Chemical constituents and antibacterial activities of Cameroonian dark brown propolis against potential biofilm-forming bacteria.

Propolis is a resinous material collected by different bee species from various plant exudates and used to seal holes in honeycombs, smoothen the internal walls, embalm intruders, improve health and prevent diseases. From its -hexane extract, eight compounds were isolated and characterised as: mangiferonic acid (); 1-hydroxymangiferonic acid (), new natural product; mangiferolic acid(); 27-hydroxymangiferolic acid (), reported here for the first time as propolis constituent; 27-hydroxymangiferonic acid (); -amyrin (); -amyrin () and lupeol (). The chemical structures of the isolated compounds were elucidated using spectroscopic methods, such as 1D and 2D-NMR, mass spectrometry and comparison with previous published reports.

Myxaoside A, a new triterpenoid saponin from L. (Boraginaceae).

The phytochemical study of L. led to the isolation, through chromatographic techniques, of a new triterpenoid saponin, 3--[--rhamnopyranosyl-(1→3)-(6--acetyl---glucopyranosyl)]-22-hydroxyolean-12-ene () namely Myxaoside A, together with three known compounds, Soyasaponine I (), oleanolic acid (), and 3--acetyl-oleanolic acid (). All structures were established, based on 1 & 2D-NMR spectroscopic analysis and comparison with previous published reports.

and Evaluation of Anticholinesterase and Antidiabetic Effects of Furanolabdanes and Other Constituents from (Linn.) Griffith.

is a tropical plant noticeable for its variegated leaves and exploited for various medicinal purposes. In this study, seven compounds, including three furanolabdane diterpenoids, i.e.

Euphol from Tapinanthus sp. Induces Apoptosis and Affects Signaling Proteins in Glioblastoma and Prostate Cancer Cells.

Background: Plants play an important role in cancer therapy. They are source of natural molecules which can induce apoptosis in cancer cells by affecting molecular mechanisms implicated in cancer progression. The MAP Kinase/ERK1/2 and PI3K/AKT signaling pathways are two classical signaling pathways implicated in cancer progression and constitute therapeutic targets against cancer.

A novel pentacyclic triterpene acid from the stem barks of F. Hoffm (Combretaceae).

A phytochemical study was carried out on stem bark of F. Hoffm., a medicinal plant belonging to the Combretaceae family and used traditionally in the treatment of various ailments.

A new flavonoid glycoside from (Loranthaceae) and evaluation of anticancer activity of extract and some isolated compounds.

The present work describes the isolation and anticancer activity of which is a hemi parasitic plant harvested on , the host plant. Phytochemical study afforded a new flavonoid glycoside, tapinantoside () isolated for the first time from natural source, alongside six known compounds (-). Structure of compounds were elucidated by extensive spectroscopic analyses including 1 D and 2 D NMR, mass spectrometry and by comparison with literature data.

Glycosides of polygalacic acid from the stem barks of Piper guineense Schum and Thonn.

In a continuation of our study on constituents of P. guineense now focusing on the search for saponins, phytochemical investigation of the n-BuOH fraction of P. guineense stem bark led to the isolation of three previously undescribed triterpenoid saponins, named guineenosides A─C (1─3).

Antiplasmodial activities of indole alkaloids from Tabernaemontana penduliflora K. Schum (Apocynaceae).

Five undescribed carboxy-indole alkaloids with corynanthe skeleton, penduflorines A-E (1-3) as well as a voacangine-N-oxide alkaloid, tabernaemontine (4), were isolated along with eight other known compounds (5-12) from the trunk bark of Tabernaemontana penduliflora K. Schum (Apocynaceae). Their structures were determined by means of spectroscopic and spectrometric methods such as UV, IR, NMR and HR-ESI-MS.

Anticancer Activity of Combretum fragrans F. Hoffm on Glioblastoma and Prostate Cancer Cell Lines.

Background: Cancer incidence has been growing in an alarming rate worldwide and new therapeutics are needed, particularly for intractable and chemoresistant cases. We evaluated the cytotoxic effects of Combretum fragrans F. Hoffm (Combretaceae) on glioblastoma (U87MG and C6) and prostate (PC-3) cancer cell lines.

Antiplasmodial and antileishmanial inhibitory activity of triterpenes and steroidal alkaloid from the leaves of Funtumia elastica (Preuss) Stapf (Apocynaceae).

The phytochemical study of leaves of Funtumia elastica led to the isolation of three undescribed ursane derivatives, funtumic acids A, B and C (1-3), as well as one steroidal alkaloid, elasticine (4) and five other known compounds (5-9). Their structures were elucidated on the basis of NMR, MS, IR, UV spectroscopic data as well as by comparison with the literature. The compound 5-hydroxypyridine-3-carboxamide (9) was isolated for the first time from the Apocynaceae family.

Antimicrobial and cytotoxic activities of indole alkaloids and other constituents from the stem barks of Sond (Apocynaceae).

Twenty indole alkaloids, among which two undescribed ones named rauvolfianoids A () and B (), were isolated from the stem barks of Sond along with eight other compounds from other biosynthetic pathways. The structures were elucidated by analysis of spectroscopic data, including 1 D and 2 D NMR; absolute configurations of and were determined by CD exciton chirality method. Compounds and were evaluated for antimicrobial and anticancer activities against three bacterial strains (, and ) and CRC-related opportunistic pathogens.

A new isoquinoline and ceramide from the stem barks of (Pax) Prain (Euphorbiaceae) with antiproteinase and cytotoxic activities.

Two new compounds, an isoquinoline () and caloneuramide (), a ceramide were isolated from the stem bark of together with seven known compounds namely aurantiamide acetate (), acetylaleuritolic acid (), 3-hydroxylaleuritolic acid 2-p-hydroxybenzoate (), mixture of stigmasterol () and -sitosterol (), mixture of 7-oxo-stigmasterol () and 7-oxo--sitosterol (). Their structures were determined based on data from literature and spectroscopic methods. Derivatization reactions on the isoquinoline led to two new compounds, the methylated () and acetylated () derivatives.

Antileishmanial activity of long chain alkyl benzene and other constituents from seeds of L (Pedaliaceae).

The methanolic extract of the waste seeds of L. (Pedaliaceae) was subjected to chromatographic fractionation; it led to the isolation of an alkyl benzene identified as 1,3-bis (pentadecyl)benzene () along with three known fatty acids: oleic acid (), linoleic acid (), and palmitic acid (); one monosaturated cardanol, 3-pentadecylphenol () and two phytosteroids identified as sitostanol () and campestanol (). The structures of these compounds were elucidated by chemical and spectroscopic analyses.

Heterophynone and methyl ester of Colic acid, two new compounds with antimicrobial activity from (Sterculiaceae).

The ethyl acetate fraction, the stem bark and the residual methanolic extracts from the leaves of (Sterculiaceae) led to the isolation of two new compounds: Heterophynone () and methyl ester of Colic acid (), along with four known triterpenes: betulinic acid (), oleanolic acid (), ursolic acid () and chletric acid (). Structures of compounds were established by different spectroscopic methods that included 1D and 2D NMR experiment. The antimicrobial activity of isolated compounds was evaluated against two yeasts, NR 29456 and 1415; and five Gram-positive bacterial, , NR 46003, NR46374 and HM 601).

Cordidepsine is A Potential New Anti-HIV Depsidone from , Baker.

Chemical investigation of Baker resulted in the isolation of a new depsidone, cordidepsine (), along with twelve known compounds including cyclooctasulfur (), lup-20(29)-en-3-triacontanoate (), 1-(26-hydroxyhexacosanoyl)glycerol (), glyceryl-1-hexacosanoate () betulinic acid (), lupenone (), -amyrone (), lupeol (), -amyrin (), allantoin (), 2'-(4-hydroxyphenyl)ethylpropanoate () and stigmasterol glycoside (). Hemi-synthetic reactions were carried out on two isolated compounds ( and ) to afford two new derivatives, that is, cordicerol A () and cordicerol B (), respectively. The chemical structures of all the compounds were established based on analysis and interpretation of spectroscopic data such as electron ionization mass spectrometry (EI-MS), high resolution electrospray ionization mass spectrometry (HR-ESI-MS), fast atom bombardment mass spectrometry (FAB-MS), one dimension and two dimension nuclear magnetic resonance (1D and 2D-NMR) spectral data as well as X-ray crystallography (XRC).

Secondary metabolites from Triclisia gilletii (De Wild) Staner (Menispermaceae) with antimycobacterial activity against Mycobacterium tuberculosis.

Triclisinone (2), a new ochnaflavone derivative, was isolated from the aerial parts of Triclisia gilletii, along with known drypemolundein B (1) and eight other known compounds. The chemical shifts of drypemolundein B (1) have been partially revised based on reinterpretation of NMR spectroscopic data. The eight other secondary metabolites are composed of: (+)-nonacosan-10-ol (3); stigmasterol (4), 3-O-β-D-glucopyranosylsitosterol (5), 3-O-β-D-glucopyranosylstigmasterol (6); oleanic acid (7); myricetin (8), quercetin (9) and 3-methoxyquercetin (10).

Rauvolfianine, a new antimycobacterial glyceroglycolipid and other constituents from Rauvolfia caffra. Sond (Apocynaceae).

The chemical investigation of the extract of the dried leaves of Rauvolfia caffra (Sond) (synonym Rauvolfia macrophylla) (Apocynaceae) led to isolation of a new glycoside derivative, rauvolfianine (1) as well as six known compounds: oleanolic acid (2), sitosterol-3-O-β-D-glucopyranoside (3), betulinic acid (4), vellosimine (5), sarpagine (6) and D-fructofuranosyl-β-(2→1)-α-D-glucopyranoside (7). Compounds 1, 2, 3, 4 and 7 were evaluated for antitubercular activity. Compounds 1 and 2 were the most active (MIC = 7.

New flavonoids C-glycosides from Rhabdophyllum arnoldianum.

Two new flavone glycosides, 3″-O-acetyl-7-O-methylvitexin (1) and 6″-α-rhamnopyranosyl-7-O-methylvitexin (2), along with nine known compounds (3-11) were isolated from the leaves of Rhabdophyllum arnoldianum (Ochnaceae). The structures of the new compounds were established by detailed spectroscopic studies and mass spectrometry, while known compounds were characterised by direct comparison of their reported NMR data with those found in the literature. All these compounds were the first reported from Rhabdophyllum genus.

Chemical constituents of Millettia barteri and their antimicrobial and antioxidant activities.

Context: Millettia barteri (Benth.) Dunn (Fabaceae) is an African medicinal plant used in folk medicine to treat many diseases. This species, as well as other Mellettia species, has been of interest to researchers because of their wide range of traditional uses.

Phenolic dimers and an indole alkaloid from Campylospermum flavum (Ochnaceae).

From the leaves and stem bark of Campylospermum flavum (Ochnaceae), three compounds, namely 4‴-O-methylagathisflavone, flavumchalcone, and flavumindole have been isolated together with 10 known compounds, including three flavonoids, two biflavonoids, two alkaloids, two nitrile glucosides, and glucopyranosyl-β-sistosterol. The structures of these compounds and their relative configurations were established by 1D and 2D NMR experiments. The methanolic crude extracts of leaves and stem bark of C.

Nitrile glucosides and serotobenine from Campylospermum glaucum and Ouratea turnarea.

Two nitrile glucosides (1S,3S,4S,5R)-4-benzoyloxy-2-cyanomethylene-3,5-dihydroxycyclohexyl-1-O-beta-glucopyranoside (campyloside A) and (1S,3S,4S,5R)-5-benzoyloxy-2-cyanomethylene-3-hydroxy-4-(2-pyrrolcarboxyloxy)cyclohexyl-1-O-beta-glucopyranoside (campyloside B) were isolated from the stem roots of Campylospermum glaucum, whereas serotobenine was isolated from Ouratea turnarea. The structure elucidations were based on spectroscopic evidence. The biological assays of compounds and crude extract of plant species showed good antimicrobial activity of crude extracts against Gram-positive cocci.

Two biflavonoids from Ouratea nigroviolacea.

The leaves of Ouratea nigroviolacea (Ochnaceae) afforded two biflavonoids, ouratine A and B together with agathisflavone and stigmasterol. The biflavonoids were characterized as 4'-O-methylated apigeninyl-(I-6, II-8)-4'-O-methylatedapigenin and 4'-O-methylated apigeninyl-(I-6, II-8) apigenin by spectral and chemical transformation studies.

Antimicrobial biflavonoids from the aerial parts of Ouratea sulcata.

Investigation of the aerial parts of Ouratea sulcata led to the isolation of a biflavonoid named sulcatone A, together with the known compounds, 3-hydroxy-2,3-dihydroapigenyl-[I-4',O,II-3']-dihydrokaempferol, amentoflavone, lophirone A, agathisflavone, stigmasterol and stigmasteryl-3-O-beta-D-glucopyranoside. The structure of the compound was assigned as apigenyl-[I-4',O,II-3']-dihydrokaempferol, by means of spectroscopic analysis. Sulcatone A and 3-hydroxy-2,3-dihydroapigenyl-[I-4',O,II-3']-dihydrokaempferol exhibited significant in vitro antimicrobial activities against a range of microorganisms.