Two new sphingolipids from the stem bark of Synsepalum msolo (Sapotaceae)

Synsepalum msolo commonly known as Bang Bali in Bali-Nguemba, Cameroon is used in traditional medicine against various diseases. The leaves and stem bark extracts were subjected to silica gel and Sephadex LH20 column chromatography to yield pure compounds. The structures of the compounds were determined by detail analysis of NMR and Mass spectroscopic data and by comparison with data reported in the literature. Amongst the isolates, were two new sphingolipids: synsepaloside B (1), synsepaloside C (2), and five known compounds: (+)-catechin (3), (−)-epicatechin (4), myricitrin (5), triacontanol (6), and aurantiamide acetate (7). Compounds 1–5 were screened for their antibacterial and anti-yeast activities on several microorganisms. All the tested compounds exhibited weak antibacterial (MIC ≥ 200 μg/mL) and anti-yeast (MIC > 200 μg/mL) activities as compared to standard: ciprofloxacin 0.468 0.234 μg/mL and fluconazole MIC = 0.05 μg/mL, respectively

Cytotoxic constituents from the fruit of <i>Solanum aculeastrum</i>

A new triterpene, aculeastrumone A (1), a new triterpene saponin aculeastrumoside A (2), and eleven known compounds (3–13) were isolated from MeOH/Water (80/20) extract of the fruits of Solanum aculeastrum (Solanaceae). Their structures were established by detailed 1D and 2D NMR spectroscopic studies and mass spectrometry. The isolated compounds were evaluated against three human cancer cells ((MCF-7 (breast cancer), NCI-H460 (lung cancer), and Hela (cervical cancer)) and normal human fibroblast (BJ) cell lines. Among them, saponins 2–5, 7–8, and Carpesterol 10 possess significant cytotoxic activity with IC50 ≤ 10 µM against the three cancer cell lines.</p

Antrocarines A-F, antiplasmodial ergostane steroids from the stem bark of Antrocaryon klaineanum.

During a study on the chemistry and biological activity of Antrocaryon klaineanum Pierre, six new sterols including 4,24(28)-ergostadiene-6alpha,7alpha-diol (1), 6alpha-methoxy-4,24(28)-ergostadiene-7alpha,20S-diol (2), 6alpha-methoxy-4,24(28)-ergostadien-7alpha-ol (3), 20S-hydroxy-24(28)-ergosten-3-one (4), 7alpha-hydroxy-4,24(28)-ergostadien-3-one (5), and 24(28)-ergostene-3beta,6alpha-diol (6) were characterized by physical and spectroscopic means. The known steroids 7 and 8 were also isolated. The crude extract and the isolated compounds were evaluated for their ability to inhibit the 3D7 strain of Plasmodium falciparum. Compounds 2, 3, and 8 showed potent activity while that of the crude extract was moderate

Quinones from Cordia species from 1972 to 2023: isolation, structural diversity and pharmacological activities

Abstract Plants of the genus Cordia (Boraginaceae family) are widely distributed in the tropical regions of America, Africa, and Asia. They are extensively used in folk medicine due to their rich medicinal properties. This review presents a comprehensive analysis of the isolation, structure, biogenesis, and biological properties of quinones from Cordia species reported from 1972 to 2023. Meroterpenoids were identified as the major quinones in most Cordia species and are reported as a chemotaxonomic markers of the Cordia. In addition to this property, quinones are reported to display a wider and broader spectrum of activities, are efficient scaffold in biological activity, compared to other classes of compounds reported in Cordia, hence our focus on the study of quinones reported from Cordia species. About 70 types of quinones have been isolated, while others have been identified by phytochemical screening or gas chromatography. Although the biosynthesis of quinones from Cordia species is not yet fully understood, previous reports suggest that they may be derived from geranyl pyrophosphate and an aromatic precursor unit, followed by oxidative cyclization of the allylic methyl group. Studies have demonstrated that quinones from this genus exhibit antifungal, larvicidal, antileishmanial, anti-inflammatory, antibiofilm, antimycobacterial, antioxidant, antimalarial, neuroinhibitory, and hemolytic activities. In addition, they have been shown to exhibit remarkable cytotoxic effects against several cancer cell lines which is likely related to their ability to inhibit electron transport as well as oxidative phosphorylation, and generate reactive oxygen species (ROS). Their biological activities indicate potential utility in the development of new drugs, especially as active components in drug-carrier systems, against a broad spectrum of pathogens and ailments. Graphical Abstrac

<i>In Vitro</i> and <i>In Silico</i> Evaluation of Anticholinesterase and Antidiabetic Effects of Furanolabdanes and Other Constituents from <i>Graptophyllum pictum</i> (Linn.) Griffith

Graptophyllum pictum 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., Hypopurin E, Hypopurin A and Hypopurin B, as well as with Lupeol, β-sitosterol 3-O-β-d-glucopyranoside, stigmasterol 3-O-β-d-glucopyranoside and a mixture of β-sitosterol and stigmasterol, were isolated from G. pictum, and their structures were deduced from ESI-TOF-MS, HR-ESI-TOF-MS, 1D and 2D NMR experiments. The compounds were evaluated for their anticholinesterase activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BchE), as well as their antidiabetic potential through inhibition of α-glucosidase and α-amylase. For AChE inhibition, no sample had IC50 within tested concentrations, though the most potent was Hypopurin A, which had a percentage inhibition of 40.18 ± 0.75%, compared to 85.91 ± 0.58% for galantamine, at 100 µg/mL. BChE was more susceptible to the leaves extract (IC50 = 58.21 ± 0.65 µg/mL), stem extract (IC50 = 67.05 ± 0.82 µg/mL), Hypopurin A (IC50 = 58.00 ± 0.90 µg/mL), Hypopurin B (IC50 = 67.05 ± 0.92 µg/mL) and Hypopurin E (IC50 = 86.90 ± 0.76 µg/mL). In the antidiabetic assay, the furanolabdane diterpenoids, lupeol and the extracts had moderate to good activities. Against α-glucosidase, lupeol, Hypopurin E, Hypopurin A and Hypopurin B had appreciable activities but the leaves (IC50 = 48.90 ± 0.17 µg/mL) and stem (IC50 = 45.61 ± 0.56 µg/mL) extracts were more active than the pure compounds. In the α-amylase assay, stem extract (IC50 = 64.47 ± 0.78 µg/mL), Hypopurin A (IC50 = 60.68 ± 0.55 µg/mL) and Hypopurin B (IC50 = 69.51 ± 1.30 µg/mL) had moderate activities compared to the standard acarbose (IC50 = 32.25 ± 0.36 µg/mL). Molecular docking was performed to determine the binding modes and free binding energies of Hypopurin E, Hypopurin A and Hypopurin B in relation to the enzymes and decipher the structure–activity relationship. The results indicated that G. pictum and its compounds could, in general, be used in the development of therapies for Alzheimer’s disease and diabetes

New triterpene saponins from the roots of <i>Acacia macrostachya</i> (Mimosaceae)

<p>Four new oleanane-type saponins, macrostachyaosides A, B, C, and D (<b>1</b>–<b>4</b>) were isolated from the roots of <i>Acacia macrostachya</i>. Their structures were elucidated on the basis of extensive 1D- and 2D-NMR data and HR-ESI-MS analyses. At concentrations of 100 μM of each compounds, none of the tested compounds caused a significant growth reduction against HL60 cells.</p> <p>Four new oleanane-type saponins were isolated from <i>Acacia macrostachya</i>. Their structures were elucidated using 1D and 2D NMR and HRESIMS.</p