Azepine-Indole Alkaloids From Psychotria nemorosa Modulate 5-HT2A Receptors and Prevent in vivo Protein Toxicity in Transgenic Caenorhabditis elegans.

Nemorosine A (1) and fargesine (2), the main azepine-indole alkaloids of Psychotria nemorosa, were explored for their pharmacological profile on neurodegenerative disorders (NDs) applying a combined in silico-in vitro-in vivo approach. By using 1 and 2 as queries for similarity-based searches of the ChEMBL database, structurally related compounds were identified to modulate the 5-HT2A receptor; in vitro experiments confirmed an agonistic effect for 1 and 2 (24 and 36% at 10 µM, respectively), which might be linked to cognition-enhancing properties. This and the previously reported target profile of 1 and 2, which also includes BuChE and MAO-A inhibition, prompted the evaluation of these compounds in several Caenorhabditis elegans models linked to 5-HT modulation and proteotoxicity. On C. elegans transgenic strain CL4659, which expresses amyloid beta (Aß) in muscle cells leading to a phenotypic paralysis, 1 and 2 reduced Aß proteotoxicity by reducing the percentage of paralyzed worms to 51%. Treatment of the NL5901 strain, in which α-synuclein is yellow fluorescent protein (YFP)-tagged, with 1 and 2 (10 µM) significantly reduced the α-synuclein expression. Both alkaloids were further able to significantly extend the time of metallothionein induction, which is associated with reduced neurodegeneration of aged brain tissue. These results add to the multitarget profiles of 1 and 2 and corroborate their potential in the treatment of NDs.

Secondary-metabolites fingerprinting of Argania spinosa kernels using liquid chromatography-mass spectrometry and chemometrics, for metabolite identification and quantification as well as for geographic classification.

Argan (Argania spinosa L.) fruit kernels' composition has been poorly studied and received less research intensity than the resulting Argan oil. The Moroccan Argan kernels contain a wealth of metabolites and can be investigated for nutritional and health aspects as well as for economic benefits. Ultra-Performance Liquid Chromatography Mass Spectrometry (UPLC-MS) was employed to trace the geographical origin of Argan kernels based on secondary-metabolite profiles. One-hundred and twenty Argan fruit kernels from five regions ('Agadir', 'Ait-Baha' 'Essaouira', 'Tiznit' and 'Taroudant') were studied. Characterization and quantification of 36 secondary metabolites (33 polyphenolic and 3 non-phenolic) were achieved. Those metabolites are highly influenced by the geographic origin. Then, the untargeted UPLC-MS fingerprint was decomposed by metabolomic data handling tools, such as multivariate curve resolution alternating least squares (MCR-ALS) and XCMS. The two resulting data matrices were pretreated and prepared separately by chemometric tools and then two data fusion strategies (low- and mid-levels) were applied on them. The four data sets were comparatively investigated. Principal component analysis (PCA), Partial Least Squares Discriminant Analysis (PLS-DA), and Soft Independent Modeling of Class Analogies (SIMCA) were used to classify samples. The exploration or classification models demonstrated a good ability to discriminate and classify the samples in the geographical-origin based classes. Summarized, the developed fingerprints and their metabolomics-based data handling successfully allowed geographical traceability evaluation of Moroccan Argan kernels.

Modelling approaches for chiral chromatography on polysaccharide-based and macrocyclic antibiotic chiral selectors: A review.

An overview of molecular modelling approaches, related to chiral separations on polysaccharide-based and macrocyclic antibiotic chiral selectors, is presented. Both atomistic calculations and empirical fitting procedures are discussed. Atomistic calculations, such as docking and molecular dynamics can be used to model the interactions between enantiomers and the chiral stationary phase. This may help obtaining information about the chiral recognition mechanism. Conversely, in empirical fitting procedures, mathematical models for relevant separation parameters are fitted to experimental observations. The latter use theoretical molecular descriptors, calculated from the molecular structure, which are combined into a model to predict a given response, for example, retention. Such relationships, when used in chiral separations, are often called quantitative structure enantioselective retention relationships (QSERR) and an increased interest in them can be observed in the literature. Different regression models are discussed, such as multiple linear regression and partial least squares.

UPLC-PDA-ESI-QTOF-MS/MS and GC-MS analysis of Iranian Dracocephalum moldavica L.

Dracocephalum moldavica L. is a significant component in the Iranian food basket. This study aimed to investigate the bioactive compounds and biological activities of different extracts obtained from D. moldavica aerial parts. From the aerial parts, a crude methanolic (MeOH) extract and its four sub-fractions, that is, petroleum ether (Pet), ethyl acetate (EtOAc), n-butanol (n-BuOH), and aqueous (water) extracts were obtained. The total phenolic and flavonoid contents as well as the antioxidant and cytotoxic activities of the extracts were determined. Moreover, the phytochemical profiles of the essential oil (EO) and of those extracts with the highest antioxidant activity measured by GC/MS and UPLC-PDA-ESI-QTOF-MS/MS. Results showed that the highest concentrations of phenols and flavonoids as well as the most potent antioxidant potential according to the DPPH method were determined in the EtOAc and MeOH extracts with IC50 values of 22.0 and 34.4 µg.ml-1, respectively. Quantitative analysis of these extracts was subsequently performed by UPLC-PDA-ESI-QTOF-MS/MS. Both extracts contained mainly rosmarinic acid, caffeic acid, and 2-hydroxycinnamic acid, which may be responsible for their high antioxidant activity. Moreover, none of the extracts showed cytotoxic effects against MCF7, SW48, and a normal cell line of mouse embryonic fibroblast cells (NIH/3T3) in the tested concentrations (up to 400 µg.ml-1). Additionally, GC-MS analysis showed that oxygenated monoterpenes (55.4%) were the main constituents of the EO of D. moldavica.

Quality Control of Herbal Medicines: From Traditional Techniques to State-of-the-art Approaches.

Herbal medicines are important options for the treatment of several illnesses. Although their therapeutic applicability has been demonstrated throughout history, several concerns about their safety and efficacy are raised regularly. Quality control of articles of botanical origin, including plant materials, plant extracts, and herbal medicines, remains a challenge. Traditionally, qualitative (e.g., identification and chromatographic profile) and quantitative (e.g., content analyses) markers are applied for this purpose. The compound-oriented approach may stand alone in some cases (e.g., atropine in Atropa belladonna). However, for most plant materials, plant extracts, and herbal medicines, it is not possible to assure quality based only on the content or presence/absence of one (sometimes randomly selected) compound. In this sense, pattern-oriented approaches have been extensively studied, introducing the use of multivariate data analysis on chromatographic/spectroscopic fingerprints. The use of genetic methods for plant material/plant extract authentication has also been proposed. In this study, traditional approaches are reviewed, although the focus is on the applicability of fingerprints for quality control, highlighting the most used approaches, as well as demonstrating their usefulness. The literature review shows that a pattern-oriented approach may be successfully applied to the quality assessment of articles of botanical origin, while also providing directions for a compound-oriented approach and a rational marker selection. These observations indicate that it may be worth considering to include fingerprints and their data analysis in the regulatory framework for herbal medicines concerning quality control since this is the foundation of the holistic view that these complex products demand.

Cytotoxicity and Antiviral Activities of Haplophyllum tuberculatum Essential Oils, Pure Compounds, and Their Combinations against Coxsackievirus B3 and B4.

Haplophyllum tuberculatum is a plant commonly used in folk medicine to treat several diseases including vomiting, nausea, infections, rheumatism, and gastric pains. In the current study, H. tuberculatum essential oils, hydrosols, the pure compounds R-(+)-limonene, S-(-)-limonene, and 1-octanol, as well as their combinations R-(+)-limonene/1-octanol and S-(-)-limonene/1-octanol, were screened for their cytotoxicity on HEp-2 cells after 24, 48, and 72 h, and then tested for their activity against Coxsackievirus B3 and B4 (CV-B3 and CV-B4) at 3 different moments: addition of the plant compounds before, after, or together with virus inoculation. Results showed that the samples were more cytotoxic after 72 h than after 24 h or 48 h cell contact. However, the combinations R-(+)-limonene/1-octanol and S-(-)-limonene/1-octanol showed less effect on HEp-2 cells than pure R-(+)-limonene and S-(-)-limonene after 24 h, 48 h, and 72 h. 1-octanol exhibited the highest concentration causing 50% cytotoxicity (CC50) on HEp-2 cells after 24 h (CC50 = 93 µg/mL) and 48 h (CC50 = 83 µg/mL). The antiviral assays showed that the tested samples exhibited potent inhibition of CV-B. IC50 values ranged from 0.66 µg/mL to 28.4 µg/mL. In addition, CV-B3 was more sensitive than CV-B4. Both CV-B strains are more inhibited when cells were pretreated with the plant compounds. The hydrosols have no effect, neither on HEp-2 cells nor on the virus. 1-octanol, S-(-), and R-(+)-limonene/1-octanol had important selectivity indexes over time. Although essential oils had potent antiviral activity, they can be considered for application in the pretreatment of cells. However, 1-octanol and the combinations are within the safety limits, and thus, they can be used as an active natural antiviral agent for CV-B3 and CV-B4 inhibition.

In Vitro & In Vivo Anti-Hyperglycemic Potential of Saponins Cake and Argan Oil from Argania spinosa.

The Argan tree (Argania spinosa. L) is an evergreen tree endemic of southwestern Morocco. For centuries, various formulations have been used to treat several illnesses including diabetes. However, scientific results supporting these actions are needed. Hence, Argan fruit products (i.e., cake byproducts (saponins extract) and hand pressed Argan oil) were tested for their in-vitro anti-hyperglycemic activity, using α-glucosidase and α-amylase assays. The in-vivo anti-hyperglycemic activity was evaluated in a model of alloxan-induced diabetic mice. The diabetic animals were orally administered 100 mg/kg body weight of aqueous saponins cake extract and 3 mL/kg of Argan oil, respectively, to evaluate the anti-hyperglycemic effect. The blood glucose concentration and body weight of the experimental animals were monitored for 30 days. The chemical properties and composition of the Argan oil were assessed including acidity, peroxides, K232, K270, fatty acids, sterols, tocopherols, total polyphenols, and phenolic compounds. The saponins cake extract produced a significant reduction in blood glucose concentration in diabetic mice, which was better than the Argan oil. This decrease was equivalent to that detected in mice treated with metformin after 2-4 weeks. Moreover, the saponins cake extract showed a strong inhibitory action on α-amylase and α-glucosidase, which is also higher than that of Argan oil.

New insights into the Argan oil categories characterization: Chemical descriptors, FTIR fingerprints, and chemometric approaches.

The characterization of Argan oils to classify them in three categories ('Extra Virgin', 'Virgin' and 'Lower quality') was evaluated. A total of 120 Moroccan Argan oils samples from the Taroudant Argan forest was investigated. The free acidity, peroxide value, spectrophotometric indices (K232 and K270), fatty acids, sterols, and tocopherol contents were assessed. The samples were also scanned by FTIR spectroscopy. The Principal Component Analysis (PCA) and four classification methods, Partial Least Squares Discriminant Analysis (PLS-DA), Soft Independent Modelling of Class Analogy (SIMCA), K-nearest Neighbors (KNN), and Support Vector Machines (SVM), were applied on both the chemical and spectral data. Besides the conventional chemical profiling, FTIR spectra were evaluated for their feasibility as a rapid non-invasive approach for classifying and predicting the oil quality categories. The most important variables for differentiating the oil categories were identified as K232, peroxide value, É£-tocopherol, δ-tocopherol, acidity, stigma-8-22-dien-3ß-ol, stearic acid (C18:0) and linoleic acid (C18:2) and could be used as quality indicators. Eight chemical descriptors or key features from the FTIR spectra (selected by interval-PLS) could also be established as indicators of quality and freshness of Argan oils.

Four Pistacia atlantica subspecies (atlantica, cabulica, kurdica and mutica): A review of their botany, ethnobotany, phytochemistry and pharmacology.

ETHNOPHARMACOLOGICAL RELEVANCE: Pistacia atlantica (wild pistachio) belongs to the Anacardiaceae family, and growing from the Mediterranean basin to central Asia, especially in Iran, Turkey, Iraq and Saudi Arabia where it is extensively used in traditional medicine for a wide range of ailments related to relieving upper abdominal discomfort and pain, dyspepsia and peptic ulcer. OBJECTIVE: Despite the diverse biological activities of P. atlantica, there is no current review summarizing medicinal properties of its subspecies, including cabulica, kurdica and mutica. Thus, this paper aims to explore the current understanding of the chemical, pharmacological, and biochemical properties of the extracts and the main active constituents found in each subspecies of this plant. METHODS: Peer-reviewed articles, using "Pistacia atlantica" as search term (″all fields″), were retrieved from Scifinder, Pubmed, Science direct, Wiley, Springer, ACS, Scielo, Web of Science and other web search instruments (Google Scholar, Yahoo search). Papers published until July 2020 are considered. In addition, various books were consulted that contained botanical and ethnopharmacological information. The information provided in this review is based on peer-reviewed papers in English and French. RESULTS: Phytochemical studies have shown the presence of numerous valuable compounds, including volatile compounds, flavonoids, phenolic compounds, fatty acids, tocopherols and phytosterols. P. atlantica contains also minerals and trace elements, like iron, lead, copper, potassium, sodium and calcium; fatty acids, like oleic, linoleic, and palmitic acid; fat-soluble vitamins, such as α, ß, γ and δ tocopherols; phytosterols, like betasitosterol, stigmasterol, campesterol and Δ5-avenasterol. Crude extracts and isolated compounds from P. atlantica show a wide range of pharmacological properties, such as antimicrobial, antifungal, anti-inflammatory, analgesic, antinociceptive, wound healing, anticancer, cytotoxic, anticholinesterase, antidiabetic, hepatoprotective, urease inhibition, antihypertension, nipple fissure healing, antileishmanial and antiplasmodial activities. However, there are no reports summarizing the P. atlantica bioactivity, its therapeutic value, and the roles played by each of the numerous phytoconstituents. CONCLUSION: Many traditional uses of P. atlantica and its subspecies have now been confirmed by pharmacologic research. Systematic phytochemical investigation of the P. atlantica subspecies and the pharmacological properties, especially the mechanisms of action and toxicology, to illustrate their ethnomedicinal use, to explore the therapeutic potential and support further health-care product development, will undoubtedly be the focus of further research. Therefore, detailed and extensive studies and clinical evaluation of P. atlantica subspecies should be carried out in future for the safety approval of therapeutic applications.

Improvement of quantitative structure-retention relationship models for chromatographic retention prediction of peptides applying individual local partial least squares models.

In Reversed-Phase Liquid Chromatography, Quantitative Structure-Retention Relationship (QSRR) models for retention prediction of peptides can be built, starting from large sets of theoretical molecular descriptors. Good predictive QSRR models can be obtained after selecting the most informative descriptors. Reliable retention prediction may be an aid in the correct identification of proteins/peptides in proteomics and in chromatographic method development. Traditionally, global QSRR models are built, using a calibration set containing a representative range of analytes. In this study, a strategy is presented to build individual local Partial Least Squares (PLS) models for peptides, based on selected local calibration samples, most similar to the specific query peptide to be predicted. Similar local calibration peptides are selected from a possible calibration set. The calibration samples with the lowest Euclidian distances to the query peptide are considered as most similar. Two Euclidian distances are investigated as similarity parameter, (i) in the autoscaled descriptor space and, (ii) in the PLS factor space of the global calibration samples, both after variable selection by the Final Complexity Adapted Models (FCAM) method. The predictive abilities of individual local QSRR PLS models for peptides, developed with both Euclidian distances, are found significantly better than those of two global models, i.e. before and after FCAM variable selection. The predictive abilities of the local models, developed with distances calculated in the PLS factor space, were best.

Three promising antimycobacterial medicinal plants reviewed as potential sources of drug hit candidates against multidrug-resistant tuberculosis.

Regimens of current drugs for tuberculosis are lengthy and are associated with many adverse effects. Currently, the emergence of different resistant strains has been observed. This urges a need for the discovery and development of novel drugs. The main sources of drug lead candidates are based on natural products. Zanthoxylum leprieurii, Lantana camara, and Cryptolepis Sanguinolenta are among the plants that have antimycobacterial activity. Recent technological methods, such as metabolomics, can rapidly detect and identify active compounds from medicinal plants. In this review, we aim to provide an overview and discussion of the antimycobacterial activity, phytochemical analysis and toxicity profile of these plants and their products as well as the potential of metabolomic fingerprinting of medicinal plants with a given activity on microbes, in the search for the potential drug hit molecules. The information for this review was extracted from databases such as Excerpta Medica Database, Google Scholar, Springer, and PubMed Central. Primary studies, using a combination of the keywords antimycobacterial medicinal plant, multidrug-resistant tuberculosis, phytochemistry, toxicity, Zanthoxylum leprieurii, Lantana camara, Cryptolepis sanguinolenta, and plant metabolomics/metabolic fingerprinting of plant extracts, have been considered. The above-mentioned plant species showed antimycobacterial activity against drug-resistant strains of M. tuberculosis. They may provide potential candidates for novel drugs against multidrug-resistant tuberculosis. However, extensive work is still needed. To our knowledge, there is no or limited literature that reports the metabolic fingerprints of these plants. The analysis of the metabolite fingerprints of medicinal plants with similar antimicrobial activity could be important to determine whether the activity results from common metabolites within different plant species. This review shows that these plants are potential candidates to provide drug hits against multidrug-resistant tuberculosis strains. Future studies of compound optimization, in vivo safety and efficacy, as well as of the specific mechanisms of action are however required.

Application of Rank Annihilation Factor Analysis for Antibacterial Drugs Determination by Means of pH Gradual Change-UV Spectral Data.

The main objective of this study was to develop a simple and efficient spectrophotometric technique combined with chemometrics for the simultaneous determination of sulfamethoxazole (SMX) and trimethoprim (TMP) in drug formulations. Specifically, we sought: (i) to evaluate the potential use of rank annihilation factor analysis (RAFA) to pH gradual change spectrophotometric data in order to provide sufficient accuracy and model robustness; and (ii) to determine SMX and TMP concentration in drug formulations without tedious pre-treatments such as derivatization or extraction techniques which are time-consuming and require hazardous solvents. In the proposed method, the spectra of the sample solutions at different pH values were recorded and the pH-spectra bilinear data matrix was generated. On these data, RAFA was then applied to estimate the concentrations of SMX and TMP in synthetic and real samples. Applying RAFA showed that the two drugs could be determined simultaneously with concentration ratios of SMX to TMP varying from 1:30 to 30:1 in the mixed samples (concentration range is 1-30 µg mL-1 for both components). The limits of detection were 0.25 and 0.38 µg mL-1 for SMX and TMP, respectively. The proposed method was successfully applied to the simultaneous determination of SMX and TMP in some synthetic, pharmaceutical formulation and biological fluid samples. In addition, the means of the estimated RSD (%) were 1.71 and 2.18 for SMX and TMP, respectively, in synthetic mixtures. The accuracy of the proposed method was confirmed by spiked recovery test on biological samples with satisfactory results (90.50-109.80%).

Analytical techniques for metabolomic studies: a review.

Metabolomics is the comprehensive study of small-molecule metabolites. Obtaining a wide coverage of the metabolome is challenging because of the broad range of physicochemical properties of the small molecules. To study the compounds of interest spectroscopic (NMR), spectrometric (MS) and separation techniques (LC, GC, supercritical fluid chromatography, CE) are used. The choice for a given technique is influenced by the sample matrix, the concentration and properties of the metabolites, and the amount of sample. This review discusses the most commonly used analytical techniques for metabolomic studies, including their advantages, drawbacks and some applications.

Antioxidant activity of Vitis vinifera, Punica granatum, Citrus aurantium and Opuntia ficus indica fruits cultivated in Algeria.

Four edible fruits from Vitis vinifera, Punica granatum, Citrus aurantium and Opuntia ficus indica from Algeria were analyzed in order to determine the total polyphenol, total flavonoid and flavonol contents using classical spectrophotometric methods. The antioxidant activity was established by three different single-electron-transfer-based assays (ABTS radical cation, FRAP, and DPPH assays) and one hydrogen-atom-transfer based assay (ORAC). Among the four fruits tested, the Vitis vinifera hydroalcoholic extract showed the highest antioxidant capacity with all methods. The results indicated that the antioxidant activity and the total phenolic content of the selected plants are significantly different (p < 0.001).

First inter-laboratory study of a Supercritical Fluid Chromatography method for the determination of pharmaceutical impurities.

Supercritical Fluid Chromatography (SFC) has known a strong regain of interest for the last 10 years, especially in the field of pharmaceutical analysis. Besides the development and validation of the SFC method in one individual laboratory, it is also important to demonstrate its applicability and transferability to various laboratories around the world. Therefore, an inter-laboratory study was conducted and published for the first time in SFC, to assess method reproducibility, and evaluate whether this chromatographic technique could become a reference method for quality control (QC) laboratories. This study involved 19 participating laboratories from 4 continents and 9 different countries. It included 5 academic groups, 3 demonstration laboratories at analytical instrument companies, 10 pharmaceutical companies and 1 food company. In the initial analysis of the study results, consistencies within- and between-laboratories were deeply examined. In the subsequent analysis, the method reproducibility was estimated taking into account variances in replicates, between-days and between-laboratories. The results obtained were compared with the literature values for liquid chromatography (LC) in the context of impurities determination. Repeatability and reproducibility variances were found to be similar or better than those described for LC methods, and highlighted the adequacy of the SFC method for QC analyses. The results demonstrated the excellent and robust quantitative performance of SFC. Consequently, this complementary technique is recognized on equal merit to other chromatographic techniques.

Pharmacological activities of the organic extracts and fatty acid composition of the petroleum ether extract from Haplophyllum tuberculatum leaves.

ETHNOPHARMACOLOGICAL RELEVANCE: Haplophyllum tuberculatum is used in traditional medicine to treat many disorders including inflammation and pain. The aim of this study is to investigate the organic extracts from H. tuberculatum leaves against inflammation, gastric ulcer and pain. MATERIALS AND METHODS: Acute toxicity was studied in vivo to determine the toxic doses of the organic extracts. Anti-inflammatory activity was also evaluated in vivo using carrageenan-induced paw edema in Wistar rats. Gastroprotective activity was tested using the HCl/ethanol-induced gastric ulcer test in rats. Peripheral and central analgesic activities were assessed using the acetic acid-induced writhing test and the hot-plate method, respectively. The chemical composition of the fatty acids in the petroleum ether (PE) extract was determined with GC-MS. RESULTS: At 25, 50 and 100mg/kg PE extract was the most active against inflammation. Percentages inhibition 5h after carrageenan-injection were 51.12; 86.71% and 96.92%, respectively. The same extract at 100mg/kg showed good analgesic activities using the acetic acid-induced writhing test and the hot-plate method. The chloroform, ethyl acetate (EtOAc) and butanolic (n-BuOH) extracts exhibited strong anti-inflammatory, gastroprotective and analgesic activities at 100mg/kg. The GC-FID analysis revealed that the PE extract was rich in γ-linolenic acid (45.50%) followed by palmitic acid (18.48%), linoleic acid (10.73%), erucic acid (4.72), stearic acid (3.96%) and oleic acid (2.57%). CONCLUSION: The results of the present study support the traditional use of the leaves of H. tuberculatum and may possibly serve as prospective material for further development of safe new phytochemical anti-inflammatory, gastroprotective and/or analgesic agents.

Polyphenolic contents, antioxidant activities and UPLC-ESI-MS analysis of Haplophyllum tuberculatum A. Juss leaves extracts.

The aim of this study is to determine the phytochemical profile, the total polyphenolic contents and the antioxidant activities of Haplophyllum tuberculatum leaves extracts. The most active extracts were analyzed by ultra-high performance liquid chromatography coupled to electrospray ionization mass spectrometry. Antioxidant activities were screened by the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) test and measured by the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and ß-carotene bleaching inhibition assays. Phytochemical screening of the extracts revealed the presence of various secondary metabolites. The ethyl acetate extract was the richest extract in phenolics and flavonoids with 262mg gallic acid equivalents/g and 99.1mg quercetin equivalent/g of dry weight, respectively. The same extract showed an important scavenging effect on DPPH, ABTS and ß-carotene/linoleic acid with IC50 of 0.020mg/mL, 0.029mg/mL and 0.022mg/mL, respectively. The correlations between the antioxidant capacities and the polyphenolic content were ranging between 0.889 and 0.256 and occasionally found to be significant. The UPLC-ESI-MS analysis showed the presence of polyphenolic and alkaloid compounds. Arabelline, majidine, dictamine and a qudsine derivative are found for the first time in H. tuberculatum. The results indicate that polyphenolic and alkaloid compounds may be major contributors to the antioxidant activity of these extracts.

Targeted Isolation of Monoterpene Indole Alkaloids from Palicourea sessilis.

Phytochemical investigation of the alkaloid extract of Palicourea sessilis by LC-HRMS/MS using molecular networking and an in silico MS/MS fragmentation approach suggested the presence of several new monoterpene indole alkaloids. These compounds were isolated by semipreparative HPLC, and their structures confirmed by means of HRMS, NMR, and ECD measurements as 4-N-methyllyaloside (3), 4-N-methyl-3,4-dehydrostrictosidine (4), 4ß-hydroxyisodolichantoside (6), and 4α-hydroxyisodolichantoside (7), as well as the known alkaloids alline (1), N-methyltryptamine (2), isodolichantoside (5), and 5-oxodolichantoside (8). In addition, the acetylcholinesterase inhibitory activity of the compounds was evaluated up to 50 µM.

Antiplasmodial Activity, Cytotoxicity and Structure-Activity Relationship Study of Cyclopeptide Alkaloids.

Cyclopeptide alkaloids are polyamidic, macrocyclic compounds, containing a 13-, 14-, or 15-membered ring. The ring system consists of a hydroxystyrylamine moiety, an amino acid, and a ß-hydroxy amino acid; attached to the ring is a side chain, comprised of one or two more amino acid moieties. In vitro antiplasmodial activity was shown before for several compounds belonging to this class, and in this paper the antiplasmodial and cytotoxic activities of ten more cyclopeptide alkaloids are reported. Combining these results and the IC50 values that were reported by our group previously, a library consisting of 19 cyclopeptide alkaloids was created. A qualitative SAR (structure-activity relationship) study indicated that a 13-membered macrocyclic ring is preferable over a 14-membered one. Furthermore, the presence of a ß-hydroxy proline moiety could correlate with higher antiplasmodial activity, and methoxylation (or, to a lesser extent, hydroxylation) of the styrylamine moiety could be important for displaying antiplasmodial activity. In addition, QSAR (quantitative structure-activity relationship) models were developed, using PLS (partial least squares regression) and MLR (multiple linear regression). On the one hand, these models allow for the indication of the most important descriptors (molecular properties) responsible for the antiplasmodial activity. Additionally, predictions made for interesting structures did not contradict the expectations raised in the qualitative SAR study.

LC-MS analysis combined with principal component analysis and soft independent modelling by class analogy for a better detection of changes in N-glycosylation profiles of therapeutic glycoproteins.

Therapeutic proteins are among the top selling drugs in the pharmaceutical industry. More than 60 % of the approved therapeutic proteins are glycosylated. Nowadays, it is well accepted that changes in glycosylation may affect the safety and the efficacy of the therapeutic proteins. For this reason, it is important to characterize both the protein and the glycan structures. In this study, analytical and data processing methods were developed ensuring an easier characterization of glycoprofiles. N-glycans were (i) enzymatically released using peptide-N-glycosidase F (PNGase F), (ii) reduced, and (iii) analyzed by hydrophilic interaction liquid chromatography coupled to a high-resolution mass spectrometer (HILIC-HRMS). Glycosylation changes were analyzed in human plasma immunoglobulin G samples which had previously been artificially modified by adding other glycoproteins (such as ribonuclease B and fetuin) or by digesting with enzyme (neuraminidase). Principal component analysis (PCA) and classification through soft independent modelling by class analogy (SIMCA) were used to detect minor glycosylation changes. Using HILIC-MS-PCA/SIMCA approach, it was possible to detect small changes in N-glycosylation, which had not been detected directly from the extracted-ion chromatograms, which is current technique to detect N-glycosylation changes in batch-to-batch analysis. The HILIC-MS-PCA/SIMCA approach is highly sensitive approach due to the sensitivity of MS and appropriate data processing approaches. It could help in assessing the changes in glycosylation, controlling batch-to-batch consistency, and establishing acceptance limits according to the glycosylation changes, ensuring safety and efficacy. Graphical abstract N-glycosylation characterization using LC-MS-PCA approach.