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The objective of this study was to investigate the single- and multiple-dose pharmacokinetics of chelerythrine (CHE) and its metabolite, dihydrochelerythrine (DHCHE), after oral and IM administrations in pigs.Six crossbreed (Landrace × Large White) female pigs (7-8 weeks old; 24.1 ± 2.6 kg bw) administered oral and IM CHE at a dose of 0.1 mg/kg orally and intramuscularly in a cross-over design. Multiple oral administration was performed at 0.1 mg/kg a time, three times a day at 8-h intervals for three consecutive days. Blood samples were collected from the anterior vena cava and placed into heparinized centrifuge tubes before dosing (time 0 h) and at different times after oral and IM administrations. Pre-treatment plasma was analysed by high-performance liquid chromatography-tandem mass spectrometry.After IM administration, CHE and DHCHE rapidly reached peak concentrations (Cmax, 69.79 ± 15.41 and 3.47 ± 1.23 ng/mL) at 0.42 ± 0.13 and 0.33 ± 0.13 h, respectively. After single oral administration, CHE and DHCHE rapidly increased to reach Cmax of 5.04 ± 1.00 and 1.21 ± 0.35 ng/mL at 1.83 ± 0.26 and 1.67 ± 0.26 h, respectively. The half-life (T1/2) was 2.03 ± 0.26 and 2.56 ± 1.00 h for CHE and DHCHE, respectively. After multiple oral administration, the average steady-state concentrations (Css) of CHE and DHCHE were 2.51 ± 0.40 and 0.6 ± 0.06 ng/mL, respectively.CHE is metabolized rapidly after a single oral administration, multiple daily doses and long-term use of CHE are recommended.

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Chelerythrine (CHE) and dihydrochelerythrine (DHCHE), two typical benzophenanthridine alkaloids, have a wide range of pharmacological activities, such as antibacterial, anti-tumour and antiparasitic activities. To date, the biological activities of CHE and DHCHE are well reported, but the biotransformation of CHE and DHCHE in vivo remains unknown. This study aims to clarify the metabolic pathway of CHE and DHCHE in rat liver microsomes (RLMs) in vitro and in vivo. An ultra-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC/ESI-QTOF-MS) method was developed for metabolites identification of CHE and DHCHE. The urine, feces, bile, and plasma samples and RLMs samples were collected for analyzing the biotransformation pathway of CHE and DHCHE. The result showed that there is a phenomenon of mutual reversible interconversion between CHE and DHCHE in vivo and in vitro. The other biotransformation pathways of CHE and DHCHE including demethylation, hydroxylation, methylene dioxy cycle opening, and glucuronidation mainly occurred in the side chain of benzophenanthridine parent structure. Twenty-five phase I and eight phase II metabolites of CHE, twenty-two phase I and eight phase II metabolites of DHCHE were detected. The results will help to develop a deeper understanding of CHE and DHCHE in vivo process and provide some references for the biotransformation research of other benzophenanthridine alkaloids.

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Dihydrochelerythrine was isolated from the ethanol extract of Corydalis yanhusuo by chromatographic and recrystallization techniques. To our knowledge, this is the first report that dihydrochelerythrine was found to be unstable. The NMR, HPLC, and LC-MS were applied to monitor the structural conversion process of dihydrochelerythrine. The results showed that when dissolved in polar deuteration solvent (e.g., DMSO-d6 & MeOD), dihydrochelerythrine is directly converted to chelerythrine gradually. However, if used non-polar reagent (e.g.,CD2Cl2), the sample of dihydrochelerythrine undergoes the formation of pseudobase, chelerythrine, and bimolecular ether then followed by oxidation to oxychelerythrine as the major final product. Which leads to this phenomenon maybe is that the C-6 in dihydrochelerythrine is highly reactive to nucleophiles, and is easily converted to different derivatives in different solvents attributed to the solvent effect. This finding will contribute to the extraction and isolation, bioactivity screening, and quality evaluation of medicinal materials containing dihydrochelerythrine and other similar derivatives.

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BACKGROUND: A glioblastoma is a primary CNS tumor that is more aggressive and lethal than other brain tumors. Its location, rapid proliferation, invasive growth, angiogenesis and immunosuppression are the main factors that limit its treatment, making it a major challenge to neuro-oncology. OBJECTIVE: This study investigated the in vitro effects of the alkaloid dihydrochelerythrine (DHC), which is extracted from Zanthoxylum stelligerum, on the viability, proliferation, cell death and ß-catenin, NFκB, STAT3/pSTAT3 and interleukins roles. METHOD: In vitro experimental models of human (U251 and GL-15) and murine (C6) glioblastoma cells were cultured in the presence of DHC at increasing concentrations for MTT assay and exclusion trypan blue dye to determine EC50. Afterward, C6 and U251 cells were treated with 100 µM DHC or DMSO 0.1% for cell cycle, annexin and expression of ß-catenin/NFκB/STAT3/pSTAT3 by flow cytometry or immunofluorescence. Interleukin quantification was made by Cytometric Bead Array. RESULTS: A significant decrease was observed in C6 and U251 cell viability in a time and dose-dependent manner. GL-15 cell viability decreased only when treated with 200 µM DHC. This maximum concentration affected neither astrocytes nor microglia viability. A cytostatic effect of DHC was observed in C6 and U251 cells after 48 h of 100 µM DHC treatment. After 72 h of DHC treatment, C6 presented 80% of annexin-V+ cells compared to 10% of annexin-V+ U251 cells. C6 cells demonstrated significant high levels of NFκ B and ß-catenin cytoplasmic fraction. Additionally, DHC treatment resulted in higher significant levels of IL-6 than did other interleukins and STAT3 up-regulation in U251 cells. CONCLUSION: These results demonstrate that DHC acts as a chemosensitizing agent selective for glioma cells not affecting non-tumor cells. Considering tumor heterogeneity, DHC demonstrated an anti-cancer potential to activate different cell death pathways. DHC demonstrated could be used for chemotherapy and immunotherapy applications in glioblastomas in the future.

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Dihydrochelerythrine was isolated from the ethanol extract of Corydalis yanhusuo by chromatographic and recrystallization techniques. To our knowledge, this is the first report that dihydrochelerythrine was found to be unstable. The NMR, HPLC, and LC-MS were applied to monitor the structural conversion process of dihydrochelerythrine. The results showed that when dissolved in polar deuteration solvent (e.g., DMSO-₆ & MeOD), dihydrochelerythrine is directly converted to chelerythrine gradually. However, if used non-polar reagent (e.g.,CD₂Cl₂), the sample of dihydrochelerythrine undergoes the formation of pseudobase, chelerythrine, and bimolecular ether then followed by oxidation to oxychelerythrine as the major final product. Which leads to this phenomenon maybe is that the C-6 in dihydrochelerythrine is highly reactive to nucleophiles, and is easily converted to different derivatives in different solvents attributed to the solvent effect. This finding will contribute to the extraction and isolation, bioactivity screening, and quality evaluation of medicinal materials containing dihydrochelerythrine and other similar derivatives.

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A series of C(6)-substituted dihydrobenzo[c]phenanthridines were synthesized by mild copper-catalyzed C(sp3)-H functionalization of dihydrosanguinarine (2) and dihydrochelerythrine (3) with certain nucleophiles selected to enhance cytotoxicity against human breast, colorectal, and prostate cancer cell lines. We also investigated the cytotoxicity of our previously reported C(6)-functionalized N-methyl-5,6-dihydrobenzo[c]phenanthridines 1a-1e to perform structure-activity relationship (SAR) studies. Among the target compounds, five ß-aminomalonates (1a, 1b, 2a, 2b, and 3b), one α-aminophosphonate (2c), and one nitroalkyl derivative (2h) exhibited half maximal inhibitory concentration (IC50) values in the range of 0.6-8.2 µM. Derivatives 1b, 2b and 2h showed the lowest IC50 values, with 2b being the most potent with values comparable to those of the positive control doxorubicin. On the basis of their IC50 values, derivatives 1a, 1b, 2a, 2b, 2h, and 3b were selected to evaluate the apoptotic PC-3 cell death at 10 µM by flow cytometry using propidium iodide and fluorescein isothiocyanate-conjugated Annexin V dual staining. The results indicated that the cytotoxic activity of the tested compounds in PC-3 cells is due to the induction of apoptosis, with 1a and 2h being the most active (55% of early apoptosis induction). Our preliminary SAR study showed that the incorporation of specific malonic esters, dialkyl phosphites and nitro alkanes on scaffolds 1-3 significantly enhanced their cytotoxic properties. Moreover, it appears that the electron donating 7,8-methylenedioxy group allowed derivatives of 2 to exhibit higher cytotoxicity than derivatives of 1 and 3. The present results suggest that derivatives 2b and 2h may be considered as potential lead compounds for the development of new anticancer agents.

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A convenient route was envisaged toward the synthesis of dihydrochelerythrine (DHCHL), 4 by intramolecular Suzuki coupling of 2-bromo-N-(2-bromobenzyl)-naphthalen-1-amine derivative 5 via in situ generated arylborane. This compound was converted to (±)-6-acetonyldihydrochelerythrine (ADC), 3 which was then resolved by chiral prep-HPLC. Efficiency of DHCHL for the stabilization of promoter quadruplex DNA structures and a comparison study with the parent natural alkaloid chelerythrine (CHL), 1 was performed. A thorough investigation was carried out to assess the quadruplex binding affinity by using various biophysical and biochemical studies and the binding mode was explained by using molecular modeling and dynamics studies. Results clearly indicate that DHCHL is a strong G-quadruplex stabilizer with affinity similar to that of the parent alkaloid CHL. Compounds ADC and DHCHL were also screened against different human cancer cell lines. Among the cancer cells, (±)-ADC and its enantiomers showed varied (15-48%) inhibition against human colorectal cell line HCT116 and breast cancer cell line MDA-MB-231 albeit low enantio-specificity in the inhibitory effect; whereas DHCHL showed 30% inhibition against A431 cell line only, suggesting the compounds are indeed cancer tissue specific.

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A specific and reliable HPLC-MS/MS method was developed and validated for simultaneously determination of sanguinarine, chelerythrine and their metabolites (dihydrosanguinarine and dihydrochelerythrine) in chicken tissue for the first time. This is important because these compounds are related to the use of a naturally occurring and novel feed additive with many benefits, but the levels of these compounds must be strictly controlled. The compounds were extracted by acetonitrile and 1% HCl-methanol solution successively and then separated on a C18 column. A triple-quadrupole mass spectrometer equipped with an electrospray ionization (ESI) source was used for detection. Quantification was performed using multiple reaction monitoring with positive mode. The method was validated in terms of specificity, linearity, precision, accuracy and stability. The calibration curves were linear over the concentration range of 0.5-100.0ng/g for sanguinarine, 0.5-100.0ng/g for chelerythrine, 0.2-100.0ng/g for dihydrosanguinarine and 0.1-100ng/g for dihydrochelerythrine, respectively. All of the recovery rates of the four analytes were over 85%. The RSD of intra-day and inter-day precision was less than 5.0%, and the relative error was all within 12.0%. This validated method has been successfully applied to assess the drug residue and metabolite residue characteristics of sanguinarine and chelerythrine in chicken tissue after oral administration of the extracts of Macleaya cordata (Willd.) R. Br, and to investigate the pharmacokinetic parameters of sanguinarine and dihydrosanguinarine in chicken plasma.

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Four quinolone-terpene alkaloids, chelerybulgarine (1), 2'-episimulanoquinoline (3), 2,11-didemethoxyvepridimerine B (4), and rhetsidimerine (5) were isolated from the root bark of Zanthoxylum rhetsa DC. Chelerybulgarine (1) is a C-C linked terpene alkaloid where the C-6 of dihydrochelerythrine is linked to C-11 of the sesquiterpenoid 10ß-methoxybulgarene. 2'-Episimulanoquinoline is a dimeric alkaloid containing dihydrochelerythrine and 8-methoxy-N-methylflindersine moieties, whereas 2,11-didemethoxyvepridimerine B and rhetsidimerine are dimeric prenylated quinolone alkaloids. Seven of the isolated compounds exhibited weak cytotoxicity when tested against a panel of six human stomach-cancer cell lines.

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The quaternary benzo[c]phenanthridine alkaloids (QBAs) are an important subgroup of plant secondary metabolites. Their main representatives, sanguinarine (SG) and chelerythrine (CHE), have pleiotropic biological effects and a wide spectrum of medicinal applications. The biotransformation of SG and CHE has only been partially studied while subsequent oxidative transformation of their dihydro derivates, the main metabolites, is practically unknown. The aim of this study was to characterize the biotransformation of CHE and dihydrochelerythrine (DHCHE) in detail, with respect to their more extensive biotransformation than SG. Phase I as well as phase II biotransformation of both compounds was examined in human hepatocyte suspensions. Liquid chromatography with electrospray-quadrupole time-of-flight mass spectrometry (LC-ESI-QqTOF MS) was used for analysis of the metabolites. Using the LC-ESI-QqTOF MS method, we analyzed and then suggested the putative structures of 11 phase I and 5 phase II metabolites of CHE, and 11 phase I and 6 phase II metabolites of DHCHE. For the most abundant metabolites of CHE, DHCHE and O-demethylated DHCHE, their cytotoxicity on primary cultures of human hepatocytes was analyzed. Both metabolites were nontoxic up to 50µM concentration and this indicates decreasing toxic effects for CHE biotransformation products, i.e. DHCHE and O-demethylated DHCHE.

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Objective To study the anti-HBV constituents from Corydalis saxola. Methods The constituents were repeatedly purified by column chromatography and were identified on the basis of spectral analysis and comparison of their spectral data with those previously reported. Compounds isolated in large amounts were assayed against HBV. Results Sixteen compounds were identified to be dihydrosanguinarine (1), d-corydaline (2), cavidine (3), stylopine (4), 6-acetonyl-5, 6-dihydrosanguinarine (5), dihydrochelerythrine (6), tetrahydropalmatine (7), adlumidine (8), (-)-salutaridine (9), palmatine (10), protopine (11), berberine (12), coptisine (13), thalifaurine (14), dehydroapocavidine (15), and (+)-magnoflorine (16). Compounds 5, 6, 8-11, 13, and 16 with high amounts were chosen to detect anti-HBV activities. Compounds 5 and 8 were moderately active, compounds 11 and 16 showed weak inhibitory effects, while compound 6 exihibited the most potent activity against HBsAg and HBeAg secretions in HepG 2.2.15 cell line, followed by compound 9. Conclusion Compounds 1, 4-6, 8, 9, 13, 14, and 16 are isolated from C. saxicola for the first time. Compound 10 is the main constituent and compound 6 exihibits the most potent activity against HBV.

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Com o aumento da resistência bacteriana aos antibióticos disponíveis, tornou-se imprescindível a busca por novos fármacos ou protótipos. Os metabólitos secundários produzidos por alguns vegetais como cumarinas, alcaloides e terpenoides podem apresentar várias atividades biológicas, dentre elas, atividade antibiótiotica. O objetivo deste trabalho foi avaliar a atividade antimicrobiana in vitro, pelo método de difusão em disco, das diferentes partes de duas espécies pertencentes à família Rutaceae coletadas na Chapada Diamantina, Bahia, Brasil: Spiranthera odoratissima A. St.-Hil. e Zanthoxylum stelligerum Turcz., bem como do alcaloide diidroqueleritrina, isolado do extrato metanólico de Z. stelligerum frente a cepas padrão de microrganismos e isolados clínicos. Os resultados apresentados indicam que o extrato da raiz da espécie Z. stelligerum e o alcaloide extraído desta apresentaram propriedades antimicrobianas contra as cepas Gram positivas e leveduras. A E. coli foi a única cepa Gram negativa que se mostrou sensível ao extrato e ao alcaloide.

With the increase in bacterial resistance to available antibiotics, it became imperative to search for new drugs or prototypes. The secondary metabolites produced by some plants as coumarins, alkaloids and terpenoids have several biological activities, among them, antibiotic activity. The objective of this study was to evaluate the antimicrobial activity in vitro by the disk diffusion method, from different parts of two species belonging to the family Rutaceae, collected in the Chapada Diamantina, Bahia, Brazil: Spiranthera odoratissima A. St Hil. and Zanthoxylum stelligerum Turcz., and the alkaloid dihydrochelerythrine, isolated from the methanolic extract of Z. stelligerum front of standard strains of microorganisms and clinical isolates. The results indicate that the extract from the roots of Z. stelligerum and the alkaloid had antimicrobial properties against Gram positive and yeast strains. The E. coli was the only Gram negative strain that was sensitive to extract and the alkaloid.