RESUMO
Benzylisoquinoline alkaloids are the major bioactive components in Chelidonium majus, a plant that has a long usage history for the treatment of gastrointestinal ailments in European and Asian phytomedicine. This study reports on the development and application of a supercritical fluid chromatography technique for the simultaneous qualitative and quantitative determination of seven benzylisoquinoline alkaloids in under six minutes using a Viridis BEH 2-EP column and a modifier comprising methanol with 30% acetonitrile and 20 mM ammonium formate. The method was fully validated according to ICH guidelines showing, e.g., excellent linearity (≥ 0.9997) and maximum deviations for intraday and inter-day precision of 2.99 and 2.76%, respectively. The new supercritical fluid chromatography assay was not only employed for the analysis of several C. majus samples but was also used for the subsequent development of a fast centrifugal partition chromatography technique, whereby five benzylisoquinoline alkaloids could be isolated within approximately 2.5 h, with only two of them, protopine and chelidonine, requiring an additional purification step. To achieve this, a solvent system composed of chloroform/methanol/0.3 M hydrochloric acid was used in descending mode. By injecting 500 mg of crude extract, stylopine (1.93 mg), sanguinarine (0.57 mg), chelidonine (1.29 mg), protopine (1.95 mg), and coptisine (7.13 mg) could be obtained. The purity of compounds was confirmed by supercritical fluid chromatography and MS.
Assuntos
Alcaloides , Benzilisoquinolinas , Chelidonium , Chelidonium/química , Benzilisoquinolinas/isolamento & purificação , Benzilisoquinolinas/química , Benzilisoquinolinas/análise , Alcaloides/isolamento & purificação , Alcaloides/química , Alcaloides/análise , Cromatografia com Fluido Supercrítico/métodos , Extratos Vegetais/química , Benzofenantridinas/química , Benzofenantridinas/isolamento & purificação , Chelidonium majusRESUMO
Genuine multipartite entanglement represents the strongest type of entanglement, which is an essential resource for quantum information processing. Standard methods to detect genuine multipartite entanglement, e.g., entanglement witnesses, state tomography, or quantum state verification, require full knowledge of the Hilbert space dimension and precise calibration of measurement devices, which are usually difficult to acquire in an experiment. The most radical way to overcome these problems is to detect entanglement solely based on the Bell-like correlations of measurement outcomes collected in the experiment, namely, device independently. However, it is difficult to certify genuine entanglement of practical multipartite states in this way, and even more difficult to quantify it, due to the difficulty in identifying optimal multipartite Bell inequalities and protocols tolerant to state impurity. In this Letter, we explore a general and robust device-independent method that can be applied to various realistic multipartite quantum states in arbitrary finite dimension, while merely relying on bipartite Bell inequalities. Our method allows us both to certify the presence of genuine multipartite entanglement and to quantify it. Several important classes of entangled states are tested with this method, leading to the detection of genuinely entangled states. We also certify genuine multipartite entanglement in weakly entangled Greenberger-Horne-Zeilinger states, showing that the method applies equally well to less standard states.
RESUMO
As recently shown, some fungal pigments exhibit significant photoactivity turning them into promising agents for the photodynamic treatment of microbial infections or malignant diseases. In the present study, a separation strategy for fungal anthraquinones was developed based on centrifugal partition chromatography. A suitable method was explored employing a methanolic extract of the fruiting bodies of Cortinarius sanguineus (Agaricales, Basidiomycota). An excellent fractionation was achieved using a biphasic solvent system comprising chloroform/ethyl acetate/methanol/water/acetic acid (3:1:3:2:1, v/v/v/v/v) operating in ascending mode. Experiments on an analytical scale with extracts of closely related Cortinarius species exhibited broad applicability of the devised system. Up to six pigments could be purified directly from the crude extract. Preparative-scale fractionation of the methanol extracts of C. malicorius and C. sanguineus demonstrated that up-scaling was possible without compromising selectivity.
Assuntos
Antraquinonas , Extratos Vegetais , Cromatografia Líquida/métodos , Metanol/química , Extratos Vegetais/química , Solventes/químicaRESUMO
Due to their hostile habitats, characterized by a high exposure to UV-A and UV-B radiation, red algae are known to synthesize unique secondary metabolites: mycosporine-like amino acids (MAAs). These small molecules possess an extremely high UV absorption capacity and therefore mainly act as photoprotective agents. In this study, the first ultrahigh-performance liquid chromatography (UHPLC) method with diode-array detection (DAD) was developed for the determination of eleven MAAs in various algal species. All of the analytes could be separated in under 8 min on a Phenomenex Luna Omega C18 1.6 µm column. The mobile phase comprised water with 0.25% formic acid and 20 mM ammonium formate (A) and acetonitrile (B). Elution was carried out in gradient mode. Method validation following ICH guidelines confirmed excellent linearity (R2 ≥ 0.9998), selectivity, precision and accuracy (from 97.41 to 103.38%) for all analytes. The assay's LOD was always 0.01 µg/mL; its LOQ was not higher than 0.04 µg/mL. Practical applicability was assured by analyzing several algae (e.g., Gracilaria chilensis, Pyropia plicata) using the developed method, and results indicated a high variation in MAA profiles as well as content. Whilst some MAAs were only found in specific samples, shinorine, which was always present, occurred in concentrations from 0.05 to 4.14 mg/g of dried biomass. As UHPLC-MS was also feasible, this method showed high flexibility concerning the detection mode, surpassing established procedures for MAA analysis not only concerning separation efficiency and analysis time.
Assuntos
Aminoácidos , Rodófitas , Aminoácidos/química , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida , Rodófitas/química , Raios UltravioletaRESUMO
Marine rhodophyta are known to synthesize specific secondary metabolites, mycosporine-like amino acids (MAAs), to protect themselves from harmful UV-radiation. Shinorine and porphyra-334 are among the most abundant representatives of this compound class. In the present work, a novel approach for their isolation is described. As a first step, a fast centrifugal partition chromatography method, with an aqueous two-phase system comprising water, ethanol, ammonium sulfate and methanol in ascending mode, was developed to isolate the two MAAs from crude aqueous-methanolic extracts of three algal species within 90 min. The compounds could be isolated when just one of them was present in a sample or also both at the same time. By employing solid phase extraction as a second purification step, the individual MAAs were obtained in high purity and good quantity within a much shorter time frame than the established purification protocols, e.g., semi-preparative HPLC. For example, from 4 g Porphyra sp. (Nori) crude extract, 15.7 mg shinorine and 36.2 mg porphyra-334 were isolated. Both were highly pure, as confirmed by TLC, HPLC-MS and NMR analyses.
Assuntos
Aminoácidos/isolamento & purificação , Rodófitas/metabolismo , Aminoácidos/química , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Cromatografia em Camada Fina , Espectroscopia de Ressonância Magnética , Metabolismo Secundário , Extração em Fase SólidaRESUMO
(E/Z)-3-(4-((E)-1-(4-Hydroxyphenyl)-2-phenylbut-1-enyl)phenyl)acrylic acid (GW7604) as a carrier was esterified with alkenols of various lengths and coordinated through the ethylene moiety to PtCl3, similar to Zeise's salt (K[PtCl3(C2H4)]). The resulting GW7604-Alk-PtCl3 complexes (Alk = Prop, But, Pent, Hex) degraded in aqueous solution only by exchange of the chlorido ligands. For example, GW7604-Pent-PtCl3 coordinated the amino acid alanine in the cell culture medium, bound the isolated nucleotide 5'-GMP, and interacted with the DNA (empty plasmid pSport1). It accumulated in estrogen receptor (ER)-positive MCF-7 cells primarily via cytosolic vesicles, while it was only marginally taken up in ER-negative SKBr3 cells. Accordingly, GW7604-Pent-PtCl3 and related complexes were inactive in SKBr3 cells. GW7604-Pent-PtCl3 showed high affinity to ERα and ERß without mediating agonistic or ER downregulating properties. GW7604-Alk ligands also increased the cyclooxygenase (COX)-2 inhibitory potency of the complexes. In contrast to Zeise's salt, the GW7604-Alk-PtCl3 complexes inhibited COX-1 and COX-2 to the same extent.
Assuntos
Antineoplásicos , Humanos , Antineoplásicos/farmacologia , Receptor alfa de Estrogênio/genética , Células MCF-7 , Receptores Proteína Tirosina Quinases , Receptor beta de Estrogênio , LigantesRESUMO
Different Senecio species, especially S. inaequidens - a neophyte native to South Africa - have widely spread across Europe and now are found worldwide. The entire genus is known to contain toxic pyrrolizidine alkaloids (PAs), which renders them a possible health hazard to humans and livestock. As they can enter the food chain or occur as contaminants in herbal crops and phytopharmaceutical formulations (e.g. teas), efficient and straightforward assays for their qualitative and quantitative analysis are in high demand. Different techniques have been used for this purpose, most commonly HPLC or GC. As the analysis of PAs is a challenging task, alternative methodologies like ultra-high performance SFC (UHPSFC) may offer an additional benefit in terms of their separation efficiency and orthogonal selectivity. In this study an UHPSFC approach for the simultaneous determination of six PAs (free bases as well as N-oxides) is presented, which achieved the baseline separation of all standard compounds in seven min. Optimal separation was carried out in gradient mode on a Torus™ DEA column with 0.05% ammonia in methanol as modifier. The column temperature was 25 °C, ABPR 1900 psi and flow rate 1.1 mL/min, with a detection wavelength of 215 nm. The assay was validated and fulfilled all ICH criteria exhibiting good linearity (R2 ≥ 0.9994), precision (inter-day variance ≤ 3.67%, intra-day variance ≤ 3.92%) and recovery rates (96.3-104.1%), with detection limits typical for SFC-PDA (≤ 4.24 µg/mL). Furthermore, it could conveniently be coupled to MS-detection, which increased the sensitivity significantly. To confirm practical suitability of the method, different Senecio samples were analyzed, indicating a high qualitative as well as quantitative difference in their PA profile (e.g. total amounts of PA between 0.09 and 4.63 mg/g).
Assuntos
Cromatografia com Fluido Supercrítico , Alcaloides de Pirrolizidina , Senécio , Humanos , Alcaloides de Pirrolizidina/análise , Senécio/química , Cromatografia Líquida de Alta Pressão , Europa (Continente)RESUMO
Boswellic acids, a class of triterpenes, are the bioactive constituents in Indian frankincense, an herbal drug with pronounced anti-inflammatory activity. In this study their separation and quantification in B. serrata extracts is reported for the first time by using Supercritical Fluid Chromatography. Under optimized conditions, i.e. a Viridis HSS C18 SB column and carbon dioxide, methanol, acetonitrile and ammonium hydroxide as mobile phase, six boswellic acids could be separated in under 6 min. The assay fulfilled all validation criteria with coefficients of determination higher than 0.999, a wide linear range (30-1000 µg/mL), recovery rates from 97.1-103.0 %, excellent precision, and detection limits typical for SFC with UV-detection (≤ 5.5 µg/mL). The method could easily be hyphenated to mass spectrometry, which was helpful to tentatively assign further compounds (mainly derivatives of tirucallic acid) and to increase the assay's sensitivity. Its practical applicability was confirmed by analyzing several commercial products, which mainly contained ß-boswellic acid as dominant triterpene, yet in extremely variable amounts ranging from 0.9 to 16.9 %.
Assuntos
Boswellia , Cromatografia com Fluido Supercrítico , Franquincenso , Triterpenos , Suplementos Nutricionais , Extratos Vegetais , Triterpenos/análiseRESUMO
HLA-DPB1 antigens are mismatched in about 80% of allogeneic hematopoietic stem cell transplantations from HLA 10/10 matched unrelated donors and were shown to be associated with a decreased risk of leukemia relapse. We recently developed a reliable in vitro method to generate HLA-DPB1 mismatch-reactive CD4 T-cell clones from allogeneic donors. Here, we isolated HLA-DPB1 specific T cell receptors (TCR DP) and used them either as wild-type or genetically optimized receptors to analyze in detail the reactivity of transduced CD4 and CD8 T cells toward primary AML blasts. While both CD4 and CD8 T cells showed strong AML reactivity in vitro, only CD4 T cells were able to effectively eliminate leukemia blasts in AML engrafted NOD/SCID/IL2Rγc-/- (NSG) mice. Further analysis showed that optimized TCR DP and under some conditions wild-type TCR DP also mediated reactivity to non-hematopoietic cells like fibroblasts or tumor cell lines after HLA-DP upregulation. In conclusion, T cells engineered with selected allo-HLA-DPB1 specific TCRs might be powerful off-the-shelf reagents in allogeneic T-cell therapy of leukemia. However, because of frequent (common) cross-reactivity to non-hematopoietic cells with optimized TCR DP T cells, safety mechanisms are mandatory.