Search Results (69)

Alkaloid biosynthesis is a central topic in plant specialized metabolism because many alkaloids have ecological, pharmacological, and biotechnological relevance. Isoquinoline alkaloids (IAs) and Amaryllidaceae alkaloids (AAs) are both connected to aromatic amino acid metabolism, but they differ in taxonomic distribution, scaffold-forming chemistry, pathway resolution, and biotechnological development. This review compares the historical and methodological trajectories that have shaped IA and AA pathway elucidation, from compound isolation, radiotracer experiments, and biochemical inference to transcriptomics, metabolomics, functional enzymology, isotope-guided active-tissue identification, regulatory studies, and heterologous pathway reconstruction. In IAs, especially benzylisoquinoline alkaloids, broad genomic and transcriptomic resources have supported candidate gene discovery and functional characterization of several branches, including morphinan, protoberberine, benzophenanthridine, and aporphine-related pathways. In contrast, AA biosynthesis has advanced more recently through function-driven approaches that clarified key steps such as N4OMT-mediated 4′-O-methylation, NBS/NR-mediated norbelladine formation, CYP96T-dependent regioselective oxidative coupling, and transient reconstruction of major scaffold-forming branches. Remaining gaps include the unresolved enzymatic formation of 3,4-dihydroxybenzaldehyde in AAs and incomplete functional validation across less-studied IA scaffold classes. By integrating biochemical logic, omics-guided discovery, enzyme evolution, tissue specificity, regulation, and synthetic biology, this review identifies priorities for future alkaloid pathway discovery and sustainable production. Full article

Lymphoma remains a major hematological malignancy associated with treatment resistance and systemic toxicity, highlighting the need for novel anticancer agents derived from natural products. In this study, dicentrine (5), an aporphine alkaloid isolated from Stephania venosa, was investigated for its anti-lymphoma activity in Raji and Ramos cells. Among the isolated compounds, dicentrine (5) exhibited the strongest cytotoxic activity, with IC₅₀ values of 9.03 ± 0.53 and 5.16 ± 0.44 µg/mL in Raji and Ramos cells, respectively, while demonstrating favorable selectivity toward lymphoma cells relative to peripheral blood mononuclear cells (PBMCs). Dicentrine (5) significantly suppressed c-Myc and phosphorylated c-Myc expression, reduced lymphoma cell proliferation, and decreased total viable cell numbers in a dose-dependent manner. Cell cycle analysis revealed G0/G1 arrest in Raji cells and G2/M arrest in Ramos cells. Furthermore, dicentrine (5) induced apoptosis, as evidenced by increased Annexin V-positive populations and elevated cleaved caspase-3 expression. Molecular docking analysis demonstrated strong binding affinities of dicentrine (5) toward Akt, PI3K, caspase-3, and caspase-9, while network pharmacology identified AKT1 and the PI3K/Akt signaling pathway as potential targets associated with lymphoma suppression. Western blot analysis further demonstrated that dicentrine (5) significantly reduces total Akt protein expression. Overall, the present findings indicate that dicentrine (5) suppresses lymphoma progression by inhibiting cell proliferation and promoting apoptotic cell death, highlighting its potential as a promising natural therapeutic candidate for lymphoma. Full article

Cassytha filiformis is a folkloric herbal medicine used to treat type 2 diabetes mellitus (T2DM). In this study, an oxidized aporphine alkaloid, designated as Filiforidine (3,10,11-trimethoxy-1,2-methylenedioxy-7-oxoaporphine), was isolated from C. filiformis, and its structure was elucidated through comprehensive spectroscopic analysis. Owing to its novel structure and significant glucose consumption activity, the total synthesis of Filiforidine was achieved for the first time. The key steps featured an electrophilic addition reaction, involving the reduction of a nitro group to an amino group with lithium tetrahydroaluminum, and a copper bromide-catalyzed oxidative aromatization reaction as well as a photocyclization reaction. Several experimental steps were optimized. Furthermore, a complex post-treatment method was developed, which reduced the column chromatography separation steps. Specifically, 2-(4-methoxybenzo[d][1,3]dioxol -5-yl) ethan-1-amine is salted with dilute hydrochloric acid. Cytotoxicity assay and glucose oxidase assay showed that Filiforidine had significant glucose consumption-promoting effects on HL-7702 cells at 0.625 μM, 1.25 μM, and 2.5 μM but without cytotoxicity. Therefore, Filiforidine might be a promising drug candidate for the treatment of diabetes. Full article

Aporphine alkaloids were the characteristic compounds with hypoglycemic effects in Cassytha filiformis. Utilizing chromatographic separation techniques including silica gel and semi-preparative high-performance liquid chromatography, three new aporphine alkaloids were successfully isolated and purified. Their structures were elucidated using various spectroscopic techniques, including one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopy, as well as high-resolution electrospray ionization mass spectrometry (HRESIMS). The new compounds were identified as 10-demethylcassythine (1), 3-demethylcassythine (2), and N-demethyllastourvilline (3). The absolute configurations of the new compounds were determined using electronic circular dichroism (ECD) calculations. The effects of the new compounds on promoting glucose consumption in HepG2 cells at varying concentrations were tested. The results indicate that compound 1 significantly enhanced glucose consumption at 20 μM. Full article

Advanced renal cell carcinoma (RCC) has a poor prognosis; this drives the exploration of alternative systemic therapies to identify more effective treatment options. Recent research has revealed that crebanine, an alkaloid derivative of the Stephania genus, induces apoptotic effects in various cancers; however, a thorough investigation of the role of crebanine in RCC has not been conducted thus far. For this study, we evaluated tumor cell viability, clonogenicity, cell-cycle distributions, morphological changes, and cell mortality with the aim of exploring the antitumor effects of crebanine in RCC. Furthermore, we compared gene and protein expressions using RNA sequencing analysis and Western blotting. The findings indicated that crebanine significantly inhibited RCC colonies and caused G1-phase cell-cycle arrest with sub-G1-phase accumulation, thus leading to suppressed cell proliferation and cell death. In addition, Hoechst 33342 staining was used to observe apoptotic cells, which revealed chromatin condensation and a reduction in the nuclear volume associated with apoptosis. Further, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that differentially expressed genes are involved in the initiation of DNA replication, centrosome duplication, chromosome congression, and mitotic processes in the cell cycle along with signaling pathways, such as I-kappaB kinase/NF-kappaB signaling, Hippo signaling, and intrinsic apoptotic pathways. Consistent with GO and KEGG analyses, increased levels of cleaved caspase-3, cleaved caspase-7, and cleaved PARP, and decreased levels of cIAP1, BCL2, survivin, and claspin were observed. Finally, the expressions of G1/S phase transition cyclin D1, cyclin E/CDK2, and cyclin A2/CDK2 complexes were downregulated. Overall, these findings supported the potential of crebanine as an adjuvant therapy in RCC. Full article

The medicinal plant Stephania yunnanensis is rich in aporphine alkaloids, a type of benzylisoquinoline alkaloid (BIA), with aporphine being the representative and most abundant compound, but our understanding of the biosynthesis of BIAs in this plant has been relatively limited. Previous research reported the genome of S. yunnanensis and preliminarily identified the norcoclaurine synthase (NCS), which is involved in the early stages of the BIA biosynthetic pathways. However, the key genes promoting the formation of the aporphine skeleton have not yet been reported. In this study, based on the differences in the content of crebanine and several other BIAs in different tissues, we conducted transcriptome sequencing of roots, stems, and leaves. We then identified candidate genes through functional annotation and sequence alignment and further analyzed them in combination with the genome. Based on this analysis, we identified three CYP80 enzymes (SyCYP80Q5-1, SyCYP80Q5-3, and SyCYP80G6), which exhibited different activities toward (S)- and (R)-configured substrates in S. yunnanensis and demonstrated strict stereoselectivity enroute to aporphine. This study provides metabolomic and transcriptomic information on the biosynthesis of BIAs in S. yunnanensis, offers valuable insights into the elucidation of BIA biosynthesis, and lays the foundation for the complete analysis of pathways for more aporphine alkaloids. Full article

Background/Objectives: We assessed the influence of long-term injection of magnoflorine (MAG) on memory acquisition in mice for the first time. Methods: This isoquinoline alkaloid that belongs to the aporphines was isolated from the roots of Berberis vulgaris by centrifugal partition chromatography (CPC) using a biphasic solvent system composed of chloroform: methanol: water in the ratio 4:3:3 (v/v/v) with 20 mM of hydrochloric acid and triethylamine, within 64 min. Results: Our results indicated that long-term injection of MAG 20 mg/kg dose improve the long-term memory acquisition in mice that were evaluated in the passive avoidance (PA) test with no toxicity records. The analysis of brain lysates and animal plasma by HPLC-ESI-QTOF-MS/MS showed the ability of the compound to cross the blood–brain barrier, and an elevated level of phosphatidylcholine PC (14:1(9Z)/14:1(9Z)) with the molecular formula of C₃₆H₆₉NO₈P was observed in both treated groups with 10 mg/kg and 20 mg/kg MAG in comparison to the control group. Conclusions: This phenomenon may explain MAG’s cognition-enhancing properties as the PC may induce the synthesis and strengthening of neuronal cells. Also, the 7-day-long administration of MAG at 10 mg/kg and 20 mg/kg increased the mean number of parvalbumin (PV)-IR neurons in the hippocampus. Statistically, the largest PV-IR neurons were observed at the 20 mg/kg dose, which may indicate a potential effect of MAG on Ca²⁺ metabolism. However, no statistical differences were observed in the mean number of PV-IR nerve fibers in both doses of MAG, regardless of the hippocampal fields. This positive effect of MAG on hippocampal neurons provides further support for the neuroprotective effect of this alkaloid. Full article

Serotonin (5-hydroxytryptamine, 5-HT) is a neurotransmitter regulating numerous physiological functions, and its dysregulation is a crucial component of the pathological processes of schizophrenia, depression, migraines, and obesity. 5-HT interacts with 14 different receptors, of which 5-HT_1A-1FRs, 5-HT_2A-CRs, and 5-HT_4-7Rs are G protein-coupled receptors (GPCRs), while 5-HT₃R is a ligand-gated ion channel. Over the years, selective orthosteric ligands have been identified for almost all serotonin receptors, yielding several clinically relevant drugs. However, the high degree of homology between 5-HTRs and other GPCRs means that orthosteric ligands can have severe side effects. Thus, there has recently been increased interest in developing safer ligands of GPCRs, which bind to less conserved, more specific sites, distinct from that of the receptor’s natural ligand. The present review describes the identification of allosteric ligands of serotonin receptors, which are largely natural compounds (oleamide, cannabidiol, THC, and aporphine alkaloids), complemented by synthetic modulators developed in large part for the 5-HT_2C receptor. The latter are positive allosteric modulators sought after for their potential as drugs preferable over the orthosteric agonists as antiobesity agents for their potentially safer profile. When available, details on the interactions between the ligand and allosteric binding site will be provided. An outlook on future research in the field will also be provided. Full article

The present study was performed to determine the chemical constituents, cytotoxicity, antioxidant and enzyme inhibition activities of the aerial parts of Glaucium acutidentatum Hausskn. and Bornm. (family Papaveraceae). Methanolic and aqueous extracts were prepared by maceration, homogenizer-assisted extraction (HAE) and infusion. Results showed that the highest total phenolic and flavonoids contents were obtained from the methanol extracts obtained by HAE (53.22 ± 0.10 mg GAE/g) and maceration (30.28 ± 0.51 mg RE/g), respectively. The aporphine, beznyltetrahydroisoquinoline, and protopine types of Glaucium alkaloids have been tentatively identified. Among them, glaucine was identified in all extracts. Flavonoids, phenolic acids, coumarins, organic acids and fatty acids were also detected. Methanolic extract obtained using the HAE method displayed the highest anti-DPPH (41.42 ± 0.62 mg TE/g), total antioxidant (1.20 ± 0.17 mmol TE/g), Cu²⁺ (113.55 ± 6.44 mg TE/g), and Fe³⁺ (74.52 ± 4.74 mg TE/g) reducing properties. The aqueous extracts obtained by infusion and HAE methods exerted the best anti-ABTS (103.59 ± 1.49 mg TE/g) and chelating (19.81 ± 0.05 mg EDTAE/g) activities, respectively. Methanolic extract from HAE recorded the highest acetylcholinesterase (2.55 ± 0.10 mg GALAE/g) and α-amylase (0.51 ± 0.02 mmol ACAE/g) inhibition activities, while that obtained by maceration showed the best butyrylcholinesterase (3.76 ± 0.31 mg GALAE/g) inhibition activity. Both extracts revealed the best tyrosinase inhibitory activity (25.15 ± 1.00 and 26.79 ± 2.36 mg KAE/g, p ≥ 0.05). G. acutidentatum maceration-derived aqueous extract showed selective anticancer activity against cells originating from human hypopharyngeal carcinoma. In conclusion, these findings indicated that G. acutidentatum is a promising source of alkaloids and phenolic compounds for variable pharmaceutical formulations. Full article

Ocotea, the largest genus in the Lauraceae family, encompasses numerous species of scientific interest. However, most Ocotea species have only been described morphologically. This study used an untargeted metabolomics workflow with UHPLC-HRMS and GNPS-FBMN to provide the first chemical evaluation of the polar specialized metabolites of O. delicata leaves. Leaves from three O. delicata specimens were extracted using ultrasound-assisted extraction with 70% ethanol. Among the examined samples, 44 metabolites, including alkaloids and flavonoids, were identified. In contrast to other Ocotea species, O. delicata has a wider diversity of kaempferol derivatives than quercetin. The biomass of the specimens showed a significant correlation with the chemical profile. The similarity among specimens was mostly determined by the concentrations of quinic acid, kaempferol glycosides, and boldine. The evaluated specimens exhibited chemical features similar to those of species classified as New World Ocotea, with the coexistence of aporphine and benzylisoquinoline alkaloids. Full article

The total synthesis of laurolitsine was achieved for the first time. This reaction was accomplished in 14 steps with a 2.3% yield (this was calculated using 3-hydroxy-4-methoxybenzaldehyde as the starting material) starting from two simple materials, 3-hydroxy-4-methoxybenzaldehyde and 2-(3-hydroxy-4-methoxyphenyl)acetic acid, and the longest linear sequence consisted of 11 steps. The key steps included an electrophilic addition reaction in which a nitro group was reduced to an amino group using lithium tetrahydroaluminum and a Pd-catalyzed direct biaryl coupling reaction. In this paper, many of the experimental steps were optimized, and an innovative postprocessing method in which 2-(3-(benzyloxy)-4-methoxyphenyl)ethanamine is salted with oxalic acid was proposed. Full article

Bisbenzylisoquinoline and aporphine alkaloids are the two main pharmacological compounds in the ancient sacred lotus (Nelumbo nucifera). The biosynthesis of bisbenzylisoquinoline and aporphine alkaloids has attracted extensive attention because bisbenzylisoquinoline alkaloids have been reported as potential therapeutic agents for COVID-19. Our study showed that NnCYP80A can catalyze C-O coupling in both (R)-N-methylcoclaurine and (S)-N-methylcoclaurine to produce bisbenzylisoquinoline alkaloids with three different linkages. In addition, NnCYP80G catalyzed C-C coupling in aporphine alkaloids with extensive substrate selectivity, specifically using (R)-N-methylcoclaurine, (S)-N-methylcoclaurine, coclaurine and reticuline as substrates, but the synthesis of C-ring alkaloids without hydroxyl groups in the lotus remains to be elucidated. The key residues of NnCYP80G were also studied using the 3D structure of the protein predicted using Alphafold 2, and six key amino acids (G39, G69, A211, P288, R425 and C427) were identified. The R425A mutation significantly decreased the catalysis of (R)-N-methylcoclaurine and coclaurine inactivation, which might play important role in the biosynthesis of alkaloids with new configurations. Full article

The species Fissistigma oldhamii (Hemsl.) Merr. (Annonaceae) has long been used as a traditional herbal medicine in China to treat diverse human diseases. Decoctions from the roots of the plant (Guā Fù Mù) are used to treat body pain and inflammatory pathologies, such as rheumatic syndromes, sciatica, and osteoarthritis. The phytochemical content of the plant and the associated pharmacological activities have been analyzed. Seventy natural products were identified in the different parts of the plants, namely, the roots, stems, leaves, fruits, and seeds. The compounds comprise many tri- and tetracyclic alkaloids (aporphine-type), anthraquinones, terpenoids, flavonoids, and others. The pharmacological properties of these molecules were analyzed to point out the anti-inflammatory, antioxidant, anticancer, and/or antimicrobial effects, together with the underlying modulated pathways and molecular targets in some cases. The panel of phytoconstituents present in F. oldhamii extracts is large, with the majority of bioactive products identified in the roots and stems. Multiple molecules can contribute to the anti-inflammatory properties of the extracts. Network pharmacology analyses of the phytoconstituents are needed to better delineate the effective components and their targets. Full article

Genus Hypecoum Tourn. ex L. belongs to the poppy family Papaveraceae and comprises about 19 species occurring in Europe, Northern Africa and Asia. Hypecoum species have been widely used in traditional medicine as antipyretic, analgesic and anti-inflammatory remedies. Their effects are associated with the biologically and pharmacologically active isoquinoline alkaloids in them, such as protopines, protoberberines, benzophenanthridines, aporphines, simple isoquinolines, secoberbines, spirobenzylisoquinolines and others. In this study, we aimed to review and organize information on ethnomedicinal, phytochemical, chemotaxonomical and pharmacological studies of alkaloids and extracts obtained from Hypecoum plants, and to suggest opportunities for further research. Full article

Traumatic spinal cord injury (SCI) results in wide-ranging cellular and systemic dysfunction in the acute and chronic time frames after the injury. Chronic SCI has well-described secondary medical consequences while acute SCI has unique metabolic challenges as a result of physical trauma, in-patient recovery and other post-operative outcomes. Here, we used high resolution mass spectrometry approaches to describe the circulating lipidomic and metabolomic signatures using blood serum from mice 7 d after a complete SCI. Additionally, we probed whether the aporphine alkaloid, boldine, was able to prevent SCI-induced changes observed using these ‘omics platforms’. We found that SCI resulted in large-scale changes to the circulating lipidome but minimal changes in the metabolome, with boldine able to reverse or attenuate SCI-induced changes in the abundance of 50 lipids. Multiomic integration using xMWAS demonstrated unique network structures and community memberships across the groups. Full article