色素.考察了5种大孔树脂的吸附性能,结果表明,HPD100A对酸浆宿萼色素的精制效果较好,最佳工艺条件为:温度20℃,pH 6.0,上柱流速为1.5mL/min,以无水乙醇、丙酮阶段洗脱时能达到较好的精制效果.     

大孔树脂分离纯化丹酚酸的研究

比较了D301R、D392、D380大孔阴离子交换树脂和X-5.AB-8、NKA-9、SP825大孔吸附树脂对丹参水溶性成分的吸附和解吸能力,筛选出效果较好的SP825进行分离纯化丹酚酸的研究.实验表明,大孔吸附树脂SP825能分离出纯度为95.32%的丹参素,在梯度洗脱条件下可得到以丹参素(水洗脱)和丹酚酸B(乙醇洗脱)为主的产品.在最佳吸附与解吸工艺参数下,丹参素、紫草酸、迷迭香酸、丹酚酸A和丹酚酸B的收率分别为:36.92%、80.39%、82.45%、43.07%和41.03%.     

Sin/Si-n(n=2-6)的结构和电子亲合能的密度泛函理论研究

选用四种不同的密度泛函理论方法(B3LYP,BLYP,BP86,B3P86),在全电子的双ζ加极化加弥散函数基组(DZP++)下,研究Sin/Si-n (n=2 -6 )体系的结构和电子亲合能.预测Si2 /Si-2 ,Si3 /Si-3 ,Si4 /Si-4 ,Si5 /Si-5 和Si6 /Si-6 的基态结构分别为C∞h(3Σ-g ) /C∞h(2Σ+g ),D3h(3A′2 ) /C2υ(2A1 ),D2h(1Ag) /D2h(2B2g),D3h(1A′1 ) /D3h(2A″2 )和C2υ(1A1 ) /D4h(2A2u).在电子亲合能方面,B3LYP方法预测的电子亲合能是最可靠的.预测Si2,Si3,Si4,Si5和Si6的电子亲合能分别为 2. 05, 2. 34, 2. 16, 2. 48和 2. 13eV.     

红纹马先蒿中木脂素衍生物成分研究

红纹马先蒿(Pedicularis striata)是玄参科马先蒿属植物,其主要成分为苯丙素甙。本文报道对该植物进一步研究中分离得到的2个微量甙类化合物,命名为红纹马先蒿甙A和B[Striatoside A(1)和B(2)]。     

冬凌草甲素的晶体结构

冬凌草甲素,C_(20)H_(28)O_6,Mr=364.44,是一种从中药中提取的抗癌药,它的晶体结构分析表明晶体属正交晶系的空间群P2_12_12_1,晶胞参数为α=13.316(9),b=21.302(2),c=13.015(1),V=3697(9)~3。Z=8,D_c=1.31g/cm~3,D_o=1.30g/cm~3,F(000)=1568。该分子是四环二萜类化合物,A环和C环是椅型结构,B环是船型结构;D环是部分共轭五员环,为半椅型结构,环上相邻的两个双重键侧基组成一个六原子的共轭平面。     

第5届全国大学生化学实验邀请赛笔试题答案

一、选择题1B2D3A4D5C6D7B8A9B10D11A12C13C14A15D16A17D18B19D20C21B22C23D24C25B26D27D28C29A30B31B32A33B34C35C36A37B38D39B40A41B42C43A44D45B46B47A48D49A50C51A52D53B54A55A56B57C58A59A60D61D62C63B64A65B66A67C68D69B70B二、填空题(每题分数在题号后,共45分)1(2.5分,每个空0.5分)加热饱和趁热过滤冷却过滤2(2分,每个空1分)x值算式为((19.0538-18.4212)/159.5):(19.4156-19.0538)=1:x求得x值>53(1.5分,每个空0.5分)过滤离心分离颗粒较大密度较大4(1分,每个空0.5分)方向能量5(1分,每个空0.5分)长减弱6(…     

Simultaneous pharmacokinetics and stability studies of physalins in rat plasma and intestinal bacteria culture media using liquid chromatography with mass spectrometry

Physalins are the major steroidal constituent of Physalis plants and display a range of biological activities. For this study, a rapid and sensitive high‐performance liquid chromatography with triple quadrupole mass spectrometry method was developed for the simultaneous quantification of six physalins. Specifically, it was for the quantification of physalin A, physalin B, physalin D, physalin G, 4,7‐didehydroneophysalin B, and isophysalin B in rat plasma and rat intestinal bacteria. After a solid‐phase extraction, analytes and internal standards (prednisolone) were separated on a Shield reverse‐phase C18 column (measuring 3 mm × 150 mm with an internal diameter of 3.5 μm) and determined using multiple reactions in a monitoring mode with a positive‐ion electrospray ionization source. The mobile phase was a mixture of 0.1% formic acid in water (A) and acetonitrile (B) and was used at a flow rate of 0.6 mL/min. The intra‐ and interday precisions were within 15% with accuracies ranging from 86.2 to 114%. The method was validated and successfully applied to pharmacokinetics and stability studies of six physalins in rat plasma and rat intestinal bacteria, respectively. The results showed that physalin B and isophysalin B could not be absorbed by rats, and rat intestinal bacteria could quickly transform physalins.     

LC–MS/MS method for simultaneous determination of flavonoids and physalins in rat plasma: Application to pharmacokinetic study after oral administration of Physalis alkekengi var. franchetii (Chinese lantern) extract

A rapid and sensitive liquid chromatography with tandem mass spectrometry (LC‐MS/MS) method was developed and validated for the simultaneous determination of luteolin, luteolin‐7‐O ‐β ‐D‐glucopyranoside, physalin A, physalin D and physalin L in rat plasma. Scutellarein and dexamethasone were used as the internal standards (IS). Plasma samples were prepared by liquid‐liquid extraction with ethyl acetate. The five constituents were separated on an Acquity UPLC BEH C₁₈ column (100 mm × 2.1 mm, 1.7 μm). A gradient elution procedure was used with acetonitrile (A)‐0.1% aqueous formic acid (B). Mass spectrometric detection was performed in negative ion multiple reaction monitoring mode with an electrospray ionization (ESI) source. This method showed good linearity (r ² > 0.997) over a concentration range of 2.0–500 ng/mL with a lower limit of quantification of 2.0 ng/mL for all five compounds. The inter‐ and intra‐day accuracy ranged from 91.7 to 104%, and precisions (RSD) were <6.46% for all analytes. The extraction recoveries of all analytes were >85%. This validated method was successfully applied for the first time to the pharmacokinetic study of five ingredients after oral administration of 70% ethanol extract of Chinese lantern in rats.     

Biotransformation of physalin H and leishmanicidal activity of its transformed products

The transformation of physalin H (1) with Rhizopus stolonifer and Cunninghamella elegans has afforded two new physalins, 6,7-dehydrophysalin H (2) and 6-deoxyphysalin H (3), along with a known isophysalin B (4). Their structures were elucidated by spectroscopic analysis. All of these compounds have shown potent leishmanicidal activity with IC50 values in the range of 6.03-13.80 microM.     

In vivo pharmacokinetics of and tissue distribution study of physalin B after intravenous administration in rats by liquid chromatography with tandem mass spectrometry

A rapid and sensitive liquid chromatography tandem mass spectrometry quantitative analysis method was established for the pharmacokinetics and tissue distribution study of physalin B in rat. Physalin B and physalin H (internal standard, IS) were separated on an Agilent Eclips XDB C₈ column. MS detection was performed on a triple quadrupole tandem mass spectrometer in the multiple reaction monitoring mode with a positive eletrospray ionization source. The assay was validated in the concentration ranges of 22.6–22600 ng/mL for heart and lung and 4.52–4520 ng/mL for other tissues. The intra‐ and inter‐day precisions (RSD) were ≤9.23 and ≤12.51%, respectively, with accuracy (%) in the range of 88.07–113.2%. A pharmacokinetic study showed that physalin B has a long dwell time with a half‐life of 321.2 ± 29.5 min and clearance of 175.4 ± 25.7 mL/min/kg after intravenous administration. Additionally, physalin B showed a wide tissue distribution with a special higher penetration in lung. The data presented in this study could provide useful information for the further study of physalin B. Copyright © 2016 John Wiley & Sons, Ltd.     

Two Novel Neophysalins from Physalis alkekengi L. var. franchetii

Two novel neophysalins, named physalin W ( 1 ) and physalin X ( 2 ), were isolated from the EtOH extract of the aerial parts of Physalis alkekengi L. var. franchetii (Solanaceae). Their structures were determined mainly by spectroscopic techniques including 2D‐NMR (HMBC, HSQC, ¹H,¹H‐COSY, NOESY) and MS experiments.     

Identification and quantitative analysis of physalin D and its metabolites in rat urine and feces by liquid chromatography with triple quadrupole time‐of‐flight mass spectrometry

Physalin D is known to show extensive bioactivities. However, no excretion study has elucidated the excretion of physalin D and its metabolites. This study investigates the excretion of physalin D and its metabolites in rats. Metabolites in rat urine and feces were separated and identified by liquid chromatography with triple quadrupole time‐of‐flight mass spectrometry. Furthermore, a validated high‐performance liquid chromatography with tandem mass spectrometry method was developed to quantify physalin D, physalin D glucuronide, and physalin D sulfate in rat feces and urine after the intragastric administration of physalin D. The analyte showed good linearity over a wide concentration range (r  > 0.995), and the lower limit of quantification was 0.0532 μg/mL and 0.226 μg/g for urine and feces, respectively. Nine metabolites, including five phase I and four phase II metabolites, were identified and clarified after dosing in vivo. Only 4.0% of the gavaged dose, including physalin D and its phase II metabolites, was excreted in urine, whereas 10.8% was found in feces in the unchanged form. The results indicate that the extensive and rapid metabolism may be the main factors leading to the short half‐life of physalin D. These results can provide a basis for further studies on the structural modification and pharmacology of physalin D.     

A new 22,26-seco physalin steroid from Physalis angulata

Abstract

A new 22,26-seco physalin, physalin XI (1) together with 5 known compounds, were isolated from the dichloromethane extract of Physalis angulata L. The structure of isolated compounds was elucidated by spectroscopic analysis. The effects of isolated compounds on in vitro cytotoxicity were investigated. Compound 1 was assessed for its cytotoxicity against cancer cell lines (HepG2, HeLa, HuCCA-1, T47-D and A-549) and a normal cell line (MRC-5), and the result showed that it has no activity. Compounds 2 and 4 are highly toxic to H69AR and MDA-MB-23 cell lines. This property appears to be related to the presence of their conjugated double bond or epoxy groups and is a more reliable indication of toxicity than substitution on C(5)–C(6).     

Employing ultra high pressure liquid chromatography as the second dimension in a comprehensive two-dimensional system for analysis of Stevia rebaudiana extracts

Stevia rebaudiana extracts and plant materials are increasingly used as natural sweeteners. Polyphenolic and stevioside compounds contained in S. rebaudiana extracts were separated by comprehensive LC. A polyamine column operated in normal phase mode was used for the first dimension separation (D1), and a UHPLC C18 column operated in reversed phase mode was used for the second dimension separation (D2). The sub-2 μm column (2.1 mm × 30 mm, maintained at 70°C) and the UHPLC pump employed for D2 elution allowed a separation/cycle time of 20 s, with a backpressure oscillating between 805 and 922 bar at 3.4 mL/min. The reduced D2 cycle time allowed 3-12 D2 samplings for each peak eluted by D1. Polyphenolic and stevioside compounds were identified by combining the information coming from the position of the compounds in the 2D plot and UV spectra with that of reference materials.     

Withanolides from Physalis alkekengi var. francheti

Two new withanolides, namely (20S,22R)‐15α‐acetoxy‐5α‐chloro‐6β,14β‐dihydroxy‐1‐oxowitha‐2,24‐dienolide ( 1 ) and (22R)‐5β,6β : 14α,17 : 14β,26‐triepoxy‐2α‐ethoxy‐13,20,22‐trihydroxy‐1,15‐dioxo‐16α,24‐cyclo‐13,14‐secoergosta‐18,27‐dioic acid 18→20,27→22‐dilactone ( 2 ), along with six known compounds, physagulin B ( 3 ), withangulatin A ( 4 ), physalin I ( 5 ), withaminimin ( 6 ), physagulin J ( 7 ), and ergosta‐5,25‐diene‐3β,24ξ‐diol ( 8 ), were isolated from the whole plant of Physalis alkekengi var. francheti. Their structures were elucidated on the basis of spectroscopic analyses.     

红树林植物尖瓣海莲内生真菌Penicillium sp.B21次级代谢产物的分离鉴定

研究了红树林植物尖瓣海莲叶内生真菌Penicillium sp.B21次级代谢产物。 用硅胶柱层析、制备薄层层析和重结晶等方法,从该菌发酵液的乙酸乙酯萃取相中首次分离获得5个单体化合物,运用现代波谱技术、单晶X射线衍射以及文献数据对照,鉴定其结构分别为8-羟基-6甲基-1-甲氧羰基酮(1)、大黄素(2)、ω-羟基大黄素(3)、(3R,4S)-6,8-二羟基-3,4,5-三甲基-3,4-二氢异香豆素(4)和3,6,8-三羟基-3,5,7-三甲基-3,4-二氢异香豆素(5)。 首次获得了sclerotinin B单晶结构。