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Four previously unreported triterpenoid saponins named 3β-hydroxy-23-oxours-12-en-28-oic acid 28- O -β- D -glucopyranosyl ester (mannioside G) ( 1 ), 23- O -acetyl-3β-hydroxyurs-12-en-28-oic acid 28- O -β- D -glucopyranosyl ester (mannioside H) ( 2 ), ursolic acid 28- O -[α- L -rhamnopyranosyl-(1→4)-β- D -glucopyranosyl-(1→6)-β- D -glucopyranosyl] ester (mannioside I) ( 3 ), and 3β-hydroxy-23-oxolup-20(29)-en-28-oic acid 28- O -β- D -glucopyranosyl ester (mannioside J) ( 4 ) were isolated as minor constituents from the EtOAc soluble fraction of the MeOH extract of the leaves of Schefflera mannii along with the known compounds 23-hydroxyursolic acid 28- O -β- D -glucopyranosyl ester ( 5 ), ursolic acid 28- O -β- D -glucopyranosyl ester ( 6 ), pulsatimmoside B ( 7 ) betulinic acid 28- O -[α- L -rhamnopyranosyl-(1→4)-β- D -glucopyranosyl-(1→6)-β- D -glucopyranosyl] ester ( 8 ), 23-hydroxy-3-oxo-urs-12-en-28-oic acid ( 9 ), hederagenin ( 10 ), ursolic acid ( 11 ), betulinic acid ( 12 ), and lupeol ( 13 ). Their structures were elucidated by a combination of 1D and 2D NMR analysis and mass spectrometry. The MeOH extract, the EtOAc and n -BuOH fractions, and some of the isolated compounds were evaluated for their antibacterial activity against four bacteria: Staphylococcus aureus ATCC1026, Staphylococcus epidermidis ATCC 35984, Escherichia coli ATCC10536, and Klepsiella pnemoniae ATCC13882. They were also screened for their antioxidant properties, but no significant results were obtained.

Microbial infections are leading causes of death and morbidity all over the world due to the development of the resistance to antibiotics by certain microorganisms. In this study, the chemical exploration of the ethanol (EtOH) extract of the aerial part of Dracaena stedneuri (Dracaenaceae) led to the isolation of one previously unreported chalcone derivative, i.e., 2',4'-dihydroxy-2,3'-dimethoxychalcone ( 1 ), together with 12 known compounds: 8-( C )-methylquercetagetin-3,6,3'-trimethyl ether ( 2 ), methylgalangine ( 3 ), quercetin ( 4 ), kaempferol ( 5 ), 6,8-dimethylchrysin ( 6 ), ombuine-3- O -rutinoside (4',7-dimethylquercetin-3- O - α -L-rhamnopyranosyl-(1 → 6) - β -D-glucopyranoside) ( 7 ), alliospiroside A ( 8 ), β -sitosterol 3- O -glucopyranoside ( 9 ), ishigoside ( 10 ), betulinic acid ( 11 ), oleanolic acid ( 12 ), and lupeol ( 13 ). The structures were determined by spectroscopic and spectrometric analysis including 1- and 2-Dimensional Nuclear Magnetic Resonance (1D- and 2D-NMR), High-Resolution Electrospray Ionization Mass Spectrometry (HRESIMS), and comparison with literature data. The isolated secondary metabolites and crude extract displayed antibacterial activity against some multidrug-resistant strains with minimal inhibitory concentration (MIC) values ranging from 32 to 256 μg/mL. The antibacterial activity of compound 13 against Enterobacter aerogenes ATCC13048 (MIC value: 32 μg/mL) was higher than that of chloramphenicol used as the reference drug (MIC = 64 μg/mL).

Aim: To identify the bioactive hepatoprotective components of the ethanol extract of Pentaclethra macrophylla stem bark using in vitro and in vivo approaches., Methods: The bioguided-fractionation of the ethanol extract was based on the substances' capacity to prevent in vitro, the lipid peroxidation of hepatocytes' membranes induced by hydrogen peroxide. For the in vivo hepatoprotective test, mice were treated orally with the ethyl acetate (EtOAc) fraction of the ethanol extract at doses of 50 and 75 mg/kg/day for one week and subjected to d-galactosamine/lipopolysaccharide (GaIN/LPS)-induced hepatotoxicity. Blood samples were collected for alanine aminotransferase (ALAT), aspartate aminotransferase (ASAT), TNF-α and IL-1β assays. The liver was harvested for histological and biochemical (proteins, glutathione (GSH), catalase and superoxide dismutase (SOD)) analysis., Results: The ethanol extract and fractions induced concentration-dependent inhibition of lipid peroxidation (IC 50 : 3.21-48.90 μg/mL) greater than that of silymarin (IC 50 : 117.4 μg/mL). The purification of the sub-fractions of EtOAc fraction yielded: (7R)-7-hydroxyhexacosanoic acid (1), (7R)-1-(7-hydroxyhexacosanoyl) glycerol (2), bergenin (3), 11-O-galloylbergenin (4), 2-hydroxymethyl-5-(2-hydroxypropan-2-yl)phenol (5), β-sitosterol 3-O-β-d-glucopyranosyl (6) and β-sitosterol (7)), among which 11-O-galloylbergenin (IC 50 :1.8 μg/mL) was the most effective. The EtOAc fraction significantly reduced the serum level of ALAT, ASAT and TNF-α in vivo. This EtOAc fraction increased the liver protein content and protected the liver against structural damages, but did not boost the endogenous antioxidant parameters., Conclusion: The stem bark of Pentaclethra macrophylla possesses hepatoprotective effects that may result from its capacity to inhibit lipid peroxidation and could be attributed to its active components 3, 4 and 2., (Copyright © 2021. Published by Elsevier Masson SAS.)