LC-ToF-ESI-MS Patterns of Hirsutinolide-like Sesquiterpenoids Present in the Elephantopus mollis Kunth Extract and Chemophenetic Significance of Its Chemical Constituents

Bitchagno Mbahbou GT, Koffi JG, Simo IK, et al. LC-ToF-ESI-MS Patterns of Hirsutinolide-like Sesquiterpenoids Present in the Elephantopus mollis Kunth Extract and Chemophenetic Significance of Its Chemical Constituents. Molecules. 2021;26(16): 4810.A total of nine sesquiterpenoid lactones together with phenolic compounds and other terpenes were identified from the crude methanol extract of Elephantopus mollis Kunth. Compounds were isolated using different chromatographic techniques and their structures were determined by NMR and IR spectroscopy as well as mass spectrometry. The structures of some detected compounds were assigned based on LC-ToF-ESI-MS screening of main fractions/subfractions from flash chromatography and comparison with isolated analogues as standards. The findings revealed not only the in-source loss of water as the base peak in hirsutinolides but also the in-source loss of corresponding alcohol when the oxygen at position 1 is alkylated. The present study also draws up a complement of data with respect to hirsutinolide-like sesquiterpene lactones whose LC-MS characteristics are not available in the literature. The chemophenetic significance is also discussed. Some of the isolated compounds were reported for the first time to be found in the species, the genus as well as the plant family. The medium-polar fractions of the crude extract, also containing the larger amount of sesquiterpenoid lactones, exhibited activity both against a cancer cell line and bacterial strains. Isolated lactones were also active against the cancer cell line, while the chlorogenic derivatives also valuable in Elephantopus genus showed potent radical scavenging activity. This is the first report of cytotoxic and antibacterial activities of our samples against the tested strains and cell line. The present study follows the ongoing research project dealing with the characterization of taxa with antibacterial and antiparasitic activities from Cameroonian pharmacopeia

Antischistosomal Evaluation of Stem Bark's Extract and Chemical Constituents from Anonidium mannii against Schistosoma mansoni

Context Anonidium mannii (Annonaceae) has been traditionally used in Africa to treat stomach aches, schistosomiasis, and many other illnesses. However, few phytochemical study and no investigation on schistosomiasis have been conducted on this species. This neglected tropical disease, caused by a worm, comes second after malaria as the most devastating parasitical infection. Aim: The goal of this study was to evaluate the anti-Schistosoma mansoni activity of fractions and constituents from A. mannils stem bark and also to search efficient inhibitors of a recently discovered ectoenzyme of S. mansoni (S. mansoni nicotinamide adenine dinucleotide + catabolizing enzyme (SmNACED. Materials and Methods: The powdered stem bark of A. mannii was extracted with ethanol/distilled water (80:20). The extract was then subjected to a partial bioguided separation by chromatography means. The structures of compounds were elucidated using modern spectroscopic techniques. Furthermore, isolated and semisynthetic compounds were evaluated for their antischistosomal and cytotoxic activities. Results: Chemical investigation led to the isolation and identification of eight compounds, in the majority, obtained for the first time from this genus. In addition, acetylation reactions were carried out to afford a new semisynthetic derivative. Preliminary biological screening of the extracts and compounds showed very good activities from antiparasitic and enzymatic tests and also very good percentage of cell viability evaluation. Conclusion: Like praziquantel drug, gallic acid exhibited full anthelmintic activity at concentration of 100 mu M. On the other hand, piperolactam D showed important inhibition on SmNACE (IC50 10 mu M). Thus, standardization of bioactive fraction can help in improving traditional medicine. The optimization of those two compounds will enhance their selectivity/effectiveness and could be used as seed for the development of new remedies against schistosomiasis. Further, the study will be focus on other pathogens species of Schistosoma genus

Dewerin and gilbertionol two new secondary metabolites from the stem bark of Gilbertiodendron dewevrei (De Wild) J. Leonard.

Stephanie DM, Stephane FFY, Jules BKJ, et al. Dewerin and gilbertionol two new secondary metabolites from the stem bark of Gilbertiodendron dewevrei (De Wild) J. Leonard. Natural product research. 2020.The phytochemical investigation of the methanol extract of the stem bark of Gilbertiodendron dewevrei led to the isolation of two new secondary metabolites, 5,7-dihydroxy-4'-methoxyisoflavan-2,4-dione (1) and 23-hydroxy-2-tricosanone (2) along with 19 known compounds (3-21). The structure of these compounds were established by interpretation of their spectral data, mainly HR-TOFESIMS, 1D NMR (1H, 13C and DEPT) and 2D NMR (1H-1H COSY, HSQC, HMBC, and NOESY), and by comparison with those reported in the literature. The methanol extract and some isolates were screened for their antiradical, antibacterial, and inhibitory properties against acetylcholinesterase

Alkenylbenzoquinones and other compounds from the fruit of Maesa lanceolata exhibited potent cytotoxic, antibacterial, and antiradical scavenging activities

Seumo AS, Nanfack ARD, Ndontsa BL, et al. Alkenylbenzoquinones and other compounds from the fruit of Maesa lanceolata exhibited potent cytotoxic, antibacterial, and antiradical scavenging activities. Natural Product Research . 2021.A phytochemical study of the methanol extract of the fruit of Maesa lanceolata resulted in the isolation of a new alkenylbenzoquinone (1), alongside the known compounds (Z)-2,5-dihydroxy-6-methyl-3-(pentadec-10'-enyl)-1,4-benzoquinone (2), 2,5-dihydroxy-6-methyl-3-(nonadec-14'-enyl)-1,4-benzoquinone (3), 2,5-dihydroxy-6-methyl-3-(tridecyl)-1,4-benzoquinone (4), (2S,3S,4R,2'R,9E)-[2'-hydroxytetraeicosanoyl]-2-aminooctadec-9-ene-1,3,4-triol (5), monopalmitin (glyceryl palmitate) (6), lupeol (7), and 3-O-(beta-D-glucopyranoside)-beta-sitosterol (8). The structures of the compounds were established by the means of spectroscopic (1D- and 2D-NMR) and spectrometric techniques (MS). The isolated compounds were assessed for their antibacterial, cytotoxic, and antiradical activities. Compound 2 showed moderate activity against Staphylococcus warneri (DSMZ 20036), while the other compounds were inactive. The two quinones 1 and 2 were significantly cytotoxic, with IC50 values of 0.005M and 12.5M respectively, and were weakly active towards DPPH radical (IC50 >250g/mL)

Manniindole, an indole derivative from the roots ofAnonidium manniiand combined antischistosomal and enzymatic activities

A new alkaloid, manniindole1, together with four known compounds: aristolactam AII2, aristolactam BII3, piperolactam D4and polycarpol5were isolated from the crude extract EtOH-H2O (8:2) of the roots ofAnonidium manniiby chromatographic separation. The structure elucidation was performed on the basis of a spectroscopic analysis (IR, HRESI MS, 1D and 2D NMR) as well as a comparison of their spectral data with those reported in the literature. For the first time, the crude extract and those isolated compounds were evaluated for their anti-schistosomal activity againstSchistosoma mansoniand for cytotoxicity activity against Huh7 and A549 cells. Furthermore, they were also testedin vitroon the recent characterizedSchistosoma mansoniNAD(+)catabolizing enzyme (SmNACE) for their impact on this enzyme which is localized on the outer surface of the adult parasite. Compound2displayed quite good worm killing capability, while4showed significant inhibition ofSmNACE

Two new flavone glycosides from the leaves of Ochna afzelii Oliv. (Ochnaceae)

Kakabi MHD, Simo Mpetga JD, Tamokou J-D-D, et al. Two new flavone glycosides from the leaves of Ochna afzelii Oliv. (Ochnaceae). Natural Product Research . 2022.Two new glycosylflavones, 6''-O-acetyl-8-C-beta-D-galactopyranosylchrysoeriol (1) and 8-C-beta-D-galactopyranosylchrysoeriol (2) were isolated from the methanol extract of the leaves of Ochna afzelii Oliv., along with four known compounds namely 8-C-beta-D-galactopyranosylapigenin (3), ochnaflavone (4), sitosterol-3-O-beta-D-glucopyranoside (5) and D-mannitol (6). Isolation was performed chromatographically and the structures of the purified compounds were elucidated by analyzing their spectroscopic and mass spectrometric data. The antibacterial activity of extract, fractions, and compounds 1-4 was evaluated using broth microdilution method against Gram-positive and Gram-negative bacteria while the antioxidant capacity was performed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the ferric reducing antioxidant power (FRAP) methods. The new flavones (1 and 2) displayed moderate antibacterial activities (MIC = 32-64g/mL) and weak antioxidant properties

In vitro antiplasmodial activity and toxicological profile of extracts, fractions and chemical constituents of leaves and stem bark from Dacryodes edulis (Burseraceae)

Dongmo KJJ, Tali MBT, Fongang YSF, et al. In vitro antiplasmodial activity and toxicological profile of extracts, fractions and chemical constituents of leaves and stem bark from Dacryodes edulis (Burseraceae). BMC Complementary Medicine and Therapies. 2023;23(1): 211.BACKGROUND: Dacryodes edulis is a plant that belongs to the Burseraceae family. It is widely used traditionally alone or in association with other plants in Cameroonian folk medicine to cure wounds, fever, headaches, and malaria. The aim of this work was to investigate the leaves and stem bark of D. edulis with an emphasis on the antiplasmodial and cytotoxic effects of extracts, fractions, and isolated compounds.; METHODS: Extracts, fractions, and some isolated compounds were subjected to antiplasmodial activity screening in vitro against chloroquine-sensitive 3D7 and multidrug resistant Dd2 strains of Plasmodium falciparum using a SyBr Green fluorescence-based assay. The cytotoxicity of active extracts, fractions, and compounds was tested against mammalian Raw cell lines using an in vitro resazurin-based viability assay. The structures of the compounds were determined based on their NMR and MS data. The in vivo toxicity using female BALB/c mice was performed on the most active extract according to the protocol of OECD (2002), guideline 423.; RESULTS: The hydroethanolic extract from the leaves of D. edulis displayed good antiplasmodial activity with IC50 values of 3.10 and 3.56mug/mL respectively on sensitive (3D7) and multiresistant (Dd2) strains of P. falciparum. Of the sixteen compounds isolated, 3,3',4-tri-O-methylellagic acid (4) exhibited the highest antiplasmodial activity against PfDd2 strains with an IC50 value of 0.63mug/mL. All extracts, fractions, and isolated compounds demonstrated nocytotoxicity against Raw cell lines with CC50>250mug/mL. In addition, the most active extract on both strains of P. falciparum was nontoxic in vivo, with a LD50 greater than 2000 and 5000mg/kg. A phytochemical investigation of the stem bark and leaves of D. edulis afforded sixteen compounds, including two xanthones (1-2), three ellagic acid derivatives (3-5), one phenolic compound (6), one depside (7), one triglyceride (8), one auranthiamide acetate (9), one gallic acid derivative (10), four triterpenoids (11-14), and two steroids (15-16). Compounds 1, 2, 5, 7, 8, and 9 were herein reported for the first time from the Burseraceae family.; CONCLUSION: This work highlights the good in vitro antiplasmodial potency of the hydroethanolic extract of the leaves of this plant and that of two isolated constituents (3,3',4-tri-O-methylellagic acid and ethylgallate) from the plant. These biological results support the use of D. edulis in traditional medicine against malaria. © 2023. The Author(s)

Constituents of Peperomia vulcanica Baker & C. H. Wright (Piperaceae) with antiparasitic activity

Chouna HSD, Bankeu JJK, Fongang YSF, et al. Constituents of Peperomia vulcanica Baker & C. H. Wright (Piperaceae) with antiparasitic activity. PHYTOCHEMISTRY LETTERS. 2021;41:14-20.The investigation of the CH2Cl2-MeOH (1:1) extract of Peperomia vulcanica which showed antileishmanial activity during preliminary screening led to the isolation of two previously unknown compounds named peperolignan (1) and peperotannin (2) along with 13 known compounds. Their structures were determined on the basis of their spectroscopic data. The isolated compounds were assessed in vitro for their antileishmanial and antiplasmodial activities against Leishmania donovani 1S (MHOM/SD/62/1S) promastigotes and the Plasmodium falciparum chloroquine-sensitive 3D7 strain (Pf3D7), respectively. They were also assessed for their cytotoxicity on Raw 264.7 macrophage cells. The mixture of 4-hydroxy-2[(3,4-methylenedioxyphenyl)nonanoyl)cyclo-hexan-1,3-dione and 4-hydroxy-2[(3,4-methylenedioxyphenyl) undecanoyl] cyclo-hexane-1,3-dione (10a and 10b) exhibited potent antiplasmodial activity (IC50 = 0.35 mu g/mL) with selectivity index higher than 10-fold (SI = 63.4) and moderate leishmanicidal activity (IC50 = 12.17 mu g/mL) with very low selectivity index (SI = 1.82). The obtained results could provide an extent of validation to the traditional uses of Peperomia vulcanica for the treatment of malaria in endemic areas

Foetidumins A-D, and other chemical constituents from Helichrysum foetidum (L.) Moench (Asteraceae) with antiparasite activity

Nono HW, Donfack Nanfack AR, Tchegnitegni BT, et al. Foetidumins A-D, and other chemical constituents from Helichrysum foetidum (L.) Moench (Asteraceae) with antiparasite activity. Phytochemistry. 2023;210: 113672.The phytochemical investigation of the MeOH and CH2Cl2-MeOH (1:1) extracts from the flowers and twigs of Helichrysum foetidum (L.) Moench (Asteraceae), which showed antileishmanial and antiplasmodial activities during the preliminary screening, led to the isolation of four undescribed compounds, including two ent-beyer-15-ene-type diterpenoids, foetidumins A (1) and B (2), one flavonoid, foetidumin C (3) and one chalcopyrone, foetidumin D (4). Additionally, fourteen known compounds comprising, two ent-beyer-15-ene-type diterpenoids (5-6), six flavonoids (7-12), two steroids (13-14), three triterpenoids (15-17), and one glyceryl monostearate (18) were also isolated. The chemical structures of foetidumins A-D were fully elucidated by analyses of their spectroscopic data. The structure and the stereochemistry of foetidumin A (1) were confirmed by SC-XRD analyses. Among the tested compounds, foetidumin C (3), erythroxylol A (6), and kaempferol (7) displayed the highest antileishmanial potency with IC50 values of 13.0, 11.8, and 11.1 muM, respectively. Foetidumin C (3) had no cytotoxicity toward Vero cells with the selectivity index > 3.59. Meanwhile, extracts of flowers and twigs had higher activity against Plasmodium falciparum chloroquine-sensitive (Pf3D7) strain with IC50 values of 3.66 and 10.52 mug/mL, respectively. Copyright © 2023. Published by Elsevier Ltd

Bioguided fractionation and isolation of an antiplasmodial saponin from the roots of Nauclea xanthoxylon (A.Chev.) Aubrev

Nangmou Nkouayeb BM, Maza Djomkam HL, Tabekoueng GB, et al. Bioguided fractionation and isolation of an antiplasmodial saponin from the roots of Nauclea xanthoxylon (A.Chev.) Aubrev. Chemistry & Biodiversity . 2023: e202200271.The root extract of Nauclea xanthoxylon (A.Chev.) Aubrev. displayed significant 50% inhibition concentration (IC50s) of 0.57 and 1.26 g/mL against chloroquine resistant and sensitive Plasmodium falciparum (Pf) Dd2 and 3D7 strains, respectively. Bio-guided fractionation led to an ethyl acetate fraction with IC50s of 2.68 and 1.85 g/mL and subsequently, to the new quinovic acid saponin named xanthoxyloside (1) with IC50s of 0.33 and 1.30 M, respectively against the tested strains. Further compounds obtained from ethyl acetate and hexane fractions were the known clethric acid (2), ursolic acid (3), quafrinoic acid (4), quinovic acid (5), quinovic acid 3-O-beta-D-fucopyranoside (6), oleanolic acid (7), oleanolic acid 3-acetate (8), friedelin (9), beta-sitosterol (10a), stigmasterol (10b) and stigmasterol 3-O-beta-D-glucopyranoside (11). Their structures were characterised with the aid of comprehensive spectroscopic methods (1 and 2D NMR, Mass). Bio-assays were performed using nucleic acid gel stain (SYBR green I)-based fluorescence assay with chloroquine as reference. Extracts and compounds exhibited good selectivity indices (SIs) of ˃10. Significant antiplasmodial activities measured for the crude extract, the ethyl acetate fraction and xanthoxyloside (1) from that fraction can justify the use of the root of N. xanthoxylon in ethnomedicine to treat malaria. © 2023 Wiley-VCH GmbH