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Two new 30-norfriedelane triterpenoids namely glaucalactone C (1) and glaucanoic acid (2) along with sixteen known compounds (3-18) have been isolated from the methanolic extracts of the stem bark and fruits of Caloncoba glauca (P.Beauv.) Gilg (Achariaceae). The structures of all the isolated compounds have been established with the aid of their extensive spectroscopic analyses (1D and 2D-NMR) as well as mass spectrometry. Six compounds (1-5, 9) were screened for antiplasmodial activity against two strains P. falciparum Dd2 and P. falciparum 3D7. The results showed that glaucanoic acid (2) was the most active one with IC 50 values of (3.5 ± 0.1 μg/mL) and (4.6 ± 0.7 μg/mL) against PfDd2 and Pf3D7, respectively, while glaucalactone C (1) moderately inhibited PfDd2 (9.4 ± 0.1 μg/mL) and weakly Pf3D7 (15.9 ± 2.3 μg/mL). The molecular docking analyses of the isolated compounds showed that compounds 1-4 and 9-11 are potential drug targets and were further supported by their ADMET studies that revealed welwitschiilactones B and C (4 and 5) as well as β-sitosterol (10) as the most qualified compounds to be safe as drugs. The results indicate that C. glauca is an important source of good candidates in new antiplasmodial drug development., Competing Interests: Declaration of Competing Interest None., (Copyright © 2023 Elsevier B.V. All rights reserved.)

In Cameroon, malaria is still the cause of several deaths yearly and leading to the continued search for new potent leads to fight against Plasmodium falciparum . Medicinal plants like Hypericum lanceolatum Lam. are introduced in local preparations for the treatment of affected people. The bioassay-guided fractionation of the crude extract of the twigs and stem bark of H. lanceolatum Lam. led to the identification of the dichloromethane-soluble fraction as the most active (with 32.6% of the parasite P. falciparum 3D7 survival) which was further purified by successive column chromatography to obtain four compounds identified by their spectrometric data as two xanthones 1,6-dihydroxyxanthone ( 1 ) and norathyriol ( 2 ) and two triterpenes betulinic acid ( 3 ) and ursolic acid ( 4 ). In the antiplasmodial assay against P. falciparum 3D7, the triterpenoids 3 and 4 displayed the most significant potencies with IC 50 values of 2.8 ± 0.8  μ g/mL and 11.8 ± 3.2  μ g/mL, respectively. Furthermore, both compounds were also the most cytotoxic against P388 cell lines with IC 50 values of 6.8 ± 2.2  μ g/mL and 2.5 ± 0.6  μ g/mL, respectively. Further insights on the inhibition method of the bioactive compounds and their drug-likeness were obtained from their molecular docking and ADMET studies. The results obtained help in identifying additional antiplasmodial agents from H. lanceolatum and support its use in folk medicine for the treatment of malaria. The plant might be considered as a promising source of new antiplasmodial candidates in new drug discovery., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2023 Gervais Mouthé Happi et al.)

Ethnopharmacological Relevance: Malaria remains one of the greatest threats to human life especially in the tropical and sub-tropical regions where it claims hundreds of thousands of lives of young children every year. Meliaceae represent a large family of trees and shrubs, which are widely used in African traditional medicine for the treatment of several ailments including fever due to malaria. The in vitro and in vivo antiplasmodial as well as insecticidal investigations of their extracts or isolated compounds have led to promising results but to the best of our knowledge, no specific review on the traditional uses, phytochemistry of the antiplasmodial, insecticidal and cytotoxic lead compounds and extracts of Meliaceae plants has been compiled., Aims: To review the literature up to 2021 on the Meliaceae family with antiplasmodial, insecticidal and cytotoxic activity., Materials and Methods: A number of online libraries including PubMed, Scifinder, Google Scholar and Web of Science were used in searching for information on antiplasmodial metabolites from Meliaceous plants. The keywords Meliaceae, malaria, Plasmodium, Anopheles and antiplasmodial were used to monitor and refine our search without language restriction., Results: The phytochemical investigations of genera of the family Meliaceae led to the isolation and characterization of a wide range of structural diversity of compounds, 124 of which have been evaluated for their antiplasmodial potency against 11 chloroquine-sensitive and chloroquine-resistant Plasmodium falciparum strains. A total of 45 compounds were reported with promising insecticidal potentials against two efficient vector species, Anopheles stephensi Liston and A. gambiae Giles. Limonoids were the most abundant (51.6%) reported compounds and they exhibited the most promising antiplasmodial activity such as gedunin (3) which demonstrated an activity equal to quinine or azadirachtin (1) displaying promising larvicidal, pupicidal and adulticidal effects on different larval instars of A. stephensi with almost 100% larval mortality at 1 ppm concentration., Conclusion: Studies performed so far on Meliaceae plants have reported compounds with significant antiplasmodial and insecticidal activity, lending support to the use of species of this family in folk medicine, for the treatment of malaria. Moreover, results qualified several of these species as important sources of compounds for the development of eco-friendly pesticides to control mosquito vectors. However, more in vitro, in vivo and full ADMET studies are still required to provide additional data that could guide in developing novel drugs and insecticides., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Chemical investigation of the roots of Entandrophragma congoënse (Meliaceae) led to the isolation of two new 3,4-seco-tirucallane triterpenes, namely seco-tiaminic acids B and C (1 and 2) together with nine known compounds: 3,4-secotirucalla-21-formyl-23-oxo-4(28),7,24-trien-3-oic acid (3), methyl angolensate (4), molucensin N (5), molucensin O (6), piscidinol A (7), 7α,20(S)-dihydroxy-4,24(28)-ergostadien-3-one (8), 24-methylene-cholest-5-en-3β,7α-diol (9), entilin A (10), and entilin B (11). Their structures were determined using extensive spectroscopic methods including 1D and 2D NMR, HRMS, and CD analyses; new results were compared to existing data in the literature. The two newly identified seco-tiaminic acids showed moderate antiplasmodial and cytotoxic activities against a chloroquine-sensitive strain of the malaria parasite (Plasmodium falciparum NF54) and were cytotoxic toward an L6 rat skeletal myoblast cell line, respectively., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Eight new triterpenoids, prototiamins A-G (1-6, 9) and seco-tiaminic acid A (10), were isolated along with four known compounds from the bark of Entandrophragma congoënse. Their structures were elucidated by means of HRMS and different NMR techniques and chemical transformations. Assignments of relative and absolute configurations for the new compounds were achieved using NOESY experiments and by chemical modification including the advanced Mosher's method. Additionally, the structure and relative configuration of compound 3 were confirmed by single-crystal X-ray diffraction analysis. Compounds 1, 3, and 5 displayed significant in vitro antiplasmodial activity against the erythrocytic stages of chloroquine-sensitive Plasmodium falciparum strain NF54. Prototiamin C (3) was the most potent of the compounds isolated, with an IC50 value of 0.44 μM. All compounds tested showed low cytotoxicity for the L6 rat skeletal myoblast cell line.

Two new tirucallane-type triterpenoids were isolated from the bark of Entandrophragma congoënse (Meliaceae) along with five known compounds gladoral A, bipendensin, 4-hydroxymethyl-3,5-dimethyldihydrofuran-2(3 H )-one, scopoletin and 5,7-dimethoxy-6-hydroxycoumarin. Their structures were elucidated by means of spectroscopic analyses including 1D and 2D-NMR spectroscopy, high resolution mass spectrometric data as well as the comparison of data with those reported in the literature. The tested compounds ( 1 – 4 ) displayed moderated antiplasmodial activity against erythrocytic stages of chloroquine-resistant Plasmodium falciparum strain NF54 and low cytotoxicity on L6 cell lines. All the isolated compounds are reported for the first time from the genus Entandrophragma. [ABSTRACT FROM AUTHOR]