New Iridoid Glucosides and a Lignan Diglucoside from Globularia alypumL

The four new iridoid glucosides globularicisin (2) , globularidin (5) , globularimin (9) , and globularinin (13) , the lignan diglucoside liriodendrin (18) , and syringin (20) have been isolated from Globularia alypum L. along with the previously reported glucosides globularin (1) and catalpol (4) . Compound 2 is the first report of any cinnamoyl iridoid with a cis-configuration at the acyl double bond. Compound 5 is another novel iridoid which lacks the characteristic C(3), C(4) double bond in the aglucone part. Compounds 9 and 13 are diastereomeric and contain highly oxygenated aglucone structures. The isolation of liriodendrin, from Globularia alypum is the first demonstration of the occurrence of a lignan in the family Globulariaceae. The structures have been elucidated by ¹ H - and ¹³ C-NMR . spectroscopy as well as by chemical transformations. Taxonomical significance of the cooccurrence of iridoid and lignan glycosides as well as the antileukemic potentiality of the latter are also appraised.     

A new lignan with hypoglycemic activity from Tadehagi triquetrum

A new lignan named tadehaginosin, together with a known compound 3,4-dihydro-4-(4′-hydroxyphenyl)-5,7-dihydroxycoumarin, was isolated from the aerial part of Tadehagi triquetrum. The new structure was determined by various spectroscopic techniques (¹H and ¹³C APT, HSQC, HMBC, ¹H–¹HCOSY, NOESY and HR-ESI-MS). The two isolates were evaluated for their hypoglycemic effects in vitro. Biological investigation showed that both of them possessed the capability to increase glucose consumption by HepG2 cells.     

五味子中木脂素类成分的高效液相色谱-电喷雾质谱研究

采用液相色谱-电喷雾质谱联用(HPLC-ESI-MSⁿ)技术, 对北五味子与南五味子中木脂素类成分进行了系统研究. 通过HPLC-ESI-MS技术, 获得了相应化合物的保留时间、紫外光谱和分子量等信息, 利用电喷雾多级串联质谱技术(ESI-MSⁿ), 获得了相应化合物的结构信息. 研究结果表明, 北五味子与南五味子的主要木脂素成分除5个共有成分外其它成分差异较大, 并且其共有成分含量差别较大. 在此基础上, 建立了简便、快速的北五味子与南五味子药材分析鉴定的新方法.     

Complete assignments of 1H and 13C NMR data for new dibenzocyclooctadiene lignans from Kadsura oblongifolia

Two new dibenzocyclooctadiene lignans, named kadoblongifolins A (1) and B (2), and one new natural product dibenzocyclooctadiene lignan, named kadoblongifolin C (3), were isolated from the stems of Kadsura oblongifolia (K. oblongifolia), together with five known ones, schizanrin F (4), propinquanin C (5), schisantherin G (6), heteroclitin Q (7), kadsurarin (8). The structures of these new lignans were elucidated by a combination of high‐resolution electron ionization mass spectrometry (HR‐EI‐MS), ¹H NMR, ¹³C NMR, HMQC, HMBC, and NOESY spectra. Copyright © 2009 John Wiley & Sons, Ltd.     

Identification and Quantification of Lignans,Carboxylic Acids and Sugars in the Leaves of Forsythia Species and Cultivars

Lignans, carboxylic acids and sugars were determined by gas chromatography (GC) with mass selective detection, the lignans also by high-performance liquid chromatography with UV detection in the leaf extracts of four species and four cultivars of Forsythia plant. Three methods were used to optimize the extraction of the main lignan constituents (arctiin, arctigenin), which possess significant pharmaceutical effects. Supercritical fluid extraction (SFE) proved to be the most efficient method compared to sonication and refluxation. The total lignan content of the leaves varied from 31.6 (F. ovata ‘Tetragold’) to 113.8 mg g⁻¹ (F. ovata ‘Robusta’).

     

Prenylated flavonoids from Tephrosia apollinea

In continuation of our chemical investigation on some medicinal plants of the genus Tephrosia,re-investigation of the methylenechloride/methanol(1:1) extract of the air-dried aerial part of Tephrosia apollinea afforded a new prenylated flavonoid 1, in addition to an aromatic ester,a sesquiterpene,a lignan and several known prenylated flavonoids.The structures were established by(~1H NMR,~(13)C NMR,DEPT,~1H-~1H COSY,HMQC,HMBC,NOESY and HRMS).Relative configurations of 9 and 10 were confirmed by X-ray anal...     

DNA-protector and cytotoxic activity of secoisolariciresinol diglucoside derivatives

The relationship between the chemical structure and DNA-protector and cytotoxic activities of phenylpropane lignans was studied. Analogs were synthesized from the lignan secoisolariciresinol diglucoside (SDG) isolated from Linum usitatissimum seeds. It was shown that SDG derivatives secoisolariciresinol and secoisolariciresinol-4′,4″-diacetate, which were not glucosides, exhibited greater cytotoxic activity in vitro than the starting lignan. The cytotoxicity was slightly elevated upon acetylation of the aglycon phenol hydroxyls whereas the DNA-protector activity decreased substantially. The DNA-protector activity of the derivative without the carbohydrate was slightly greater than that of the starting SDG. This was explained by binding of free radicals by the butanediol hydroxyls. It was proposed that the activity of the cytotoxic derivatives was mediated by induction of apoptosis of the tumor cells.     

Dipole moment characterization of phenol–, o-cresol–, and p-cresol–formaldehyde resins

Dipole moments and their temperature dependence have been measured in p-dioxane for fractionated novolac phenol–, o-cresol–, and p-cresol–formaldehyde polymers. The phenol–formaldehyde fractions covered a molecular weight range of 200 to 6100, and the limiting dipole moment ratio 〈μ²〉/xm² is 1.48. The p-cresol–formaldehyde dipole-moment ratio at a DP of 4 is 2.47, whereas the phenol–formaldehyde dipole-moment ratio is 1.40. That for o-cresol–formaldehyde is intermediate in value. The dipole-moment temperature coefficients are positive for p-cresol chains and negative for the phenol–formaldehyde chains. These results indicate that the hydroxyl groups along the p-cresol–formaldehyde polymer are highly ordered, with the aromatic rings closer to the sterically hindered planar position than in the phenol–formaldehyde polymers.     

A New Lignan and Four New Lignan Glycosides from Mananthes patentiflora

A new lignan, 5‐hydroxyjusticidin A (= 9‐(1,3‐benzodioxol‐5‐yl)‐5‐hydroxy‐4,6,7‐trimethoxynaphtho[2,3‐c]furan‐1(3H)‐one; 1 ), and four new diphyllin‐type lignan glycosides, mananthosides C–F ( 2 – 5 ), containing glucosyl (Glc), arabinosyl (Ara), galactosyl (Gal), and/or apiosyl residues, have been isolated from Mananthes patentiflora, together with five known compounds. Their structures and configurations were elucidated by in‐depth 1D‐ and 2D‐NMR experiments, as well as MS analysis.     

New lignans from <Emphasis Type="Italic">Syringa reticulata</Emphasis> var. <Emphasis Type="Italic">mandshurica</Emphasis>

In the search for platelet-activating-factor (PAF) antagonists, two new lignan compounds were isolated from the leaves of Syringa reticulata Hara var. mandshurica. Their structures were elucidated as (7R,8S, 8'S)-3,4,3',4'-dimethylenedioxy-8,9-dihydroxy-8.8', 7-O-9'-lignan (mandshuricol A) and (7R,8S,8'S)-3',4'methylenedioxy-4-methoxy-3,8,9-trihydroxy-8.8', 7-O-9'-lignan (mandshuricol B), Mandshuricol A and B showed antagonistic activity on PAF in the [³H] PAF receptor binding assay with IC₅₀ values of 4.8 × 10^–5 M and 3.5 × 10^–5 M, respectively.     

The phenol efficient degradation using co-culture coupled with enhanced electricity generation capability

The co-culture of strain Citrobacter sp. RDC and Geobacter sulfurreducens PCA was used in this study and it was found that the co-culture using 200 mg/L phenol as carbon source exhibited higher maximum current density than using the single strain RDC and G. sulfurreducens PCA, respectively. Meanwhile, the co-culture was used to generate electricity by degrading phenol with the current density of 699.07 μA/cm² by using 200 mg/L phenol as the sole carbon source, which was higher than that only using G. sulfurreducens PCA (236.20 μA/cm²). Especially, the degradation efficiency of 200 mg/L phenol by co-culture can reach 55.16 % within 36 h being 4.16-fold higher than the single strain G. sulfurreducens PCA. Furthermore, the component ratio of two strains was optimized for increasing electricity generation using 500 mg/L phenol as carbon source. The maximum current density was 501.54 μA/cm² under the ratio of 3 : 1 for strain RDC to G. sulfurreducens PCA. These results highlight that phenol is good carbon source for co-culture to produce electricity. The co-culture system provides a promising application pathway for phenol degradation treatment coupled with electricity generation in the future.     

Lignans and Alkaloids from Haplophyllum suaveolens

Summary.  A new lignan of the dibenzylbutyrolactone type, haplotonin, was isolated from the aerial parts of Haplophyllum suaveolens together with five known compounds-the alkaloids flindersine, 6-methoxyflindersine, N-acetoxymethylflindersine, and evoxine and the lignan 4-acetyldiphyllin. This is the first report on the occurrence of N-acetoxymethylflindersine in the genus Haplophyllum and on 6-methoxyflindersine and 4-acetyldiphyllin as constituents of the investigated species. Received August 10, 1999. Accepted (revised) October 12, 1999     

Identification of Five New Minor Constituents from the Whole Plant of Amischotolype hispida

Bioassay‐guided fractionation of the active AcOEt‐soluble layer from the whole plant of Amischotolype hispida resulted in the isolation of four new compounds, i.e., amisbenzoic acid ( 1 ), one butenolide derivative, amisnolide ( 2 ), one chlorin analog, amisphytin ( 3 ), one lignan, amislignol ( 4 ), and one metabolite isolated for the first time from nature, (?)‐glaberide I ( 5 ), along with 20 known compounds, 6 – 25 . Their structures were elucidated on the basis of UV, IR, 1D‐ and 2D‐NMR (¹H,¹H‐COSY, DEPT, HSQC, HMBC), as well as HR‐ESI‐MS, analyses. Among these isolates, palmitic acid ( 13 ) showed an antimycobacterial activity with an MIC value of 20.0 μg/ml against Mycobacterium tuberculosis H37Rv.     

Human urine certified reference material CZ 6010: creatinine and toluene metabolites (hippuric acid and o-cresol) and a benzene metabolite (phenol)

A reference material for the biological monitoring of occupational exposure to toluene, benzene and phenol was prepared. O-cresol and hippuric acid (metabolites of toluene) are used for the biological monitoring of occupational exposure to toluene. Phenol, a metabolite of benzene, is used for the biological monitoring of exposure to benzene, but phenol can of course also be used as an indicator of exposure to phenol as well. The reference material (RM) used for the determination of these metabolites was prepared by freeze-drying pooled urine samples obtained from healthy persons occupationally exposed to toluene and those taking part in an inhalation experiment. Tests for homogeneity and stability were performed by determining urine concentrations of o-cresol, hippuric acid, creatinine and phenol. To investigate the stability of the RM, the urinary concentrations of o-cresol and phenol were monitored for eighteen months using GC and HPLC, while those of hippuric acid and creatinine were followed for five and six years, respectively, using HPLC. Analysis of variance showed that the concentrations did not change. The certified concentration values (and their uncertainties) of the substances in this reference material (phenol concentration c=6.46±0.58 mg l⁻¹; o-cresol concentration c=1.17±0.15 mg l⁻¹; hippuric acid concentration c=1328±30 mg l⁻¹; creatinine concentration c=0.82±0.10 g l⁻¹) were evaluated via the interactive statistical programme IPECA.     

The case for a revised structure for hypophyllanthin - an analysis of the 13C N.M.R. spectra of aryltetralins

A revised structure for hypophyllanthin is proposed on the basis of its ¹³C n.m.r. spectrum. ¹³C n.m.r. spectra also support the previously proposed structure for nirtetralin and assist in the structural elucidation of a new aryltetralin lignan.     

Three New Lignan Derivatives from Lindera glauca (Siebold et Zucc.) Blume

Two new aryl‐tetralin lignan glycosides, linderanosides A and B ( 1 and 2 , resp.), and a new dihydrobenzofuran neolignan glycoside, linderanoside C ( 3 ), together with five known lignan derivatives ( 4 – 8 ) were isolated from the trunk of Lindera glauca. The structures of these new compounds were determined through spectroscopic analyses, including extensive 2D‐NMR data and acid hydrolysis. The absolute configurations of the compounds were clarified by circular dichroism (CD) spectroscopic studies. Compounds 1 – 8 were evaluated for their cytotoxicity against A549 (non‐small cell lung adenocarcinoma), SK‐OV‐3 (ovarian cancer cells), A498 (human kidney epithelial cells), and HCT‐15 (colon cancer cells) human tumor cell lines using sulforhodamine B assays in vitro.     

A new lignan from the roots of <Emphasis Type="Italic">Stellera chamaejasme</Emphasis>

A new lignan, stellerachama A (1), was isolated from the roots of Stellera chamaejasme. The structure of the new compound was elucidated by analysis of spectrometric data.     

A New Lignan,Cagayanin, from Nutmeg of Myristica Cagayanensis Merr

A new lignan, cagayanin, has been isolated from the nutmeg of Myristica cagayanensis Merr. and elucidated as formula (5) by spectral and chemical evidence.     

Protonation of 1,3- and 1,4-dinitrobenzene dianions

The protonation of the electrochemically generated (0.1 M solution of tetrabutylammonium perchlorate in DMF) 1,3-dinitrobenzene (1) dianions with phenol, ethanol, tert-butanol, and 1-butyl-3-methylimidazolium cation was studied by cyclic voltammetry and chronoamperometry at the carbositall working electrode. The rate constants for the protonation (k) of the dianion of compound 1 by phenol, 1-butyl-3-methylimidazolium cation, ethanol, and tert-butanol were estimated by the comparison of the data of cyclic voltammetry and chronoamperometry with the digital simulation results, being 100, 50, 1.5, and 0.01 L mol⁻¹ s⁻¹, respectively. The similarly obtained k value for the protonation of the dianion of 1,4-dinitrobenzene (2) with phenol is 13 L mol⁻¹ s⁻¹. According to the quantum chemical calculation results, the protonation of the dianions of compounds 1 and 2 with phenol and 1-butyl-3-methylimidazolium cation can be classified as orbital-controlled reactions. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1463–1466, July, 2008.     

A New Lignan,Formosanol, from Juniperus Formosana

A new lignan, formosanol, has been isolated from Juniperus formosana Hayata and elucidated as formula (5a) by spectra and chemical evidences.