Toxicity, Antibacterial, and Phytochemical Analyses of Antrocaryon klaineanum Pierre Extracts.

Medicinal plants are traditionally used in Gabon to treat several types of illnesses. The study's purpose was to determine the toxic, antibacterial, and anti-inflammatory effects of Antrocaryon klaineanum Pierre extracts and to characterize their phytochemical compounds. Toxicity was evaluated on frog tadpoles (Phrynobatrachus africanus Hallowell). The microorganism susceptibility test was performed by the diffusion method, while minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated using the microdilution technique. Anti-inflammatory activity was tested through protein denaturation and membrane stabilization methods. Chromatography and molecular network techniques were used to characterize chemical compounds. The lethality test showed that the lethal concentration (LC50) increased from 110.03 ± 1.25 to 15.86 ± 2.21 µg/mL after 24 and 96 hours of exposure. In tadpoles exposed to 7.81 µg/mL extract, the first mortalities (12.5%) were observed on the fifth day of exposure. A relative decrease in mature erythrocytes exposed to plant extracts was observed. The antibacterial activity shows that the Ak F2, Ak F3, and Ak F4 fractions (from the water-ethanol crude extract) gave the greatest antibacterial activities compared to the other extracts. The water, water-acetone, and water-ethanol extracts showed good inhibition of denaturation. The haemolysis test shows that the extracts exhibited good anti-inflammatory activities. Phytochemical characterisation revealed four major compounds, including monogallate epicatechin and hydroxy-ergostadian. The molecular network revealed five main clusters. Our study shows that A. klaineanum Pierre could be a promising natural product for the isolation of molecules with potential biological activities.

Structure elucidation of a new lanostane triterpene from Gabonese Ganoderma orbiforme fruiting bodies.

The structure and complete nuclear magnetic resonance (NMR) assignments of orbifomitellic acid, a novel lanostane triterpene isolated from the fruiting bodies of a Gabonese Ganoderma orbiforme (Polyporaceae), are reported. Within the vast catalogue of lanostanes documented from Ganoderma spp., orbifomitellic acid is the first disclosing a -COOH group at C-4.

A Study of the Therapeutic Potential of Lentinus squarrosulus (Agaricomycetes) from Gabon.

Lentinus squarrosulus is a mushroom widely used in Gabon for its culinary and medicinal properties. The bioactive potential of mushrooms might be attributable to the presence of several pharmaceutically important mycocompounds that need to be ascertained scientifically. A study of the therapeutic potential of L. squarrosulus, the species of lignicolous fungus exploited in Gabon, was carried out on the basis of a chemical screening performed on three extracts in order to highlight different important chemical groups. This chemical screening was followed by a study of the fungus's antioxidant activity and prediction of its additional pharmacological activities. Chemical screening revealed that three extracts (aqueous, hydroethanolic, and ethanolic) of L. squarrosulus were almost free of tannins and were poor in total flavonoids and moderately rich in reducing sugars. Aqueous and ethanolic extracts were rich in total polyphenols, whereas aqueous and hydroethanolic extracts were rich in alkaloids. The aqueous extract was rich in saponosides and the hydroethanolic extract was rich in coumarins. The dosage of phenolic compounds confirmed the fungus's richness in total polyphenols, especially for aqueous and ethanolic extracts, its poverty in flavonoids and absence of tannins in ethanolic and hydroethanolic extracts. Regarding antioxidant activities, the results obtained for diphenyl picryl hydrazyl trapping tests showed that the different extracts tested had antioxidant activity ranging from low to moderate (0.12 ≤ antioxidant activity index [IAA] ≤ 0.6); the greatest activity was obtained with ethanolic extract (IAA = 0.6). Hence, we conclude that L. squarrosulus extracts can be used as easily accessible sources of natural antioxidants for potential preventative therapies.