Pantaléon AMBASSA

An overview of the synthesis of coumarins via Knoevenagel condensation and their biological properties

Idriss Tchoffo Tchoupou, Melody H. Manyeruke, Sodeeq Aderotimi Salami, Charles Izuchukwu Ezekiel, Pantaléon Ambassa, Jacqueline V. Tembu et 3 autre(s)

Results in Chemistry

Coumarins and their derivatives have generated intensive scientific studies worldwide. Coumarins are an important type of naturally occurring and synthetically produced oxygen-containing heterocycles with vast medicinal properties, such as antiviral, anticancer, antioxidant, anti-inflammatory, anticoagulant and antibacterial. Various hybrids derived from this family have been employed in the treatment of a variety of medical conditions. Their structural properties significantly impact their biological function and potential applications. Furthermore, many coumarin synthesis procedures are always associated with toxic and corrosive catalysts, longer reaction time, poor yield, and low purity. For this reason, several initiatives primarily focus on developing new and more practical methods for synthesizing these compounds with the aim of addressing some of the pitfalls of traditional approaches. We have compiled a number of techniques highlighting the latest advances in the synthesis of various coumarin derivatives via Knoevenagel condensation and their biological activities.

• #synthesis of organic compounds
• #synthesis and biological activity
• #multicomponent synthesis of heterocycles
• #knoevenagel condensation

Isolation and evaluation of the antibacterial constituents of <i>Synsepalum brevipes</i>

Fomene Tsapy Raphaelle, Ache Roland Ndifor, Ngnintedo Dominique, Pantaléon Ambassa, Céline Henoumont, Njinga Ngaitad Stanislaus et 4 autre(s)

Tropical Journal of Pharmaceutical Research

Purpose: To isolate and evaluate the antibacterial constituents of Synsepalum brevipes.Methods: The compounds were isolated using varying chromatographic separation methods. The structures were established using 1D and 2D nuclear magnetic resonance (NMR) spectroscopic methods, mass spectroscopy (MS), and by comparison with existing data. Extracts, fractions, and selected compounds were assessed against six bacterial strains using the broth microdilution method.Results: Chemical constituents isolated were identified as taraxeryl acetate, taraxerol, ursolic acid, oleanolic acid, betulinic acid, lupeol, herannone, spinasterol, spinasterol-3-O-β-D-glucopyranoside, eicosanoic acid, asperphernamate, hyperoside, spinasterone, arganin C, and butyroside B. The crude extracts and fractions were inactive against all the bacterial strains. The three compounds, which include oleanolic acid, ursolic acid, and hyperoside, exhibited moderate inhibitory activity with minimum inhibitory concentration (MIC) ranging from 12.5 to 50 μg/mL against the tested bacteria. Oleanolic acid revealed moderate bactericidal effects on Escherichia coli, and methicillin-resistant Staphylococcus (minimum bactericidal concentration (MBC) = 100 μg/mL, while ursolic acid showed moderatebactericidal effects on methicillin-resistant Staphylococcus aureus (MBC = 50 μg/mL).Conclusion: These results show that two triterpenoids and one phenolic exhibit moderate antibacterial effects against Escherichia coli, methicillin-resistant Staphylococcus, and Staphylococcus aureus.

• #phytochemistry and biological activities of ficus species
• #plant tissue culture and regeneration
• #ursolic acid
• #oleanolic acid

Constituents, Nutrient Content, and In Vitro Antioxidant and Anti-Inflammatory Activity of Tricholomopsis aurea (Agaricomycetes) from Cameroon

Ache Roland Ndifor, Ngnintedo Dominique, Mossebo Dominique Claude, Raoul Kemzeu, Ferdinand Lanvin Edoun Ebouel, Yanick Kevin Melogmo Dongmo et 7 autre(s)

International journal of medicinal mushrooms

Tricholomopsis aurea is used as food in different parts of the world, but has not been investigated for its nutrients, metabolites, and biological potentials like other edible mushrooms. This work aimed to quantify the metabolic and nutrient content of T. aurea and evaluate the antioxidant and anti-inflammatory activities of the extract and isolated compounds. The method employed involves chromatographic, spectroscopic, bovine serum albumin microplate, analytical and standard assays. Oleic, elaidic, petroselinic acids, ergosterol, ergosterol peroxide, 22E724R)-24-ethylcholesta-5,7,22-trien-3β-ol, and adenosine were isolated and identified using 1D and 2D-NMR spectroscopy and spectrometric data. The metabolic content revealed high phenolics (799.62 μgGaE/g of dry matter (DM)), low flavonoids (24.54 μgQE/g DM), alkaloids (32.92 μgQiE/g DM), and saponins (88.00 μgQSE/g DM). The nutrients content was made up of proteins (4.79%), lipids (10.43%), fibers (16.01%), ashes (15.96%), carbohydrates (8.74%), dry matter (85.93%), and moisture (14.07%) with energy value of 362.89 kcal. In mg/100 g, the minerals were phosphorus (283.97%), calcium (817.25%), potassium (67.10%), magnesium (94.42%), iron (57.27%), and sodium (74.4%). The extract displayed the antioxidant activity against TAC and FRAP (100-1000 μg/mL), DPPH (SC50 of 248.95 μg/mL) and ABTS (SC50 of 180.7 μg/mL), while the test compounds were not active. The extract, adenosine, ergosterol peroxide, and ergosterol showed anti-inflammatory activity with IC50 of 49.19 μg/mL, 4.91 μg/mL, 6.85 μg/mL, and 29.51 μg/mL, respectively. Conclusively, this study will help to promote the application of T. aurea in traditional dishes and functional or nutraceutical foods.

• #fungal biology and applications
• #chemical synthesis and alkaloids
• #algal biology and biofuel production
• #agaricomycetes

Inhibitory effects of 190 compounds against SARS‐CoV‐2 M pr o protein: Molecular docking interactions

Gabriella B. Souza, Larissa Sens, Stefan Hammerschmidt, Natália Ferreira de Sousa, Maryelle A. G. de Carvalho, Carlos V. D. Dos Santos et 15 autre(s)

Archiv der Pharmazie

Abstract COVID‐19 has caused many deaths since the first outbreak in 2019. The burden on healthcare systems around the world has been reduced by the success of vaccines. However, population adherence and the occurrence of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) variants are still challenging tasks to be affronted. In addition, the newly approved drug presents some limitations in terms of side effects and drug interference, highlighting the importance of searching for new antiviral agents against SARS‐CoV‐2. The SARS‐CoV‐2 main protease (M pr o ) represents a versatile target to search for new drug candidates due to its essential role in proteolytic activities responsible for the virus replication. In this work, a series of 190 compounds, composed of 27 natural ones and 163 synthetic compounds, were screened in vitro for their inhibitory effects against SARS‐CoV‐2 M pro . Twenty‐five compounds inhibited M pro with inhibitory constant values ( K i ) between 23.2 and 241 µM. Among them, a thiosemicarbazone derivative was the most active compound. Molecular docking studies using Protein Data Bank ID 5RG1, 5RG2, and 5RG3 crystal structures of M pro revealed important interactions identified as hydrophobic, hydrogen bonding and steric interactions with amino acid residues in the active site cavity. Overall, our findings indicate the described thiosemicarbazones as good candidates to be further explored to develop antiviral leads against SARS‐CoV‐2. Moreover, the studies showed the importance of careful evaluation of test results to detect and exclude false‐positive findings.

• #synthesis and biological activity
• #computational drug discovery methods
• #cancer therapeutics and mechanisms
• #chemistry

Influence of the Incubation Time on the Inhibition in the Aquatic Microcosm of Some Bacteria of Health Importance by Synthesized O-Propargyl vanillinic Chalcones

Luciane Marlyse Moungang, Christophe Colombe Simo Fotso, Pantaléon Ambassa, Thomas Kuété, Idriss Tchoupou Tchoffo, Raphael Balock Um et 5 autre(s)

International Journal for Research in Applied Sciences and Biotechnology

Background: The germs of waterborne diseases are often associated with an increase in resistance, which contrasts with the discovery of new active molecules, thus complicating treatment. Research is therefore undertaken to discover new substances with therapeutic potential. Although plants are an important source for obtaining interesting compounds, methods based on synthetic chemistry make it possible to obtain compounds inspired by those found in nature and presenting equally important properties. One group of these compounds, called chalcone, is of great importance nowadays due to the diversity of biological activities it presents; therefore, many chalcone derivatives are synthesized and their biological activities evaluated.
 Methodology: The compounds were synthesized by Claisen-Schmidt condensation in a basic medium (potash 5%). The reaction was followed by thin layer chromatography. At the end of the reaction, filtration after cooling of the reaction medium allowed the collection of part of the product that precipitated, while liquid-liquid extraction (water-acetate) allowed to obtain the rest still dissolved. The products obtained were purified by column chromatography using the Hexane/Ethyl Acetate system. The characterization of the products was carried out on the physical properties and also the nuclear magnetic resonances of the proton and carbon 13.
 The use of isolation media for each of the 04 bacteria studied, namely ENDO, SS, TCBS and BEA agars, permitted the isolation of Escherichia coli, Salmonella typhi, Vibrio cholerae and Streptococcus feacalis, respectively. The microbiological technique for counting bacterial colonies in solid medium, as well as the microdilution in liquid medium allowed the evaluation of the action of the different chalcones.
 Results: Four O-propargyl vanillinic chalcones 5a-5d were obtained by Claisen Schmidt condensation method with respective yields of 63.6%; 66.7%; 66.7% and 70.0%. The evaluation of their antibacterial activities was done on four strains of bacteria including E. coli, S. typhi, V. cholerae and S. feacalis isolated from wells in the city of Yaoundé. Statistical data from the results of the solid-state bacterial colony counting technique revealed a lack of significance (p > 0.05) with respect to the variation of the mean bacterial abundance as a function of the concentrations of each chalcone (except that of the S. feacalis with respect to compound 5b). The results of the microdilution test showed the lowest MIC values with compound 5d (250 µg/mL), against S. typhi. Chalcones 5c and 5d exhibited better activity on E. coli (MIC value of 500 µg/mL) compared to the reference antibiotic: ampicillin (MIC > 1000 µg/mL). Chalcones 5a and 5b were the least active on all bacteria studied, with MIC values greater than or equal to 1000.
 Conclusions: The microdilution tests showed an antibacterial activity of the synthesized compounds, with a better activity for the chalcone 5d.

• #synthesis and biological activity
• #organoselenium and organotellurium chemistry
• #biochemical and biochemical processes
• #chalcone

( − )-Brunneusine, a new phenolic compound with antibacterial properties in aqueous medium from the leaves of Agelanthus brunneus (Engl.) Tiegh (LORANTHACEAE)

Moifo Kuete Thomas Wieland, Pantaléon Ambassa, Moungang Luciane Marlyse, Bathélémy Ngameni, Storr E. Thomas, Ngadjui T. Bonaventure et 1 autre(s)

Zeitschrift für Naturforschung C

Abstract Agelanthus brunneus (Loranthaceae) is a hemiparasitic plant growing on Senna siamea (Fabaceae). The chemical investigation of its leaves and flowers led to the isolation of one new phenolic compound namely (−)-brunneusine ( 1 ), together with 13 known compounds. The crude leaves and flowers extracts (CLE and CFLE) with their ethyl acetate fractions (EAFL and EAFFL) and some isolated compounds ( 1–3 ; 8–9 and 11–14 ) have been tested on four bacterial species of sanitary importance isolated in an aquatic environment. All the samples except compound 3 showed antibacterial activity with MICs ranging from 0.43 to 8.88.10 3 µg/mL and MBCs from 0.43 to 3.55.10 3 µg/mL. Compounds 9 and 14 showed better activity on all bacterial species tested with MICs ranging from 0.43 to 27.77 µg/mL. Only CLE, EAFL and compounds 14 , 2 , 8 and 9 showed bactericidal effects on all bacterial species tested.

• #phytochemistry and bioactivity studies
• #phytochemical compounds biological activities
• #insect pest control strategies
• #loranthaceae

Chemical constituents of two Cameroonian medicinal plants: Sida rhombifolia L. and Sida acuta Burm. f. (Malvaceae) and their antiplasmodial activity

Blaise Cédric Kamdoum, Ingrid Konga Simo, Steven Collins Njonté Wouamba, Mariscal Brice Tchatat Tali, Bathélémy Ngameni, Ghislain W. Fotso et 5 autre(s)

Natural Product Research

An extensive phytochemical investigation of the EtOH/H2O (7:3) extracts of Sida rhombifolia L. and Sida acuta Burm. f., yielded a previously undescribed ceramide named rhombifoliamide (1) and a xylitol dimer (2), naturally isolated here for the first time, as well as the thirteen known compounds viz, oleanolic acid (3), β-amyrin glucoside (4), ursolic acid (5), β-sitosterol glucoside (6), tiliroside (7), 1,6-dihydroxyxanthone (8), a mixture of stigmasterol (9) and β-sitosterol (10), cryptolepine (11), 20-Hydroxyecdysone (12), (E)-suberenol (13), thamnosmonin (14) and xanthyletin (15). Their structures were elucidated by the analyses of their spectroscopic and spectrometric data (1 D and 2 D NMR, and HRESI-MS) and by comparison with the previously reported data. The crude extracts, fractions, and some isolated compounds were tested against chloroquine-sensitive (3D7) and chloroquine-resistant (Dd2) Plasmodium falciparum strains. All the tested samples demonstrated moderate and/or significant activities against 3D7 (IC50 values: 0.18―20.11 µg/mL) and Dd2 (IC50 values: 0.74―63.09 µg/mL).

• #traditional and medicinal uses of annonaceae
• #ethnobotanical and medicinal plants studies
• #psidium guajava extracts and applications
• #phytochemical

A phenanthridin-6( 5H )-one derivative and a lanostane-type triterpene with antibacterial properties from Anonidium mannii (Oliv). Engl. & Diels (Annonaceae)

Marcelle Oliviane Ngangoue, Bathélémy Ngameni, Pantaléon Ambassa, Godloves Fru, Brice E. N. Wamba, Japheth O. Ombito et 4 autre(s)

Natural Product Research

The chemical investigation of Anonidium mannii root extract by column chromatography techniques led to the isolation of eight compounds among which two previously unreported compounds; a lanostane-type triterpene, lanosta-7,9(11),23-triene-3β,15α-diol 1 and an alkaloid, 9-hydroxy-8-methoxyphenanthridin-6(5H)-one 2 along with six known compounds: lanosta-7,9(11),24-triene-3β,21-diol 3, oxoanolobine 4, 3, 4-dihydroxybenzoic acid 5, stigmasterol 6, β-sitosterol 7 and 3-O-β-D-glucopyranosyl-β-stigmasterol 8. Their structures were established from spectral data, mainly HR-ESIMS, 1 D and 2 D NMR and by comparison with literature data. The crude root and stem bark extracts (AMR and AMB) and the isolated compounds (1–8) were tested against nine Gram-negative bacteria using rapid p-iodonitrotetrazolium chloride ≥97% (INT) microdilution technique. It was found that AMR, AMB and compound 5 were active against the nine tested bacteria with MIC values ranging from 64 to 1024 µg/mL. Compounds 1–4 had selective antibacterial activities whilst 6–8 were not active.

• #traditional and medicinal uses of annonaceae
• #phytochemistry and biological activities
• #natural product bioactivities and synthesis
• #stigmasterol

Hemisynthesis and Spectroscopic Characterization of Three New Chalcone Derivatives from Dorstenia barteri

Bathélémy Ngameni, Ghislain W. Fotso, Pantaléon Ambassa, Justin Kamga, Arif Daştan, Bonaventure T. Ngadjui

Chemistry of Natural Compounds

• #phytochemistry and biological activities
• #natural product bioactivities and synthesis
• #phytochemicals and antioxidant activities
• #chalcone

Synthesis and Evaluation of Antimicrobial Properties of Some Chalcones

Bathélémy Ngameni, Fokunang Charles, Pantaléon Ambassa, Nobert Azeh, Tembe-Fokunang Estella, Gonsu Kamga Hortense et 4 autre(s)

Journal of Pharmaceutical Research International

Journal of Pharmaceutical Research International (ISSN: 2456-9119) is dedicated to publish high quality papers in all areas of pharmaceutical Science including pharmaceutical drugs, community pharmacy, hospital pharmacy, clinical pharmacy, compounding pharmacy, consultant pharmacy, internet pharmacy, veterinary pharmacy, nuclear pharmacy, military pharmacy, pharmacy informatics, pharmaceutics, medicinal chemistry, pharmacognosy, pharmacotherapy, pharmacodynamics, pharmacokinetics, clinical pharmacology, neuropharmacology, psychopharmacology, pharmacogenetics, pharmacogenomics, pharmacoepidemiology, toxicology, theoretical pharmacology, posology, pharmacognosy, behavioral pharmacology, environmental pharmacology, medicine development and safety testing, drug legislation and safety, pharmaceutical microbiology, pharmaceutical molecular biology, pharmaceutical biotechnology. The journal also encourages the submission of useful reports of negative results. This is a quality controlled, OPEN peer reviewed, open access INTERNATIONAL journal.

• #synthesis and biological activity
• #multicomponent synthesis of heterocycles
• #synthesis and characterization of heterocyclic compounds
• #pharmacy

Antibacterial activity of nineteen selected natural products against multi-drug resistant Gram-negative phenotypes

Armelle T. Mbaveng, Louis P. Sandjo, Simplice B. Tankeo, Ache Roland Ndifor, Pantaléon Ambassa, Bonaventure T. Nagdjui et 1 autre(s)

SpringerPlus

The present study was designed to assess the antimicrobial activity of 19 natural products belonging to terpenoids, alkaloids, thiophenes and phenolics against a panel of 14 Gram-negative multidrug-resistant (MDR) bacteria. The results demonstrated that amongst the studied compounds, alkaloids and terpenoids were less active contrary to flavonoids: neocyclomorusin (3) and candidone (6) and isoflavonoids: neobavaisoflavone (8) and daidzein (12). Thiophene, 2-(penta-1,3-diynyl)-5-(3,4-dihydroxybut-1-ynyl)thiophene (17) showed moderate and selective activities. Compounds 3, 6, 8 and 12 displayed minimal inhibitory concentration (MIC) ranged from 4 to 256 μg/mL on all the 14 tested bacteria. MIC values below 10 μg/mL were obtained with 8, 3, 6 and 12 against 50, 42.9, 35.7 and 21.4 % of the tested bacteria. The lowest MIC value of 4 μg/mL was obtained with compound 3 against Klebsiella pneumoniae ATCC11296, Enterobacter cloacae BM47, compound 6 against Escherichia coli ATCC8739, K. pneumoniae ATCC11296, E. cloacae BM47 and compound 8 against K. pneumoniae ATCC11296 and E. cloacae BM47. The activity of flavonoid 3 was better or equal to that of chloramphenicol in all tested K. pneumoniae, Providencia stuartii, E. aerogenes, E. cloacae and Pseudomonas aeruginosa strains. Within isoflavonoids, neobavaisoflavone scaffold was detected as a pharmacophoric moiety. This study indicates that natural products such as 3, 6 and 8 could be explored more to develop antimicrobial drugs to fight MDR bacterial infections.

• #essential oils and antimicrobial activity
• #phytochemistry and biological activities
• #phytoestrogen effects and research
• #enterobacter cloacae

Flavonoids and Related Compounds from the Medicinal Plants of Africa

Bathélémy Ngameni, Ghislain W. Fotso, Justin Kamga, Pantaléon Ambassa, Abdou Tchoukoua, Aimé G. Fankam et 4 autre(s)

Elsevier eBooks

• #plant biochemistry and biosynthesis
• #phytochemicals and antioxidant activities
• #plant gene expression analysis
• #phenylpropanoid

Induction of mitochondrial dependent apoptosis and cell cycle arrest in human promyelocytic leukemia HL-60 cells by an extract from Dorstenia psilurus: a spice from Cameroon

Constant Anatole Pieme, Santosh Kumar Guru, Pantaléon Ambassa, Suresh Kumar, Bathélémy Ngameni, Jeanne Ngogang et 2 autre(s)

BMC Complementary and Alternative Medicine

BACKGROUND: The use of edible plants is an integral part of dietary behavior in the West region of Cameroon. Dorstenia psilurus (Moraceae) is widely used as spice and as medicinal plant for the treatment of several diseases in Cameroon. The aim of this study is to investigate the cytotoxic and apoptotic potential of methanol extract of D. psilurus in human promyelocytic leukemia (HL-60) cells and prostate cancer (PC-3) cells. METHODS: Cytotoxicity of D. psilurus extract was tested in HL-60 and PC-3 cells using 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay and flow cytometric methods RESULTS: The methanol extract of D. psilurus have significant in vitro cytotoxic activity in HL-60 cells and PC-3 cells with IC₅₀ value of 12 ± 1.54 μg/ml and 18 ± 0.45 μg/ml respectively after 48 h. The mechanism of antiproliferative activity showed that after 24 h, D. psilurus extract induces apoptosis on HL-60 cells by the generation of reactive oxygen species (ROS) along with concurrent loss of mitochondrial membrane potential, modification in the DNA distribution and enhance of G2/M phase cell cycle. CONCLUSION: The extract induces apoptosis of HL-60 cells associated with ROS production, loss of mitochondrial membrane potential and apoptotic DNA fragmentation.

• #traditional and medicinal uses of annonaceae
• #plant-derived bioactive compounds
• #african botany and ecology studies
• #apoptosis

Ceramides and cytotoxic constituents from Ficus glumosa Del. (Moraceae)

Frédéric Nana, Louis P. Sandjo, Félix Keumedjio, Pantaléon Ambassa, Rizwana Malik, Victor Kuete et 3 autre(s)

Journal of the Brazilian Chemical Society

Chemical investigation of the stem bark of Ficus glumosa (Moraceae) yielded two new ceramides (2R,7E)-2-hydroxy-N-[(2S,3S,4R)-1,3,4-trihydroxyhexadecan-2-yl]hexacos-7-enamide and (2R)-N-{(2S,3S,4R,9Z)-1-O-[(β-D-glucopyranosyl]-3,4-dihydroxyheptadec-9-en-2-yl}-2-hydroxypentacosanamide together with twenty one known compounds. The structures were established using NMR data, mass spectrometry, chemical transformation and by comparison with the reported data. Twenty one compounds were further tested against the prostate cancer PC-3 cell line and six of them revealed cytotoxic effect. Dongnoside E was the most active compound with an IC50 0.75 µmol L-1 against the cancer cells line PC-3 while the reference drug doxorubicin displayed 0.91 µmol L-1. This compound also proved to inhibit the cell growth of the fibrosarcoma cancer HT1080 (IC50 0.7 µmol L-1).

• #phytochemistry and biological activities of ficus species
• #phytochemistry and biological activities
• #phytochemistry and bioactive compounds
• #moraceae

Antimicrobial activities of the methanol extract, fractions and compounds from Ficus polita Vahl. (Moraceae)

Victor Kuete, Justin Kamga, Louis P. Sandjo, Bathélémy Ngameni, Herve MP Poumale, Pantaléon Ambassa et 1 autre(s)

BMC Complementary and Alternative Medicine

BACKGROUND: Many plants of the family Moraceae are used in the treatment of infectious diseases. Ficus polita Vahl., an edible plant belonging to this family is used traditionally in case of dyspepsia, infectious diseases, abdominal pains and diarrhea. The present work was designed to assess the antimicrobial activity of the methanol extract from the roots of F. polita (FPR), as well as that of its fractions (FPR1-5) and two of the eight isolated compounds, namely euphol-3-O-cinnamate (1) and (E)-3,5,4'-trihydroxy-stilbene-3,5-O-β-D-diglucopyranoside (8). METHODS: The liquid microdilution assay was used in the determination of the minimal inhibitory concentration (MIC) and the minimal microbicidal concentration (MMC), against seven bacterial and one fungal species. RESULTS: The results of the MIC determination showed that the crude extract, fractions FPR1, FPR2 and compound 8 were able to prevent the growth of the eight tested microorganisms. Other samples showed selective activity. The lowest MIC value of 64 μg/ml for the crude extract was recorded on 50% of the studied microbial species. The corresponding value for fractions of 32 μg/ml was obtained on Salmonella typhi, Escherichia coli and Candida albicans ATCC strains. The MIC values recorded with compound 8 on the resistant Pseudomonas aeruginosa PA01 strain was equal to that of chloramphenicol used as reference antibiotic. CONCLUSION: The obtained results highlighted the interesting antimicrobial potency of F. polita as well as that of compound 8, and provided scientific basis for the traditional use of this taxon in the treatment of microbial infections.

• #phytochemistry and biological activities of ficus species
• #ginger and zingiberaceae research
• #ethnobotanical and medicinal plants studies
• #moraceae

Antimicrobial activity of the crude extracts and five flavonoids from the twigs of Dorstenia barteri (Moraceae)

Armelle T. Mbaveng, Bathélémy Ngameni, Victor Kuete, Ingrid Konga Simo, Pantaléon Ambassa, René Roy et 7 autre(s)

Journal of Ethnopharmacology

• #natural product bioactivities and synthesis
• #phytochemistry and biological activities
• #biological activity of diterpenoids and biflavonoids
• #antimicrobial

ANTIMICROBIAL ACTIVITY OF THE EXTRACT FROM THE TWIGS OF DORSTENIA ELLIPTICA (MORACEAE)

François‐Xavier Etoa, Berhanu Abegaz, Victor Kuete, Bathélémy Ngameni, Merhatibeb Bezabih, Ingrid Konga Simo et 4 autre(s)

Summary The crude extract from the twigs of Dorstenia elliptica (DET) as well one of the five compounds isolated from this extract namely O-[3-(2, 2-dimethyl-3-oxo-2H-furan-5-yl)-3hydroxybutyl]bergaptol (5) were tested for their antimicrobial activity against bacteria and fungi. The Agar disc diffusion test was used to determine the sensitivity of the tested samples while the well micro-dilution was used to determine the minimal inhibition concentrations (MIC) and the minimal microbicidal concentration (MMC) of the active samples. The results of the disc diffusion assay showed that DET prevented the growth of all the 22 tested microbial species while the two tested compounds showed selective activity. At the tested MIC interval ranged from 1.22 to 156.25 µg/ml for the crude extracts and 0.08 to 39.06 µg/ml for the compounds, the activity of DET was noted on 20 of the 22 microbial species. The antimicrobial activities of DET as well as that compound 5 are being reported for the first time. The overall results provide promising baseline information for the potential use of the crude extract in the treatment of bacterial and fungal infections.

• #natural product bioactivities and synthesis
• #phytochemistry and biological activities
• #phytochemical compounds biological activities
• #moraceae

Prenylated flavonoids, monoterpenoid furanocoumarins and other constituents from the twigs of Dorstenia elliptica (Moraceae)

Berhanu M. Abegaz, Bonaventure T. Ngadjui, Gabriel N. Folefoc, Serge Fotso, Pantaléon Ambassa, Merhatibeb Bezabih et 3 autre(s)

Phytochemistry

• #bioactive natural compounds
• #natural product bioactivities and synthesis
• #plant chemical constituents analysis
• #moraceae