Isolation and antibacterial activity of anomanol B and other secondary metabolites from the stem bark of (Annonaceae).

A new Lanosta-7,9(11),22-trien-3,15,20-triol named Anomanol B together with five known compounds: manniindole , arborinine , polycarpol 8,9-dimethoxyphenanthridin-6(5)-one and 3-O--D-glucopyranosyl--sitosterol were isolated from the stem bark extract of by routine chromatography techniques. 8,9-dimethoxyphenanthridin-6(5)-one was reported from natural origin for the first time. The structures of the compounds were established by comprehensive elucidation of spectroscopic data and by comparison with literature data.

Antibacterial and antibiotic-potentiation activity of the constituents from aerial part of Donella welwitshii (Sapotaceae) against multidrug resistant phenotypes.

Background: The rise of multidrug-resistant (MDR) bacteria is a real public health problem worldwide and is responsible for the increase in hospital infections. Donella welwitschii is a liana or shrub belonging to the family Sapotaceae and traditionally used to cure coughs.

Objective: This study was conducted with the objective to validate the medicinal properties of this plant, the aerial part was studied for its phytochemical composition using column and PTLC chromatography and exploring its antibacterial and antibiotic-modifying activity as well as those of its phytochemicals.

Identification of 3,3'-O-dimethylellagic acid and apigenin as the main antiplasmodial constituents of Endodesmia calophylloides Benth and Hymenostegia afzelii (Oliver.) Harms.

Background: Endodesmia calophylloides and Hymenostegia afzelii belong to the Guttiferae and Caesalpiniaceae plant families with known uses in African ethno-medicine to treat malaria and several other diseases. This study aimed at identifying antiplasmodial natural products from selected crude extracts from H. afzelii and E.

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

An extensive phytochemical investigation of the EtOH/HO (7:3) extracts of L. and Burm. f.

Design, synthesis, characterization, and anticancer activity of a novel series of O-substituted chalcone derivatives.

A new series of O-substituted chalcone derivatives bearing an/a allyl-, prenyl- or propargyl-substituent at different positions of rings A and B and their derivatives as drug leads, was designed, synthesized, and characterized. The chalcone derivatives were synthesized via base catalyzed Claisen-Schmidt condensation in MeOH or EtOH solutions of appropriately substituted aromatic ketones with O-allyl, and O-propargylvanillin, respectively. The intermediates O-substituted phenylketone derivatives were firstly synthesized by nucleophilic substitution reaction.

Synthesis of Novel Stilbene-Coumarin Derivatives and Antifungal Screening of -Specialized Metabolites Against .

is one of the most toxigenic phytopathogens causing diseases and reduced agricultural productivity worldwide. Current chemical fungicides exhibit toxicity against non-target organisms, triggering negative environmental impact, and are a danger to consumers. In order to explore the chemical diversity of plants for potential antifungal applications, crude extract and fractions from were screened for their activity against two multi-resistant strains: and .

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

The chemical investigation of 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 and an alkaloid, 9-hydroxy-8-methoxyphenanthridin-6()-one along with six known compounds: lanosta-7,9(11),24-triene-3β,21-diol , oxoanolobine , 3, 4-dihydroxybenzoic acid stigmasterol βsitosterol and 3-O-β-D-glucopyranosyl-β-stigmasterol 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 () were tested against nine Gram-negative bacteria using rapid -iodonitrotetrazolium chloride ≥97% (INT) microdilution technique. It was found that AMR, AMB and compound were active against the nine tested bacteria with MIC values ranging from 64 to 1024 µg/mL.

Trypanocidal and leishmanicidal activity of six limonoids.

Six limonoids [kotschyienone A and B (1, 2), 7-deacetylgedunin (3), 7-deacetyl-7-oxogedunin (4), andirobin (5) and methyl angolensate (6)] were investigated for their trypanocidal and leishmanicidal activities using bloodstream forms of Trypanosoma brucei and promastigotes of Leishmania major. Whereas all compounds showed anti-trypanosomal activity, only compounds 1-4 displayed anti-leishmanial activity. The 50% growth inhibition (GI) values for the trypanocidal and leishmanicidal activity of the compounds ranged between 2.

Antistaphylococcal Activity of Extracts, Fractions, and Compounds of Wild (Fabaceae).

is a medicinal plant traditionally used to treat livestock diseases and gastrointestinal infections; our study was undertaken to evaluate the antistaphylococcal activities of the methanolic leaf, bark, and root extracts, fractions, and compounds from against a panel of 14 multidrug-resistant bacterial strains overexpressing efflux pumps. The study was also extended to investigate two possible modes of action, that is, influence on bacterial growth kinetics and influence on proton-ATPase pumps, of the most active compound against a reference strain. .

Polyacanthoside A, a new oleanane-type triterpenoid saponin with cytotoxic effects from the leaves of (Fabaceae).

The chemical investigation of the leaves and stem bark of (Fabaceae) led to the isolation of a new oleanane-type triterpenoid saponin named polyacanthoside A together with fifteen known compounds. Their structures were established from spectral , mainly HRESIMS, 1D NMR and 2D NMR and by comparison with literature data. The cytotoxicity of compound and the analogues as well as doxorubicin was determined in a panel of 9 cancer cell lines including sensitive and drug resistant phenotypes.

Secondary metabolites with antiproliferative effects from Albizia glaberrima var glabrescens Oliv. (Mimosoideae).

A new 5-dehydroxyflavan, namely Albiziaflavan B or (+)-(2R, 3S, 4R)-3',4', 7-trihydroxy-4-methoxy-2,3-trans-flavan-3,4-trans-diol (1) was isolated from the root bark of Albizia glaberrima, together with six known compounds including three flavans: (+)-mollisacacidin (2), (+)-fustin (3) and butin (4); two steroids: chondrillasterol (5) and chondrillasterone (6), and a triterpenoid: lupeol (7). The structure of 1 was established by detailed analysis of its spectroscopic data, especially 1D and 2D NMR spectra, HRESIMS and CD data. Compounds 1-6 were assayed for their antiproliferative effects on two human cancer cells, HeLa at 50 μM (n = 2) and HL60 at 20 μM (n = 2).

Antimycobacterial activity of medicinal plants against the causative agent of buruli ulcer: Mycobacterium ulcerans.

Objective/background: Buruli ulcer, known as necrotizing skin disease caused by Mycobacterium ulcerans, has emerged as the most prevalent mycobacteriosis after leprosy and tuberculosis. Accordingly, it has been classified by the World Health Organization as a neglected disease with high significance in tropical areas, including Cameroon. So far, the control of the disease relies mainly on the rifampin-streptomycin combination.

In vitro antibacterial activities of p-toluenesulfonyl-hydrazinothiazoles and hydrazinoselenazoles against multi-drug resistant Gram-negative phenotypes.

Background: Bacterial multidrug resistance (MDR) constitutes a major hurdle in the treatment of infectious diseases worldwide. The present study was designed to evaluate the antibacterial activities of synthetic p-toluenesulfonyl-hydrazinothiazoles against multidrug resistant Gram-negative bacteria.

Methods: The broth microdilution method was used to determine the minimal inhibitory concentrations (MIC).

Cytotoxicity of three naturally occurring flavonoid derived compounds (artocarpesin, cycloartocarpesin and isobavachalcone) towards multi-factorial drug-resistant cancer cells.

Introduction: Cancer remains an aggressive deadly disease, if drug resistance develops. This problem is aggravated by the fact that multiple rather than single mechanisms are involved in resistance and that multidrug resistance (MDR) phenomena cause inefficacy of many clinical established anticancer drugs. We are seeking for novel cytotoxic phytochemicals to combat drug-resistant tumour cells.

Cytotoxicity of two naturally occurring flavonoids (dorsmanin F and poinsettifolin B) towards multi-factorial drug-resistant cancer cells.

Introduction: The expression of diverse resistance mechanisms in cancer cells is one of the major barriers to successful cancer chemotherapy.

Methods: In the present study, we assessed the cytotoxicity of two naturally occurring flavonoids dorsmanin F (1, a flavanone) and poinsettifolin B (2, a chalcone) against 9 drug-sensitive and multidrug-resistant (MDR) cancer cell lines. The resazurin reduction assay was used to evaluate the cytotoxicity of these compounds, whilst caspase-Glo assay was used to detect caspase activation.

Anti-inflammatory and anticholinesterase activity of six flavonoids isolated from Polygonum and Dorstenia species.

This study was aimed at investigating the anti-inflammatory and anticholinesterase activity of six naturally occurring flavonoids: (-) pinostrobin (1), 2',4'-dihydroxy-3',6'-dimethoxychalcone (2), 6-8-diprenyleriodictyol (3), isobavachalcone (4), 4-hydroxylonchocarpin (5) and 6-prenylapigenin (6). These compounds were isolated from Dorstenia and Polygonum species used traditionally to treat pain. The anti-inflammatory activity was determined by using the Griess assay and the 15-lipoxygenase inhibitory activity was determined with the ferrous oxidation-xylenol orange assay.

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.

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.

Antimicrobial action mechanism of flavonoids from Dorstenia species.

Naturally occurring flavonoids have been reported to possess antimicrobial activity against a wide range of pathogens. However, the antimicrobial action mechanism of these compounds has not yet been elucidated. This study investigated the mechanism underlying the antibacterial activity of four flavonoids: 6,8-diprenyleriodictyol (1), isobavachalcone (2), 6-prenylapigenin (3) and 4-hydroxylonchocarpin (4).

Cytotoxicity and modes of action of four naturally occuring benzophenones: 2,2',5,6'-tetrahydroxybenzophenone, guttiferone E, isogarcinol and isoxanthochymol.

Introduction: The emergence of drug-resistant cancer cells drastically reduces the efficacy of many antineoplasic agents and, consequently, increases the frequency of therapeutic failure. Benzophenones are known to display many pharmacological properties including cytotoxic activities. The present study was aimed at investigating the cytotoxicity and the modes of action of four naturally occurring benzophenones 2,2',5,6'-tetrahydroxybenzophenone (1), isogarcinol (2), isoxanthochymol (3) and guttiferone E (4) on a panel of eleven cancer cell lines including various sensitive and drug-resistant phenotypes.

Antimicrobial activities of the methanol extract and compounds from the twigs of Dorstenia mannii (Moraceae).

Background: Dorstenia mannii (Moraceae) is a medicinal herb used traditionally for the treatment of many diseases. In the present study, the methanol extract of D. mannii and nine of its isolated compounds, namely dorsmanin A (1), B (2), C (3), D (4), E (6), F (7), G (8) dorsmanin I (9) and 6,8-diprenyleriodictyol (5), were tested for their antimicrobial activities against yeast, Mycobacteria and Gram-negative bacteria.

Cytotoxicity and mode of action of four naturally occuring flavonoids from the genus Dorstenia: gancaonin Q, 4-hydroxylonchocarpin, 6-prenylapigenin, and 6,8-diprenyleriodictyol.

Several flavonoid-like compounds were found to possess good antiproliferative properties. Herein, we examined the ability of four naturally occuring and biologically active flavonoids from the genus Dorstenia, gancaonin Q (1), 6-prenylapigenin (2), 6,8-diprenyleriodictyol (3), and 4-hydroxylonchocarpin ( 4), to inhibit the proliferation of a panel of fourteen cancer cell lines including leukemia and solid cancer cells, as well as AML12 normal hepatocytes. The study was extended to the analysis of cell cycle distribution, apoptosis induction, and caspase 3/7 activity and the antiangiogenic properties of the four compounds.

A New Ceramide Isolated from Ficus lutea Vahl (Moraceae).

In addition to benjaminamide (2), β-amyrin, β-amyrin acetate, lupeol, betulinic acid, β-sitosterol glucoside, a new ceramide glycoside was isolated from the woods of Ficus lutea Vahl (Moraceae). Using mass fragmentation pattern, 1 and 2D NMR spectra and by comparison with published data, the new compound was characterized as 1-O-β-D-glucopyranosyl-(2S,3R,5E,12E)-2N-[(2'R)-hydroxyhexadecanoyl]-octadecasphinga-5,12-dienine (1a) for which the trivial name lutaoside was proposed. Some isolated compounds were evaluated for their antimicrobial activities.

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

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.

Traditional medicine: past, present and future research and development prospects and integration in the National Health System of Cameroon.

Traditional medicine refers to health practices, approaches, knowledge and beliefs incorporating plant, animal and mineral based medicines, spiritual therapies, manual techniques and exercises, applied singularly or in combination to treat, diagnose and prevent illnesses or maintain well-being. In the last decade traditional medicine has become very popular in Cameroon, partly due to the long unsustainable economic situation in the country. The high cost of drugs and increase in drug resistance to common diseases like malaria, bacteria infections and other sexually transmitted diseases has caused the therapeutic approach to alternative traditional medicine as an option for concerted search for new chemical entities (NCE).