Jacques KOUAM

Screening of some Cameroonian Medicinal Plants against Bacterial and Yeasts involved in Gastrointestinal Disorders

Laure Brigitte Kouitcheu Mabeku, Tchouangueu Thibau Flaurant, Jacques Kouam

International Journal of Biology

The present study was designated to evaluated the antimicrobial activities of methanol and ethyl acetate extracts of Carcia arereh, Nelsonia canescens, Ficus thonningu, Bryophillum pinnatum, Cyclosorus striatus, Euphorbia cordifolia, Euphorbia hirta, Erygium foetidum and Mimosa pudica. The selected plants species are used as traditional folk medicine in Cameroon for the treatment of various diseases. Thiazolyl blue tetrazolium bromide colorimetric assay was used to evaluate the antimicrobial activity against 16 microbial species. Preliminary phytochemical screening of plant sample was also carried out. Alkaloids and anthraquinones were the most frequent secondary metabolite in the tested plant extracts. The MIC values obtained ranging from 32 to >1024

• #ethnobotanical and medicinal plants studies
• #phytochemistry and biological activities of ficus species
• #psidium guajava extracts and applications
• #mimosa pudica

Synergetic Effects of Plant Extracts and Antibiotics on Vibrio cholerae O1 Strains Isolated From Clinical Specimens

Laure Brigitte Mabeku Kouitcheu, Talla Emmanuel, Jacques Kouam, Tizé Zra, Oyono Essame Jean Louis

International Journal of Biology

The objective of this study was to evaluate in vitro synergy of extracts from Picralima nitida, Cylicodiscus gabunensis, Cassia arereh and Trichilia emetica and known antimicrobial agents against clinical isolate of vibrio cholerae. The in vitro antibacterial activity of plant-extracts was evaluated alone and in combination with standard antibiotics against Vibrio cholerae using disc-diffusion and microdilution method. Only antibiotics acting by inhibiting proteins synthesis shown strong bactericidal activity with inhibition zone diameter ranging from 11 ± 0.0 to 26 ± 0.6 mm. we also noticed that methanolic extract of Cassia arereh and Trichilia emetica and ethyl acetate extract of Cassia arereh contain bioactive compounds. These extracts were effective anticholeric agents with MIC ranging between 12.207 and 97.656 µg/ml and MBC between 48.828 and 781.25 µg/ ml. Cassia arereh extract showed the greatest activity with MIC and MBC values of 12.207 and 48.828 µg/ ml respectively. Synergism was observed between antimicrobial agents and the best anticholeric plant-extract with significant reduction in the MICs of antibiotics against the strains tested. Administration of both compounds together resulted in an MIC ranging from 0.078 to 10 µg/ ml which represents a 2 to 16-fold reduction in the MICs of the antibiotics tested alone. This change in MIC was noticed even with antibiotics showed weak antibacterial activity.

• #essential oils and antimicrobial activity
• #ethnobotanical and medicinal plants studies
• #vibrio bacteria research studies
• #vibrio cholerae

Antimicrobial Glycosides and Derivatives from Roots of Picralima nitida

Jacques Kouam, Laure B. Kouitcheu Mabeku, Jules Roger Kuiaté, Alembert Tiabou Tchinda, Zacharias T. Fomum

International Journal of Chemistry

Phytochemical screening was performed on the roots of Picralima nitida, resulting in the isolation of three new coumestan glycosides, 3-hydroxy-9-methoxy-2-[2’(E)-3’-methyl-4’-O-?-D-galactopyranosylbutenyl]-8- isoprenylcoumestan (1), 3-hydroxy-9-methoxy-2-[2’(E)-3’-methyl-4’-O-?-D-glucopyranosylbutenyl]-8-[2”(E) -3”-methyl-4”-oxobutenyl]coumestan (2), and 3-hydroxy-9-methoxy-4-[2’(E)-3’-methyl-4’-O-?-D- glucopyranosylbutenyl]-8-[2”(E)-3”-methyl-4”-oxobutenyl]coumestan (3). Acid hydrolysis of 1, 2 and 3 afforded three new coumestan, 3-hydroxy-9-methoxy-2-[2’(E)-4’-hydroxy-3’-methylbutenyl]-8- isoprenylcoumestan (4), 3- hydroxy-9-methoxy-2-[2’(E)-4’-hydroxy-3’-methylbutenyl]-8-[2”(E)-3”-methyl-4”- oxobutenyl]coumestan (5), and 3-hydroxy-9-methoxy-4-[2’(E)-4’-hydroxy-3’-methylbutenyl]-8-[2”(E)-3”- methyl-4”-oxobutenyl]coumestan (6), respectively. Structures of these compounds were elucidated on the basis of spectroscopic data and chemical transformations. Compounds 1 - 6 showed antimicrobial activities against Escherichia coli, Staphylococcus aureus, and Proteus vulgaris.

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

ChemInform Abstract: Triterpenoid Derivatives from Cylicodiscus gabunensis.

Pierre Mkounga, Alembert Tiabou Tchinda, Jacques Kouam

ChemInform

Abstract The stem bark of the title tree is used in the traditional African medicine for various therapeutic purposes.

• #natural product bioactivities and synthesis
• #phytochemistry and biological activities
• #natural antidiabetic agents studies
• #chemistry

Triterpenoid Derivatives from Cylicodiscus gabunensis

Pierre Mkounga, Alembert Tiabou Tchinda, Jacques Kouam

Chemical and Pharmaceutical Bulletin

Three new olean-12-ene derivatives (1-3), together with known urs-12-ene-3beta, 28-diol (4) were isolated from the stem root of Cylicodiscus gabunensis. The structures of the new compounds were established by chemical and spectroscopic means as beta-amyrin-n-nonyl ether (1), 22alpha-hydroxyolean-12-en-3beta-yl-beta-D-galactopyranoside (2), and 24-hydroxyolean-12-en-3beta-yl-beta-D-glucopyranoside (3).

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

Coumestan Glycosides from the Stem Bark of Cylicodiscus Gabunensis

Kazie Nchancho, Jacques Kouam, Pierre Tane, Victor Kuete, Jean Watchueng, Zacharias T. Fomum

Natural Product Communications

Two new coumestan glycosides, coumestoside C (1) and coumestoside D (2), were isolated from the stem bark of Cylicodiscus gabunensis Harms. Their structures were established by spectroscopic means and chemical transformations as 9-O-alpha-L-rhamnopyranosyl-3-hydroxy-4-(5'-hydroxy-3'-methylbut-2'E-enyl) coumestan (1) and 9-O-beta-D-galactopyranosyl-3-O- prenyl-4-hydroxycoumestan. Coumestoside C exhibited antimicrobial activity against Proteus vulgaris.

• #natural product bioactivities and synthesis
• #phytochemistry and biological activities
• #phytoestrogen effects and research
• #glycoside

ChemInform Abstract: Sigmoiside F (Ia) and Propyloxyamyrin (Ib), Two New Triterpenoid Derivatives from Erythrina sigmoidea (Fabaceae)

Jacques Kouam, Alain Méli Lannang, M. Iqbal Choudhary, Zacharias Tanee Fomum

ChemInform

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

• #phytochemistry and biological activities
• #bioactive natural compounds
• #natural product bioactivities and synthesis
• #chemistry

Flavanones from the Stem Bark of Erythrina Sigmoidea

Jacques Kouam, Alain Méli Lannang, Victor Kuete, Zacharias T. Fomum

Natural Product Communications

Chemical analysis of the stem bark of Erythrina sigmoidea Hua yielded two new flavonoids, designated sigmoidin M (1) and sigmoidin N (2). Their structures were established by chemical and spectroscopic means as 5,7-dihydroxy-3′-O-prenyl-(3″,4″-dihydroxy-2″,2″-dimethylpyrano)[5″,6″:4′,5']flavanone (1) and 5,7,3′-trihydroxy-(3″-hydroxy-2″-(1-hydroxyisopropyl)-[4′,5:4″,5″]furanoflavanone (2), respectively. Sigmoidin M exhibited antimicrobial activity.

• #bioactive natural compounds
• #synthesis of organic compounds
• #phytochemicals and antioxidant activities
• #flavanone

<b>SIGMOISIDE E: A NEW ANTIBACTERIAL TRITERPENOID SAPONIN FROM <i>ERYTHRINA SIGMOIDEA</i> (HUA)</b>

Jacques Kouam, X. Siewe Noundou, Laure B. Kouitcheu Mabeku, Alain Méli Lannang, M. Iqbal Choudhary, Zacharias Tanee Fomum

Bulletin of the Chemical Society of Ethiopia

Chemical analysis of the stem bark of Erythrina sigmoidea (Leguminoseae) yielded two known isoflavones, 6,8-diprenylgenisteine (3) and warangalone (4) as well as a new triterpenoid saponin designated sigmoiside E (1). Its structure was established by chemical and spectroscopic means as 16-O-β-D-galactopyranosyl maniladiol (1). Sigmoiside E exhibited antibacterial activity against gram-negative bacteria. KEY WORDS: Erythrina sigmoidea, Stem bark, Triterpenoid, Saponin, Isoflavone, Leguminoseae Bull. Chem. Soc. Ethiop. 2007, 21(3), 373-378.

• #natural product bioactivities and synthesis
• #chemistry
• #erythrina
• #saponin

Coumestoside A, Coumestoside B and Erythrodiside A, Three Glycosides from Cylicodiscus gabunensis (Mimmosaceae)

Jacques Kouam, Pierre Tane, Meli Lanang Alain, Xavier Siwe‐Noundou, M. Iqbal Choudhary, Zacharias Tanee Fomum

Natural Product Communications

Chemical analysis of the stem bark of Cylicodiscus gabunensis (Mimosaceae) yielded, in addition to the known eryhrodiol (4) and sojagol (IV) (5), three new glycosides designated coumestoside A (1), coumestoside B (2) and erythrodiside A (3). Their structures were established by chemical and spectroscopic means as 9- O-β-D-glucopyranosyl-4-hydroxycoumestrol, 9- O-α-L-rhamnopyranosyl-4-hydroxycoumestrol and 3- O-α-L-rhamnopyranosylerythrodiol-28- O-β-D-galactopyranoside, respectively.

• #ethnobotanical and medicinal plants studies
• #phytochemistry and biological activities
• #natural product bioactivities and synthesis
• #glycoside

Evaluation of antidiarrhoeal activity of the fruit-rind of <i>Picralima nitida</i> (Apocynaceae)

Kouitcheu Mabeku B Laure, V Beng Penlap, Jacques Kouam, Bonaventure T. Ngadjui, ZT Fomum, FX Etoa

African Journal of Traditional Complementary and Alternative Medicines

The methanol (M) extract of the fruit-rind of Picralima nitida (PN) (Apocynaceae) was tested for its anti-diarrhoeal activity. Like loperamide (3 mg/kg body weight), a single oral dose of PN-M (375, 750 mg/kg body weight) produced a significant decrease in the frequency of defecation and severity of diarrhoea. To understand the mechanism of its anti-diarrhoeal activity, its effect was further evaluated on intestinal transit; castor oil-induced intestinal fluid accumulation (enteropooling) and electrolyte concentration in the small intestinal fluid. PN-M produced a decrease in intestinal transit (18.81-21.86%) as compared to castor oil treated animals. Unlike atropine, PN-M significantly inhibited castor oil-induced enteropooling. However it did not alter the electrolyte concentration in intestinal fluid as compared to castor oil treated rats. Keywords: Picralima nitida, antidiarrhoeal activity, castor oil African Journal of Traditional, Complementary and Alternative Medicines Vol. 3(4) 2006: 66-73

• #african botany and ecology studies
• #botanical research and applications
• #polysaccharides composition and applications
• #antidiarrhoeal

Evaluation of antidiarrhoeal activity of the stem bark of Cylicodiscus gabunensis (mimosaceae)

B Kouitcheu Mabeku Laure, Véronique Penlap Beng, Jacques Kouam, T Ngadjui Bonaventure, Z. Tanee Fomum, F. X. Etoa

AFRICAN JOURNAL OF BIOTECHNOLOGY

The ethyl acetate (EA) extract of the stem bark of Cylicodiscus gabunensis (CG) (Mimosaceae) was analysed for its anti-diarrhoeal activity. Like loperamide (3 mg/Kg body weight), a single oral dose of C. gabunensis ethyl acetate extract (CG-EA) (375, 750 mg/Kg body weight) produced a significant decrease in the severity of diarrhoea. To understand the mechanism of its anti-diarrhoeal activity, its effect was further evaluated on intestinal transit, castor oil induced intestinal fluid accumulation (enteropooling) and electrolyte concentration in the small intestinal fluid. CG-EA produced a decrease in intestinal transit (10.26-30.75%), and unlike atropine, it significantly inhibited castor oil induced enteropooling. However, it did not alter the electrolyte concentration in intestinal fluid as compared to castor oil-treated rats.

• #ethnobotanical and medicinal plants studies
• #advances in cucurbitaceae research
• #child nutrition and water access
• #antidiarrhoeal

Phenolic metabolites from Erythrina species

Augustin E. Nkengfack, Timothee W. Vouffo, Juliette Cathérine Vardamides, Jacques Kouam, Zacharias T. Fomum, Michèle Meyer et 1 autre(s)

Phytochemistry

• #bioactive natural compounds
• #biological and pharmacological studies of plants
• #synthesis of indole derivatives
• #flavanone

An isoflavanone and a coumestan from Erythrina sigmoidea

Augustin E. Nkengfack, Jacques Kouam, Timothee W. Vouffo, Michèle Meyer, Michael S. Tempesta, Z. Tanee Fomum

Phytochemistry

• #bioactive natural compounds
• #biological and pharmacological studies of plants
• #natural product bioactivities and synthesis
• #erythrina

Further flavonoids from Erythrina species

Augustin E. Nkengfack, Jacques Kouam, W.T. Vouffo, Z. Tanee Fomum, Ermias Dagne, Olov Sterner et 2 autre(s)

Phytochemistry

• #biological activity of diterpenoids and biflavonoids
• #bioactive natural compounds
• #phytochemistry and biological activities
• #flavanone

Two New Triterpenoid Saponins from Erythrina sigmoidea

Jacques Kouam, Augustin Ephrem Nkengfack, Zacharias Tanee Fomum, Rosa Ubillas, Michael S. Tempesta, Michèle Meyer

Journal of Natural Products

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTwo New Triterpenoid Saponins from Erythrina sigmoideaJ. Kouam, A. Ephrem Nkengfack, Z. Tanee Fomum, Rosa Ubillas, Michael S. Tempesta, and Michèle MeyerCite this: J. Nat. Prod. 1991, 54, 5, 1288–1292Publication Date (Print):September 1, 1991Publication History Published online1 July 2004Published inissue 1 September 1991https://pubs.acs.org/doi/10.1021/np50077a008https://doi.org/10.1021/np50077a008research-articleACS PublicationsRequest reuse permissionsArticle Views136Altmetric-Citations20LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

• #natural product bioactivities and synthesis
• #phytochemistry and bioactive compounds
• #phytochemistry and biological activities
• #citation