Mixture Of Alkaloids Research Articles

Effect of gemcitabine-ALK-014 combination on MMP9 expression in primary pancreatic adenocarcinoma CELL cultures (PCCs).

332 Background: Pancreatic ductal adenocarcinoma (PDAC) is the fourth highest cause of death in the western world. The adjuvant chemotherapy can increase the overall survivor (OS) of PDAC patients. The Gemcitabine (GEM) and alkaloids mixture (ALK-014) combination shows the increase two time the OS non resectable in PDAC patients with respect to gemcitabine treatment alone. Indeed the Alkaoids compound modulated the Matrix MetalloProteinase 9 (MMP9) in PDAC cell clines. AIM: Our goal was to investigate the MMP 9 protein modulation in primary cell cultures (PCCs) of PDAC by Gem and ALK-014 combination treatment. Methods: Two PCCs (LPc006 and LPc028) were seeded in 4 multi-well chamber slids (8,000 each/well) for cytotoxicity study by Gem [10 Nm], ALk-014 [1µm]and their combination. After 48 h of treatment the cells were stained Immunocytochemistry (IHC) using polyclonal antibody for MMP9. We used no-treated cells to evaluate basic level of MMP9 protein. No–stained cells were used as negative control. All experiments were done in triplicates. We evaluated protein expression and cellular morphology by computer for imaging analysis (D-Sight, Menarini, Italy). The expression differences was evaluated by ANOVA and t-test analyses. Results: We found a significant reduction of MMP9 expression in both cell lines treated with Gem/ALK-014 combination with respect to their controls ( p<0.01). The same drug combination reduced significantly the number of proliferating cells and showed the modification of the structure of nuclei with respect to untreated cells (p<0.001). Conclusions: New therapeutic approaches are warranted to reduce the metastatic behavior of PDAC. The present drug combination seems to be a promising tool for PDAC treatment in vitro. The new computerized approach for MMP9 evaluation could be a first quantitative attempt for protein quantification in preclinical model.

Variation in alkaloid-based microbial defenses of the dendrobatid poison frog Oophaga pumilio

Conspicuously colored dendrobatid frogs possess alkaloid-based antipredator defenses that are sequestered from a diet of arthropods. The type and quantity of alkaloids in dendrobatids vary substantially with geographic location, mainly due to differences in arthropod availability. It has been experimentally demonstrated that some individual alkaloids inhibit the growth of certain microbes, and that different alkaloids vary in their antimicrobial efficacy. We further tested this hypothesis by examining the antimicrobial effectiveness of naturally occurring mixtures of alkaloids (i.e., alkaloid cocktails) isolated from the dendrobatid frog Oophaga pumilio from five different locations in Costa Rica and Panama. Alkaloid cocktails in frogs from these locations varied significantly in their alkaloid composition. Bacterial cultures of Escherichia coli and Bacillus subtilis, and the fungus Candida albicans were subjected to alkaloid cocktails from individual frogs. These antimicrobial susceptibility tests demonstrated significant inhibition of bacterial and fungal growth of cultures incubated with these alkaloids, suggesting that the mixture of alkaloids present naturally in O. pumilio has the potential to defend frogs against natural microbes. Furthermore, there were significant differences in the degree of microbial inhibition among alkaloid cocktails, suggesting that frogs from different locations vary in their defense against microbes.

Alkaloid extracts of Ficus species and palm oil-derived tocotrienols synergistically inhibit proliferation of human cancer cells

Tocotrienols have been reported to possess anticancer effects other than anti-inflammatory and antioxidant activities. This study explored the potential synergism of antiproliferative effects induced by individual alkaloid extracts of Ficus fistulosa, Ficus hispida and Ficus schwarzii combined with δ- and γ-tocotrienols against human brain glioblastoma (U87MG), lung adenocarcinoma (A549) and colorectal adenocarcinoma (HT-29) cells. Cell viability and morphological results demonstrated that extracts containing a mixture of alkaloids from the leaves and bark of F. schwarzii inhibited the proliferation of HT-29 cells, whereas the alkaloid extracts of F. fistulosa inhibited the proliferation of both U87MG and HT-29 cells and showed synergism in combined treatments with either δ- or γ-tocotrienol resulting in 2.2–34.7 fold of reduction in IC50 values of tocotrienols. The observed apoptotic cell characteristics in conjunction with the synergistic antiproliferative effects of Ficus species-derived alkaloids and tocotrienols assuredly warrant future investigations towards the development of a value-added chemotherapeutic regimen against cancers.

Unambiguous characterization of analytical markers in complex, seized opiate samples using an enhanced ion mobility trace detector-mass spectrometer.

Ion mobility spectroscopy (IMS)-based trace-compound detectors (TCDs) are powerful and widely implemented tools for the detection of illicit substances. They combine high sensitivity, reproducibility, rapid analysis time, and resistance to dirt with an acceptable false alarm rate. The analytical specificity of TCD-IMS instruments for a given analyte depends strongly on a detailed knowledge of the ion chemistry involved, as well as the ability to translate this knowledge into field-robust analytical methods. In this work, we introduce an enhanced hybrid TCD-IMS/mass spectrometer (TCD-IMS/MS) that combines the strengths of ion-mobility-based target compound detection with unambiguous identification by tandem MS. Building on earlier efforts along these lines (Kozole et al., Anal. Chem. 2011, 83, 8596-8603), the current instrument is capable of positive and negative-mode analyses with tightly controlled gating between the IMS and MS modules and direct measurement of ion mobility profiles. We demonstrate the unique capabilities of this instrument using four samples of opium seized by the Canada Border Services Agency (CBSA), consisting of a mixture of opioid alkaloids and other naturally occurring compounds typically found in these samples. Although many analytical methods have been developed for analyzing naturally occurring opiates, this is the first detailed ion mobility study on seized opium samples. This work demonstrates all available analytical modes for the new IMS-MS system including "single-gate", "dual-gate", MS/MS, and precursor ion scan methods. Using a combination of these modes, we unambiguously identify all signals in the IMS spectra, including previously uncharacterized minor peaks arising from compounds that are common in raw opium.

Chemoecological studies on marine natural products: terpene chemistry from marine mollusks

AbstractSome species of nudibranchs (Mollusca) protect themselves from predatory attacks by storing defensive terpene chemicals acquired from dietary sponges (Porifera) in specialized body parts called MDFs (mantle dermal formations), often advertising their unpalatability to potential predators by means of bright coloration patterns. Consequently, the survival of these trophic specialist species is closely related to the possibility of obtaining the defensive tools from sponges that live in their immediate vicinity; therefore, it is important to determine as precisely as possible the chemical composition of nudibranch extracts prior to any ecological studies addressing issues that involve their alimentary behavior and their defensive strategies, including the significance of their color patterns. Some of our recent studies on the chemical composition of terpene extracts from nudibranchs belonging to the genera Chromodoris and Hypselodoris are summarized. We also report the development of a method to assay extracts and purified metabolites for their feeding deterrent activity against co-occurring generalist predators. In a recent chemoecological study, showing that repugnant terpene chemicals are accumulated at extremely high concentrations in exposed parts of the nudibranchs’ bodies, the feeding deterrence assays were carried out on the generalist marine shrimp Palaemon elegans, very common in the Mediterranean. We have modified this assay for use with the Australian shrimp species P. serenus, and confirmed the ecological validity of the assay by analysis of extracts from species of sponges and mollusks that live in the same habitat as P. serenus. The deterrent properties of haliclonacyclamine alkaloids isolated from the sponge Haliclona sp. were demonstrated, with the alkaloid mixture demonstrating palatability deterrence at concentrations as low as 0.05 mg/mL, and complete deterrence at 0.75 mg/mL. In contrast, the diterpene thuridillin metabolites from the sacoglossan mollusk Thuridilla splendens did not deter feeding by P. serenus.

NSC-631570 alkaloid mixture modulates the human equlibrative transporter nucleoside 1 and deoxycytidine kinase gene expressions in pancreatic ductal adenocarcinoma cell cultures

Pancreatic ductal adenocarcinoma (PDAC) is treated by palliative chemotherapy for advanced disease. Gemcitabine is the standard drug in both adjuvant and palliative treatment, but yields a marginal impact on disease outcome. Several attempts to improve the efficacy of gemcitabine by addition of a second cytotoxic or targeted agent have not shown a significant survival advantage. NSC-631570, showed greater median survival in combination with gemcitabine compared to gemcitabine alone in the palliative treatment of unresectable PDAC. However, the authors did not study the interactions between alkaloids and molecular determinant expressions involved in the metabolism of gemcitabine. Therefore, the aim of present study was to evaluate the modulation of the expression of two pivotal genes (hENT1 and dCK) involved in gemcitabine activity. In vitro studies on cell lines and primary cell Cultures from PDAC patients were treated with NSC-631570 at IC50 concentration for 48h. the quantitation of gene expression was performed using the standard curve method and the ΔΔCT calculation. Alkaloids mixture positively modulates the expression of hENT1 mRNA in all PDAC cell cultures. The 2 (-ΔΔCt) analyses revealed a mean increase of 2.8 fold with respect to untreated control cells. In two cell lines cells alkaloids positively affects mRNA expression of dCK gene as well. Based on the previous clinical data the Alkaloids-gemcitabine combination appears a promising regimen and the results of the present study provide the experimental basis for the further clinical testing of the NSC-631570-gemcitabine schedule in PDAC patients.

Chemical Composition and Cytotoxic Activities of Petroleum Ether Fruit Extract of Fruits of <i>Brucea javanica</i> (Simarubaceae)

Purpose: To investigate the chemical composition and antitumor activity of the petroleum ether extract of the dried ripe fruits of Brucea javanica. Methods: The composition of petroleum ether extract was analyzed by gas chromatography/mass spectrometric (GC/MS) and their antitumor activities were determined by MTT assay. Results: GC/MS spectrometry results indicate that the petroleum ether extract was a mixture of esters, fatty acids, sterides, pregnanones, terpenes, alkaloids, alkenes, alcohols, ketones, aldehydes and other compounds. The results also revealed the significant antitumor activity of the extract with IC50 of 9.14, 12.45, 15.15, 16.13, 22.26, and 27.97 μg/mL against A549, CNE, MCF-7, NCI-H460, HepG2, and KB-3-1 cell lines, respectively. Conclusion: The study establishes the chemical composition and cytotoxic activity of the petroleum ether extract of the plant fruits. There is need for further investigations to isolate more potent compounds and structurally modify the known compounds to retain activity and lower toxicity and thus lead to the possible development of Brucea javanica oil.

Fire ant alarm pheromone and venom alkaloids act in concert to attract parasitic phorid flies, Pseudacteon spp.

Pseudacteon tricuspis, Pseudacteon obtusus and Pseudacteon curvatus are three species of parasitic phorid flies (Diptera: Phoridae), which have been introduced as classical biological control agents of imported, Solenopsis fire ants (Hymenoptera: Formicidae) in the southern USA. Previous studies demonstrated the behavioral response of P. tricuspis to the venom alkaloids and alarm pheromone of the fire ant, S. invicta. In the present study, we compared the responses of P. tricuspis, P. obtusus and P. curvatus to Solenopsis invicta alarm pheromone, venom alkaloids, or a mixture of both chemicals in four-choice olfactometer bioassays. The main hypothesis tested was that the fire ant alarm pheromone and venom alkaloids act in concert to attract Pseudacteon phorid flies. Both sexes of all three Pseudacteon species were attracted to low doses of the fire ant alarm pheromone or venom alkaloids (i.e. 1 ant worker equivalent) alone. However, the flies were significantly more attracted to a mixture of both chemicals (i.e., 1:1 mixture of alarm pheromone+alkaloids) than to either chemical. The results suggest an additive rather than a synergistic effect of combining both chemicals. Comparing the fly species, P. tricuspis showed relatively greater attraction to cis alkaloids, whereas the alkaloid mixture (cis+trans) was preferred by P. obtusus and P. curvatus. In general, no key sexual differences were recorded, although females of P. tricuspis and P. obtusus showed slightly higher response than conspecific males to lower doses of the alarm pheromone. The ecological significance of these findings is discussed, and a host location model is proposed for parasitic phorid flies involving the use of fire ant alarm pheromone and venom alkaloids as long range and short range attractants, respectively.

Mechanisms of Hemostimulating Effect of Aconitum baicalense Diterpene Alkaloids

A mixture of diterpene alkaloids of Aconitum baicalense exhibited pronounced regenerative hemostimulating properties on the model of cytostatic myelosuppression. The therapeutic effect is based on activation of hemopoietic progenitor cells against the background of increased feeder capacity of stromal compartment of the hemopoiesis-inducing microenvironment and decreased count of mesenchymal stem cells in the bone marrow.

Inhibition of Cholinergic Contractions of Rat Ileum by Tropane-Type Alkaloids Present in Schizanthus hookeri

The relative lack of specificity of atropine as a competitive antagonist of muscarinic receptors is a frequent cause of undesirable parasympathetic side effects. Consequently, new tropane alkaloids with potentially greater selectivity are usually seen with real interest. The cholinergic antagonistic effects of a purified mixture of tropane alkaloids extracted from Schizanthus hookeri were evaluated in rat ileum. For this purpose, ileal segments were obtained from randomly selected male Sprague-Dawley rats, and the effect of 1 x 10(-4), 1 x 10(-3), and 1 x 10(-2) mg/mL of the purified mixture of alkaloids on the contractile response of the ileum induced with increasing doses of carbachol (5 x 10(-8) - 10(-4) M) was determined. The results were compared with those obtained in the presence of 3.46 x 10(-7), 3.46 x 10(-6), and 3.46 x 10(-5) mg/mL atropine as an agonist. Tropane alkaloids extracted from Schizanthus hookeri competitively antagonized acetylcholine muscarinic receptors.

Comparison of TLC and Different Micro TLC Techniques in Analysis of Tropane Alkaloids and Their Derivatives Mixture from Datura Inoxia Mill. Extract.

Planar chromatography is a very useful tool for analysis of wide range of different mixtures. Thanks to its possibility for rapid separation of large number of samples simultaneously, low solvent consumption and ability to analyse rough material allow to receive precise and reliable results in short time and low cost. Miniaturization of planar techniques brings a lot of advantages, such as shortening distance and time of chromatogram development, and further lowering of solvent consumption. Besides, it often allows to improve separation parameters and raise efficiency of chromatographic system. In this paper, ability of analysis of tropane alkaloids mixture from Datura Inoxia Mill. extract using conventional TLC technique with five micro TLC techniques (short distance TLC, HPTLC, UTLC, OPLC and ETLC) in maximally closed chromatographic conditions was compared in order to present abilities of micro TLC techniques in plant material analysis.

Capillary electrophoretic study of the synergistic biological effects of alkaloids from Chelidonium majus L. in normal and cancer cells

In this study, the synergistic biological action of five celandine alkaloids in normal and cancer cells was investigated by capillary electrophoresis with light-emitting diode-induced native fluorescence detection. The specific capacity of each alkaloid to penetrate into the cells was estimated by monitoring alkaloid concentration decreases in the cell medium during incubation with murine fibroblast NIH/3T3, mouse melanoma B16F10, and human breast cancer MCF7 cell lines. Mixtures of isoquinoline alkaloids containing protopine, chelidonine, sanguinarine, allocryptopine, and stylopine were applied to cell cultures for 20 and 40 min, and the content of alkaloids in the cell media was measured by capillary electrophoresis (CE). CE separation of isoquinoline alkaloids was performed in 30 mM phosphate buffer (pH 2.5). As these alkaloids have native fluorescence, they were directly detected using the commercially available UV light-emitting diode without troublesome fluorescent derivatization. The results showed a differential ability of celandine alkaloids to penetrate into the normal and cancer cell interior, which was inversely proportional to their cytotoxic activity. While the most effective transport of celandine alkaloids from the cell medium to the cell interior was observed for normal murine fibroblast NIH/3T3 cells (about 55% of total content), cytotoxicity tests demonstrated selective and profound apoptotic effects of a five-alkaloid combination in the mouse melanoma B16F10 cell line.

An Electron Transferred Alkaloid Mixture Composed for Until Now Incurable Hepatitis B

The ideas to start investigate protoberberines curable influence to infected patients is based on the fact that certain African tribe uses Enantia chlorantha species. The multiple electron transfer of natural bis-benzyl-isoquinoline alkaloid (protoberberine) mixture was successfully to recover hepatitis B. Therefore we decided research in details recovering powder tested on laboratory animals; it was found that the processed electron transferred alkaloid mixture was regenerative in traumatized laboratory rodents liver. The alkaloid mixture had a positive influence both on the cirrhotic animals and also on the artificially virally infected liver and, in general, on lesions caused by toxins. The rehabilitation seems to be independent on the lesions caused by trauma, which only agreed with the suddenly appearing liver anastomoses formation, which produces an unobstructed blood flow and also simultaneously destroys the hindrance originating from dissipating fibrous or RNA overgrowth into hepacytes, made by lymphocytes and giant cells. In this article it has to be concluded that the key issue is the finding that hot water can transfer a tiny amount of energy as seen in the electropherogram. Such a dynamic molecular self-organisation in electron transfer remains a substantial challenge for pharmaceutical chemistry or chemistry in general.

Investigating the chemical Composition and the antimicrobial activity of the essential oil and Crude Extracts of Sedum Microcarpum (Sm.) schönl Growing Wild in Jordan

Background: Several Sedum species, such as S. album L., S. acre L., S. palaestinum Bieb, and S. pallidum are used in traditional medicine to heal wounds, hemorrhoids, constipation, food fungi, and as laxative and diuretic agents. Materials and Methods: In this study, the antimicrobial activities of the hexane, n-butanol and aqueous methanol extracts as well as the essential oil from Jordanian sedum microcarpum (Sm.) schönl were investigated and Analysis of the oil constituents by using Gas chromatography-Mass spectrometer (GC/MS). Conclusion: The hexane extract showed no antibacterial activity against seven strains. The butanol and aqueous methanol extracts were active against the Gram-positive bacteria Staphylococcus epidermidis, Bacillus cereus and the Gram negative bacteria including Enterococcus faecalis, Escherichia coli, Klebsiella pneumonia and Serratia marcescens. Phytochemical screening of the active extracts revealed the presence of a mixture of quinones, tannins, alkaloids and flavonoids. The essential oil showed moderate activities against the tested strains. Analysis of the oil using Gas chromatography-Mass spectrometer (GC/MS) revealed a complex mixture of aldehydes, mono- and sesquiterpenes in addition to alkaloids. Oxygenated monoterpenes dominated the different classes of compounds detected (36.39%). The major volatile constituents from S. microcarpum included Myrtenol (21.7%), Caryophyllene oxide (8.2%) and z-1, 6-dioldihydromyrcene (5.87%).

Effect of a 60‐Day Oral Gavage of a Crude Alkaloid Extract From Chromolaena odorata Leaves on Hormonal and Spermatogenic Indices of Male Rats

The present study was aimed at investigating the effects of the crude alkaloids isolated from Chromolaena odorata leaves on the hormonal and spermatogenic indices of male rats. The alkaloids obtained from C odorata leaves using standard methods were administered to male rats for 60 days at the doses of 250, 500, and 1000 mg/kg body weight. Thin-layer chromatographic analysis of the alkaloid mixture produced 8 spots, 3 of which were alkaloids with R(f) values of 0.41, 0.49, and 0.55 as confirmed by the formation of orange color and creamy precipitates with both Dragendorff and Mayer reagents, respectively. The alkaloids were represented in the extract by a yield of 20.28 g, corresponding to a percentage yield of 90.05% of the total extract of 22.52 g. The final body weights of both the control and alkaloid-treated animals increased significantly (P < .05) compared with their respective body weights before treatment. The alkaloids significantly decreased (P < .05) the testes-body weight ratio; the concentrations of testicular total protein, glycogen, sialic acid, and cholesterol; and the activities of γ-glutamyl transferase, acid phosphatase, and alkaline phosphatase. The serum luteinizing hormone and follicle-stimulating hormone levels, as well as testicular and serum testosterone levels, also decreased significantly (P < .05). There were decreases in the sperm count, motility, and density, as well as morphological changes in the sperm cells. The pH and whitish-gray color of the semen were not significantly affected. All of the doses of the alkaloids increased the total mean number of sperm cell abnormalities, with the secondary type predominating over the primary sperm cell abnormality. The alterations in the levels of the hormones and secretory and synthetic constituents of the testes and the spermatotoxic effects by the alkaloids from C odorata leaves may be due to nonavailability or deprivation of testosterone to the target organ. This lack of testosterone may have consequential effects on the reproductive process of the male rat.

The geographic isolation of Leucojum aestivum populations leads to divergation of alkaloid biosynthesis

Leucojum aestivum, an industrial source of the acetylcholinesterase inhibitor galanthamine, shows a great chemodiversity in its alkaloid synthesis. Samples from various geographically distinct populations from Bulgaria and the Balearic Islands were studied by GC–MS. The alkaloid pattern of the plants of L. aestivum (subsp. pulchellum) from the Balearic Islands were dominated by crinine type compounds. Populations of homolycorine chemotype were distributed along the Danube river in the north part of Bulgaria, which is separated from the south part by the Balkan mountains. Populations with high accumulation of lycorine were found in East Bulgaria near the sea coast, while the south populations were dominated by galanthamine type synthesis. The average of the galanthamine content was found to vary from 0.003 to 0.08% (referred to dry weight) in the north, and up to 0.42% in the southern Bulgarian populations. Some individuals showed up to 0.65% galanthamine. The galanthamine content of the plants from the Balearic island was 0.1% of DW. The galanthamine percentage in the total alkaloid mixture ranged from 0.2 to 95% of the total alkaloids. Our study demonstrated that the geographic isolation of the populations of L. aestivum has led to divergation in the alkaloid biosynthesis and consequently to the occurrence of different chemotypes. This chemodiversity in both alkaloid patterns and galanthamine content provides an opportunity for further selection work toward a galanthamine-rich crop, on the one hand, and makes the species an excellent biological system for molecular studies leading to further improvement of the galanthamine production, which is a valuable alkaloid used in medicine for the treatment of Alzheimer's disease.

Quantitative Analysis of Substituted N,N-Dimethyl-tryptamines in the Presence of Natural Type XII Alkaloids

This paper reports the qualitative and quantitative analysis (QA) of mixtures of hallucinogens, N,N-dimethyltryptamine (DMT) (1), 5-methoxy- (la) and 5-hydroxy-N,N-dimethyltryptamine (1b) in the presence of beta-carbolines (indole alkaloids of type XII) ((2), (3) and (5)}. The validated electronic absorption spectroscopic (EAs) protocol achieved a concentration limit of detection (LOD) of 7.2.10(-7) mol/L {concentration limit of quantification (LOQ) of 24.10(-7) mol/L) using bands (lambda max within 260+/-0.23-262+/-0.33 nm. Metrology, including accuracy, measurement repeatability, measurement precision, trueness of measurement, and reproducibility of the measurements are presented using N,N-dimethyltryptamine (DMA) as standard. The analytical quantities of mixtures of alkaloids 4, 6 and 7 are: lambda max 317+/-0.45, 338+/-0.69 and 430+/-0.09 for 4 (LOD, 8.6.10(-7) mol/L; LOQ, 28.66(6), mol/L), as well as 528+/-0.75 nm for 6 and 7 (LOD, 8.2.10(-7) mol/L; LOQ, 27.33(3), mol/L), respectively. The partially validated protocols by high performance liquid chromatography (HPLC), electrospray ionization (ESI), mass spectrometry (MS), both in single and tandem operation (MS/MS) mode, as well as matrix/assisted laser desorption/ionization (MALDI) MS are elaborated. The Raman spectroscopic (RS) protocol for analysis of psychoactive substances, characterized by strong fluorescence RS profile was developed, with the detection limits being discussed. The known synergistic effect leading to increase the psychoactive and hallucinogenic properties and the reported acute poisoning cases from 1-7, make the present study emergent, since as well the current lack of analytical data and the herein metrology obtained contributed to the elaboration of highly selective and precise analytical protocols, which would be of interest in the field of criminal forensic analysis.

Forensic analysis of mesembrine alkaloids in Sceletium tortuosum by nonaqueous capillary electrophoresis mass spectrometry

The consumption of legal and illegal drugs follows an organic trend comparable to the current trend in food consumption. The investigation of such drugs is therefore of interest to characterize the active ingredients of plants and drug preparations. A new method of nonaqueous capillary electrophoresis coupled to mass spectrometry (NACE-MS) as a powerful tool for the separation of complex alkaloid mixtures in difficult matrices is presented in this study for the analysis of samples of Sceletium tortuosum and drug products called Kanna made thereof. The method was found to be suitable for the investigation of the alkaloid composition and relative quantification of the ingredients. It proved of value to separate a large number of isobaric compounds, most probably including diastereomers, double-bond isomers, and further structurally closely related compounds. A comparison of plant samples from different vendors, self-fermented samples, and products ready for consumption was made. The high separation power obtained allowed a better description of the chemotypic differences of plant samples as well as Kanna preparations compared to other methods presented in the literature so far. Thus, the use of the NACE-MS enables a new perspective on the alkaloid profile of Sceletium species.

Implementation of a design of experiments to study the influence of the background electrolyte on separation and detection in non‐aqueous capillary electrophoresis–mass spectrometry

Non-aqueous capillary electrophoresis (NACE) background electrolytes are most often composed of a mixture of methanol and acetonitrile (ACN) with soluble ammonium salts added as electrolyte. In this study on NACE-MS, we used a mixture of glacial acetic acid and ACN giving rise to an acidic background electrolyte (BGE) with a very low dielectric constant. Impressive changes in selectivity and resolution were observed for structurally closely related indole alkaloids including diastereomers upon addition of ammonium formate as electrolyte and upon variation of the solvent ratio. In order to obtain best separation and MS detection conditions and to reveal the influence of the parameters of the BGE on separation and detection and vice versa of the MS parameters on separation, an optimization strategy was employed using a design of experiments in a central composite design with response surface methodology. It was proven that at high electroosmotic flow conditions capillary electrophoretic separations and thus optimization can be realized without interference from the coupling to an MS system. Several significantly interacting parameters were revealed, which are not accessible with classical univariate optimization approaches. With this optimization, alkaloid mixtures from a plant extract of Mitragyna speciosa, containing a large number of diastereomeric compounds were successfully separated.

Molecular docking and molecular dynamic studies of semi-synthetic piperidine alkaloids as acetylcholinesterase inhibitors

The mixture of semi-synthetic derivatives (-)-3-O-acetyl-cassine hydrochloride and (-)-3-O-acetyl-spectaline hydrochloride, prepared from the mixture of natural alkaloids (-)-cassine and (-)-spectaline (4:1) isolated from Senna spectabilis, has been shown to be a potent acetylcholinesterase (AChE) inhibitor, thereby prompting further molecular studies. In this sense, docking and dynamic molecular studies were carried out in this work, aiming to acquire a deeper understanding about all the structural aspects of molecules (-)-3-O-acetyl-cassine and (-)-3-O-acetyl-spectaline hydrochlorides, which differ with respect to their AChE inhibitory potentials. Both molecules establish important interactions with the peripheral anionic site within the catalytic gorge of Torpedo californica AChE. However, only the major compound (-)-3-O-acetyl-cassine hydrochloride significantly interacts with the catalytic triad. Explicit-solvent molecular dynamic simulations were conducted in order to gain better understanding about the hypothetical interactions taking place between the semi-synthetic alkaloid molecules (-)-3-O-acetyl-cassine and (-)-3-O-acetyl-spectaline hydrochlorides and AChE. The data obtained in this study indicated that (-)-3-O-acetyl-cassine hydrochloride is the most potent inhibitor of AChE possibly due to the favorable interactions of this molecule with the target protein, with lower desolvation cost. These results suggested that the size of the side chain has an effect on the inhibitory potential of the evaluated molecules and may represent the starting point for the development of new derivatives of (-)-3-O-acetyl-cassine hydrochloride, with a view to the discovery of new effective AChE inhibitors.