Multitarget anti-parasitic activities of isoquinoline alkaloids isolated from Hippeastrum aulicum (Amaryllidaceae).

BACKGROUND: Chagas disease and leishmaniasis affect a significant portion of the Latin American population and still lack efficient treatments. In this context, natural products emerge as promising compounds for developing more effective therapies, aiming to mitigate side effects and drug resistance. Notably, species from the Amaryllidaceae family emerge as potential reservoirs of antiparasitic agents due to the presence of diverse biologically active alkaloids. PURPOSE: To assess the anti-Trypanosoma cruzi and anti-Leishmania infantum activity of five isolated alkaloids from Hippeastrum aulicum Herb. (Amaryllidaceae) against different life stages of the parasites using in silico and in vitro assays. Furthermore, molecular docking was employed to evaluate the interaction of the most active alkaloids. METHODS: Five natural isoquinoline alkaloids isolated in suitable quantities for in vitro testing underwent preliminary in silico analysis to predict their potential efficacy against Trypanosoma cruzi (amastigote and trypomastigote forms) and Leishmania infantum (amastigote and promastigote forms). The in vitro antiparasitic activity and mammalian cytotoxicity were investigated with a subsequent comparison of both analysis (in silico and in vitro) findings. Additionally, this study employed the molecular docking technique, utilizing cruzain (T. cruzi) and sterol 14α-demethylase (CYP51, L. infantum) as crucial biological targets for parasite survival, specifically focusing on compounds that exhibited promising activities against both parasites. RESULTS: Through computational techniques, it was identified that the alkaloids haemanthamine (1) and lycorine (8) were the most active against T. cruzi (amastigote and trypomastigote) and L. infantum (amastigote and promastigote), while also revealing unprecedented activity of alkaloid 7­methoxy-O-methyllycorenine (6). The in vitro analysis confirmed the in silico tests, in which compound 1 presented the best activities against the promastigote and amastigote forms of L. infantum with half-maximal inhibitory concentration (IC50) 0.6 µM and 1.78 µM, respectively. Compound 8 exhibited significant activity against the amastigote form of T. cruzi (IC50 7.70 µM), and compound 6 demonstrated activity against the trypomastigote forms of T. cruzi and amastigote of L. infantum, with IC50 values of 89.55 and 86.12 µM, respectively. Molecular docking analyses indicated that alkaloids 1 and 8 exhibited superior interaction energies compared to the inhibitors. CONCLUSION: The hitherto unreported potential of compound 6 against T. cruzi trypomastigotes and L. infantum amastigotes is now brought to the forefront. Furthermore, the acquired dataset signifies that the isolated alkaloids 1 and 8 from H. aulicum might serve as prototypes for subsequent structural refinements aimed at the exploration of novel leads against both T. cruzi and L. infantum parasites.

[Characterization and identification of alkaloids in Phellodendri Chinensis Cortex and Phellodendri Amurensis Cortex based on UHPLC-IM-Q-TOF-MS].

A strategy combining collision cross section(CCS) prediction and quantitative structure-retention relationship(QSRR) model for quinoline and isoquinoline alkaloids was established based on UHPLC-IM-Q-TOF-MS and applied to Phellodendri Chinensis Cortex and Phellodendri Amurensis Cortex. The strategy included the following three steps.(1) The molecular features were extracted by the "find features" algorithm.(2) The potential quinoline and isoquinoline alkaloids were screened by filtering the original characteristic ions extracted from Phellodendri Chinensis Cortex and Phellodendri Amurensis Cortex by the established CCS vs m/z prediction interval.(3) According to the retention time of candidate compounds predicted by QSRR model, the chemical constituents were identified in combination with the characteristic fragment ions and pyrolysis law of secondary mass spectrometry. With the strategy, a total of 80 compounds were predicted, and 15 were identified accurately. The strategy is effective for the identification of small analogs of traditional Chinese medicine.

Two new isoquinoline alkaloids from Cryptocarya wrayi and their biological activities.

Two new isoquinoline alkaloids, cryptowrayines A (1) and B (2), along with one known pavine alkaloid (-)-12-hydroxyeschscholtzidine (3), were isolated from the twigs of Cryptocarya wrayi. The structures of new compounds were elucidated by extensive spectroscopic data analysis and electronic circular dichroism (ECD) calculations. Both compounds 1 and 2 exhibited moderate quinone reductase inducing activity in Hepa 1c1c7 cells.

Isolation and characterization of phellodendronoside A, a new isoquinoline alkaloid glycoside with anti-inflammatory activity from Phellodendron chinense Schneid.

Bark of Phellodendron chinense Schneid. (Rutaceae), called "Huang Bai" in China, is one of the 50 most used Chinese medicines in clinical practice. In this paper, a new isoquinoline alkaloid glycoside was isolated from P. chinense, and its structure was elucidated using spectroscopic method. The compound was eventually identified as (1S, 3"S)-1, 2, 3, 4-tetrahydro-7-hydroxy-1-[(4-hydroxybenzyl) methyl]-2-methyl-8-O-isoquinolinyl-[3-hydroxy-3-methylglutaryl]-ß-D-glucopyranoside and named as Phellodendronoside A (PDA). The results of molecular docking showed that PDA could stably bind to an extracellular signal-regulated kinase (ERK), stress-activated protein kinase (JNK) and p38 mitogen-activated protein kinase (p38MAPK) proteins that are closely related to inflammation. Further, the anti-inflammatory activity of PDA was evaluated using the lipopolysaccharide (LPS) induced RAW264.7 macrophage model. We observed that PDA can effectively reduce the levels of nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and decrease the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Moreover, we found that PDA inhibits the activation of ERK, JNK and p38MAPK proteins in the MAPK signaling pathway. Collectively, the present study demonstrates that PDA has excellent anti-inflammatory effect in vitro by inhibiting the overproduction of pro-inflammatory mediators, and its mechanism of action involves suppressing the activation of MAPK pathways, suggesting that PDA may be a potential agent for the treatment of inflammatory illness.

Fast analysis of alkaloids from different parts of Mahonia bealei (Fort.) Carr. studied for their anti-Alzheimer's activity using supercritical fluid chromatography.

In this study, a rapid and highly efficient method was developed for the separation of eight isoquinoline alkaloids using supercritical fluid chromatography. The separation conditions were carefully optimized including stationary phases, additives, backpressure, and temperature. Compared to high-performance liquid chromatography, the use of supercritical fluid chromatography could provide a 13 times faster separation. Subsequently, the method was validated and applied for the determination of eight alkaloids from different parts of Mahonia bealei (Fort.) Carr. (stem, root, leaf, and seed). The results indicated a good repeatability with relative standard deviations for overall precisions lower than 3.2%. The limit of detection was between 0.4 and 2.3 µg/mL while limit of quantitation ranged from 1.5 to 7.5 µg/mL. Recovery ranged from 95.7 to 102.5% indicating a validity of recovery. The content of total eight alkaloids was the highest in stem (66.0 µg/g) and root (65.1 µg/g) compared to leaf or seed. Moreover, anti-acetylcholinesterase activity for those extracts was evaluated by Ellman's colorimetric assay. As a result, the acetylcholinesterase inhibitory activity of the extracted samples was in the following decreasing order: stem > root > leaf or seed. In conclusion, the results indicated that supercritical fluid chromatography could be a useful tool for quality control of Mahonia bealei (Fort.) Carr. containing alkaloids as active compounds.

Application of HPLC-DAD for In Vitro Investigation of Acetylcholinesterase Inhibition Activity of Selected Isoquinoline Alkaloids from Sanguinaria canadensis Extracts.

Isoquinoline alkaloids may have a wide range of pharmacological activities. Some of them have acetylcholinesterase activity inhibition. Nowadays, neurodegenerative disorders such as Alzheimer's disease have become a serious public health problem. Searching for new effective compounds with inhibited acetylcholinesterase activity is one of the most significant challenges of modern scientific research. The aim of this study was the in vitro investigation of acetylcholinesterase activity inhibition of extracts obtained from Sanguinaria canadensis collected before, during and after flowering. The acetylcholinesterase activity inhibition of these extracts has not been previously tested. The aim was also to quantify selected alkaloids in the investigated extracts by high performance liquid chromatography (HPLC). The analyses of alkaloid content were performed using HPLC in reversed phase (RP) mode using Polar RP column and mobile phase containing acetonitrile, water and ionic liquid (IL). The acetylcholinesterase activity inhibition of the tested plant extracts and respective alkaloid standards were examined using high performance liquid chromatography with diode-array detector (HPLC-DAD) for the quantification of 5-thio-2-nitro-benzoic acid, which is the product of the reaction between the thiocholine (product of the hydrolysis of acetylthiocholine reaction) with Ellman reagent. The application of the HPLC method allowed for elimination of absorption of interfering components, for example, alkaloids such as sanguinarine and berberine. It is revealed that the HPLC method can be successfully used for the evaluation of the acetylcholinesterase inhibitory activity in samples such as plant extracts, especially those containing colored components adsorbing at wavelength in the range 405-412 nm. The acetylcholinesterase inhibition activity synergy of pairs of alkaloid standards and mixture of all investigated alkaloids was also determined. Most investigated alkaloids and all Sanguinaria canadensis extracts exhibited very high acetylcholinesterase activity inhibition. IC50 values obtained for alkaloid standards were from 0.36 for berberine to 23.13 µg/mL for protopine and from 61.24 to 89.14 µg/mL for Sanguinaria canadensis extracts. Our investigations demonstrated that these plant extracts can be recommended for further in vivo experiments to confirm their acetylcholinesterase activity inhibition.

A new pyrrole alkaloid from the roots of Cissampelos pareira.

Phytochemical investigation of the roots of Cissampelos pareira Linn. led to the isolation of one new pyrrole alkaloid, cissampeline (1), together with ten known alkaloids, (-)-curine (2), (-)-cyclanoline (3), (+)-tetrandrine (4), (+)-obaberine (5), (+)-obamegine (6), (-)-oblongine (7), (+)-homoaromoline (8), (-)-nor-N׳-chondrocurine (9), trans-N-feruloyltyramine (10) and (+)-coclaurine (11). Their structures were elucidated by extensive NMR and MS spectroscopic analyses. Interestingly, compound 1 represents the first example of pyrrole alkaloid found in the genus Cissampelos. Moreover, compounds 5-11 were isolated for the first time from this genus. Among them, compound 6 showed the highest anti-acetylcholinesterase activity with an IC50 value of 3.26 µM, whereas compound 8 displayed the most potent cytotoxicity against human colon cancer (HT29) cells with an IC50 value of 7.89 µM.

Two new isoquinoline alkaloids from the seeds of Nandina domestica.

Two new isoquinoline alkaloids, 6 R,6aS-N-nantenine Nß-oxide (1), 6S,6aS-N-nantenine Nα-oxide (2), along with nine known alkaloids, nantenine (3), oxonantenine (4), protopine (5), nornantenine (6), N-methyl-laurotetanine (7), isocorydine (8), O-methyflavinantine (9), N-methyl-2,3,6-trimethoxymorphinan-dien-7-one Nß-oxide (10) and (+)-10-O-methylhernovine Nß-oxide (11) were isolated from the seeds of Nandina domestica. Their structures were elucidated by extensive analyses of spectroscopic data (IR, UV, HRESIMS, 1 D and 2 D NMR), ECD calculation and comparison with the related literatures. In addition, the cytotoxicity against A549 cells of these alkaloids was determined by the MTT assay.

Phenethyisoquinoline alkaloids from the leaves of Androcymbium palaestinum.

Thirteen compounds were isolated from the methanolic extract of the leaves of Androcymbium palaestinum Baker (Colchicaceae). Of these, three were new, two were new natural products, and eight were known. The new isolated compounds were (+)-1-demethylandrocine (5), (-)-andropalaestine (8), and (+)-2-demethyl-ß-lumicolchicone (10), while the new natural products were (+)-O-methylkreysigine-N-oxide (3) and (+)-O,O-dimethylautumnaline (9). Moreover, two known compounds are reported for the first time from this species, specifically (-)-colchicine (11) and (-)-3-demethyldemecolcine (13). The structures of the isolated compounds were elucidated using a series of spectroscopic and spectrometric techniques, principally HRESIMS, 1D-NMR (1H and 13C NMR) and 2D-NMR (COSY, edited-HSQC, and HMBC). ECD spectroscopy was used for assigning the absolute configurations of compounds 3, 5, and 10. The cytotoxic activities of the isolated compounds were evaluated using the MDA-MB-435 (melanoma), MDA-MB-231 (breast), and OVCAR3 (ovary) cancer cell lines. Compound 11 was the most potent against all tested cell lines, with IC50 values of 12, 95 and 23 nM, respectively.

Diverse alkaloids and biological activities of Fumaria (Papaveraceae): An ethnomedicinal group.

Fumaria species, commonly known as fumitory or earth smoke, are considered weeds in many regions. However, several Fumaria species have long been used in folk medicine, such as F. capreolata L., F. densiflora DC., F. indica (Hausskn.) Pugsley, F. officinalis L., F. parviflora Lam., and F. vaillantii Loisel. as well. The ethnobotany, phytochemistry, and pharmacology of 24 Fumaria species have been investigated. Phytochemical studies on Fumaria species revealed the presence of numerous alkaloids, flavonoids, saponins, and terpenoids. Phthalideisoquinolines (PTIs), protoberberines, and spirobenzylisoquinolines (SBIs) are the major alkaloids in the genus Fumaria. The plants biosynthesize a diverse group of biologically active isoquinoline alkaloids, and these may help to explain the use of various Fumaria species in folk medicine. Pharmacological studies revealed a broad spectrum of bioactivities such as hepatoprotective, anti-inflammatory, antimicrobial, antioxidant, and antitumor activities. We found 159 articles published from 1969-2019 by searching the keyword "Fumaria" using databases such as SciFinder, Google Scholar, and PubMed. Based on our reading of these papers, Fumaria species appear to be a source of bioactive isoquinoline alkaloids and ethnomedicines. The lack of studies on pharmacological mechanisms, pharmacokinetics, clinical efficacy, quality control, and toxicology are discussed in this review. There is great potential for broader medicinal applications of this genus.

Chemical and Biological Aspects of Montanine-Type Alkaloids Isolated from Plants of the Amaryllidaceae Family.

Plants of the Amaryllidaceae family are promising therapeutic tools for human diseases and have been used as alternative medicines. The specific secondary metabolites of this plant family, called Amaryllidaceae alkaloids (AA), have attracted considerable attention due to their interesting pharmacological activities. One of them, galantamine, is already used in the therapy of Alzheimer's disease as a long acting, selective, reversible inhibitor of acetylcholinesterase. One group of AA is the montanine-type, such as montanine, pancracine and others, which share a 5,11-methanomorphanthridine core. So far, only 14 montanine-type alkaloids have been isolated. Compared with other structural-types of AA, montanine-type alkaloids are predominantly present in plants in low concentrations, but some of them display promising biological properties, especially in vitro cytotoxic activity against different cancerous cell lines. The present review aims to summarize comprehensively the research that has been published on the Amaryllidaceae alkaloids of montanine-type.

Preparative separation of isoquinoline alkaloids from Corydalis impatiens using middle chromatogram isolated gel column coupled with positively charged reversed-phase liquid chromatography.

Positively charged reversed-phase liquid chromatography was employed for the efficient preparative separation of isoquinoline alkaloids from Corydalis impatiens. Ten commercially available columns were compared for isoquinoline alkaloids analysis. While tailing, overloading, lower resolution, and buffer salts limited the application in purification of isoquinoline compounds of many of these columns, one positively charged reversed-phase C18 column (XCharge C18) overcame these drawbacks, allowing for favorable separation resolution, even when loading isoquinoline compounds on a larger, preparative scale. The general separation process is as follows. First, isoquinoline alkaloids are enriched with Corydalis impatiens extract via a middle chromatogram isolated gel column. After column selection, separation is performed on an XCharge C18 analytical column, from which two evident chromatographic peaks are readily obtained. Finally, two isoquinoline alkaloids (protopine and corydamine) are selectively purified on the XCharge C18 preparative column. These results demonstrate that a middle chromatogram isolated gel column coupled with positively charged reversed-phase liquid chromatography is effective for the preparative separation of isoquinoline alkaloids from Corydalis impatiens.

New phthalideisoquinoline hemiacetal alkaloid derivatives from Corydalis decumbens.

Two new phthalideisoquinoline hemiacetal alkaloid derivatives, named corybensines A and B (1 and 2), and four known alkaloids (3-6) were isolated from the bulbs of Corydalis decumbens. Their structures were characterized by analysis of 1D/2D NMR and ECD data, quantum chemical ECD calculations, and X-ray diffraction analysis. Among them, compound 2 represents the first naturally occurring phthalideisoquinoline hemiacetal alkaloid derivative with a 2-pyrrolidinone moiety. The activity of the isolated compounds towards neuronal excitability was examined.

Hypepontine, a new quaternary alkaloid with antimicrobial properties.

New isoquinoline alkaloid hypepontine (1) together with a five known compounds, were identified in Hypecoum ponticum Velen, the partial synonym of Hypecoum procumbens L. The structure of the new substance was elucidated based on spectroscopic evidence. The tertiary and quaternary alkaloid mixtures as well as the isolated alkaloids were evaluated for their antibacterial and antifungal activity. The result revealed that the crude alkaloid mixture containing quaternary isoquinoline alkaloids showed potent antifungal and antibacterial activity.

Applicability of a Monolithic Column for Separation of Isoquinoline Alkalodis from Chelidonium majus Extract.

Isoquinoline alkaloids are the main group of secondary metabolites present in Chelidonium majus extracts, and they are still the object of interest of many researchers. Therefore, the development of methods for the investigation and separation of the alkaloids is still an important task. In this work, the application potential of a silica-based monolithic column for the separation of alkaloids was assessed. The influence of the organic modifier, temperature, salt concentration, and pH of the eluent on basic chromatographic parameters such as retention, resolution between neighboring peaks, chromatographic plate numbers, and peak asymmetry were investigated. Based on the obtained results, a gradient elution program was developed and used to separate and quantitatively determine the main alkaloids in a Chelidonium majus root extract.

New aporphine alkaloids with selective cytotoxicity against glioma stem cells from Thalictrum foetidum.

Seven new isoquinoline alkaloids, 9-(2'-formyl-5', 6'-dimethoxyphenoxy)-1, 2, 3, 10-tetramethoxy dehydroaporphine (1), 9-(2'-formyl-5', 6'-dimethoxyphenoxy)-1, 2, 3, 10-tetramethoxy oxoaporphine (2), 3-methoxy-2'-formyl oxohernandalin (3), (-)-9-(2'-methoxycarbonyl-5', 6'-dimethoxyphenoxy)-1, 2, 3, 10-tetramethoxy aporphine (4), (-)-2'-methoxycarbonyl thaliadin (5), (-)-9-(2'-methoxyethyl-5', 6'-dimethoxyphenoxy)-1, 2, 3, 10-tetramethoxy aporphine (6), (-)-3-methoxy hydroxyhernandalinol (7), together with six known isoquinoline alkaloids (8-13) were isolated from the roots of Thalictrum foetidum. Their structures were elucidated by extensive spectroscopic measurements. Compounds 1 and 2 showed significant selective cytotoxicity against glioma stem cells (GSC-3# and GSC-18#) with IC50 values ranging from 2.36 to 5.37 µg·mL-1.

Cytotoxic and Proapoptotic Activity of Sanguinarine, Berberine, and Extracts of Chelidonium majus L. and Berberis thunbergii DC. toward Hematopoietic Cancer Cell Lines.

Isoquinoline alkaloids belong to the toxic secondary metabolites occurring in plants of many families. The high biological activity makes these compounds promising agents for use in medicine, particularly as anticancer drugs. The aim of our study was to evaluate the cytotoxicity and proapoptotic activity of sanguinarine, berberine, and extracts of Chelidonium majus L. and Berberis thunbergii DC. IC10, IC50, and IC90 doses were established toward hematopoietic cancer cell lines using trypan blue staining. Alterations in the expression of 18 apoptosis-related genes in cells exposed to IC10, IC50, and IC90 were evaluated using real-time PCR. Sanguinarine and Chelidonium majus L. extract exhibit significant cytotoxicity against all studied cell lines. Lower cytotoxic activity was demonstrated for berberine. Berberis thunbergii DC. extract had no influence on cell viability. Berberine, sanguinarine, and Chelidonium majus L. extract altered the expression of apoptosis-related genes in all tested cell lines, indicating the induction of apoptosis. The presented study confirmed the substantial cytotoxicity and proapoptotic activity of sanguinarine, berberine, and Chelidonium majus L. extract toward the studied hematopoietic cell lines, which indicates the utility of these substances in anticancer therapy.

Isolation and Identification of Aryl Hydrocarbon Receptor Modulators in White Button Mushrooms (Agaricus bisporus).

Natural aryl hydrocarbon (AHR) ligands have been identified in food and herbal medicines, and they may exhibit beneficial activity in humans. In this study, white button (WB) feeding significantly decreased AHR target gene expression in the small intestine of both conventional and germ-free mice. High-performance liquid chromatography (HPLC) fractionation and ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) combined with an AHR-responsive cell-based luciferase gene reporter assay were used to isolate and characterize benzothiazole (BT) derivatives and 6-methylisoquinoline (6-MIQ) as AHR modulators from WB mushrooms. The study showed dose-dependent changes of AHR transformation determined by the cell-based luciferase gene reporter assay and transcription of CYP1A1 in human Caco-2 cells by BT derivatives and 6-MIQ. These findings suggested that WB mushroom contains new classes of natural AHR modulators and demonstrated HPLC fractionation and UHPLC-MS/MS combined with a cell-based luciferase gene reporter assay as a useful approach for isolation and characterization of the previously unidentifed AHR modulators from natural products.

Far infrared-assisted removal of extraction solvent for capillary electrophoretic determination of the bioactive constituents in Plumula Nelumbinis.

Far infrared radiation was employed in the rapid removal of the solvents in the extracts of Plumula Nelumbinis and standard mixture solutions to prevent the interference of the solvent peaks toward their capillary electrophoretic measurements. The sample solutions in small vials were exposed to far infrared ray at 60°C for 3 min to remove solvent. The dried samples in the vials were each dissolved into running buffer with the aid of ultrasonication for capillary electrophoresis analysis. The far infrared-assisted solvent removal approach was sucessfully applied in the rapid determination of neferine, liensinine, isoliensinine, rutin and hyperoside in Plumula Nelumbinis. The five analytes could be well separated within 12 min in a 40 cm long fused silica capillary at a separation voltage of 12 kV in a 50 mM borate buffer (pH 9.2). The results indicated that the interferences of the solvent peaks in the capillary electropherograms of the herbal drugs were eliminated completely.

Bioactive isoquinoline alkaloids from Cissampelos pareira †.

The phytochemical and biological investigation of Cissampelos pareira leads to the isolation of one new isoquinoline alkaloid (7) along with six known isoquinoline alkaloids, namely, magnoflorine (1), magnocurarine (2), cissamine (3), curine (4), hayatinine (5) and cycleanine (6). Magnoflorine (1) and magnocurarine (2) were isolated for the first time from C. pareira. A new, rapid, simple and sensitive UPLC method was developed for simultaneous quantification of five pure compounds (1-5). Seasonal variation study revealed higher content of these compounds during the rainy season. The chloroform (CPCF) and n-butanol (CPBF) fractions showed cytotoxic efficacy against KB cells. Among pure compounds, hayatinine (5) was found to be most active against KB and A549, while, cycleanine (6) against KB cells.