Chiral resolution and bioactivity of enantiomeric furofuran lignans from Juglans mandshurica Maxim

Abstract

Enantiomers have generally been reported mostly for racemic mixtures with a 1:1 ratio, as in that case there were weak Cotton effects in the ECD spectrum and negligible optical rotations. A furofuran lignan (sesamin), with a remarkable rotation and significant Cotton effects, was isolated from Juglans mandshurica Maxim. Subsequently, sesamin was resolved by chiral HPLC to afford a pair of enantiomers, (+)-sesamin (a) and (?)-sesamin (b), in a ratio of approximately 1:3. Their absolute configurations were determined by computational analysis of their electronic circular dichroism (ECD) spectrum. In addition, the pair of enantiomers were evaluated for the inhibition of self-induced Aβ aggregation. Interestingly, (+)-sesamin (a) (67.7%) and (?)-sesamin (b) (80.6%) exhibited different degrees of anti-Aβ aggregation activity. The different inhibition profiles were further explained by molecular dynamics and docking simulation study.     

Clay Catalysed Convenient Isomerization of Natural Furofuran Lignans Under Microwave Irradiation

The naturally occuring furofuron lignans, (+)-sesamin, (+)-eudesmin, (+)-syringaresinol and (+)-yangambin underwent rapid isomerization to their corresponding C-7 epimers under microwave irradiation in the presence of montmorillonite KSF as catalyst.     

Simultaneous quantitative analyses of five constituents in crude and salt-processed Cuscutae Semen using a validated high-performance thin-layer chromatography method

Predominantly, the innate medicinal value of Cuscutae Semen has accounted for its extensive usage as a herbal remedy in China for centuries. Specifically, the broad applications of the medicine include aging inhibitors, anti-inflammatory agents, pain relievers, and aphrodisiacs. According to the records of crude Cuscutae Semen (CCS) and salt-processed Cuscutae Semen (PCS) in the Pharmacopoeia of the People’s Republic of China, the difference in the chemical composition between CCS and PCS is limited. In addition, an unprecedented high-performance thin-layer chromatography (HPTLC) method intended for the simultaneous quantitative determination of rutin, chlorogenic acid, hyperin, isoquercitrin, and astragalin in CCS and PCS was successfully developed. In order to achieve optimum separation, a mobile phase of ethyl acetate–formic acid–water–toluene (9:1:1:0.5, V/V) was cautiously integrated. Moreover, the densitometric determination method was executed at specified wavelengths for various standard compounds in refection/absorption mode. In particular, the calibration curves appeared to be linear in the range of 32.64–1139.19 ng per spot for rutin, 12.94–1048.36 ng per spot for chlorogenic acid, 13.71–1110.17 ng per spot for hyperin, 1.16–297.83 ng per spot for isoquercitrin, and 2.19–710.55 ng per spot for astragalin. The proposed method is simple, precise, specific, and accurate. The statistical analysis of the data obtained proves that the method is reproducible and selective, and can be used for the routine analysis of the reported compounds in CCS and PCS samples. This study could be benefit to investigate the processing mechanism of PCS as well as support their clinical applications.

     

An efficient asymmetric synthesis of furofuran lignans: (+)-sesamin and (−)-sesamin

An efficient synthesis of (+)-sesamin 1a and (−)-sesamin 1b is described. The key reactions include highly stereoselective aldol condensation of piperonal 7 with the dianion of chiral oxazolidinone 8, followed by intramolecular ring cyclization of aldol product 11 in high yield.     

补肾益脾方剂中Se的测定

采用荧光法测定了补肾益脾方剂中党参、枸杞子、当归、补骨脂、何首乌、女真子、菟丝子等中的Ｓｅ含量。为探索富Ｓｅ中草药提供依据，可作为低Ｓｅ患者补Ｓｅ的参考。     

Identification of MMP-1 and MMP-9 inhibitors from the roots of Eleutherococcus divaricatus,and the PAMPA test

The purpose of this study was the isolation of metalloproteinases MMP-1 and MMP-9 inhibitors from the chloroform extract of the Eleutherococcus divaricatus roots. Using GC-MS, ¹H and ¹³C NMR, HMQC, HMBC, COSY and DEPT, (+)-sesamin has been identified as a new anti-MMP inhibitor. We report for the first time that (+)-sesamin inhibited MMP-1 and MMP-9 activity in 40% and 17%, respectively. The high inhibitory potential has been shown by ursolic acid (90.9% and 89.8% for MMP-1 and MMP-9). In the PAMPA test, the Pe value for sesamin was established as 17.4 × 10^? 6 cm/s, that for ursolic acid as 30.0 × 10^? 6 cm/s. Verapamil and theophylline were used as a positive and negative control (Pe 42.1 and 2.9 × 10^? 6 cm/s). To our best knowledge, no information was available on this activity of sesamin and other compounds. These studies provide a biochemical basis for the regulation of MMP-1 and MMP-9 by E. divaricatus compounds.     

Nine components pharmacokinetic study of rat plasma after oral administration raw and prepared Semen Cassiae in normal and acute liver injury rats

In China, Semen Cassiae has long been used to protect liver, brighten eyes, and relieve constipation. Prepared Semen Cassiae is produced from raw Semen Cassiae by processing, the two forms of Semen Cassiae have different clinical applications. Pathological state is an important factor affecting the efficacy of drugs, the pharmacokinetic behavior of drugs could be significantly changed when people or animal were under different pathological state. To clarify the effect of processing mechanism and pathological state for pharmacokinetic behavior, the pharmacokinetics of nine components of raw and prepared Semen Cassiae under normal and acute liver injury rats were examined. The results showed that the bimodal phenomenon appeared on the plasma concentration‐time profiles of obtusin, emodin, chrysophanol, aloe emodin and rhein. The T_max of aurantio‐obtusin, obtusin, chrysoobtusin, emodin, chrysophanol, aloe emodin, physcion in normal groups administrated prepared Semen Cassiae were shorter than those administrated raw Semen Cassiae. For the AUC_0–t, aurantio‐obtusin, obtusin, chrysoobtusin, chrysophanol, aloe emodin and physcione in model groups administrated prepared Semen Cassiae were significantly higher than other groups, unlike above components, rhein had poor absorption in model groups. The study would be useful for further studies on pharmacokinetics and clinical application of raw and prepared Semen Cassiae.     

Furofuran lignans from the bark of <Emphasis Type="Italic">Magnolia kobus</Emphasis>

A new furofuran lignan (1) along with four knownones (2-5) were isolated from the bark of Magnolia kobus. Their structures were elucidated as (+)-2α-(3’,4’-dimethoxyphenyl)-6α-(3″-hydroxy-4″,5″-dimethoxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (1), (+)-sesamin (2), (+)-yangambin (3), (+)-kobusin (4), and (+)-eudesmin (5) on the basis of their comprehensive spectroscopic analysis, including 2D NMR, and by comparison of their spectral data with those of related compounds. Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 338–341, July–August, 2008.     

Comparison of Bi(1), Bi(3) and C(60) primary ion sources for ToF-SIMS imaging of patterned protein samples

Imaging time-of-flight secondary ion mass spectrometry (ToF-SIMS) has been used to study protein bound to a photolithographically-patterned, commercial poly(ethylene glycol) (PEG)-based polymer film. The effect of different ion sources on the fragmentation pattern from this sample was analyzed with respect to the surface sensitivity of characteristic protein fragments and contrast in the ion images. The method demonstrates that, under similar fluence (below the static limit), Bi(3) (+) provides better surface sensitivity for low mass fragments and the best image contrast as compared to Bi(1) (+) and C(60) (+) cluster sources. Principal component analysis (PCA) was utilized to process depth profiles for this sample and shows that a primary ion fluence of approximately 20 × 10(12) ions/cm(2) is required to etch through the adsorbed protein layer.     

五种十字花科植物中芥子碱的有效提取和高效液相色谱定量分析

本文采用超声,乙醇回流、石油醚脱脂后醇提等提取方法,并通过正交试验,对五种十字花科植物种子白芥子、黄芥子、葶苈子、莱菔子和油菜籽中的芥子碱进行了有效提取,同时采用高效液相色谱法对各种方法得到的提取液进行了定量分析。结果表明:超声提取时间短、提取率高,五种种子中芥子碱的含量分别为5.80mg.g-1、5.13mg.g-1、2.62mg.g-1、2.98mg.g-1和3.31mg.g-1。     

生、炒决明子中无机元素的分析测定

为测定生决明子中无机元素水平,探讨其药效物质基础及炒制对其含量的影响,采用原子荧光法和等离子发射光谱法等测定了不同产地、批次的生、炒决明子中重金属及微量元素的含量。结果表明,不同产地的生、炒决明子含有的重金属元素均没有超过食品卫生标准。决明子经过炮制后,无机元素变化情况:硫、钠、铬、钡、锂、镍、锶等元素炮制前后变化不大;钙、钾、镁、锰、锌有益元素的含量略有增高;汞、铅、砷有害元素的含量略有下降。可见决明子饮片药用是安全的,炒制工艺对决明子无机元素含量有一定影响,其特有无机元素的种类和含量对揭示决明子药效的物质基础具有意义。     

Stereoselective total synthesis of styryl-lactones: (+)-crassalactones B and C, (+)-howiionol A, (+)-tricinnamate, (+)-goniofufurone and (+)-dicinnamoyl goniofufurone

The total synthesis of (+)-crassalactone B, (+)-crassalactone C, (+)-howiionol A, (+)-tricinnamate, (+)-goniofufurone, and (+)-dicinnamoyl goniofufurone is achieved by a ‘chiron approach’ starting from diacetone d-glucose (DAG). Mitsunobu inversion, Wittig olefination and ring closing metatheses were used as key steps for (+)-howiionol A and (+)-tricinnamate. Meldrum’s acid was used for the synthesis of (+)-crassalactone C, (+)-goniofufurone, and (+)-dicinnamoyl goniofufurone. Yamaguchi esterification was used for (+)-crassalactone B, while a Grignard reaction followed by concomitant deallylation was first reported in the synthesis of (+)-dicinnamoyl goniofufurone.     

基于UPLC-Q-Orbitrap MS/MS技术研究酸枣仁发酵过程中的化学成分转化

利用超高效液相色谱-四极杆-静电场轨道阱串联质谱（UPLC-Q-Orbitrap MS/MS）研究了酸枣仁经茯苓发酵前后的主要化学成分变化，初步探讨了茯苓对酸枣仁发酵的转化规律.鉴定了发酵产物中24种化学成分，整合多元统计方法对酸枣仁发酵0，7和14 d后的差异性化学成分进行研究，采用正交偏最小二乘分析找到7个差异成分.采用t-检验对24种化学成分的相对含量进行分析；并分析了酸枣仁中黄酮苷、皂苷类成分的代谢反应途径.通过茯苓发酵，酸枣仁中化学成分主要发生了脱酰基和脱糖基等水解反应.为酸枣仁发酵产物的化学成分检测提供了快速、直观且准确的方法，为酸枣仁-茯苓共发酵产物的深入开发与利用提供了科学依据.     

Analysis of volatile components in herbal pair Semen Persicae‐Flos Carthami by GC‐MS and chemometric resolution

Analysis of volatile components in herbal pair (HP) Semen Persicae‐Flos Carthami (SP‐FC) was performed by GC‐MS coupled with chemometric resolution method (CRM). Furthermore, temperature‐programmed retention indices were used together with mass spectra for identification of the volatile components. With the help of CRM, the two‐dimensional data obtained from GC‐MS instruments were resolved into a pure chromatogram and a mass spectrum of each chemical compound. By use of these methods upon two‐dimensional data, 26, 49, and 59 volatile chemical components in essential oils of single herb Semen Persicae, Flos Carthami, and HP SP‐FC were determined qualitatively and quantitatively, accounting for 78.42, 81.08, and 82.48% total contents of essential oil of single herb Semen Persicae, Flos Carthami, and HP SP‐FC, respectively. It is shown that the accuracy of qualitative and quantitative analysis can be enhanced greatly by means of CRM. It is further demonstrated that the numbers of volatile chemical components of HP SP‐FC are almost the addition of those of two single herbs, but the main volatile chemical components of the former are completely different from those of single herb Semen Persicae or Flos Carthami because of chemical reactions and physical changes occurring in the process of decocting two single herbs. This means that chemical components especially pharmacologically active compounds in the recipe might be different from those of single herbs.     

(−)-Sesamin and (−)-savinin fromAcanthopanax sessiliflorum and their NMR spectra

Summary 1. The lignans (–)-sesamin and (–)-savinin have been isolated fromAcanthopanax sessiliflorum.2. On the basis of an analysis of the NMR spectrum, the cis- configuration of savinin with respect to the double bond has been proposed.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 3, pp. 149–152, 1966     

Chemical profiling and quantification analysis of flavonoids in different varieties of Euryales Semen by ultra-high-performance liquid chromatography with tandem mass spectrometry

Euryales Semen was a traditional Chinese medicine, which has been commonly used to treat spermatorrhea, enuresis, and frequent urination. Flavonoids were a critical ingredient in determining the function and quality of Euryales Semen. At present, no effective method has been established for the qualitative of Euryales Semen flavonoids. In this study, an ultra-high-performance liquid chromatography-quadrupole-time of flight-mass spectrometry method was established for flavonoids. By comparison with standard or literature data, 32 flavonoid compounds have been identified in Euryales Semen. Based on the qualitative results, an ultra-high-performance liquid chromatography-triple quadrupole tandem mass spectroscopy method was developed for the main components, and the linearity, the limit of detection, limit of quantification, repeatability, precision, stability, and recovery of the method were verified. The principal component analysis and the hierarchical clustering heatmaps analysis showed that the 30 batches of samples were distinctly separated into the North Gordon Euryale and South Gordon Euryale, and the measured contents of the six flavonoids in North Gordon Euryale were more abundant than in South Gordon Euryale, especially isoquercitrin, hesperetin, and quercetin. It provided a scientific basis for the quality control of Euryales Semen and a theoretical basis for the rational utilization of Euryales Semen resources.     

Qualitative analysis of multiple compounds in raw and prepared Semen Cassiae coupled with multiple statistical strategies

In China, Semen Cassiae is used clinically to improve eyesight, relieve constipation, and to treat headache and dizziness. Prepared Semen Cassiae is obtained by stir‐frying raw Semen Cassiae until it turned dark brown, micro dilatancy, and overflow aroma. After processing, the therapeutic effects change—the purgation effect is alleviated and the hepatoprotective effect is enhanced. To explore the changes in chemical compositions of Semen Cassiae after processing and clarify the material basis of the changed therapeutic effects, an ultra‐high performance liquid chromatography with quadrupole time‐of‐flight mass spectrometry coupled with automated data analysis software and statistical strategy was developed. As a result, 53 compounds in raw Semen Cassiae and 43 compounds in prepared Semen Cassiae were found, a total of 55 chemical compounds were identified. Principle component analysis and t‐test were processed by Markerview 1.2.1 software. Finally, 39 peaks were found to be the main contributors to the significant difference (p  < 0.05) between raw and prepared Semen Cassiae. Compared with raw Semen Cassiae, 19 peaks showed a higher intensity in prepared Semen Cassiae, while the contents of 20 compounds in prepared Semen Cassiae were lower, most of which belonged to naphthopyrones glycosides and anthraquinone glycosides.     

苦杏仁挥发油化学成分的微波-同时蒸馏萃取GC-MS分析

报道了用微波照射－同时蒸馏萃取法提取苦杏仁挥发性物质，测得苦杏仁挥发油的含量为4.5%（ω），利用GC－MS法分离确认出18种化学成分，用峰面积归一化法通过化学工作站数据处理系统得出各化学成分在挥发油中的相对含量；其中主要成分为苯甲醛，占总挥发油的89.1%；又用加成分解法分离出苯甲醛，并用IR、EI－MS法对其进行分析鉴定加以确认。     

Comprehensive metabolite profiling of Plantaginis Semen using ultra high performance liquid chromatography with electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry coupled with elevated energy technique

Plantaginis Semen is commonly used in traditional medicine to treat edema, hypertension, and diabetes. The commercially available Plantaginis Semen in China mainly comes from three species. To clarify the chemical composition and distinct different species of Plantaginis Semen, we established a metabolite profiling method based on ultra high performance liquid chromatography with electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry coupled with elevated energy technique. A total of 108 compounds, including phenylethanoid glycosides, flavonoids, guanidine derivatives, terpenoids, organic acids, and fatty acids, were identified from Plantago asiatica L., P. depressa Willd., and P. major L. Results showed significant differences in chemical components among the three species, particularly flavonoids. This study is the first to provide a comprehensive chemical profile of Plantaginis Semen, which could be involved into the quality control, medication guide, and developing new drug of Plantago seeds.     

常用十字花科药用植物中芥子碱的分布研究

十字花科植物中的芥子碱是一种非常有价值的天然抗氧剂,在抗衰老药物的研究中受到了许多学者的重视。为了考察芥子碱在我国药用植物中的分布情况,采用反相高效液相色谱法测定了我国常用的4种十字花科药用植物白芥子、莱菔子、葶苈子、黄芥子中该成分的含量。采用的色谱柱为Alltima Phenyl柱(250 mm×4.6 mm i.d.,5 μm);流动相:3%醋酸溶液和乙腈的混合溶液,梯度洗脱;检测波长:326 nm;柱温:25 ℃。该法快速,准确度高,重现性好,方法的建立不仅为上述4种药材的质量监测提供了有效的定量分析方法,而且对于芥子碱的深入研究具有重要意义。