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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.)

Phytochemical investigation of the stem bark extract of Anopyxis klaineana was carried out by various chromatographic techniques resulting in the isolation and characterization of three new tirucallane triterpenoids, namely 3,23-dioxotirucalla-7,24-dien-21-oic acid (1), 3,4-secotirucalla-23-oxo-4(28)7,24-trien-3,21-dioic acid (2) and 3,4-secotirucalla-4-hydroxy-23-oxo-7,24-diene-3,21-dioic acid-21-methyl ester (3), along with nine known compounds (4-12). The structural elucidation of the compounds was performed by means of high-resolution mass spectrometry (HRMS(n)), nuclear magnetic resonance (NMR), and by comparison to literature data. Although none of the isolated compounds showed antibacterial efficacy against selected environmental and clinically important pathogenic Gram-positive and -negative bacteria, they demonstrated moderate DPPH free radical scavenging properties. Furthermore, compounds 1 and 7 exhibited remarkable anti-inflammatory potential in a prostaglandin E2 (PGE2) competitive enzyme immunoassay with IC50 values of 3.63 μM and 10.23 μM, respectively., (Copyright © 2015 Elsevier B.V. All rights reserved.)

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(3H)-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., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Bioassay guided fractionation of Hypericum riparium leaves extract has resulted in the isolation and characterization of three new compounds namely chipericumin E (1), hyperenone C (3), and hyperixanthone (5), together with twenty known compounds. Their structures were elucidated based on comprehensive interpretation of spectroscopic and spectrometric data. Compounds 1-4, and 6-8 displayed moderate antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and cytotoxic effects on the human gastric cell line BGC-823 with IC50 values ranging from 6.54 to 18.50μM., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Two unusual dibenzofurans, preussiafurans A-B (1-2), together with six known compounds have been isolated from the fungus Preussia sp. occurring in Enantia chlorantha Oliv. The structures were established on the basis of 1D and 2D NMR spectroscopy and MS analysis. Compounds 1-4 showed antiplasmodial activity against erythrocytic stages of chloroquine-resistant Plasmodium falciparum (NF54) and moderate cytotoxicity on L6 cell lines with IC50 values of 8.67 and 14.8 μM, respectively., (Copyright © 2014 Elsevier B.V. All rights reserved.)

A new hopene-type triterpenoid, namely sonhafouonic acid 1a was isolated from Zehneria scabra camerunensis, together with eight known compounds. The structure of 1a was established by extensive NMR and high resolution MS techniques and confirmed by single-crystal X-ray crystallographic analysis. Compound 1a exhibited inhibitory activity against mycelial growth of two peronosporomycete phytopathogens Pythium ultimum and Aphanomyces cochliodes and cytotoxicity towards brine shrimp larvae (Artemia salina) at 10 μg/mL., (Copyright © 2013 Elsevier B.V. All rights reserved.)