Sesquiterpene Lactones from : Structural Characterization and Biological Evaluation.

The genus is an extremely rich source of biologically active sesquiterpene lactones. The present report describes the spectroscopic structure elucidation and the cytotoxic and antimicrobial properties of five hitherto unknown germacranolide-like sesquiterpenoids and several known compounds. These new derivatives include a compound () with an unprecedented 10/5/5/6 tetracyclic framework featuring a hexahydro-1,3,7-furo[3',4':3,4]furo[3,2-]pyridin-1-one core resulting from an intramolecular cyclization cascade involving a methacrylate substituent and a low molecular weight amine.

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

A phytochemical study of the methanol extract of the fruit of resulted in the isolation of a new alkenylbenzoquinone (), alongside the known compounds ()-2,5-dihydroxy-6-methyl-3-(pentadec-10'-enyl)-1,4-benzoquinone (), 2,5-dihydroxy-6-methyl-3-(nonadec-14'-enyl)-1,4-benzoquinone (), 2,5-dihydroxy-6-methyl-3-(tridecyl)-1,4-benzoquinone (), (2,3,4,2',9E)-[2'-hydroxytetraeicosanoyl]-2-aminooctadec-9-ene-1,3,4-triol (), monopalmitin (glyceryl palmitate) (), lupeol (), and 3--(-D-glucopyranoside)--sitosterol (). The structures of the compounds were established by the means of spectroscopic (1 D- and 2 D-NMR) and spectrometric techniques (MS). The isolated compounds were assessed for their antibacterial, cytotoxic, and antiradical activities.

Prenylated Flavonoids and C-15 Isoprenoid Analogues with Antibacterial Properties from the Whole Plant of (L.) Raeusch (Gramineae).

The local botanical in Cameroon was investigated for its antibacterial potency. The methanol extract afforded a total of seven compounds, including five hitherto unreported compounds comprising three flavonoids (-) and two C-15 isoprenoid analogues ( and ) together with known derivatives ( and ). The novelty of the flavonoids was related to the presence of both methyl and prenyl groups.

Botanicals and phytochemicals from the bark of Hypericum roeperianum (Hypericaceae) had strong antibacterial activity and showed synergistic effects with antibiotics against multidrug-resistant bacteria expressing active efflux pumps.

Ethnopharmacological Relevance: Infections due to multidrug-resistant (MDR) bacteria constitute a real problem in the public health worldwide. Hypericum roeperianum Schimp. ex A.

Two new triterpenoid fatty acid esters from Harms (Araliaceae).

Two new fatty acid esters of triterpenoids (-) together with eleven known compounds (-) were obtained after investigation of the CHCl-MeOH (1:1) crude extract from the leaves of Harms. All these compounds (-) were isolated for the first time from this plant among which compounds , , and - were also isolated from the genus for the first time. The structures of the isolated compounds were elucidated by analyses of their spectroscopic data (1D and 2D NMR, and MS).

New Alkenylresorcinols with Cytotoxic and Antimicrobial Activities from the Leaves of Embelia schimperi.

A phytochemical study of the methanol extract of the leaves of resulted in the isolation of three new alkenylresorcinols, 1:  - 3: , together with the known analogs 4:  - 7: . Their structures were established by a combination of spectroscopic techniques. Compounds 1:  - 7: exhibited moderate cytotoxic activity against human cervical cancer cells HeLa-S3 and more pronounced antimicrobial properties towards bacteria and filamentous fungi.

A new ceramide from the leaves of (Hochst. ex A.Rich.) Engl.

A new ceramide is being reported herein together with six known compounds from the methanol extract of the leaves of (Hochst. ex A.Rich.

Cytotoxycity and antiplasmodial activity of phenolic derivatives from Albizia zygia (DC.) J.F. Macbr. (Mimosaceae).

Background: The proliferation and resistance of microorganisms area serious threat against humankind and the search for new therapeutics is needed. The present report describes the antiplasmodial and anticancer activities of samples isolated from the methanol extract of Albizia zygia (Mimosaseae).

Material: The plant extract was prepared by maceration in methanol.

-clerodane diterpenoids from Sch.Bip. ex A.Rich.

Two hitherto unknown -clerodane-type diterpenoids along with twelve known compounds have been isolated from Sch.Bip. ex A.

Caffeate and piperidine-3-ol derivatives from the stem bark of .

A new caffeate derivative from the ethanol extract of the stem bark of DC. is described herein along with the known secondary metabolites spectaline (), -6-cassine (), 3--methyl--inositol (), monobehenin (), octyl nonadecyloate (), -sitosterol (), stigmasterol () and sitosterol 3---D-glucopyranoside (). The chemical structures were elucidated by means of various spectroscopic and spectrometric techniques.

A new polyketide from the bark of Schimp. (Hypericaceae).

The isolation and spectroscopic data of a hitherto undescribed polyketide () from Schimp. (Hypericaceae) together with six known compounds (-) is herein reported. The structure elucidation is based on extensive 1D- and 2D-NMR, infrared, UV and MS experiments.

Saponin with antibacterial activity from the roots of .

An unprecedented saponin is being reported herein together with five known compounds from the methanol extract of the roots of . The metabolites were obtained over repeated open column chromatography methods and spectroscopic followed by spectrometric techniques. The isolated compounds were tested against eleven Gram-negative bacteria including multidrug resistant strains.

Cytotoxicity of Crude Extract and Isolated Constituents of the Bark towards Multifactorial Drug-Resistant Cancer Cells.

The effectiveness of anticancer chemotherapy is greatly impeded by the resistance of malignant cells to cytotoxic drugs. In this study, the cytotoxicity of the crude extract (DCB) and compounds isolated from the bark of namely, betulinic acid (), glyceryl-1-hexacosanoate (), 7-hydroxy-2-(4-hydroxyphenyl)-4-chromen-4-one (), and 6-hydroxy-2-(4-hydroxyphenyl)-4-chromen-4-one (), was investigated. The study was extended to the assessment of the mode of induction of apoptosis by DCB and compound .

Antibacterial and antibiotic-modifying activities of fractions and compounds from Albizia adianthifolia against MDR Gram-negative enteric bacteria.

Background: Albizia adianthifolia (Schum.) is medicinally used in Cameroon to manage bronchitis and skin diseases. Our previous study documented the antibacterial potential of its roots' methanol extract.

Cytotoxicity of ungeremine towards multi-factorial drug resistant cancer cells and induction of apoptosis, ferroptosis, necroptosis and autophagy.

Background: Successful cancer chemotherapy is hampered by resistance of cancer cells to established anticancer drugs. Numerous natural products reveal cytotoxicity towards tumor cells.

Purpose: The present study was aimed to determine the cytotoxicity of a betaine-type alkaloid, ungeremine, towards 9 cancer cell lines including various sensitive and drug-resistant phenotypes.

Cytotoxicity of the crude extract and constituents of the bark of Fagara tessmannii towards multi-factorial drug resistant cancer cells.

Ethnopharmacological Relevance: Fagara tessmannii Engl. is an African medicinal plant used in Cameroonian traditional medicine to treat various types of cancers.

Aim Of The Study: This work was designed to determine the cytotoxicity of the crude extract (FTB), fractions (FTBa-d) and compounds isolated from the bark of Fagara tessmannii, namely lupeol (1), fagaramide (2), zanthoxyline (3), hesperidin (4), nitidine chloride (5), fagaridine chloride (6), and β-sitosterol-3-O-β--glucopyranoside (7).

Furoquinolines and dihydrooxazole alkaloids with cytotoxic activity from the stem bark of Araliopsis soyauxii.

Two new furoquinoline alkaloids, maculine B (1) and kokusaginine B (2) and one new dihydrooxazole alkaloid, veprisazole (3), along with four known compounds namely, N-methyl-3-methoxyrutaecarpine (4), flindersiamine (5), skimmianine (6) and tilianin (7) were isolated from the methanol extract of the stem bark of Araliopsis soyauxii Engl. by various chromatographic methods. Their structures were determined using spectrometry and spectroscopic techniques including NMR and MS.

Cardenolides and dihydro-β-agarofuran sesquiterpenes from the seeds of Salacia staudtiana.

Phytochemical studies of the seeds of the Cameroonian medicinal plant, Salacia staudtiana, resulted in the isolation and identification of five new cardenolides (1-5) as well as a new dihydro-β-agarofuran (9), along with eight known compounds. The structures of all compounds were elucidated by 1D/2D NMR, ESI-HRMS data and comparison with literature data. The relative configurations of the new compounds were defined by X-ray crystallography analysis, NOESY correlations and coupling constants.

A new alkylbenzoquinone from Gilg. (Myrsinaceae).

A new alkylbenzoquinone named embeliquinone () together with five known compounds, lupeol (), 3--[6'--palmitoyl--d-glucosyl]-spinasta-7,22(23)-diene (), quercetin (), (2,3,4,8)-2-[(2')-2'-hydroxy-heneicosanoylamino]-heneicosane-1,3,4-triol-8-ene (), and -sitosterol-3---d-glucopyranoside () were isolated from the MeOH leaf extract of by using repeated open column chromatography techniques. The structure of the new compound was characterized by analyses of 1D- and 2D-NMR, and MS data. Embeliquinone () had moderate anti-cell proliferation activity against A549 cell line with the IC value of 21.

Antimicrobial and antioxidant activities of triterpenoid and phenolic derivatives from two Cameroonian Melastomataceae plants: Dissotis senegambiensis and Amphiblemma monticola.

Background: Antimicrobial resistance is a serious threat against humankind and the search for new therapeutics is needed. This study aims to investigate the antimicrobial and antioxidant activities of ethanol extracts and compounds isolated from Dissotis senegambiensis and Amphiblemma monticola, two Cameroonian Melastomataceae species traditionally used for the treatment of fever, malaria and infectious diseases.

Methods: The plant extracts were prepared by maceration in ethanol.

A naturally occuring triterpene saponin ardisiacrispin B displayed cytotoxic effects in multi-factorial drug resistant cancer cells via ferroptotic and apoptotic cell death.

Introduction: Multidrug resistance of cancer cells constitutes a serious problem in chemotherapy and a challenging issue in the discovery of new cytotoxic drugs. Many saponins are known to display anti-cancer effects. In this study, the cytotoxicity and the modes of action of a naturally occuring oleanane-type tritepene saponin, ardisiacrispin B isolated from the fruit of Ardisia kivuensis Taton (Myrsinaceae) was evaluated on a panel of 9 cancer cell lines including various sensitive and drug-resistant phenotypes.

Guttiferone BL with antibacterial activity from the fruits of .

genus, an endless source of bioactive compounds, was investigated for its antibacterial properties. The chemical study of the methanol extract from the fruits of resulted in the isolation of the undescribed guttiferone BL () along with the known kaempferol (), morelloflavone (), morelloflavone 7″---D-glucopyranoside (), -sitosterol 3---D-glucopyranoside and -sitosterol. Their structures were determined using spectrometry and spectroscopic techniques.

Cardenolides from the stem bark of Salacia staudtiana.

Seven new cardenolides, staudtianoside A-F (1-6) and staudtianogenin A (8), were isolated along with six known compounds from the stem bark of the Cameroonian medicinal plant Salacia staudtiana Loes. ex Fritsch. The structures were elucidated by means of ESI-HRMS and NMR spectroscopic methods and by comparison with literature data.