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1.
Dog's mercury (Mercurialis perennis L.) is an old medicinal plant, nowadays used in complementary medicine. Aqueous fermented extracts of the plant are being mainly applied in remedies to treat external inflammations, but a thorough phytochemical characterization is still lacking. Therefore, the conversion of characteristic compound classes from M. perennis extracts during fermentation and storage was investigated. The microbial transformation of the two main depsides phaselic acid (=(2R)‐O‐[(E)‐caffeoyl]malic acid; 1 ) and mercurialis acid (=(2R)‐[(E)‐caffeoyloxy]glutaric acid; 2 ) was monitored by HPLC‐DAD. The degradation followed a second‐order kinetic, and the calculated half‐life periods of both constituents were 67 and 30 months, respectively. Several depside metabolites were detected by GC/MS in AcOEt extracts as tBuMe2Si (TBDMS) derivatives after derivatization, mainly dihydrocinnamic acids. Moreover, numerous α‐hydroxy acids were found, allegedly as degradation products from amino acids or peptides. The microbial alteration of the main alkaloid hermidin was also examined. After three days of fermentation, three novel N‐metabolites were formed and thoroughly assigned in CH2Cl2 extracts as a mixture of 3‐ethylhermidin, 3‐ethylhermidin quinone, and (E/Z)‐3‐ethylidenehermidin by GC/MS and NMR methods, as well as by means of total synthesis. A mechanism for the formation of these N‐metabolites starting from dimeric hermidin oxidation products is proposed. The obtained results reveal the complex pathways plant constituents may undergo during the fermentation of the extracts.  相似文献   

2.
The relative merits of the methods employed to determine enantiomeric excess (ee) values and absolute configurations of chiral arene and alkene cis‐1,2‐diol metabolites, including boronate formation, using racemic or enantiopure (+) and (?)‐2‐(1‐methoxyethyl)phenylboronic acid (MEPBA), are discussed. Further applications of: 1) MEPBA derived boronates of chiral mono‐ and poly‐cyclic arene cis‐dihydrodiol, cyclohex‐2‐en‐1‐one cis‐diol, heteroarene cis/trans‐2,3‐diol, and catechol metabolites in estimating their ee values, and 2) new chiral phenylboronic acids, 2‐[1‐methoxy‐2,2‐dimethylpropyl]phenyl boronic acid (MDPBA) and 2‐[1‐methoxy‐1‐phenylmethyl]phenyl boronic acid (MPPBA) and their advantages over MEPBA, as reagents for stereochemical analysis of arene and alkene cis‐diol metabolites, are presented.  相似文献   

3.
A phytochemical investigation of the branches and leaves of Cephalotaxus lanceolata resulted in the isolation of three new cephalotaxus alkaloids, cephalancetines A, B, and D ( 1, 2 , and 4 , resp.), together with ten known alkaloids, 3 and 5 – 13 . The structures of the alkaloids were elucidated on the basis of spectroscopic analyses, including 1D‐ and 2D‐NMR, and HR‐ESI‐MS, and single‐crystal X‐ray diffraction. All isolated compounds were tested for their cytotoxicities against four human tumor cell lines, A549, HCT116, SK‐BR‐3, and HepG2. Compounds 12 and 13 showed remarkable activities against A549, HCT116, and HepG2 cell lines.  相似文献   

4.
Introduction – Pyrrolizidine alkaloids (PAs) serve an important function in plant defence. Objective – To compare different extraction methods and detection techniques, namely gas chromatography with nitrogen phosphorus detection (GC‐NPD) and liquid chromatography tandem mass spectrometry (LC‐MS/MS) with quadrupole analysers for analysing PAs in Jacobaea vulgaris. Methodology – Both formic acid and sulfuric acid were tested for PA extraction from dry plant material. For GC‐NPD, reduction is required to transform PA N‐oxides into tertiary amines. Zinc and sodium metabisulfite were compared as reducing agents. Results – The lowest PA concentration measured with GC‐NPD was approximately 0.03 mg/g and with LC‐MS/MS 0.002 mg/g. The detection of major PAs by both techniques was comparable but a number of minor PAs were not detected by GC‐NPD. With the LC‐MS/MS procedure higher concentrations were found in plant extracts, indicating that losses may have occurred during the sample preparation for the GC‐NPD method. Zinc proved a more effective reducing agent than sodium metabisulfite. The sample preparation for LC‐MS/MS analysis using formic acid extraction without any reduction and purification steps is far less complex and less time consuming compared to GC‐NPD analysis with sulfuric acid extraction and PA N‐oxide reduction with zinc and purification. Conclusions – In terms of sensitivity and discrimination, formic acid extraction in combination with LC‐MS/MS detection is the method of choice for analysing PAs (both free and N‐oxides forms) in plant material. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

5.

Introduction

The tuberous roots of Stephania kwangsiensis, which contain bioactive alkaloids, are used as a traditional Chinese medicine. Overexploitation of the roots has made the plant increasingly rare, and the abundant leaves of the same plant may offer a potential alternative. However, there is insufficient phytochemical information for a comparison of alkaloid compositions in the two parts.

Objective

To characterise and compare the alkaloids in the leaves and roots of S. kwangsiensis.

Methods

The alkaloids in S. kwangsiensis were characterised using high pressure liquid chromatography coupled with positive electrospray ionisation quadrupole time‐of‐flight tandem mass spectrometry (HPLC‐(+)ESI‐QTOF‐MS/MS). The alkaloid compositions in the leaves and roots were compared by visual inspection combined with principal component analysis (PCA) of the HPLC‐MS data.

Results

Seventy‐five alkaloids comprising aporphine‐, proaporphine‐, protoberberine‐, benzylisoquinoline‐, bisbenzylisoquinoline‐ and morphine‐type alkaloids were identified or tentatively identified in the roots and leaves of S. kwangsiensis. Sixty‐three of these alkaloids have not been previously reported in this species, and three have not been previously reported in the literature. The roots and leaves had similarities in alkaloid composition but differences in the peak intensities of most alkaloids. The PCA revealed that the samples were clustered into two distinct groups, which corresponded to leaves and roots.

Conclusion

This study further clarified the chemical constituents in the roots of S. kwangsiensis, and revealed that diverse alkaloids were also present in the leaves. The comparative chemical profiling of the two parts provides useful information on their potential medicinal use. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

6.
The amino acid sequences of the plastocyanins from Mercurialis perennis and Capsella bursa-pastoris have been determined. The amides at positions 64 and 68 in the Mercurialis sequence were positioned by ‘homology’ Both proteins are single polypeptide chains of 99 residues and are closely related to other higher plant plastocyanins.  相似文献   

7.
  • 1 Volatiles from the hindgut extracts of males of the Oriental spruce engraver Pseudips orientalis (Wood & Yin) (Coleoptera: Curculionidae, Scolytinae) of different phases of gallery development were analyzed by gas chromatography‐mass spectrometry‐flame ionization detection (GC‐MS/FID) with both polar and enantioselective columns.
  • 2 GC‐MS/FID analyses showed that unmated males or males mated with one female produced approximately 95%‐(?)‐ipsenol and (?)‐cis‐verbenol as major components, as well as (?)‐trans‐verbenol, myrtenol, approximately 70%‐(+)‐ipsdienol and (?)‐verbenone as minor or trace components. The release of these male‐produced compounds was confirmed by GC analysis of an aeration sample of a P. orientalis‐infested spruce log. Mating reduced production of the male‐specific hindgut volatiles.
  • 3 A field‐trapping bioassay in Qinghai, China, showed that a ternary blend containing two major components, 97%‐(?)‐ipsenol (i.e. close to naturally produced enantiomeric ratio) and (?)‐cis‐verbenol, plus a minor component (?)‐trans‐verbenol, caught significantly more P. orientalis beetles (♂: ♀ = 1: 2.7) compared with the unbaited control. Subtraction of (?)‐trans‐verbenol from the active ternary blend had no significant effect on trap catches. The addition of (±)‐ipsdienol (at 0.2 mg/day release) to the active ternary or binary blends significantly interrupted their trap catches. Replacing 97%‐(?)‐ipsenol with (±)‐ipsenol in the ternary blend significantly reduced trap catches to a level that was no different from the blank control.
  • 4 Pseudips species were sister to all other Ipini genera in a phylogeny reconstructed with mitochondrial cytochrome oxidase I DNA data for 51 Ipini and outgroup species.
  • 5 The results obtained suggest that the two major components, 95%‐(?)‐ipsenol and (?)‐cis‐verbenol (at approximately 4–5 : 1), produced by unmated fed males, are probably the primary aggregation pheromone components for P. orientalis. In light of the phylogeny, the use of terpenoid semiochemicals as pheromones probably occurred early in the evolution of Ipini and these semiochemical blends were subsequently modified in the process of speciation.
  相似文献   

8.
Thirteen acylated flavonoid glycosides, 1 – 13 , including eleven new congeners, 3 – 13 , were isolated from the aerial parts of Pritzelago alpina (Brassicaceae) by a combination of column chromatography on Sephadex LH‐20, and preparative and semi‐preparative HPLC. The structures were established by extensive NMR and MS experiments in combination with acid hydrolysis and sugar analysis by GC/MS. The new compounds were shown to be kaempferol and quercetin glycosides acylated for most of them by a branched short chain fatty acid or a hydroxycinnamic acid residue on the sugar portion. As shown by a HPLC‐DAD analysis of a MeOH extract, these compounds are the main phenolic constituents in the aerial parts of the plant.  相似文献   

9.
Aconitum carmichaelii Debeaux is a widely used traditional Chinese medicine and an important source of clinical drugs, of which the parent and lateral roots are known as ‘Chuanwu’ and ‘Fuzi’, respectively. Four new C19‐diterpenoid alkaloids, carmichasines A – D ( 1 – 4 ), were isolated from the roots of Aconitum carmichaelii, together with twelve known compounds ( 5 – 16 ). Their structures were elucidated via spectroscopic analyses, including HR‐ESI‐MS, IR, and NMR. Carmichasine A ( 1 ) is the first natural C19‐diterpenoid alkaloid possessing a cyano group. Most of the diterpenoid alkaloids isolated were C19‐category, which might provide further clues for understanding the chemotaxonomic significance of this plant. The cytotoxicity of the new compounds was also investigated against several human cancer cell lines, including MCF‐7, HCT116, A549, and 786‐0, and none of them showed considerable cytotoxic activity.  相似文献   

10.
A phytochemical investigation of the bulbs of Crinum asiaticum L. var. sinicum Baker resulted in the isolation of two new alkaloids, asiaticumines A and B ( 1 and 2 , resp.), together with 21 known compounds, including nine alkaloids, four amides, five phenolic compounds, and three flavonoids. All 23 compounds were isolated for the first time from Crinum asiaticum L. var. sinicum Baker . Their structures were elucidated by spectroscopic methods. In addition, ten alkaloids, 1 – 10 , were evaluated for their cytotoxic activities against human tumor cell lines A549, LOVO, HL‐60, and 6T‐CEM. Compounds 3, 4 , and 7 – 10 selectively showed remarkable inhibition against one or more of the tested cell lines.  相似文献   

11.
Introduction – Cistus ladanifer is an aromatic shrub that is widespread in the Mediterranean region. The labdanum exudate is used in the fragrance industry and has been characterised. However, there is not enough information about the phenolic content of the raw plant, the aerial part of it being a very rich source of bioactive compounds. Objective – Characterisation of the bioactive compounds of the raw plant and its aerial parts. Methodology – High‐performance liquid chromatography with diode array and electrospray ionisation mass spectrometric detection was used to carry out the comprehensive characterisation of a Cistus ladanifer shrub aqueous extract. Two different MS techniques were coupled to HPLC: time‐of‐flight mass spectrometry and tandem mass spectrometry. Results – Many well‐known compounds present in Cistus ladanifer were characterised, such as flavonoids, phenolic acids, ellagitanins, hexahydroxydiphenoyl and derivatives, and other compounds. Conclusion – The method described simultaneously separated a wide range of phenolic compounds and the proposed characterisation of the major compounds of this extract was carried out. It is important to highlight that, to our knowledge, this is the first time that a Cistus ladanifer aqueous extract from the raw plant has been characterised. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

12.
The stem bark of Raputia simulans (Rutaceae) has been reported to contain simple and dimeric indole alkaloids. Further phytochemical investigation of R. simulans stem bark resulted in the isolation of three new alkaloids. These compounds represent a relatively new category of dimeric indole alkaloids with a cyclohexene moiety in their core. Their structure elucidations were based on NMR and HR‐MS techniques, while structural aspects concerning their relative configuration were investigated using molecular mechanics calculations and NOESY experiments.  相似文献   

13.
Verapamil (VER) is commercialized as a racemic mixture of the (+)‐(R)‐VER and (?)‐(S)‐VER enantiomers. VER is biotransformed into norverapamil (NOR) and other metabolites through CYP‐dependent pathways. N‐hexane is a solvent that can alter the metabolism of CYP‐dependent drugs. The present study investigated the influence of n‐hexane (nose‐only inhalation exposure chamber at concentrations of 88, 176, and 352 mg/m3) on the kinetic disposition of the (+)‐(R)‐VER, (?)‐(S)‐VER, (R)‐NOR and (S)‐NOR in rats treated with a single dose of racemic VER (10 mg/kg). VER and NOR enantiomers in rat plasma was analyzed by LC‐MS/MS (m/z = 441.3 > 165.5 for the NOR and m/z 455.3 > 165.5 for the VER enantiomers) using a Chiralpak® AD column. Pharmacokinetic analysis was performed using a monocompartmental model. The pharmacokinetics of VER was enantioselective in control rats, with higher plasma proportions of the (?)‐(S)‐VER eutomer (AUC0?∞ = 250.8 vs. 120.4 ng/ml/h; P ≤ 0.05, Wilcoxon test). The (S)‐NOR metabolite was also found to accumulate in plasma of control animals, with an S/R AUC0?∞ ratio of 1.5. The pharmacokinetic parameters AUC0?∞, Cl/F, Vd/F, and t1/2 obtained for VER and NOR enantiomers were not altered by nose‐only exposure to n‐hexane at concentrations of 88, 176, or 352 mg/m3 (P > 0.05, Kruskal‐Wallis test). However, the verapamil kinetic disposition was not enantioselective for the animals exposed to n‐hexane at concentrations equal to or higher than the TLV‐TWA. This finding is relevant considering that the (?)‐(S)‐VER eutomer is 10–20 times more potent than R‐(+)‐VER in terms of its chronotropic effect on atrioventricular conduction in rats and humans. Chirality 2010. © 2009 Wiley‐Liss, Inc.  相似文献   

14.
Mercurialis tomentosa L. has been used in Spanish ethnomedicine. In the present study the first phytochemical characterisation of a lipid fraction from Mtomentosa was performed. The CHCl3 extraction of aerial parts from Mtomentosa and GC/MS investigations revealed the occurrence of cuticular lipid and wax constituents, like long chain n‐alcohols and n‐aldehydes (C22 – C30), besides several aromatic constituents, i.e., phenylpropanoids and n‐alkylresorcinols. The latter were further purified by CC and analysed by LC/MSn. In contrast to other Mercurialis species, i.e., Mannua, Mperennis, which exclusively contain 5‐n‐alkylresorcinols ( 1a  –  j , Cn), mainly 5‐n‐alkyl‐2‐methylresorcinols ( 2a  –  j , Cn*) with side chain lengths of C15 – C25 were found in Mtomentosa, in addition to 1a  –  j . Thus, the latter compounds may be utilised for analytical characterisation and authentication of Mtomentosa based on fingerprinting methods. For structure elucidation a novel facile total synthesis of one representative 5‐n‐alkyl‐2‐methylresorcinol homologue ( 2d , C19*) was developed, starting with a Grignard reaction from a substituted benzoic acid chloride ( 19 ). The compound obtained by synthesis was identical to the natural product 2d in terms of its chromatographic and spectroscopic features. Futhermore, 2d exhibited satisfactory DPPH free radical scavenging activity (IC50 = 37.8 μm ) when compared to trolox (IC50 = 21.0 μm ), corroborating the antioxidant features of these amphipathic molecules.  相似文献   

15.
Introduction – Methyl jasmonate (MJ) contains two chiral centres at C‐3 and C‐7 in its chemical structure, which implies that it can exist in four possible stereoisomeric forms, namely (+)‐MJ, (?)‐MJ, (+)‐epiMJ and (?)‐epiMJ. The absolute configuration of the two side chains of MJ affects the biological activity associated with this compound. Objective – To isolate pure (?)‐MJ from a natural source, Jasminum polyanthum Franch., with the intention of increasing the knowledge about its biological properties, including its effect on the biosynthesis of plant metabolites. Methodology – The method used was based on steam distillation extraction (SDE) as an extraction technique followed by high‐performance liquid chromatography (HPLC) as a purification procedure. The HPLC flow‐rate as well as the number of fractions accumulated were optimised to achieve the concentration and purity required. Results – The employment of 0.3 mL/min as HPLC flow‐rate and the accumulation of three HPLC fractions allowed the required enantiomeric purity (95%) and concentration (0.36 mg/L in each HPLC fraction) to efficiently obtain (?)‐methyl jasmonate from Jasminum polyanthum Franch. to be achieved. Conclusion – The approach proposed may enable the properties and effect of pure (?)‐MJ on plant responses to be studied. The use of a natural source to obtain (?)‐MJ is presented as an alternative to the enantioselective synthesis and enantiomeric resolution from the standard racaemic mixture. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

16.
Four new hetisine‐type C20‐diterpenoid alkaloids, named as coreanines A–D ( 1 – 4 ), were isolated from the roots of Aconitum coreanum, together with thirteen known alkaloids ( 5 – 17 ). Their structures were elucidated by extensive spectroscopic methods including IR, HR‐ESI‐MS and NMR techniques. All the isolated compounds were screened for the acetylcholinesterase (AChE) inhibitory effects, and none of them showed considerable inhibitory activity.  相似文献   

17.
Mercurialis annua and M. perennis are medicinal plants used in complementary medicine. In the present work, analytical methods to allow a chemotaxonomic differentiation of M. annua and M. perennis by means of chemical marker compounds were established. In addition to previously published compounds, the exclusive presence of pyridine‐3‐carbonitrile and nicotinamide in CH2Cl2 extracts obtained from the herbal parts of M. annua was demonstrated by GC/MS. Notably, pyridine‐3‐carbonitrile was identified for the first time as a natural product. Further chromatographic separation of the CH2Cl2 extracts via polyamide yielded a MeOH fraction exhibiting a broad spectrum of side‐chain saturated n‐alkylresorcinols. While the n‐alkylresorcinol pattern was similar for both plant species, some specific differences were observed for particular n‐alkylresorcinol homologs. Finally, the investigation of H2O extracts by LC/MS/MS revealed the presence of depside constituents. Whereas, in M. perennis, a mixture of mercurialis acid (=(2R)‐[(E)‐caffeoyl]‐2‐oxoglutarate) and phaselic acid (=(E)‐caffeoyl‐2‐malate) could be detected, in M. annua solely phaselic acid was found. By comparison with synthesized enantiomerically pure (2R)‐ and (2S)‐phaselic acids, the configuration of the depside could be determined as (2S) in M. annua and as (2R) in M. perennis.  相似文献   

18.
Introduction – The popular use of black cohosh products (Actaea racemosa L., syn. Cimicifuga racemosa L.) is growing as the demand for alternatives to estrogen therapy has increased. Critical to safe use is the assurance of unadulterated, high‐quality products. Questions have been raised about the safety of black cohosh due to cases of liver toxicity in patients who reported taking it; subsequent evaluation found some products to be adulterated with other related herbal species. Correct plant species identification is a key first step for good manufacturing practices of safe black cohosh products. Objectives – To develop analytical methods which distinguish black cohosh from other species (American and Asian) of Actaea increasingly found as adulterants in commercially available black cohosh products. Material and methods – Fifteen species of Actaea were collected from North America and Asia, and the phytochemical fingerprints of these samples were established using HPLC‐PDA and LC‐MS techniques. Results – The HPLC and LC‐MS fingerprints for polyphenols and triterpene glycosides revealed distinct patterns that make black cohosh clearly distinguishable from most other species of Actaea. Two marker compounds, cimifugin and cimiracemoside F, were found to be important to distinguish black cohosh from most Asian species of Actaea. Formononetin was not found from either Asian or American species of Actaea. Conclusions – Phytochemical fingerprinting is a practical, reliable method for authenticating black cohosh and distinguishing it from other species of Actaea increasingly found as adulterants in commercially available black cohosh products. This should facilitate the continued development of high‐quality, unadulterated black cohosh products. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

19.
Introduction – The two enantiomers of hyoscyamine, an alkaloid found in many plant species, have distinct pharmacological and biological properties. Methods for the discrimination of both enantiomers are almost exclusively based on chiral HPLC/UV. Determination of the enantiomeric ratio (e.r.) of hyoscyamine is a challenging problem since this compound tends to racaemise, forming atropine during acid–base extraction. Objective – To develop a protocol for the calculation of enantiomeric ratio of hyoscyamine in a plant extract using a 13C NMR method. Methodology – Samples were prepared by extraction of dried Datura stramonium seeds. Observation of C12 and C15 NMR signals of hyoscyamine in the presence of one equivalent of TFA and sub‐stoichiometric amount of Yb(hfc)3 allowed the calculation of the e.r. of S‐(?) and R‐(+)‐hyoscyamine. Results – The method was optimised with various mixtures of (+) and (?)‐hyoscyamine ranging from 50:50 (racaemic mixture, i.e. atropine) to 98.5:1.5. The e.r. measured by NMR on the signals of aromatic C12 and C15 were in agreement with the gravimetrically prepared samples. The method was then applied to an extract of Datura stramonium and S‐(?)‐hyoscyamine was the unique enantiomer. Conclusion – The study showed that the e.r. determination of atropine/hyoscyamine was achieved with a routine NMR spectrometer, using CLSR/TFA on pure compounds as well as on the crude extract of Datura stramonium. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

20.
Plant galls are widely distributed, and their extracts are used in traditional medicine worldwide. Traditional remedies containing extracts of plant galls in China, India and some African countries have effective in the treatment of various pathologies. To open a new promising procedure for screening bioactive compounds from plant galls, standardized plant materials were generated in vitro and used for phytochemical and biological investigations. Methanol aqueous chloroform and hexane extracts of Nicotiana tabacum leafy galls induced by Rhodococcus fascians were used to evaluate phenolic and flavonoid contents, and to investigate antioxidant activity by 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging and ferric reducing antioxidant/power assays and anti‐inflammatory activity by the lipoxygenase inhibition assay. Infection by R. fascians modifies significantly the phytochemical profile of N. tabacum as well as its biological properties. The total polyphenolic content was increased (120–307%), and that of flavonoids was reduced (20–42.5%). Consequently, antioxidant and anti‐inflammatory activities of non‐infected tobacco extracts are significantly modified compared to plants treated with leafy gall extracts. This shows that infection by R. fascians favoured the production of anti‐inflammatory and antioxidant compounds in N. tabacum. The study indicates the benefit of plant galls used in traditional medicines against various pathologies.  相似文献   

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