Constituents of Antrodia Cinnamomea

We describe identification of seven components from Antrodia cinnamomea. Their structures were determined on the basis of spectral analysis and comparison with authentic samples. These compounds include two steroids (1, 2) (β-sitosterol and eburicol), two new steroids (3, 4) [methyl-4α-methylergost-8,24(28)-dien-3,7,11-trion-26-oate and methyl-4α-methylergost-8,24(28)-dien-3,11-dion-26-oate], two lignans (5, 6) [(+)-sesamin and 4-hydroxysesamin], and one long chain methyl ester (7) (methyl oleate). Among them, compounds 3 and 4 are first isolated from nature.     

Two novel polycyclic spiro lignans from Gymnotheca involucrata

Two novel lignans, gymnothespirolignans A (1) and B (2), possessing a rare polycyclic spiro skeleton, were isolated from the endemic plant of Gymnotheca involucrata Pei. Their structures were determined by spectroscopic evidences and the absolute configurations were confirmed by single crystal X-ray diffraction analysis. Compounds 1 and 2 showed promising antiviral activities against RSV with an IC₅₀ value of 31.87 and 17.51 μM, respectively.     

Mass fragmentation study of the trimethylsilyl derivatives of arctiin,matairesinoside, arctigenin,phylligenin, matairesinol,pinoresinol and methylarctigenin: Their gas and liquid chromatographic analysis in plant extracts

The mass fragmentation patterns and the characteristic behavior of the trimethylsilyl (TMS) derivatives of the dibenzylbutyrolactone-type (arctiin, arctigenin, methylarctigenin, matairesinoside, matairesinol) and those of the diphenylperhydrofurotetrahydrofurane-type (phylligenin, pinoresinol) lignans, obtained by gas chromatography–mass spectrometry (GC–MS), were presented. It was shown that upon acidic hydrolysis the dibenzylbutyrolactone-type lignans are stable while the diphenylperhydrofurotetrahydrofurane-type ones decompose. As a novelty to the field we confirmed that the fragment species of the derivatized lignan glycosides, in the presence of excess hexamethyldisilazane, leaded to their in situ derivatization. Quantification of the selective fragment ions of the TMS derivatives by GC–MS, in respect of the ions found one by one, and concerning the selective fragment ions {SFI(s)} in total, provided acceptable reproducibilities, suitable for quantitation purposes: varying between 1.20% and 6.6% relative standard deviation percentages (RSD%). For characterization of the behavior of various type of lignans, analyses were performed with the untreated and with the trifluoroacetic acid hydrolyzed plant extracts, from the same sample, in parallel, both by GC–MS and by high performance liquid chromatography–mass spectrometry, working in the positive electron ionization mode (HPLC–ESPI-MS). The analysis of lignans in fruit and leaf extracts (obtained from the Arctium, Centaurea and Forsythia plants) was confirmed both by GC–MS and by HPLC–ESPI-MS. Our multicomponent system (including the identification and quantification of sugars, sugar alcohols, and several members of various homologous series of acids, anthraquinones and flavonoids) has been extended to the analysis of lignan glycosides and to the free lignans. Reproducibilities in the quantitation of lignans in plant matrices, as averages on GC and HPLC basis, varied between 0.9% and 11% (RSD). The distribution of the lignan constituents was presented for 5 Arctium, for 8 Centaurea and for 4 Forsythia plant extracts: the total of lignan contents varied between 0.42 and 87.9 mg/g, respectively.     

Taiwanin H,A New Lignan from the Barks of Taiwania Cryptomerioides Hayata

A new lignan, taiwanin H, has been isolated from the barks of Taiwania cryptomerioides Hayata and elucidated as formula ( 6a ) by chemical and physical evidence.     

A new lignan derivative from the root of Ilex pubescens

One new compound, ilexlignan A （1）, was isolated from the root of llex pubescens. Its structure was elucidated by the combination of one- and two-dimensional NMR analysis, mass spectrometry, CD spectrum measurement and chemical evidence.     

How stereochemistry influences the taste of wine: Isolation,characterization and sensory evaluation of lyoniresinol stereoisomers

Wine expresses its beauty by sending a sensory message to the taster through molecules coming from grapes, yeast metabolism or oak wood. Among the compounds released during barrel aging, lyoniresinol has been recently reported as a relevant contributor to wine bitterness. As this lignan contains three stereogenic carbons, this work aimed at investigating the influence of stereochemistry on wine taste by combining analytical and sensorial techniques. First, an oak wood extract was screened by Liquid Chromatography–High Resolution Mass Spectrometry to target isomers separable in a symmetric environment and a diastereoisomer called epi-lyoniresinol was isolated for the first time. Then, an original racemic resolution based on natural xylose-derivatives was carried out to obtain lyoniresinol enantiomers. Chiroptical spectroscopic measurements associated with theoretical calculations allowed the unambiguous determination of their absolute configuration. The taste properties of all these stereoisomers revealed that only one lyoniresinol enantiomer is strongly bitter whereas the other one is tasteless and the diastereoisomer is slightly sweet. The presence of these three compounds was established in an oaked Bordeaux wine by chiral and non-chiral chromatography, suggesting the significant influence of stereochemistry on wine taste.     

A new aryltetrahydronaphthalene lignan from Epimedium brevicornum

A new aryltetrahydronaphthalene lignan,(+)-cycloolivil formaldehyde condensate(1),was isolated from the whole plants of Epimedium brevicornum(Berberidaceae).Its structure was elucidated on the basis of MS,1D and 2D NMR techniques.     

A new lignan from Gynostemma pentaphyllum

A new lignan ligballinone 1 with the know ligballinol 2 were isolated from plant Gynostemma pentaphyllum.Their structures were determined through spectroscopic methods including ESI-MS,1D and 2D NMR (1H,13C,DEPT,1H-1H COSY,HMQC,RMBC) and X-ray diffraction experiment for 2.     

Four new constituents from Taraxacum mongolicum

Two new flavone glycosides,isoetin-7-O-β-D-glucopyranosyl-2′-O-α-L-arabinopyranoside (1) and isoetin-7-O-β-D-glucopyr- anosyl-2′-O-α-D-glucopyranoside (2),a new lignan,mongolicumin A (3),and a new guaianolide,mongolicumin B (4) were isolated from the aerial part of Taraxacum mongolicum.Their structures were elucidated mainly by spectral analyses.     

Determination and pharmacokinetic study of four lignans in rat plasma after oral administration of an extract of Valeriana amurensis by ultra‐high performance liquid chromatography with tandem mass spectrometry

A selective and sensitive ultra‐high performance liquid chromatography with tandem mass spectrometry method was developed and validated for the determination and pharmacokinetic study of (+)‐8‐hydroxypinoresinol‐4’‐O‐β ‐D‐glucopyranoside, prinsepiol‐4‐O‐β‐D‐glucopyranoside, (+)‐pinoresinol‐4,4’‐di‐O‐β‐D‐glucopyranoside, and (−)‐massoniresinol 3α‐O‐β‐D‐glucopyranoside in rat plasma after the oral administration of a Valeriana amurensis extract. The analytes and ethyl 4‐hydroxybenzoate (internal standard) were separated on a Waters ACQUITY UPLC HSS T3 chromatographic column. The detection was performed on a triple quadrupole tandem mass spectrometer in multiple reaction monitoring mode using an electrospray ionization source operating in negative ionization mode. The linear ranges (ng/mL) of the standard curves were 0.39–154.00, 0.62–244.70, 0.50–198.60, and 0.34–134.50 for (+)‐8‐hydroxypinoresinol‐4’‐O‐β‐D‐glucopyranoside, prinsepiol‐4‐O‐β‐D‐glucopyranoside, (+)‐pinoresinol‐4,4’‐di‐O‐β‐D‐glucopyranoside, and (−)‐massoniresinol 3α‐O‐β‐D‐glucopyranoside, respectively. The inter‐ and intra‐day precisions were less than 11.0%, the accuracies were between −5.9 and 7.7%, and the extraction recoveries of the four analytes were > 81.2% from rat plasma. The method was successfully applied to a pharmacokinetic study of the four analytes after oral administration of a Valeriana amurensis extract to rats. The developed method has the potential for pharmacokinetic analysis and to provide additional information in the clinical application of Valeriana amurensis.