Selective Activity Against Amastigote Forms of Trypanosoma cruzi and Leishmania infantum of Diastereomeric Dicentrine N-oxides.

As part of our continuous research for the discovery of bioactive compounds against Trypanosoma cruzi and Leishmania infantum, the alkaloid (6aS)-dicentrine (1) was oxidized to afford (6aS,6S)- (2) and (6aS,6R)- (3) dicentrine-N-oxides. Evaluation of the cytotoxicity against NCTC cells indicated that 2 and 3 are non-toxic (CC50>200 µM) whereas 1 demonstrated CC50 of 52.0 µM. Concerning T. cruzi activity against amastigotes, derivatives 2 and 3 exhibited EC50 values of 9.9 µM (SI>20.2) and 27.5 µM (SI>7.3), respectively, but 1 is inactive (EC50>100 µM). Otherwise, when tested against L. infantum amastigotes, 1 and 3 exhibited EC50 values of 10.3 µM (SI=5.0) and 12.7 µM (SI>15.7), respectively, being 2 inactive (EC50>100 µM). Comparing the effects of positive controls benznidazol (EC50=6.5 µM and SI>30.7) and miltefosine (EC50=10.2 µM and SI=15.2), it was observed a selective antiparasitic activity to diastereomers 2 and 3 against T. cruzi and L. infantum. Considering stereochemical aspects, it was suggested that the configuration of the new stereocenter formed after oxidation of 1 played an important role in the bioactivity against amastigotes of both tested parasites.

New aporphine alkaloids with antitumor activities from the roots of Thalictrum omeiense.

Two new aporphine alkaloids, 6aR-2'-(3-oxobutenyl)-thaliadin (1) and N-methylthalisopynine (2), along with ten known analogs (3-12), were isolated from the roots of Thalictrum omeiense W. T. Wang et S. H. Wang. Their structures were determined by extensive spectroscopic and X-ray crystallographic analyses. Compounds 1-7 and 9-12 were tested for their antiproliferative effects in vitro against two human cancer cell lines (A549 and MCF-7). Among them, compounds 1, 3, and 7 exhibited moderate inhibitory activity against the tested cell lines with IC50 values ranging from 23.73 to 34.97 µM.

Identification of the cytochrome P450s responsible for the biosynthesis of two types of aporphine alkaloids and their de novo biosynthesis in yeast.

Aporphine alkaloids have diverse pharmacological activities; however, our understanding of their biosynthesis is relatively limited. Previous studies have classified aporphine alkaloids into two categories based on the configuration and number of substituents of the D-ring and have proposed preliminary biosynthetic pathways for each category. In this study, we identified two specific cytochrome P450 enzymes (CYP80G6 and CYP80Q5) with distinct activities toward (S)-configured and (R)-configured substrates from the herbaceous perennial vine Stephania tetrandra, shedding light on the biosynthetic mechanisms and stereochemical features of these two aporphine alkaloid categories. Additionally, we characterized two CYP719C enzymes (CYP719C3 and CYP719C4) that catalyzed the formation of the methylenedioxy bridge, an essential pharmacophoric group, on the A- and D-rings, respectively, of aporphine alkaloids. Leveraging the functional characterization of these crucial cytochrome P450 enzymes, we reconstructed the biosynthetic pathways for the two types of aporphine alkaloids in budding yeast (Saccharomyces cerevisiae) for the de novo production of compounds such as (R)-glaziovine, (S)-glaziovine, and magnoflorine. This study provides key insight into the biosynthesis of aporphine alkaloids and lays a foundation for producing these valuable compounds through synthetic biology.

Cholinesterase inhibitors assessment of aporphine alkaloids from Annona crassiflora and molecular docking studies.

Annona crassiflora Mart. is an endemic plant from Brazilian Cerrado (savanna) biome, commonly employed in traditional medicine to treat wounds, diarrhea, and scalp infections. The pulp of the fruits is edible and has a characteristic taste, being employed to prepare sweets like jam, cakes, and ice cream by the people who live in the region of the Cerrado, although the peels are discarded. In this way, the A. crassiflora fruit peels ethanol extract was prepared and subjected to liquid-liquid extraction, which yielded the alkaloidal fraction (CH2Cl2). Subjected to high-performance liquid chromatography separations, this fraction allowed the purification of the aporphine alkaloids stephalagine (1), liriodenine (2), and atherospermidine (3), that were structurally characterized by high-resolution mass spectrometry with electrospray ionization, and nuclear magnetic resonance spectroscopy analyses. Aporphine alkaloids are recognized for their acetylcholinesterase (AChE) inhibitory activity, an important target in Alzheimer's disease therapy. Thus, the ethanol extract, alkaloidal fraction, and compounds1,2,and3were evaluated for acetyl- and butyrylcholinesterase (BChE) inhibitory activities. Compound1(IC50 104.2 µmol L-1) exhibited better BChE inhibitory activity than the standard compound galanthamine (IC50 162.7 µmol L-1), while2had a comparable result(and IC50 167.3 µmol L-1). Furthermore, molecular docking was performed to predict the compound's binding mode to the human AChE at a molecular level. Semiempirical calculation results show that the enthalpy interaction energy (ΔHint) between AChE and BChE active sites and all ligands were favorable for both enzymes, with the ligands interacting even more strongly with AChE, corroborating with IC50 results.

A Systematic Method for the Identification of Aporphine Alkaloid Constituents in Sabia schumanniana Diels Using UHPLC-Q-Exactive Orbitrap/Mass Spectrometry

Sabia schumanniana Diels (SSD) is a plant whose stems are used in traditional folk medicine for the treatment of lumbago and arthralgia. Previous studies have revealed chemical constituents of SSD, including triterpenoids and aporphine alkaloids. Aporphine alkaloids contain a variety of active components, which might facilitate the effective treatment of lumbago and arthralgia. However, only 5-oxoaporphine (fuseine) has been discovered in SSD to date. In this study, we sought to systematically identify the aporphine alkaloids in SSD. We established a fast and reliable method for the detection and identification of these aporphine alkaloids based on ultra-high-performance liquid chromatography (UHPLC)-Q-Exactive-Orbitrap/mass spectrometry combined with parallel reaction monitoring (PRM). We separated all of the analyzed samples using a Thermo Scientific Hypersil GOLD™ aQ C18 column (100 mm × 2.1 mm, 1.9 µm). Finally, we identified a total of 70 compounds by using data such as retention times and diagnostic ions. No fewer than 69 of these SSD aporphine alkaloids have been reported here for the first time. These findings may assist in future studies concerning this plant and will ultimately contribute to the research and development of new drugs.

Natural potential neuroinflammatory inhibitors from Stephania epigaea H.S. Lo.

Stephania epigaea H. S. Lo is a folk medicine widely distributed in the south of China, especially in Yunnan and Guangxi province. An in vitro anti-neuroinflammatory study showed that total alkaloids of it can potently inhibit LPS-induced NO releasing of BV2 cells with an IC50 value of 10.05 ± 2.03 µg/mL (minocycline as the positive drug, IC50 15.49 ± 2.14 µM). The phytochemical investigation of the total alkaloids afforded three new phenanthrene (1-3), two lactams (4a, 4b), and nine aporphine derivatives (5-13). The final structure of 1 was identified by computer-assisted structure elucidation (ACD/Structure Elucidator software and the 13C NMR calculation with GIAO method) due to many possibilities of the substituent pattern. All isolates were evaluated for their anti-neuroinflammatory effects, and as a result, 5, 8, 10, and 11 exhibited stronger inhibitory activities than the minocycline. The results suggested S. epigaea could provide potential therapeutic agents for neurodegenerative diseases.

Aporphine Alkaloids from Ocotea puberula with Anti-Trypanosoma Cruzi Potential - Activity of Dicentrine-ß-N-Oxide in the Plasma Membrane Electric Potentials.

One new aporphine, dicentrine-ß-N-oxide (1), together with five related known alkaloids dehydrodicentrine (2), predicentrine (3), N-methyllaurotetanine (4), cassythicine (5), and dicentrine (6) were isolated from the leaves of Ocotea puberula (Lauraceae). Antiprotozoal activity of the isolated compounds was evaluated in vitro against trypomastigote forms of Trypanosoma cruzi. Among the tested compounds, alkaloid 1 exhibited higher potential with EC50 value of 18.2 µM and reduced toxicity against NCTC cells (CC50 >200 µM - SI>11.0), similar to positive control benznidazole (EC50 of 17.7 µM and SI=10.7). Considering the promising results of dicentrine-ß-N-oxide (1) against trypomastigotes, the mechanism of parasite death caused by this alkaloid was investigated. As observed, this compound reached the plasma membrane electric potential directly after 2 h of incubation and triggered mitochondrial depolarization, which probably leads to trypomastigote death. Therefore, dicentrine-ß-N-oxide (1), reported for the first time in this work, can contribute to future works for the development of new trypanocidal agents.

Natural Aporphine Alkaloids with Potential to Impact Metabolic Syndrome.

The incidence and prevalence of metabolic syndrome has steadily increased worldwide. As a major risk factor for various diseases, metabolic syndrome has come into focus in recent years. Some natural aporphine alkaloids are very promising agents in the prevention and treatment of metabolic syndrome and its components because of their wide variety of biological activities. These natural aporphine alkaloids have protective effects on the different risk factors characterizing metabolic syndrome. In this review, we highlight the activities of bioactive aporphine alkaloids: thaliporphine, boldine, nuciferine, pronuciferine, roemerine, dicentrine, magnoflorine, anonaine, apomorphine, glaucine, predicentrine, isolaureline, xylopine, methylbulbocapnine, and crebanine. We particularly focused on their impact on metabolic syndrome and its components, including insulin resistance and type 2 diabetes mellitus, endothelial dysfunction, hypertension and cardiovascular disease, hyperlipidemia and obesity, non-alcoholic fatty liver disease, hyperuricemia and kidney damage, erectile dysfunction, central nervous system-related disorder, and intestinal microbiota dysbiosis. We also discussed the potential mechanisms of actions by aporphine alkaloids in metabolic syndrome.

Advances in Chemistry and Bioactivity of Magnoflorine and Magnoflorine-Containing Extracts.

The review collects together some recent information on the identity and pharmacological properties of magnoflorine, a quaternary aporphine alkaloid, that is widely distributed within the representatives of several botanical families like Berberidaceae, Magnoliaceae, Papaveraceae, or Menispermaceae. Several findings published in the scientific publications mention its application in the treatment of a wide spectrum of diseases including inflammatory ones, allergies, hypertension, osteoporosis, bacterial, viral and fungal infections, and some civilization diseases like cancer, obesity, diabetes, dementia, or depression. The pharmacokinetics and perspectives on its introduction to therapeutic strategies will also be discussed.

Cytotoxic and Anti-Plasmodial Activities of Stephania dielsiana Y.C. Wu Extracts and the Isolated Compounds.

Natural products remain a viable source of novel therapeutics, and as detection and extraction techniques improve, we can identify more molecules from a broader set of plant tissues. The aim of this study was an investigation of the cytotoxic and anti-plasmodial activities of the methanol extract from Stephania dielsiana Y.C. Wu leaves and its isolated compounds. Our study led to the isolation of seven alkaloids, among which oxostephanine (1) is the most active against several cancer cell lines including HeLa, MDA-MB231, MDA-MB-468, MCF-7, and non-cancer cell lines, such as 184B5 and MCF10A, with IC50 values ranging from 1.66 to 4.35 µM. Morever, oxostephanine (1) is on average two-fold more active against cancer cells than stephanine (3), having a similar chemical structure. Cells treated with oxostephanine (1) are arrested at G2/M cell cycle, followed by the formation of aneuploidy and apoptotic cell death. The G2/M arrest appears to be due, at least in part, to the inactivation of Aurora kinases, which is implicated in the onset and progression of many forms of human cancer. An in-silico molecular modeling study suggests that oxostephanine (1) binds to the ATP binding pocket of Aurora kinases to inactivate their activities. Unlike oxostephanine (1), thailandine (2) is highly effective against only the triple-negative MDA-MB-468 breast cancer cells. However, it showed excellent selectivity against the cancer cell line when compared to its effects on non-cancer cells. Furthermore, thailandine (2) showed excellent anti-plasmodial activity against both chloroquine-susceptible 3D7 and chloroquine-resistant W2 Plasmodium falciparum strains. The structure-activity relationship of isolated compound was also discussed in this study. The results of this study support the traditional use of Stephania dielsiana Y.C. Wu and the lead molecules identified can be further optimized for the development of highly effective and safe anti-cancer and anti-plasmodial drugs.

Novel findings to the biosynthetic pathway of magnoflorine and taspine through transcriptomic and metabolomic analysis of Croton draco (Euphorbiaceae).

BACKGROUND: Croton draco is an arboreal species and its latex as well as some other parts of the plant, are traditionally used in the treatment of a wide range of ailments and diseases. Alkaloids, such as magnoflorine, prevent early atherosclerosis progression while taspine, an abundant constituent of latex, has been described as a wound-healer and antitumor-agent. Despite the great interest for these and other secondary metabolites, no omics resources existed for the species and the biosynthetic pathways of these alkaloids remain largely unknown. RESULTS: To gain insights into the pathways involved in magnoflorine and taspine biosynthesis by C. draco and identify the key enzymes in these processes, we performed an integrated analysis of the transcriptome and metabolome in the major organs (roots, stem, leaves, inflorescences, and flowers) of this species. Transcript profiles were generated through high-throughput RNA-sequencing analysis while targeted and high resolution untargeted metabolomic profiling was also performed. The biosynthesis of these compounds appears to occur in the plant organs examined, but intermediaries may be translocated from the cells in which they are produced to other cells in which they accumulate. CONCLUSIONS: Our results provide a framework to better understand magnoflorine and taspine biosynthesis in C. draco. In addition, we demonstrate the potential of multi-omics approaches to identify candidate genes involved in the biosynthetic pathways of interest.

New aporphine alkaloids from the aerial parts of Piper semiimmersum §.

Two new aporphine alkaloids, semiimmersumines A (1) and B (2), along with 20 known compounds, were isolated from the aerial parts of Piper semiimmersum (Piperaceae). The structures of the new compounds were elucidated based on the analysis of 1D and 2D NMR, MS, and CD data. The absolute configuration of semiimmersumine A (1) was determined by single crystal X-ray diffraction analysis using anomalous dispersion with copper radiation. The effects of all compounds from the plant on rabbit platelet aggregation induced by thrombin (IIa) or PAF were also evaluated.

[Research on anticancer activity of isocorydine and its derivatives].

Isocorydine and its analogs were extracted from Dicranostigma leptopodum and Stephania yunnanensis through the method of natural products chemistry. Its derivatives were prepared by chemical structure modifications from isocorydine. MTT method was used to study the inhibitory effect of those compounds on the growth of HepG2, HeLa and MGC-803 cancer cell lines in vitro. The results showed that isocorydine and its analogs all have the growth inhibition for those cancer cell lines. This paper investigated the structure-activity relationship of isocorydine and its derivatives with anticancer activity in the aspect of stereochemical structure, functional groups positions of the compounds and the electron density of aromatic rings based on the single crystal diffraction structure and the molecular docking of EGFR and isocorydine.

Tetrahydroisoquinolines affect the whole-cell phenotype of Mycobacterium tuberculosis by inhibiting the ATP-dependent MurE ligase.

OBJECTIVES: (S)-Leucoxine, isolated from the Colombian Lauraceae tree Rhodostemonodaphne crenaticupula Madriñan, was found to inhibit the growth of Mycobacterium tuberculosis H37Rv. A biomimetic approach for the chemical synthesis of a wide array of 1-substituted tetrahydroisoquinolines was undertaken with the aim of elucidating a common pharmacophore for these compounds with novel mode(s) of anti-TB action. METHODS: Biomimetic Pictet-Spengler or Bischler-Napieralski synthetic routes were employed followed by an evaluation of the biological activity of the synthesized compounds. RESULTS: In this work, the synthesized tetrahydroisoquinolines were found to inhibit the growth of M. tuberculosis H37Rv and affect its whole-cell phenotype as well as the activity of the ATP-dependent MurE ligase, a key enzyme involved in the early stage of cell wall peptidoglycan biosynthesis. CONCLUSIONS: As the correlation between the MIC and the half-inhibitory enzymatic concentration was not particularly strong, there is a credible possibility that these compounds have pleiotropic mechanism(s) of action in M. tuberculosis.

Characterization and simultaneous quantification of biological aporphine alkaloids in Litsea cubeba by HPLC with hybrid ion trap time-of-flight mass spectrometry and HPLC with diode array detection.

The root and rhizome of Litsea cubeba (Lour) Pers., named 'Dou-chi-jiang' in Chinese, has been traditionally used for treatment of cardiovascular and cerebrovascular diseases, rheumatic arthralgia, and other diseases in China. Aporphine alkaloids are its characteristic ingredients and responsible for its bioactivities, especially anti-inflammatory and analgesic effects. A sensitive and reliable high-performance liquid chromatography with diode array detection-tandem mass spectrometry method was developed for characterization and simultaneous determination of biological aporphine alkaloids in 'Dou-chi-jiang'. The optimized chromatographic conditions were performed on an Eclipse XDB C18 column with a gradient of acetonitrile/water containing 0.1% formic acid as the mass spectrometry mobile phase and acetonitrile/water containing 0.2% diethylamine (pH 3.10, adjusted by acetic acid) as the liquid chromatography mobile phase. The fragmentation pathways by loss of CO, ·CH3 , ·NH3 , and ·NH2 CH3 were detected as characteristic for aporphine alkaloids. Based on these characteristics, total 12 analogues were identified. The quantification method was validated in terms of linearity, precision, and accuracy for six major aporphine alkaloids, which was successfully applied for simultaneous determination in ten batches of samples. The established method is simple, rapid, and specific for characterization and quantitation of aporphine alkaloids in 'Dou-chi-jiang' and other traditional Chinese medicines rich in this kind of ingredient.

Phytochemical study of the alkaloidal fractions of Unonopsis duckei R. E. Fr. guided by electrospray ionisation ion-trap tandem mass spectrometry.

INTRODUCTION: The Unonopsis genus is a promising source of aporphinoid alkaloids, substances with great biological potential. These alkaloids have a well-defined mass spectrometry fragmentation pattern that, together with previous phytochemical knowledge, can guide the isolation of alkaloids not yet described for the genus. OBJECTIVE: Isolate substances not yet described in the Unonopsis genus, guided by alkaloidal profile analyses of stem barks, twigs and leaves of Unonopsis duckei using electrospray ionisation ion-trap tandem mass spectrometry (ESI-IT/MS(n) ). METHODS: Methanolic extracts from stem barks, twigs and leaves were submitted to a liquid-liquid, acid-base partitioning treatment to obtain the alkaloidal fractions. These fractions were analysed by direct infusion into an ESI-IT/MS(n) system. The major alkaloids observed for each fraction were submitted to fragmentation analysis. RESULTS: The MS fragmentation patterns revealed the presence of alkaloids previously reported for Annonaceae, including nornuciferine, anonaine, asimilobine, liriodenine and lysicamine, known for the Unonopsis genus, as well as others that were not yet described for this genus. In this way, the proaporphine alkaloid glaziovine was isolated, as well as a mixture of the aporphine alkaloids glaucine and norglaucine, all described for the first time in the Unonopsis genus. CONCLUSION: Mass spectrometry monitoring was fundamental to prioritise the isolation of substances not yet identified for the Unonopsis genus, dismissing known compounds and simplifying the phytochemical study.

Four unreported aporphine alkaloids with antifungal activities from Artabotrys hexapetalus.

In this study, the extract from Artabotrys hexapetalus showed strong antifungal activity against phytopathogenic fungi in vitro. Four unreported aporphine alkaloids, hexapetalusine A-D (1-4), were isolated from stems and roots of Artabotrys hexapetalus (L.f.) Bhandari, along with six known aporphine alkaloids (5-10). Their chemical structures were elucidated by extensive spectroscopic analysis. The absolute configurations of 1-3 were determined using single-crystal X-ray diffractions and ECD calculations. Hexapetalusine A-C (1-3) were special amidic isomers. Additionally, all isolated compounds were evaluated for their antifungal activity against four phytopathogenic fungi in vitro. Hexapetalusine D (4) exhibited weak antifungal activity against Curvularia lunata. Liriodenine (5) displayed significant antifungal activity against Fusarium proliferatum and Fusarium oxysporum f. sp. vasinfectum, which is obviously better than positive control nystatin, suggesting that it had great potential to be developed into an effective and eco-friendly fungicide.

Aporphine alkaloids and a naphthoquinone derivative from the leaves of Phaeanthus lucidus Oliv. and their α-glucosidase inhibitory activity.

Three previously undescribed aporphine alkaloids, phaeanthuslucidines E-G, one previously undescribed naphthoquinone derivative, phaeanthusnaphthoquinone, and three known compounds were isolated from an EtOAc extract of the leaves of Phaeanthus lucidus Oliv. The structures of all previously undescribed compounds were established through extensive spectroscopic investigations and high-resolution mass spectroscopy. The 6aR configuration of phaeanthuslucidines E-G was assigned by comparing their ECD spectra and specific rotation values with the reported known compounds. Some isolated compounds were evaluated for their α-glucosidase inhibitory activity. Among these compounds, phaeanthuslucidine E showed the highest α-glucosidase inhibitory activity with an IC50 value of 17.9 ± 0.4 µM. The molecular docking of phaeanthuslucidine E was further studied.

Natural aporphine alkaloids: A comprehensive review of phytochemistry, pharmacokinetics, anticancer activities, and clinical application.

BACKGROUND: Cancer is the most common cause of death and is still a serious public health problem. Alkaloids, a class of bioactive compounds widely diffused in plants, especially Chinese herbs, are used as functional ingredients, precursors, and lead compounds in food and clinical applications. Among them, aporphine alkaloids (AAs), as an important class of isoquinoline alkaloids, exert a strong anticancer effect on multiple cancer types. AIM OF REVIEW: This review aims to comprehensively summarize the phytochemistry, pharmacokinetics, and bioavailability of seven subtypes of AAs and their derivatives from various plants and highlight their anticancer bioactivities and mechanisms of action. Key Scientific Concepts of Review. The chemical structures and botanical diversity of AAs are elucidated, and promising results are highlighted regarding the potent anticancer activities of AAs and their derivatives, contributing to their pharmacological benefits. This work provides a better understanding of AAs and combinational anticancer therapies involving them, thereby improving the development of functional food containing plant-derived AA and the clinical application of AAs.

Phaeanthuslucidines A-D, dimeric aporphine alkaloid derivatives from Phaeanthus lucidus Oliv.

The first phytochemical investigation of the twigs of Phaeanthus lucidus Oliv. resulted in the isolation and identification of four undescribed alkaloids, including two aporphine dimers, phaeanthuslucidines A and B, a hybrid of aristolactam-aporphine, phaeanthuslucidine C, and a C-N linked aporphine dimer, phaeanthuslucidine D, together with two known compounds. Their structures were determined by extensive analysis of spectroscopic data, and by comparison of their spectroscopic and physical data with previous reports. Phaeanthuslucidines A-C and bidebiline E were analysed and resolved by chiral HPLC to yield the (Ra) and (Sa) atropisomers, whose absolute configurations were respectively determined by ECD calculations. Phaeanthuslucidines A and B, bidebiline E, and lanuginosine showed α-glucosidase inhibitory activities with IC50 values in the range of 6.7-29.2 µM. Moreover, molecular docking simulations of α-glucosidase inhibition of active compounds were studied.