Indole Alkaloids Research Articles

De novo biosynthesis of antiarrhythmic alkaloid ajmaline

The antiarrhythmic drug ajmaline is a monoterpenoid indole alkaloid (MIA) isolated from the Ayurvedic plant Rauvolfia serpentina (Indian Snakeroot). Research into the biosynthesis of ajmaline and another renowned MIA chemotherapeutic drug vinblastine has yielded pivotal advancements in the fields of plant specialized metabolism and engineering over recent decades. While the majority of vinblastine biosynthesis has been recently elucidated, the quest for comprehending ajmaline biosynthesis remains incomplete, marked by the absence of two critical enzymes. Here, we show the discovery and characterization of these two elusive reductases, alongside the identification of two physiologically relevant esterases that complete the biosynthesis of ajmaline. We show that ajmaline biosynthesis proceeds with vomilenine 1,2(R)-reduction followed by its 19,20(S)-reduction. This process is further modulated by two root-expressing esterases that deacetylate 17-O-acetylnorajmaline. Expanding upon the successful completion of the ajmaline biosynthetic pathway, we engineer the de novo biosynthesis of ajmaline in Baker’s yeast.

Alkaloidal Extracts from Avicennia africana P. Beauv. (Avicenniaceae) Leaf: An Antiplasmodial, Antioxidant, and Erythrocyte Viable.

The emergence of drug-resistant parasites impedes disease management and eradication efforts. Hence, a reinvigorated attempt to search for potent lead compounds in the mangroves is imperative. This study evaluates in vitro antiplasmodial activity, antioxidant properties, and cytotoxicity of A. africana leaf alkaloidal extracts. The A. africana leaves were macerated with 70% ethanol to obtain a total crude extract. Dichloromethane and chloroform-isopropanol (3 : 1, v/v) were used to extract the crude alkaloids and quaternary alkaloids from the total crude. The antiplasmodial activities of the alkaloidal extracts were performed against 3D7 P. falciparum chloroquine-sensitive clone via the SYBR Green I fluorescence assay with artesunate serving as the reference drug. The alkaloidal extracts were further evaluated for antioxidant properties via the total antioxidant capacity (TAC), the total glutathione concentration (GSH), the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay, and the ferric-reducing antioxidant power (FRAP) methods. The cytotoxic activity of the alkaloidal extracts was tested on erythrocytes using a 3-(4,5-dimethylthiazol-2-yl)-5-diphenyltetrazolium bromide-MTT assay with little modification. The phytocompounds in the alkaloidal extracts were identified via gas chromatography-mass spectrometry (GC-MS) techniques. The total crude extract showed good antiplasmodial activity (IC50 = 11.890 µg/mL). The crude and quaternary alkaloidal extracts demonstrated promising antiplasmodial effects with IC50 values of 6.217 and 6.285 µg/mL, respectively. The total crude and alkaloidal extracts showed good antioxidant properties with negligible cytotoxicity on erythrocytes with good selectivity indices. The GC-MS spectral analysis of crude alkaloidal extracts gave indole and isoquinoline alkaloids and several other compounds. Dexrazoxane was found to be the main compound predicted, with an 86% peak area in the quaternary alkaloidal extract. The crude and quaternary alkaloidal extracts exhibited antiplasmodial activities and ability to inhibit oxidative stress with negligible toxicity on erythrocytes. This may be good characteristics to avoid oxidative stress related to Plasmodium infection in the treatment of malaria.

Root-associated Streptomyces produce galbonolides to modulate plant immunity and promote rhizosphere colonization.

The rhizosphere, which serves as the primary interface between plant roots and the soil, constitutes an ecological niche for a huge diversity of microbial communities. Currently, there is little knowledge on the nature and the function of the different metabolites released by rhizospheric microbes to facilitate colonization of this highly competitive environment. Here, we demonstrate how the production of galbonolides, a group of polyene macrolides that inhibit plant and fungal inositol phosphorylceramide synthase (IPCS), empowers the rhizospheric Streptomyces strain AgN23, to thrive in the rhizosphere by triggering the plant's defence mechanisms. Metabolomic analysis of AgN23-inoculated Arabidopsis roots revealed a strong induction in the production of an indole alkaloid, camalexin, which is a major phytoalexin in Arabidopsis. By using a plant mutant compromised in camalexin synthesis, we show that camalexin production is necessary for the successful colonization of the rhizosphere by AgN23. Conversely, hindering galbonolides biosynthesis in AgN23 knock-out mutant resulted in loss of inhibition of IPCS, a deficiency in plant defence activation, notably the production of camalexin, and a strongly reduced development of the mutant bacteria in the rhizosphere. Together, our results identified galbonolides as important metabolites mediating rhizosphere colonization by Streptomyces.

Exploring binding potential of two new indole alkaloids from Nauclea officinalis against third and fourth generation EGFR: druglikeness, in silico ADMET, docking, DFT, molecular dynamics simulation, and MMGBSA study

This study investigates the anti-cancer potential of recently discovered indole alkaloids from Nauclea Officinalis against third and fourth-generation EGFR mutations using computational tools. Through ADMET profiling, druglikeness prediction, docking, and simulations, we assessed their pharmacokinetics, binding interactions, and stability. Promising druglikeness and binding affinity were observed, particularly for (±)-19-O-butylangustoline, which demonstrated stronger binding against both EGFR mutants. MD simulations confirmed stable interactions, with (±)-19-O-butylangustoline exhibiting the highest stability. These findings highlight these indole alkaloids as potential anti-cancer agents, with (±)-19-O-butylangustoline warranting further optimisation for therapeutic development. This study informs their potential through insights into molecular properties and binding energetics.

Mining Secondary Metabolites of Chassalia curviflora Leaves Using SIRIUS and High-Resolution Mass Spectrometry Data

Chassalia curviflora (Wall ex Kurz.) Thwaites is a flowering plant from Rubiaceae family. Previous phytochemical investigation on Chassalia species led to the isolation of benzoic acid, benzoquinone derivatives, flavonoids, monoterpenoid indole alkaloids and its essential oil composition. However, these are still scarce in terms of its scientific report on studied species. This study was carried out to investigate fast screening of secondary metabolites by using data-dependent acquisition (DDA) LC-MS/MS analysis of methanolic extract of the leaf of the C. curviflora in positive ionization mode. The data were analysed using computational mass spectrometry method from molecular structure database search implemented in Sirius. This led in discovering of 13 known secondary metabolites from a distinct tandem MS data. De novo molecular formula annotations and predictions from SIRIUS suggested five major class compounds classified as coumarin, benzofuran, fatty acids, esters and triterpenes. Stigmasterol 12 and β-sitosterol 13 were successfully isolated, thus used to verify the data obtained from the Sirius. With our results, we advocate the MS-based approach as a useful starting method for the dereplication of compounds from the complex crude extract of plants.

Vallesamidine and schizozygane alkaloids: rearranged monoterpene indole alkaloids and synthetic endeavours.

Covering 1963 to 2023Monoterpene indole alkaloids are the main sub-family of indole alkaloids with fascinating structures, stereochemistry, and diverse bioactivities (e.g., anticancer, anti-malarial and anti-arrhythmic etc.). Vallesamidine alkaloids and structurally more complex schizozygane alkaloids are small groups of rearranged monoterpene indole alkaloids with a unique 2,2,3-trialkylated indoline scaffold, while schizozygane alkaloids can generate a further rearranged skeleton, isoschizozygane, possessing a tetra-substituted, bridged tetrahydroquinoline core. In this review, the origin and structural features of vallesamidine and schizozygane alkaloids are introduced, and a discussion on the relationship of these alkaloids with aspidosperma alkaloids and a structural rearrangement hypothesis based on published studies is followed. Moreover, uncommon skeletons and potential bioactivities, such as anti-malarial and anti-tumour activities, make such alkaloids important synthetic targets, attracting research groups globally to accomplish total synthesis, resulting in impressive works on novel total synthesis, formal synthesis, and construction of key intermediates. These synthetic endeavours are systematically reviewed and highlighted with key strategies and efficiencies, providing different viewpoints on molecular structures and promoting the extension of chemical space and mining of new active scaffolds.

Anti-proliferative Effects of Pinocembrin Isolated From Anomianthus dulcis on Hepatocellular Carcinoma Cells.

Hepatocellular carcinoma (HCC) is the most prevalent primary liver cancer. Anomianthus dulcis (Dunal) J.Sinclair (syn. Uvaria dulcis) has been used in Thai traditional medicine in various therapeutic indications. Phytochemical constituents of A. dulcis have been isolated and identified. However, their effects on liver cancer and the associated mechanisms have not been elucidated. Dry flowers of A. dulcis were extracted using organic solvents, and chromatographic methods were used to purify the secondary metabolites. The chemical structures of the pure compounds were elucidated by analysis of spectroscopic data. Cytotoxicity against HCC cells was examined using SRB assay, and the effects on cell proliferation were determined using flow cytometry. The mechanisms underlying HCC inhibition were examined by molecular docking and verified by Western blot analysis. Among 3 purified flavonoids, pinocembrin, pinostrobin, and chrysin, and 1 indole alkaloid (3-farnesylindole), only pinocembrin showed inhibitory effects on the proliferation of 2 HCC cell lines, HepG2 and Li-7, whereas chrysin showed specific toxicity to HepG2. Pinocembrin was then selected for further study. Flow cytometric analyses revealed that pinocembrin arrested the HCC cell cycle at the G1 phase with a minimal effect on cell death induction. Pinocembrin exerted the suppression of STAT3, as shown by the molecular docking on STAT3 with a better binding affinity than stattic, a known STAT3 inhibitor. Pinocembrin also suppressed STAT3 phosphorylation at both Tyr705 and Ser727. Cell cycle regulatory proteins under the modulation of STAT3, namely cyclin D1, cyclin E, CDK4, and CDK6, are substantially suppressed in their expression levels. Pinocembrin extracted from A. dulcis exerted a significant growth inhibition on HCC cells via suppressing STAT3 signaling pathways and its downstream-regulated genes.

Nature-derived Alkaloids as a Promising Bioactive Compound in Drug Discovery to Meet Global Leishmania Needs

Background: Natural products have been important resources for potential drug development. Among the many classes of natural products, alkaloids have the most therapeutic applications. Treatment of leishmaniasis by chemical drugs remains a challenge because of toxic side effects, limited efficacy, and drug resistance. This review focuses to embrace all researches on leishmanicidal alkaloids over a specific range of time, with special consideration the molecular mechanism of action, and structure-related activity. Methods: All publications (in English) from Web of Science, PubMed, Science Direct, Scopus, and Google Scholar from 2000-2021 using a variety of keywords such as natural alkaloids, herbal alkaloids, marine alkaloids along with leishmaniasis were included in the present study. In this summary, the focus is mainly on natural alkaloids of plant, mineral, marine origin, etc., which have empirically demonstrated the antileishmanial effect. Results: Fourteen categories of alkaloids with anti-leishmaniasis activity were extracted from the articles. The highest number of alkaloids belonged to isoquinoline, indole, and quinoline alkaloids (21.78%, 20.67%, and 16.48% respectively). This review indicated that the mentioned alkaloids are able to inhibit the proliferation of parasites, the respiratory chain and protein synthesis, arrest the cell cycle, disrupt the mitochondrial membrane integrity, inhibit leishmanial topoisomerase, induce mitochondrial dysfunction, and changes in the parasite morphology. Discussion: The present study highlighted antileishmanial alkaloids that are active against different species of Leishmania in vitro and some of them are also active in visceral and cutaneous leishmaniasis models. However, more clinical studies are needed to clarify the anti-leishmanial activity of alkaloids against leishmania in detail. Conclusion: Among the reported compounds, two main classes of alkaloids including isoquinoline and indole alkaloids cover a wider range of anti-parasitic compounds, and structure-activity relationships (SAR) studies of these molecular skeletons may be good lead compounds and afford the structural clues to develop novel medicines with more selective therapeutic profiles.

Acidic environment favors the development and pathogenicity of the grape white rot fungus Coniella vitis

Grape white rot caused by Coniella vitis is a global concern in the grape industry. pH regulation is essential for cell growth, reproductive processes and pathogenicity in phytopathogenic fungi. In this study, we observed that the growth rate, spore production and virulence of C. vitis significantly declined in alkaline pH, as well as the suppressive effect on secretion of hydrolytic enzymes. Transcriptomic and metabolomic analyses were used to investigate the responses of C. vitis to acidic (pH=5), neutral (pH=7) and alkaline environments (pH=9). We identified 728, 1780 and 3386 differentially expressed genes (DEGs) at pH 5, pH 7 and pH 9, when compared with the host pH (pH=3), and 2122 differently expressed metabolites (DEMs) in negative and positive ion mode. Most DEGs were involved in carbohydrate metabolic process, transmembrane transport, tricarboxylic acid cycle, peptide metabolic process, amide biosynthetic process, and organic acid metabolic process. In addition, metabolomic analysis revealed ABC transporters, indole alkaloid biosynthesis, diterpenoid biosynthesis, and carotenoid biosynthesis pathways in response to the pH change. Furthermore, we found that the aspartate synthesis metabolic route associated with the TCA cycle is a key limiting factor for the growth and development of C. vitis in alkaline environments, and aspartate supplementation enables C. vitis to grow in alkaline environments. Plant cell wall-degrading enzymes (PCWDEs) could contribute to the pathogenicity, when C. vitis infected at pH 3. Importantly, aflatrem biosynthesis in acidic environment might contribute to the virulence of C. vitis and has a risk of causing human health problems due to its acute neurotoxic effects.

New cytotoxic indole derivatives with anti-FADU potential produced by the endophytic fungus Penicillium oxalicum 2021CDF-3 through the OSMAC strategy.

Fungi possess well-developed secondary metabolism pathways that are worthy of in-depth exploration. The One Strain Many Compounds (OSMAC) strategy is a useful method for exploring chemically diverse secondary metabolites. In this study, continued chemical investigations of the marine red algae-derived endophytic fungus Penicillium oxalicum 2021CDF-3 cultured in PDB media yielded six structurally diverse indole derivatives, including two new prenylated indole alkaloids asperinamide B (1) and peniochroloid B (5), as well as four related derivatives (compounds 2-4 and 6). The chemical structures of these compounds, including the absolute configurations of 1 and 5, were determined by extensive analyses of HRESIMS, 1D and 2D NMR spectroscopic data, and TDDFT-ECD calculations. Compound 1 was found to possess an unusual 3-pyrrolidone dimethylbenzopyran fused to the bicyclo[2.2.2]diazaoctane moiety, which was rare in previously reported prenylated indole alkaloids. In vitro cytotoxic experiments against four human tumor cell lines (HeLa, HepG2, FADU, and A549) indicated that 1 strongly inhibited the FADU cell line, with an IC50 value of 0.43 ± 0.03 μM. This study suggested that the new prenylated indole alkaloid 1 is a potential lead compound for anti-FADU drugs.

Structural diversity and chemical logic underlying the assembly of monoterpene indole alkaloids oligomers.

Covering: up to 2024This review aims to draw a parallel between all known oligomers of monoterpene indole alkaloids (MIAs) by illustrating the chemical logic underlying their assembly. For this purpose, oligomeric MIAs were first comprehensively listed and organized according to the names of the backbones of their constitutive monomers and the binding sites. From this extensive list, an oligomer network was generated and unprecedented MIA statistics were mined and shared herein. Subsequently, oligomeric MIAs were categorized according to the number of connections instigated between their monomeric components (single, double, triple, and mixed tethering), then subdivided according to the uniqueness or combination of oligomerization assembly reactions. This effort outlined oligomerization trends in a scaffold-specific manner, and established binding reactivity patterns facilitating the comprehension of the associated biosynthetic processes. At last, this review illustrates a unique initiative in crafting a comprehensive repository of machine-readable metadata for MIA oligomers that could be leveraged for chemoinformatic purposes.

Aza-Achmatowicz rearrangement coupled with intermolecular aza-Friedel-Crafts enables total syntheses of uleine and aspidosperma alkaloids.

Aspidosperma and uleine alkaloids belong to the large family of monoterpene indole alkaloids with diverse biological activities and thus have attracted extensive synthetic interest. Reported is the development of a new synthetic strategy that allows direct C3-C2' linkage of indoles with functionalized 2-hydroxypiperidines to construct the core common to all aspidoserma and uleine alkaloids. Such indole-piperidine linkage is enabled by coupling aza-Achmatowicz rearrangement (AAR) with indoles via an intermolecular aza-Friedel-Crafts (iAFC) reaction. This AAR-iAFC reaction proceeds under mild acidic conditions with wide tolerance of functional groups (33 examples). The synthetic application of the AAR-iAFC method was demonstrated with collective total syntheses of 3 uleine-type and 6 aspidosperma alkaloids: (+)-3-epi-N-nor-dasycarpidone, (+)-3-epi-dasycarpidone, (+)-3-epi-uleine, 1,2-didehydropseudoaspidospermidine, 1,2-dehydroaspidospermidine, vincadifformine, winchinine B, aspidospermidine, and N-acetylaspidospermidine. We expect that this AAR-iAFC strategy is applicable to other monoterpene indole alkaloids with the C3-C2' linkage of indoles and piperidines.

Total syntheses of certain asperversiamides, linearly-fused and prenylated indole alkaloids

Biogenetically-patterned total syntheses of seven prenylated alkaloids embodying the pyrano[3,2-f]indole framework have been realised alongside the preparation of several potential natural products.

The synthetic chemistry of sarpagine-ajmaline-type alkaloids.

The sarpagine-ajmaline type monoterpenoid indole alkaloids are among the most important groups of natural alkaloids, and the complex polycyclic and cage-like architectures present significant synthetic challenges. Because of their characteristic indole-fused azabicyclo[3.3.1]nonane structures and prominent biological activities, sarpagine-ajmaline related alkaloids have captured the attention of organic synthetic chemists for decades. In this chapter, the strategies employed in the synthesis of sarpagine-ajmaline related alkaloids are outlined, and the synthetic progress during the period of 2019-2023 is provided in detail. To provide potential targets for future synthetic endeavors, some sarpagine/ajmaline type alkaloids isolated in recent years with novel structures and biological activities are also summarized.

Recent Advances in Total Synthesis of Prenylated Indole Alkaloids by Transition Metal-Catalyzed Reactions as the Key Step

Recent Advances in Total Synthesis of Prenylated Indole Alkaloids by Transition Metal-Catalyzed Reactions as the Key Step

Mechanism of isorhynchophylline in lipopolysaccharide-induced acute lung injury based on proteomic technology.

Isorhynchophylline (IRN), a tetracyclic indole alkaloid, has anti-inflammatory and antioxidant activities against cardiovascular diseases and central nervous system disorders. Acute lung injury (ALI) is a manifestation of inflammation concentrated in the lungs and has a high incidence rate and mortality The purpose of this study is to explain the mechanism of IRN in the treatment of acute lung injury and to provide a new scheme for clinical treatment. The experimental mice were divided into three groups: CTRL, LPS, LPS+IRN. The mouse model of ALI was established by inhaling LPS solution through nose. After continuous administration of IRN solution for 7 days, the mice in LPS+IRN group were killed and the lung tissue was collected for detection. Proteomic (Data are available via ProteomeXchange with identifier PXD050432) results showed that 5727 proteins were detected in mouse lung tissues, and 16 proteins were screened out. IRN could reverse the trend of these differential proteins. In addition, IRN can act on integrin αM to reduce neutrophil recruitment and thereby produce anti-inflammatory effects and may suppress neutrophil migration through the leukocyte transendothelial migration pathway. TUNEL and RT-PCR experiments revealed that LPS-induced ALI in mice increases the apoptosis of lung tissues, damage to alveolar epithelial cells and levels of inflammatory factors. Treatment with IRN can repair tissues, improve lung tissue pathology and reduce lung inflammation.

In silico Analysis of Natural Products from Brazilian Biodiversity in COVID-19 Treatment: NuBBE Database against SARS-CoV-2 Papain-Like Protease

Coronavirus disease (COVID-19) pandemic has infected 630 million people and led to 6.59 million deaths worldwide since its outbreak. To control COVID-19 advance, finding new molecules with potential to inhibit viral spread is pivotal. Papain-like protease (PLpro) is one of the most interesting targets of pharmacological inhibition since it is implicated not only in viral replication but also in modulation of host immune response. Natural products are of great interest to the pharmaceutical industry due to their diverse structure and biological activities. The NuBBEDB (Nuclei of Bioassays, Biosynthesis and Ecophysiology of Natural Products Database) is an excellent source of natural products (NPs) from the Brazilian flora. In this study, we performed virtual screening, molecular dynamics, and binding energy analyses of the NuBBEDB library to target severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) papain-like protease (PLpro), the virus’s protease essential for replication. Among the top-ranked molecules, the indole alkaloids raputindoles A, C, and D emerged as potential SARS-CoV-2 inhibitors, showing significant interactions with the pivotal Beta-Loop-2 (BL2) region, including the catalytic Y268 residue. Notably, raputindole D displayed enhanced stabilization of the BL2 region, while raputindole C exhibited superior overall stability. These in silico findings suggest that raputindoles, especially D, might offer therapeutic value against COVID-19, laying the groundwork for further experimental evaluations.

Advances in the total synthesis of bis- and tris-indole alkaloids containing N-heterocyclic linker moieties.

The past several years have seen an increase in the discovery and isolation of natural products of the indole alkaloid class. Bis- and tris-indole alkaloids are classes of natural products that have been shown to display diverse, potent biological activities. Of particular interest are bis- and tris-indole alkaloids containing N-heterocyclic linker moieties. It has been reported that more than 85% of biologically active compounds contain one or more heterocyclic moieties; of these, N-heterocycles have been identified as the most prevalent. The goal of this review is to provide a detailed overview of the recent advances in isolation and total synthesis of bis- and tris-indole alkaloids that contain N-heterocyclic linker moieties. The known biological activities of these natural products will also be discussed.

Isolation and Cytotoxic Activity Test of Alkaloids from Dichloromethane Fraction of Bark of Tampa Badak (Voacanga foetida (Blume) Rolfe) Against T47D Cell Line

Cancer is a problem in the health sector because this disease has an increasing incidence of morbidity and mortality. While the treatment still leaves some drug side effects, which cause discomfort for cancers sufferers. The arises because most cancer drugs work non-selectively. Because of some of the problems above, it is necessary to encourage the search for alternative drugs treatment of cancer. Voacanga foetida (Blume) Rolfe (Apocynaceae) is a species of plant from the genus Voacanga known as the tampa badak from West Sumatra. This plant is known to be source of indole alkaloids and also bis-indole alkaloids potential as cancer drugs. Therefore, in this study we are interested to explore the potency of this plant as natural product sources with potential cytotoxic activity. The study was started from the isolation process and continued by characterization of the isolated compounds and then testing their cytotoxic activity T47D breast cancer cell line. The isolation process of alkaloid compounds were performed by acid-base extraction, liquid-liquid fractionation, and followed by separation using column chromatography. Then,the potency of cytotoxic activity of the isolates were screened through Brine Shrimp Lethality Test (BSLT) method and evaluated by MTT assay. The structure of three isolated alkaloids (VFB-DB1.1; VFB-DB2.1; and VFB-DB2.2) were charachterized using spectroscopic analyses, including UV and FT-IR. One isolated compound (VFB-DB1.1) was also characterized using 1H NMR spectroscopy. Based on the similarity of 1H NMR spectra of isolated compound when compared with the literature, compound VFB-DB1.1 was identified as voacangine. Then, the BSLT and MTT assay result showed that VFB-DB1.1 exhibited LC50 value of 15.8 µg/mL againt Artemia salina L.and IC50 value of 8.9 µg/mL against T47D breast cancer cells, respectively.

A new indole alkaloid and anti-malarial activity of the stem bark extract of Chrysophyllum albidum

Background to the study: Chrysophyllum albidum stem bark extract had been shown to be antimalarial active in various studies but the compound responsible have not been identified. Methods: Its stem bark ethanol extract was successively partitioned to obtain n-hexane, ethyl acetate, butanol fractions and the aqueous phase with the aim of isolating the antimalarial constituent(s). The fractions were all tested for chemosuppressive activities at doses 0-80 mg/kg using Peter’s four-day test in Plasmodium berghei berghei-infected mouse model with chloroquine (10 mg/kg) and normal saline as positive and negative control respectively Result: The partitioned fractions: n hexane, butanol and aqueous with ED50 44.71±4.88, 54.84±4.25 and 54.42±3.84 and 56.6±4.64 respectively were comparable (p>0.05) in activity to each other. The ethyl acetate fraction with strong reactions to Dragendorff’s reagent and similarly has good weight, was further purified by repeated column chromatography leading to the isolation of a new indole alkaloid identified and characterized as 4, 5, 7, 8-tetrahydro-1H-1, 4-epoxyazepino [1′, 2′: 1, 2] pyrido [3, 4-b] indole-2, 3, 3(2H, 13H, 13bH)-triol (1) named as albidumine with a molecular formula C16H18N2O4. In addition, eleaginine (2), previously characterised from the seed was also identified in this stem-bark through LC-MS. To the best of our knowledge, compound 1 is a new alkaloidal constituent in Chrysophyllum sp. The structure was elucidated using the data from mass spectra, 1D (1H, 13C NMR and DEPT) and 2D-NMR (HMQC and HMBC) spectra. Conclusion: A new indole alkaloid isolated from ethyl acetate fraction of the ethanol extract of the stem-bark of Chrysophyllum albidum and characterised as albidumine may likely be an antimalarial constituent of the plant