Liquid chromatography–diode array detection–electrospray ionisation mass spectrometry/nuclear magnetic resonance analyses of the anti-hyperglycemic flavonoid extract of Genista tenera

MS/MS fingerprint comparison between adjacent generations enables substructure identification: Flavonoid glycosides as cases

MS/MS spectrum matching currently serves as a favored means to identify the concerned metabolites attributing to the accessibility of several famous databases. However, the rule that takes the entire structure into account frequently leads to "0 hit" when inquiring MS/MS (usually MS2) spectrum in the databases. Conjugation plays an important role for the high-level structural diversity of metabolites in all organisms, and a given conjugate usually consists of two or more substructures. If MS3 spectra participate in database retrieval, the structural annotation potential of those databases should be dramatically expanded via identifying substructures. Attributing to the ubiquitous distribution pattern, flavonoid glycosides were deployed as the representative family to justify whether the primary fragment ion termed as Y0+, resulted from neutral loss of glycosyl residue(s), generated identical MS3 spectrum with MS2 spectrum of the aglycone cation namely [A+H]+. Because of owning unique ability to measure MS/MS spectrum with the exactly desired exciting energy, linear ion trap chamber of Qtrap-MS was responsible for generating the desired MS3 and MS2 spectra. When taking both m/z and ion intensity features into consideration, the findings included: 1) glycosides sharing identical aglycones produced the same MS3 spectra for Y0+; 2) different MS3 spectra for Y0+ occurred amongst glycosides bearing distinct, even isomeric, aglycones; 3) isomeric aglycones generated different MS2 spectra; and 4) MS3 spectra for Y0+ agreed with MS2 spectra of [A+H]+ when comparing paired glycoside and aglycone. Together, fingerprint comparison between MS3 and MS2 spectra could structurally annotate the substructures and further advance MS/MS spectrum matching towards the identification of, but not limited to, aglycones for flavonoid glycosides.

Luteolin: A promising natural agent in management of pain in chronic conditions

Pain due to chronic conditions is a frequent and insufficiently addressed problem. Current drug options for pain management (either in cases of chronic inflammatory conditions or neuropathy) do not adequately treat pain. Moreover, they are associated with important adverse events in long term use. Luteolin is a flavonoid widely present in the plant kingdom and its sources have been assembled in a comprehensive list of this paper. Luteolin has shown in several research studies a range of pharmacological properties; anti-inflammatory, antioxidant, neuroprotective, and analgesic. In this article, we summarize the effects and potential benefits from introducing luteolin as an adjuvant agent in established protocols for pain management. We review the most indicative in vivo and in vitro evidence of how luteolin can target the molecular pathways involved in pathogenesis of chronic inflammatory and neuropathic pain. The data reviewed strongly support luteolin's promising benefits in pain management and raise the need for further clinical trials that can establish its role in clinical practice.

Glycosylation of luteolin in hydrophilic organic solvents and structure–antioxidant relationships of luteolin glycosides

An effective approach was developed to biotransform luteolin glycosides in hydrophilic organic solvents. Bacillus cereus A46 cells showed high activity and stability in 5–20% (v/v) DMSO with 90–98% conversion rates of luteolin glycosides. Five glycosides of luteolin 7-O-β-glucoside, luteolin 4′-O-β-glucoside, luteolin 3′-O-β-glucoside, luteolin 7,3′-di-O-β-glucoside and luteolin 7,4′-di-O-β-glucoside were obtained. The addition of DMSO greatly promoted the solubility of luteolin and further regulated the formation of the main products from five luteolin glycosides to luteolin 7-O-β-glucoside (931.2 μM). Fourteen flavonoids and anthraquinones were used as tentative substrates. Glycosylation positions were located at the C-7, C-3′ or C4′ hydroxyl groups of flavonoids and C-5 hydroxyl group of anthraquinones. The 3′,4′-dihydroxy arrangement played the key role for the antioxidant activity of luteolin.

Efficient glycosylation of luteolin in organic solvents and the structure–antioxidant relationships of luteolin glycosides were reported for the first time.

The genus Genista L.: A rich source of bioactive flavonoids

The genus Genista L. (family Fabaceae, subfamily Papilionoideae), with its cosmopolitan distribution, has attracted the human interest since ancient times, as it is used in folk medicine and mainly in the Mediterranean area for the treatment of respiratory diseases, rheumatic disorders, diabetes and ulcer, while it is also well known for its yellow pigment. The chemical composition of the Genista species revealed the presence of more than 108 flavonoids. Isoflavones, belonging to the group of phytoestrogens, are important secondary metabolites of the genus. The extracts of the Genista species may act as important source of bioactive phytochemicals for the treatment of many human ailments, mainly inflammation and pain, estrogen related pathology, hyperglycaemia, cancer and microbial infections. Therefore, the present review summarizes and discusses the flavonoid derivatives from the genus Genista, together with their structural features and pharmacological properties, aiming to highlight the recent advances in current knowledge on Genista species as a source of bioactive flavonoids.

Evaluation of Antifungal Phenolics from Helianthus tuberosus L. Leaves against Phytophthora capsici Leonian by Chemometric Analysis

Phytophthora capsici Leonian causes destructive economical losses in pepper production, and a promising source of natural fungicides- Helianthus tuberosus leaves was reported. The antifungal activities of different extracts and compounds from H. tuberosus leaves against the phytopathogen, P. capsici Leonian, were examined by chemometric analysis, including HPLC-MS/MS and multivariate data analyses. Principal component analysis and orthogonal partial least squares-discriminate analysis were applied to examine the four groups of H. tuberosus leaves samples, including crude extracts obtained by different methods, including refluxing, macerating, and refluxing under vacuum; four fractions, namely, petroleum ether (PE), chloroform (Chl), ethyl acetate (EA), and n-butanol (NB) fractions; the samples of three H. tuberosus cultivars; and the samples at three growth stages of cultivar Nan Yu. The phenolics contents were categorized based on 3,5-Dicaffeoylquinic acid (3,5-DiCQA), 1,5-Dicaffeoylquinic acid (1,5-DiCQA), 3-O-Caffeoylquinic acid (3-CQA), and 4,5-Dicaffeoylquinic acid (4,5-DiCQA), which were predominant in all the samples. Antifungal activity assay revealed that Chl and NB fractions were more active against P. capsici Leonian with lower IC50(half of maximal inhibitory concentration) values, whereas partial least squares-discriminate analysis suggested caffeoylquinic acid isomer(4-CQA), methyl-quercetin glycoside(MQG), and caffeic acid(CA) might be the main active components in H. tuberosus leaves against P. capsici Leonian. Furthermore, microscopic evaluation demonstrated structural deformities in P. capsici Leonian treated with Chl and NB fractions, indicating the antifungal effects of H. tuberosus leaves. These results imply that H. tuberosus leaves with a high concentration of phenolics might be a promising source of natural fungicides.

C-Glycosylflavonoids: Identification, Bioactivity and Synthesis

C-Glycosylflavonoids are a group of compounds widespread in nature which have gained much interest due to their biological properties. This review focuses on the research of the last ten years concerning detection and structural characterization of C-glycosylflavonoids, their bioactivities and synthesis.

Biosynthesis of natural and non-natural genistein glycosides

Biosynthesis of various genistein glycopyranoside scaffolds using versatile GTs and SOMTs. Each compound was structurally characterized and biological activity assay was carried out.

The application of HPLC ESI MS in the investigation of the flavonoids and flavonoid glycosides of a Caribbean Lamiaceae plant with potential for bioaccumulation

As part of an exchange technology program between the government of Barbados and Environment Canada, methanolic and aqueous extracts from the flavonoid-rich Lamiaceae family were characterized using negative-ion electrospray mass spectrometry. The species investigated is part of the Caribbean Pharmacopoeia, and is used for a variety of health issues, including colds, flu, diabetes, and hypertension. The extracts were investigated for structural elucidation of phenolics, identification of chemical taxonomic profile, and evidence of bio-accumulator potential. The methanolic and aqueous leaf extracts of Plectranthus amboinicus yielded rosmarinic acid, ladanein, cirsimaritin, and other methoxylated flavonoids. This genus also shows a tendency to form conjugates with monosaccharides, including glucose, galactose, and rhamnose. The aqueous extract yielded four isomeric rhamnosides. The formation of conjugates by Plectranthus amboinicus is thus evidence of high bioaccumulator significance.

Analysis of phenolic acids of Jerusalem artichoke (Helianthus tuberosus L.) responding to salt-stress by liquid chromatography/tandem mass spectrometry

Plant phenolics can have applications in pharmaceutical and other industries. To identify and quantify the phenolic compounds in Helianthus tuberosus leaves, qualitative analysis was performed by a reversed phase high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) and quantitative analysis by HPLC. Ten chlorogenic acids (CGAs) were identified (3-o-caffeoylquinic acid, two isomers of caffeoylquinic acid, caffeic acid, p-coumaroyl-quinic acid, feruloylquinic acid, 3,4-dicaffeoyquinic acid, 3,5-dicaffeoylquinic acid, 1,5-dicaffeoylquinic acid, and 4,5-dicaffeoylquinic acid) by comparing their retention times, UV-Vis absorption spectra, and MS/MS spectra with standards. In addition, four other phenolic compounds, including caffeoyl glucopyranose, isorhamnetin glucoside, kaempferol glucuronide, and kaempferol-3-o-glucoside, were tentatively identified in Helianthus tuberosus leaves for the first time. The 3-o-caffeoylquinic acid (7.752 mg/g DW), 4,5-dicaffeoylquinic acid (5.633 mg/g DW), and 3,5-dicaffeoylquinic acid (4.900 mg/g DW) were the major phenolic compounds in leaves of Helianthus tuberosus cultivar NanYu in maturity. The variations in phenolic concentrations and proportions in Helianthus tuberosus leaves were influenced by genotype and plant growth stage. Cultivar NanYu had the highest concentration of phenolic compounds, in particular 3-o-caffeoylquinic acid and 4,5-dicaffeoylquinic acid compared with the other genotypes (wild accession and QingYu). Considering various growth stages, the concentration of total phenolics in cultivar NanYu was higher at flowering stage (5.270 mg/g DW) than at budding and tuber swelling stages. Cultivar NanYu of Helianthus tuberosus is a potential source of natural phenolics that may play an important role in the development of pharmaceuticals.

Pinostrobin and Cajanus lactone isolated from Cajanus cajan (L.) leaves inhibits TNF-α and IL-1β production: in vitro and in vivo experimentation

The tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β) inhibitory activities of Cajanus cajan (leaves) crude methanolic extract, its fractions and its phytochemical constituents were evaluated in lipopolysaccharide (LPS) stimulated RAW 264.7 and J774A.1 cells. Phytochemical investigation of the active ethyl acetate (CCE) and n-butanol (CCB) fractions of C. cajan L. leaves yielded 14 compounds. It was observed that both pinostrobin (9) and cajanus lactone (4) were found to be most active in inhibiting TNF-α (IC50<22 μM) and IL-1β (IC50<40 μM) whereas compounds 2, 3, 5-8, 10 and 14 showed moderate and mild effects (IC50=35.50-81.22 μM for TNF-α and 38.23-89.10 μM for IL-1β) in both the cell lines. Furthermore, at dose of 20mg/kg, both pinostrobin (9) and cajanus lactone (4) were found to reduce LPS-induced TNF-α levels by 48.6% and 55.0% respectively and IL-1β levels by 53.1% and 41.8% respectively in Sprague Dawley (SD) rats. These findings suggest that C. cajan L. leaves can be developed as an effective herbal remedy for the treatment and prevention of inflammation or associated ailments.

Triterpene saponins of Genista ulicina Spach

From the n-BuOH extract of the aerial parts of Genista ulicina, six triterpene saponins, 3-O-β-D-glucopyranosyl-olean-12-ene-3β,27,28,30-tetraol, 3-O-β-D-glucopyranosyl-olean-12-ene-3β,27,28,29-tetraol, 3,29-di-O-β-D-glucopyranosyl-olean-12-ene-3β,27,28,29-tetraol, 3-O-β-D-glucopyranosyl-olean-12-ene-3β,28,29-triol-27-oic acid, 3-O-β-D-glucopyranosyl-olean-12-ene-3β,27,28-triol-29-oic acid, and 3-O-β-D-glucopyranosyl-14-H-27-nor-olean-12-ene-3β,28,29-triol, were isolated together with eight known triterpene saponins and six flavonoids. Their structures were established mainly by means of spectroscopic methods (1D and 2D-NMR as well as HR-ESI-MS). The n-BuOH extract, investigated for its antitumor growth inhibition of human colon cancer HT-29 cells, presented no significant activity (IC50>100 μg).

RIKEN tandem mass spectral database (ReSpect) for phytochemicals: a plant-specific MS/MS-based data resource and database

The fragment pattern analysis of tandem mass spectrometry (MS/MS) has long been used for the structural characterization of metabolites. The construction of a plant-specific MS/MS data resource and database will enable complex phytochemical structures to be narrowed down to candidate structures. Therefore, a web-based database of MS/MS data pertaining to phytochemicals was developed and named ReSpect (RIKEN tandem mass spectral database). Of the 3595 metabolites in ReSpect, 76% were derived from 163 literature reports, whereas the rest was obtained from authentic standards. As a main web application of ReSpect, a fragment search was established based on only the m/z values of query data and records. The confidence levels of the annotations were managed using the MS/MS fragmentation association rule, which is an algorithm for discovering common fragmentations in MS/MS data. Using this data resource and database, a case study was conducted for the annotation of untargeted MS/MS data that were selected after quantitative trait locus analysis of the accessions (Gifu and Miyakojima) of a model legume Lotus japonicus. In the case study, unknown metabolites were successfully narrowed down to putative structures in the website.

Characterization of phenolic composition in Lamiaceae spices by LC-ESI-MS/MS

A total of 38 phenolic compounds in the solid/liquid extracts of five Lamiaceae spices, rosemary, oregano, sage, basil, and thyme, were identified in the present study using LC-ESI-MS/MS. These compounds were distributed in four major categories, namely, hydroxycinnamic acid derivatives, hydroxybenzoic acid derivatives, flavonoids, and phenolic terpenes. Among them, the category of flavonoids was the largest, with 17 compounds. Identification of the phenolic compounds was carried out by comparing retention times and mass spectra with those of authentic standards. If standards were unavailable, phenolic compounds were identified on the basis of accurate mass of pseudomolecular [M - H](-) ions and tandem mass spectrometry (MS/MS) data. The results of accurate mass measurements fit well with the elemental composition of the compounds. The diagnostic fragmentation patterns of the compounds during collision-induced dissociation (CID) elucidated the structural information of the compounds analyzed.

Antiproliferative and Cytotoxic Effects on Malignant Melanoma Cells of Essential Oils from the Aerial Parts of Genista sessilifolia and G. tinctoria

Genista species (family Leguminosae) show interesting biological properties. In this paper we describe the biological activity of the essential oils extracted from the aerial parts of G. sessilifolia DC. and G. tinctoria L. against M14 human melanoma cells, testing several biochemical parameters, such as cell vitality, cell membrane integrity and genomic DNA fragmentation. In addition, we report for the first time the study of the composition of the essential oil obtained from G. tinctoria. The most abundant components of the oil were carbonylic compounds such as ( E)-β-ionone (9.1%), dihydroactinidiolide (7.3%), nonanal (5.1%) and hexahydrofarnesylacetone (4.3%). The essential oils from aerial parts of both G. sessilifolia and G. tinctoria showed interesting potential anticancer activity, suggesting the presence of active compounds.

Hypoglycemic activity of Buchholzia coriacea (Capparaceae) seeds in streptozotocin-induced diabetic rats and mice

The present study evaluates the possible hypoglycemic activity and ameliorative effects of oral administration of ethanol extracts (EEBC) and butanol fraction (BFBC) of Buchholzia coriacea seeds, a plant in use traditionally for treating diabetes, hypertension, rheumatism, cold, cough and catarrh, in streptozotocin (STZ)-induced diabetic mice and rats. Fasting blood glucose (FBG) levels were evaluated before and after extracts administration. EEBC and BFBC significantly decreased (P<0.05) FBG in hyperglycemic mice and normoglycemic rats within 4 and 12 h, respectively after extract administration. The administration of EEBC, BFBC and glibenclamide (a standard antidiabetic drug) for 10 days significantly lowered (P<0.05) FBG level in STZ-induced diabetic rats by 55%, 64% and 56%, respectively. EEBC and BFBC significantly (P<0.05) decreased hepatic injury induced by STZ as evident in the decreased activity of serum alanine amino transferase and aspartate amino transferase compared to in the STZ-only treated group. Similarly, both extracts significantly decreased (P<0.05) the elevated levels of serum creatinine, urea, total cholesterol, triglyceride and thiobarbituric acid reactive species (TBARS) products in diabetic rats. Serum superoxide dismutase activity was significantly enhanced (P<0.05) by treatments with EEBC, BFBC and glibenclamide. Overall, the results suggest that B. coriacea seeds contain a potent hypoglycemic and antioxidant agent suggested to be a flavone glycoside concentrated in BFBC which may find clinical application in amelioration of diabetes-induced secondary complications.

Chemical Composition and Antimicrobial Activity of Essential Oils of Genista ulicina and G. vepres

The hydrodistilled oils from the aerial parts of Genista ulicina Spach. and G. vepres Pomel., which are endemic to Algeria, were analyzed by gas chromatography-mass spectrometry (GC-MS). In the oil of G. ulicina, 41 compounds were identified representing 90.8% of the total oil, and in G. vepres, 61 compounds representing 84.5% of the total oil. The analyses showed that the major constituents of the oils were lauric acid (14.3% – 8.5%), myristic acid (11.5% – 5%), linoleic acid (3.1% –11.7%) and palmitic acid (18.6% – 26.4%). Using a diffusion method, the oils showed significant antibacterial activities against Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and Staphylococcus aureus (ATCC 25923).

The C-glycosylation of flavonoids in cereals

Flavonoids normally accumulate in plants as O-glycosylated derivatives, but several species, including major cereal crops, predominantly synthesize flavone-C-glycosides, which are stable to hydrolysis and are biologically active both in planta and as dietary components. An enzyme (OsCGT) catalyzing the UDP-glucose-dependent C-glucosylation of 2-hydroxyflavanone precursors of flavonoids has been identified and cloned from rice (Oryza sativa ssp. indica), with a similar protein characterized in wheat (Triticum aestivum L.). OsCGT is a 49-kDa family 1 glycosyltransferase related to known O-glucosyltransferases. The recombinant enzyme C-glucosylated 2-hydroxyflavanones but had negligible O-glucosyltransferase activity with flavonoid acceptors. Enzyme chemistry studies suggested that OsCGT preferentially C-glucosylated the dibenzoylmethane tautomers formed in equilibrium with 2-hydroxyflavanones. The resulting 2-hydroxyflavanone-C-glucosides were unstable and spontaneously dehydrated in vitro to yield a mixture of 6C- and 8C-glucosyl derivatives of the respective flavones. In contrast, in planta, only the respective 6C-glucosides accumulated. Consistent with this selectivity in glycosylation product, a dehydratase activity that preferentially converted 2-hydroxyflavanone-C-glucosides to the corresponding flavone-6C-glucosides was identified in both rice and wheat. Our results demonstrate that cereal crops synthesize C-glucosylated flavones through the concerted action of a CGT and dehydratase acting on activated 2-hydroxyflavanones, as an alternative means of generating flavonoid metabolites.

Inhibitory activity of isoflavones of Pueraria flowers on nitric oxide production from lipopolysaccharide-activated primary rat microglia

Microglial activation plays an important role in alcohol-induced neuroinflammation. In search for natural medicines that may be of therapeutic potential for alcoholism, two new natural isoflavone glycosides, 6-hydroxybiochanin A-6,7-di-O-beta-d-glucopyranoside (1) and 6-hydroxygenistein-7-O-beta-d-glucopyranoside (2), were isolated from the ethanolic extract of the flowers of Pueraria thomsonii Benth., together with the seven known isoflavones, genistein (3), tectorigenin (4), irisolidone (5), genistin (7), tectoridin (8), tectorigenin-7-O-beta-d-xylosyl-(1 --> 6)-beta-d-glucopyranoside (9), and 6-hydroxygenistein-6,7-di-O-beta-d-glucopyranoside (11). Moreover, gehuain (6) and kakkalide (10) were obtained from the flowers of Pueraria lobata (Willd.) Ohwi. The structures of the new compounds were elucidated by UV, IR, HR-MS, and 1D and 2D NMR spectroscopic methods. Compounds 3-5 substantially inhibited the lipopolysaccharide-induced nitric oxide release from primary cultured rat cortical microglia (IC50: 1.3-9.3 microM). The inhibitory effects of compounds 6, 8, 9, and 11 (IC50: 38-62 microM) were significant but weaker than the above aglycones. However, compounds 1, 2, 7, and 10 showed little inhibitory activity. With regard to the structure-activity relationships of the isoflavonoids for the inhibition of microglial activation, the glycosylation at the C-7 hydroxyl group reduces the inhibitory activity. The methoxylation of 4'-hydroxyl group of 7-glycosylated isoflavonoids reduces the inhibitory activity, while the methoxyl group at the 6-position enhances the activity. The results suggest that isoflavonoids of Pueraria flowers may be of therapeutic potential in alcoholism related to microglial activation.

Bioactivity studies and chemical profile of the antidiabetic plant Genista tenera

AIM OF THE STUDY

Genista tenera is a plant endemic to the island of Madeira and is used in folk medicine to control diabetes. In the present work we evaluate the antihyperglycaemic activity of its n-butanol extract and determine its chromatographic profile. In addition, this extract, the ethyl acetate and diethyl ether plant extracts were studied in order to assess the plant antioxidant and acetylcholinesterase inhibitory activities, as well as its cyto- and genotoxicities.

MATERIALS AND METHODS

HPLC-DAD-ESI-MS was used to analyze the flavonoid profile of the n-butanol extract. The antihyperglycaemic activity of this extract was performed over streptozotocin induced diabetic Wistar rats (200 mg/kg, bw/day), for 15 days. Antioxidant activity (DPPH assay) and acetylcholinesterase inhibitory effect (Ellman method) were also performed. Acute cytotoxicity and genotoxicity were assessed by proliferative index quantification and the short-term chromosomal aberration technique, after exposure of lymphocytes to the extracts.

RESULTS AND CONCLUSIONS

The n-butanol extract, where 21 monoglycosyl and 12 diglycosyl flavonoids were detected, significantly lowered blood glucose levels, bringing them to normal values after 15 days of treatment. The best radical scavenging activity was observed for the ethyl acetate extract (48.7% at 139.1 microg/mL), which was also the most effective one at the minimal concentration tested. The highest acetylcholinesterase inhibitory activity (77.0% at 70.0 microg/mL) was also obtained with the ethyl acetate extract. In vitro toxicity studies showed no evidence for acute cytotoxicity or genotoxicity. This is the first report on antidiabetic activity of genus Genista.

Survey of grapevine Vitis vinifera stem polyphenols by liquid chromatography-diode array detection-tandem mass spectrometry

Grapes and red wine prepared from Vitis vinifera L. contain a variety of polyphenols. Some information is available about the polyphenols of the seeds and leaves of grapevine, but considerably less is known about the polyphenols of woody stems. In this paper, we describe the results of a study of polyphenolic compounds in grapevine stems. We demonstrate how a combination of reversed phase high-performance liquid chromatography with ultraviolet-diode array detection and electrospray ionization-tandem mass spectrometry ion-trap detection enables characterization of a phytochemical mixture of considerable complexity. As the polyphenol source, the stems of three frost-hardy grapevine varieties [Hasaine (Hasansky) sladki, Zilga, and Yubilei Novgoroda] were used. The main group of methanol-extractable polyphenols of stems consists of trans-resveratrol and its derivatives including oligomers and glucosides. As minor components of the extract, stilbenoid piceatannol as well as a number of nonstilbenoid polyphenols, mostly flavan-3-ols and phenolic acids glucosides, were determined. The total polyphenol content of the grapevine stems depends on the variety, whereby the stems of cultivar Yubilei Novgoroda with white grapes contain significantly less of both groups of polyphenols.

Capillary electrophoresis-mass spectrometry characterisation of secondary metabolites from the antihyperglycaemic plantGenista tenera

Genista tenera is endemic to the Portuguese island of Madeira, where an infusion of the aerial parts of the plant is used in folk medicine as an antidiabetic agent. Consequently the medicinal properties of the secondary metabolites of this plant have been the subject of an ongoing study. A recently reported LC-MS method using a 100 min separation allowed identification of five flavonoid components in an extract of the aerial parts of this plant. In order to obtain additional information on the range and complexity of the plant's secondary metabolite components a CE-MS method has been developed and applied for the analysis of an extract of G. tenera. Twenty-six different components are distinguished in an analysis time of only 10 min. Results demonstrate that CE-MS/MS rapidly generates data complementary to those obtainable by LC-MS/MS and is particularly suited to the analysis of plant metabolites where concentration is not limiting.

Simultaneous quantification of CTN986 and its deglycosylation products in rat serum using liquid chromatography/tandem mass spectrometry

A quantitative method for the simultaneous determination of CTN986, a flavonol triglycoside, and its two deglycosylation products rutin and hirsutin in rat serum was developed and validated for the investigation of the pharmacokinetics of CTN986. Analytes were isolated from the serum samples (200 microL) prior to analysis by liquid chromatography/tandem mass spectrometry (LC/MS/MS) using C(18) solid-phase extraction, and were separated on a Zorbax C(8) reversed-phase column with an isocratic mobile phase consisting of methanol/isopropanol/water/formic acid (20:10:70:0.1, v/v/v/v). The protonated analytes generated in the positive ion mode were monitored through multiple reaction monitoring in an eletrospray ionization source. Calibration was performed by internal standardization with CTN987, a flavonoid structurally similar to CTN986, and regression curves were constructed ranging from 2 to 1000 ng/mL in 200 microL serum samples. The intra- and inter-day precision values were below 11% and accuracy was between -2.37 and 1.4% for all quality control samples. This quantitation method was successfully applied to pharmacokinetic studies of CTN986 in rats following oral and intravenous administration. Rutin and hirsutin were not detected in rat serum.