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The isolation of a compound from a natural source involves many organic and mostly toxic solvents for extraction and purification. Natural deep eutectic solvents have been shown to be efficient options for the extraction of natural products. They have the advantage of being composed of abundantly available common primary metabolites, being nontoxic and environmentally safe solvents. The aim of this study was to develop a natural deep eutectic solvent-based extraction method for galanthamine, an important therapeutic agent for the treatment of Alzheimer's disease. This alkaloid can be produced by synthesis or by extraction from Narcissus bulbs. To develop an efficient extraction method, a number of different natural deep eutectic solvents was first tested for their solubilization capacity of galanthamine bromide salt. Promising results were obtained for ionic liquids, as well as some amphoteric and acidic natural deep eutectic solvents. In a two-cycle extraction process, the best solvents were tested for the extraction of galanthamine from bulbs. The ionic liquids produced poor yields, and the best results were obtained with some acid and sugar mixtures, among which malic acid-sucrose-water (1 : 1 : 5) proved to be the best, showing similar yields to that of the exhaustive Soxhlet extraction with methanol. Furthermore, the natural deep eutectic solvent was more selective for galanthamine., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Despite the extensive studies on latex, some fundamental questions on their chemical specialization and the factors influencing this specialization have yet to be investigated. To address this issue, latexes and their bearing tissues from diverse species were profiled by 1 HNMR and GC-MS. Additionally, the antiherbivory activity of these materials was tested against thrips ( Frankliniella occidentalis Pergande, 1895). The multivariate data analysis showed a clear separation between latexes and leaves from the same species. Conversely, the chemical profiles of latexes from different species were highly similar, that is, they displayed much less metabolic species-specificity. These shared chemical profiles of latexes were reflected in their overall higher mortality index (80.4% ± 7.5) against thrips compared with their bearing tissues (55.5% ± 14.9). The metabolites correlated to the antiherbivory activity of latexes were triterpenoids and steroids. However, the activity could not be attributed to any single terpenoid. This discrepancy and the reduction of the latex activity after fractionation suggested a complementary effect of the compounds when in a mixture as represented by the latex. Additionally, aqueous fractions of several latexes were found to possess simple spectra, even with only 1 metabolite. These metabolites were determined to be organic acids that might be involved in the modulation of the rate of latex coagulation, potentially increasing the sealing and trapping effects of the latex., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Moracin C from Morus alba fruits, also known as the mulberry, has been proven to exhibit inhibitory activities against lipoxygenase enzymes, TNF- α and interleukin-1 β secretion, and proprotein convertase subtilisin/kexin type 9 expression. Despite the various pharmacological activities of moracin C, its pharmacokinetic characteristics have yet to be reported. Here, the pharmacokinetic parameters and tissue distribution of moracin C have been investigated in mice, and the plasma concentration of moracin C with multiple dosage regimens was simulated via pharmacokinetic modeling. Our results showed that moracin C was rapidly and well absorbed in the intestinal tract, and was highly distributed in the gastrointestinal tract, liver, kidneys, and lungs. Moracin C was distributed in the ileum, cecum, colon, and liver at a relatively high concentration compared with its plasma concentration. It was extensively metabolized in the liver and intestine, and its glucuronidated metabolites were proposed. In addition, the simulated plasma concentrations of moracin C upon multiple treatments (i.e., every 12 and 24 h) were suggested. We suggest that the pharmacokinetic characteristics of moracin C would be helpful to select a disease model for in vivo evaluation. The simulated moracin C concentrations under various dosage regimens also provide helpful knowledge to support its pharmacological effect., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Historically, latex-bearing plants have been regarded as important medicinal resources in many countries due to their characteristic latex ingredients. They have also often been endowed with a social or cultural significance in religious or cult rituals or for hunting. Initial chemical studies focused on the protein or peptide content but recently the interest extended to smaller molecules. Latex has been found to contain a broad range of specialized metabolites such as terpenoids, cardenolides, alkaloids, and phenolics, which are partly responsible for their antibacterial, antifungal, anthelmintic, cytotoxic, and insect-repellent activities. The diversity in biology and chemistry of latexes is supposedly associated to their ecological roles in interactions with exogenous factors. Latexes contain unique compounds that are different to those found in their bearing plants. Exploring the feasibility of plant latex as a new type of bioactive chemical resource, this review paper covers the chemical characterization of plant latexes, extending this to various other plant exudates. Also, the factors influencing this chemical differentiation and the production, transportation, and chemistry of the latex exudates are described, based on ecological and biochemical mechanisms. We also proposed a latex coagulation model involving 4 general conserved steps. Therefore, the inherent defensive origin of latexes is recognized as their most valuable character and encourages one to pay attention to these materials as alternative sources to discover metabolites with insecticidal or antimicrobial activity., Competing Interests: The authors declare that they have no conflict of interest., (Georg Thieme Verlag KG Stuttgart · New York.)

Ideally, metabolomics should deal with all the metabolites that are found within cells and biological systems. The most common technologies for metabolomics include mass spectrometry, and in most cases, hyphenated to chromatographic separations (liquid chromatography- or gas chromatography-mass spectrometry) and nuclear magnetic resonance spectroscopy. However, limitations such as low sensitivity and highly congested spectra in nuclear magnetic resonance spectroscopy and relatively low signal reproducibility in mass spectrometry impede the progression of these techniques from being universal metabolomics tools. These disadvantages are more notorious in studies of certain plant secondary metabolites, such as saponins, which are difficult to analyse, but have a great biological importance in organisms. In this study, high-performance thin-layer chromatography was used as a supplementary tool for metabolomics. A method consisting of coupling 1 H nuclear magnetic resonance spectroscopy and high-performance thin-layer chromatography was applied to distinguish between Ophiopogon japonicus roots that were collected from two growth locations and were of different ages. The results allowed the root samples from the two growth locations to be clearly distinguished. The difficulties encountered in the identification of the marker compounds by 1 H nuclear magnetic resonance spectroscopy was overcome using high-performance thin-layer chromatography to separate and isolate the compounds. The saponins, ophiojaponin C or ophiopogonin D, were found to be marker metabolites in the root samples and proved to be greatly influenced by plant growth location, but barely by age variation. The procedure used in this study is fully described with the purpose of making a valuable contribution to the quality control of saponin-rich herbal drugs using high-performance thin-layer chromatography as a supplementary analytical tool for metabolomics research., Competing Interests: The authors declare that they have no conflict of interest., (Georg Thieme Verlag KG Stuttgart · New York.)

This paper describes the use of 1 H NMR profiling and chemometrics in order to facilitate the selection of medicinal plants as potential sources of collagenase inhibitors. A total of 49 plants with reported ethnobotanical uses, such as the healing of wounds and burns, treatment of skin-related diseases, rheumatism, arthritis, and bone diseases, were initially chosen as potential candidates. The in vitro collagenase inhibitory activity of hydroalcoholic extracts of these plants was tested. Moreover, their phytochemical profiles were analyzed by 1 H NMR and combined with the inhibitory activity data by an orthogonal partial least squares model. The results showed a correlation between the bioactivity and the concentration of phenolics, including flavonoids, phenylpropanoids, and tannins, in the extracts. Considering the eventual false-positive effect on the bioactivity given by tannins, a tannin removal procedure was performed on the most active extracts. After this procedure, Alchemilla vulgaris was the most persistently active, proving to owe its activity to compounds other than tannins. Thus, this plant was selected as the most promising and further investigated through bioassay-guided fractionation, which resulted in the isolation of a flavonoid, quercetin-3- O - β -glucuronide, as confirmed by NMR and HRMS spectra. This compound showed not only a higher activity than other flavonoids with the same aglycone moiety, but was also higher than doxycycline (positive control), the only Federal Drug Administration-approved collagenase inhibitor. The approach employed in this study, namely the integration of metabolomics and bioactivity-guided fractionation, showed great potential as a tool for plant selection and identification of bioactive compounds in natural product research., Competing Interests: The authors declare no conflict of interest., (Georg Thieme Verlag KG Stuttgart · New York.)

As numerous herbal products have been used as dietary supplements or functional foods, the demands of the pharmacokinetic and pharmacodynamic characteristics of active compounds are increasing in order to secure a consistent outcome (i.e., efficiency and safety). In this study, the pharmacokinetics including tissue distribution, metabolism, and protein binding of isoliquiritigenin, a chalcone found in Glycyrrhiza glabra, and its metabolite, liquiritigenin, at various doses in mice are reported. Also, correlations between the preferential tissue distribution and pharmacological effect of isoliquiritigenin in certain organs were investigated using the in vivo gastroprotective effect of isoliquiritigenin in mice with indomethacin-induced ulcer. The absorbed fraction of isoliquiritigenin was high, but the absolute bioavailability was low mainly due to its metabolism. In spite of the low bioavailability, the gastroprotective effect of isoliquiritigenin was attributed to its high distribution in the stomach. Isoliquiritigenin prevented the occurrence of gastric ulcers by indomethacin, which is associated with increased gastric mucous secretion because the pretreatment with isoliquiritigenin presumably counteracted the decreased cyclooxygenase 2 by indomethacin. This may suggest that the pharmacokinetic properties of isoliquiritigenin are useful to predict its efficacy as a gastroprotective agent in a target organ such as the stomach., (Georg Thieme Verlag KG Stuttgart · New York.)

We applied an acute stress model to zebra fish in order to measure the changes in the metabolome due to biological stress. This was done by submitting the fish to fifteen minutes of acute confinement (netting) stress, and then five minutes for the open field and light/dark field tests. A polar extract of the zebra fish was then subjected to (1)H nuclear magnetic spectroscopy. Multivariate data analysis of the spectra showed a clear separation associated to a wide range of metabolites between zebra fish that were submitted to open field and light/dark field tests. Alanine, taurine, adenosine, creatine, lactate, and histidine were high in zebra fish to which the light/dark field test was applied, regardless of stress, while acetate and isoleucine/lipids appeared to be higher in zebra fish exposed to the open field test. These results show that any change in the environment, even for a small period of time, has a noticeable physiological impact. This research provides an insight of how different mechanisms are activated under different environments to maintain the homeostasis of the body. It should also contribute to establish zebra fish as a model for metabolomics studies., (Georg Thieme Verlag KG Stuttgart · New York.)

Isoliquiritigenin, a chalcone found in licorice has shown a variety of biological activities including antioxidative, anti-inflammatory, estrogenic, chemopreventive and antitumor effects. Thus, pharmacokinetics of isoliquiritigenin and its metabolites [liquiritigenin, glucuronidated isoliquiritigenin (M1), and glucuronidated liquiritigenin (M2)] after intravenous and oral administration of isoliquiritigenin was evaluated in rats. The pharmacokinetics of isoliquiritigenin, liquiritigenin, M1, and M2 showed no dose dependence after both intravenous and oral administration of isoliquiritigenin. Although approximately 92.0 % of the oral isoliquiritigenin was absorbed, the extent of the absolute bioavailability value was only 11.8 % of the oral dose. The low absolute bioavailability value of isoliquiritigenin might be due to the considerable metabolism of isoliquiritigenin in the small intestine and liver. This was supported by the facts that the ratios of AUC(M1)/AUC(isoLQ) and AUC(M2)/AUC(isoLQ) were high (over 0.25), isoliquiritigenin disappeared, and M1 and M2 were formed mainly in S9 fractions of the liver and small intestine. The affinities of liquiritigenin, isoliquiritigenin, M1, and M2 were high in the liver, small intestine, large intestine, and/or kidney., (Georg Thieme Verlag KG Stuttgart · New York.)

Radix Bupleuri is a traditional Chinese medicine harvested from two Bupleurum species (B. chinense and B. scorzonerifolium). It is widely used and is sourced from different regions of China. 1H NMR spectroscopy and multivariate data analysis were applied to 67 Radix Bupleuri samples to discriminate the two species, and explore the influences of habitat and culture method on the quality of Radix Bupleuri based on their metabolomics profiles. Metabolites responsible for the differences between the two species were higher levels of arginine, citric acid, sucrose, saikosaponin b1/b2 analogs, volatile oil with an (E)-2-olefin aldehyde fragment, and fatty acids in B. scoreonerifolium, and more saikosaponin a/c/d analogs in B. chinense. The variances of two cultivation areas were observed due to the higher amount of saikosaponins a/c/d in samples from Shaanxi and lipidsin samples from Shanxi. No obvious difference was detected between cultivars and wild type. 1HNMR metabolomics can simultaneously detect saikosaponins and hydrocarbon aldehydes, and also differentiate the two main saikosaponin skeletons, making it a suitable tool for the species discrimination and quality evaluation of Radix Bupleuri., (Georg Thieme Verlag KG Stuttgart · New York.)

Withania somnifera (L.) Dun. (Solanaceae), known as Indian ginseng, is one of the most popular medicinal plants in India. Considering the importance and common use of this plant, it is necessary to investigate its holistic metabolite profile. However, with existing analytical methods which are based on TLC and HPLC‑UV (or MS), it is difficult to obtain information of the whole range of compounds appropriately. In this study, the metabolic characterization of Withania somnifera leaves, stems, and roots collected in six different regions in India was performed using ¹H NMR spectroscopy followed by principal component analysis (PCA) and hierarchical clustering analysis (HCA). Of the parts of Withania somnifera analyzed in this study, the leaf was found to have the widest range of metabolites, including amino acids, flavonoids, lipids, organic acids, phenylpropanoids, and sugars, as well as the main secondary metabolites of the plant, withanolides. The ¹H NMR spectra revealed the presence of two groups of withanolides: 4-OH and 5,6-epoxy withanolides (withaferin A-like steroids) and 5- OH and 6,7-epoxy withanolides (withanolides Alike steroids). The ratio of these two withanolides was found to be a key discriminating feature of Withania somnifera leaf samples from different origins., (© Georg Thieme Verlag KG Stuttgart · New York.)

A new resveratrol oligomer (1) together with eight related components (2- 9) were isolated from the seed extract of Paeonia lactiflora (Paeoniaceae) as active principles responsible for the inhibition of beta-site APP-cleaving enzyme 1 (BACE-1) in vitro. The chemical structure of 1 was established as (-)-7a,8a- CIS- ε-viniferin with the aid of spectroscopic analyses including NOESY experiments. All isolated resveratrol oligomers (1- 9) demonstrated significant inhibition on baculovirus-expressed BACE-1 in a dose-dependent manner, which was assessed by the FRET assay using Rh-EVNLDAEFK as a substrate in vitro., (© Georg Thieme Verlag KG Stuttgart · New York.)

Three new guaiane-type sesquiterpene lactones (1-3), together with nine related sesquiterpenes (4-12), were isolated from the whole extract of Ixeris dentata (Asteraceae). The chemical structures of isolates 1-12 were established by spectroscopic analyses as 3 β,8 β-dihydroxy-guaia-10(14)-en-1 α,4 α,5 α,6 β,7 α,11 βH-12,6 α-olide (1), ixerin N 6'- O-acetate (2), ixerisoside A 6'- O-acetate (3), ixerin N ( 4), ixerisoside A (5), ixerin M (6), tectroside (7), 8-epidesacylcynaropicrin glucoside (8), 8-epiisolipidiol (9), 11 βH-11,13-dihydrointegrifolin (10) 8 β-hydroxy-4 β,15-dihydrozaluzanin C (11), and integrifolin (12). Compounds 1-12 were evaluated for their inhibitory effect on the proliferation of the cultured human tumor cell lines MES-SA, MES-SA/DX5, HCT-15, and HCT15/CL02 in vitro., (© Georg Thieme Verlag KG Stuttgart · New York.)

Pilocarpine is an imidazole alkaloid that has been used for more than a century in glaucoma treatment. It is present in several species of the Pilocarpus genus (jaborandi), with its highest concentrations in P. microphyllus. In addition to pilocarpine, pilosine--an imidazole alkaloid without pharmacological use--is produced in high concentrations in mature plants. A metabolomic study was carried out on juvenile and mature plants to obtain information about pilocarpine metabolism at different developmental stages. Methanol-water and alkaloid extracts were analyzed by ¹H NMR and ESI-MS. Metabolic profiles from both techniques showed clear differences between various developmental stages. Intense signals in the aromatic region of the ¹H NMR spectrum and ions from pilosine and related alkaloids by ESI/MS were found only in extracts from mature plant. Two new imidazole alkaloids were identified by MS(n). Our results suggest that pilosine is produced exclusively in mature developmental stage, and juvenile plant material seems to be appropriate for further studies on pilocarpine biosynthesis., (© Georg Thieme Verlag KG Stuttgart · New York.)

Farnesylation of the activated RAS oncogene product by protein farnesyltransferase (FTase) is a critical step for its oncogenic function. Bioassay-guided purification of Ferula asafoetida (Umbelliferae) extract led to the isolation of the coumarin-derived sesquiterpene galbanic acid (1) as an active principal for FTase inhibitory activity, together with the four structurally related sesquiterpenes karatavicinol (2), umbelliprenin (3), farnesiferol B (4), and farnesiferol C (5). The 50 % inhibitory concentration (IC (50)) of 1 against FTase in an enzyme-based assay was calculated as 2.5 µM. Compound 1 also demonstrated potent inhibition of the proliferation of oncogenic RAS-transformed NIH3T3/Hras-F in a dose-dependent manner. The IC (50) value of 1 on the proliferation of oncogenic RAS-transformed NIH3T3/Hras-F cells was calculated as 16.2 µM, whereas its IC (50) value on control vector-transfected normal RAS-containing NIH3T3/ZIPneo cells was 58.5 µM., (© Georg Thieme Verlag KG Stuttgart · New York.)

Natural products have been the source of many drugs used in modern therapeutics, and particularly in the case of anticancer drugs, more than 50 % originally came from natural products. Their importance as a source of leads for new drugs therefore cannot be underestimated. However, due to the painstaking way of conventional lead-finding, the attention towards natural products has been deviated in the last decades. A new strategy for the detection of active compounds is necessary to get natural product research out of its stalemate. Metabolomics, with its holistic approach and the possibility it provides for the simultaneous detection of all sorts of metabolites, has the potential to be instrumental for this new approach. Therefore, this review aims at providing examples that illustrate the possibilities of using metabolomics as a tool to find active compounds from natural products, specifically anticancer drugs. Two different methods, IN SILICO and IN SITU, have been introduced as possible approaches. Current methods to detect anticancer activity in natural products have been briefly reviewed and compared in the first section, and various applications of metabolomics in cancer research are mentioned as they can provide comprehensive information of cancer metabolites utilized in the IN SITU approach. Metabolomics will certainly improve the efficiency of lead-finding from natural products and thus reinstate this prolific source of potential anticancer drugs., (Georg Thieme Verlag KG Stuttgart-New York.)

Metabolic fingerprinting techniques have received a lot of attention in recent years and the annual amount of publications in this field has increased significantly over the past decade. This increase in publications is due to improvements in the analytical performance, most notably in the field of NMR and MS analysis, and the increased awareness of the different applications of this growing field. Metabolomic fingerprinting or profiling is continuously being applied to new areas of research such as drug discovery from natural resources, quality control of herbal material, and discovering lead compounds. In this review the current state of the art of metabolic fingerprinting, focussing on NMR and MS technologies will be discussed. The application of these two analytical tools in the quality control of herbal material and phytopharmaceuticals forms the major part of this review. Finally we will look at the future developments and perspectives of these two technologies in the quality control of herbal material.

A new resveratrol dimer, (+)-vitisinol E (1) which demonstrated inhibitory activity on BACE-1 (beta-site APP-cleaving enzyme 1) in vitro, was isolated from the stembark extract of Vitis vinifera (Vitaceae) together with four known resveratrol oligomers, (+)-epsilon-viniferin (2), (+)-ampelopsin A (3), (+)-vitisin A (4) and (-)-vitisin B (5). The chemical structure of 1 was established by MR spectroscopic analyses, including HMBC. All isolated resveratrol derivatives (1-5) demonstrated significant inhibition on baculovirus-expressed BACE-1 in a dose-dependent manner, which was assessed with the FRET assay using Rh-EVNLDAEFK as a substrate in vitro.

Orthosiphon stamineus Benth. ( Orthosiphon Grandiflorus Bold. or Clerodendranthus spicatus Thunb.) is an Indonesian medicinal herb traditionally used for diseases such as hypertension, diabetes, and kidney stones. Despite the importance of this last application, there are very few reports on it. Diuretic action is an important factor in kidney stone treatment, as an increase in the volume of fluid flowing through the kidney will help to dissolve the stones, assist their passing to avoid further retention, and flush out the deposits. Among the diverse roles of adenosine A (1) receptor antagonists in renal protection, many studies have shown that they can induce diuresis and sodium excretion. A bioassay-guided fractionation of a methanol-water extract of Orthosiphon stamineus leaves using the adenosine A (1) receptor binding assay resulted in the isolation of seven methoxy flavonoids as active ligands with K(i) values in the micromolar range. The Hill slope values are not significantly different from unity (within 0.9 - 1.4), which indicates the antagonist effect to A (1)-R. The results of this study thus provide a scientific foundation for the traditional use ofOrthosiphon stamineus in kidney stone treatment, as the affinity of the active compounds isolated from it as adenosine A (1) receptor ligands allows them to be associated with diuretic activity, which is one possible treatment for renal lithiasis.

Galphimia glauca is popularly employed in Mexico for the treatment of central nervous system disorders. Pharmacological and phytochemical studies have resulted in the identification of the anxiolytic and sedative principle consisting of a mixture of nor-secofriedelanes, named the galphimine series (1 - 9). These active constituents were found in plants collected in the vicinity of a restricted region in Central Mexico, where this species is abundant. A metabolic profiling carried out by means of 1H-NMR spectroscopy and multivariate data analysis was applied to crude extracts from wild plant populations, collected from six different locations as a quality control assessment, in order to differentiate their chemical profile. Principal component analysis (PCA) of the 1H-NMR spectra revealed clear variations among the populations, with two populations out of the six studied manifesting differences, when the principal components PC-1 and PC-2 were analyzed. These two PCs permitted the differentiation of the various sample populations, depending on the presence of galphimines. This information consistently correlated with the corresponding HPLC analysis. The neuropharmacological effects of the crude extracts were evaluated by using ICR mice in the elevated plus maze, as well as the sodium pentobarbital-induced hypnosis models. Both assays demonstrated anxiolytic and sedative responses only among those sample populations which had previously been differentiated by PC-1. Partial least square regression-discriminant analysis (PLS-DA) also confirmed a strong correlation between the observed effects and the metabolic profiles of the plants. The overall results of this study confirm the benefits of using metabolic profiling for the in silico analysis of active principles in medicinal plants.

A quantitative analysis using (1)H-NMR (Q-NMR) has been developed for the determination of strychnine and brucine in Strychnos nux-vomica seeds and stems. The advantages of the method are that no reference alkaloids are needed for calibration curves, the quantification could be directly realized on a crude extract, strychnine and brucine could easily be distinguished, an overall profile of the preparation (including non alkaloid compounds) could be directly obtained, and a very significant time-gain could be achieved, in comparison to conventional HPLC methods, for instance.