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A new saponin namely diosgeninoside (25  R -spirost-5-en-3- O -[ β - D -glucopyranosyl (1→2) - β - D -glucuronic acid]) and a new fatty acid betacic acid: ( Z )-8( S *),9( S *),10( R *)-trihydroxy-11-octadecenoic acid together with six known compounds: N - trans -coumaroyl tyramine, ergosta-7,22-dien - 3 β, 5 α,6β- triol, β -sitosterol, and β -sitosterol-3- O - β - D -glucopyranoside, L -threitol and soya-cerebroside I were isolated from the methanolic extract of Solanum betaceum . The structures were elucidated by interpretation of their 1D and 2D NMR spectra and spectrometric data. The methanolic extract, the EtOAc and n -BuOH fractions, and several isolated compounds were tested for antibacterial activity against four bacteria ( Staphylococcus aureus ; Staphylococcus epidermidis ; Escherichia coli ; and Pseudomonas aeruginosa ). The methanolic extract and the EtOAc fraction showed moderate activity against Staphylococcus aureus and Pseudomonas aeruginosa with MIC value of 128 µg/mL. Compound 1 showed moderate activity against Staphylococcus aureus with MIC value of 64 µg/mL.

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.

A new 3-arylcoumarin, 7-hydroxy-6-(1,1-dimethylallyl)-2',5'-dihydroxy-4'-(3,3dimethylprenyl)-3-arylcoumarin (desmoarylcoumarin) 1 , a previously unreported oleanane-type triterpenoid, 3 β ,22 β ,23-trihydroxyolean-12-en (episoyasapogenol B) 2 , together with five known flavonoids including darbergioidin ( 3 ), isoferreirin ( 4 ), quercetin ( 5 ), vitexin ( 6 ), swertizin ( 7 ), and one carbohydrate, sucrose ( 8 ) were isolated from the methanolic extract of the roots of Desmodium salicifolium . Their structures were elucidated mainly by extensive spectroscopic analysis (1D and 2D) and mass spectrometric (HRFAB-MS) data. The methanolic extract, EtOAc and n -BuOH fractions as well as some isolated compounds were assessed for their antibacterial and antioxidant activities. The EtOAc fraction exhibited moderate activity against Enterococcus faecalis with MIC value of 128 µg/mL. The methanolic extract and the EtOAc fraction displayed DPPH scavenging activity with EC 50 values of 5.99 and 2.06 μg/mL, respectively. Compound 1 showed a moderate antibacterial activity against Enterococcus faecalis with a MIC of 16 µg/mL. It also showed moderate DPPH scavenging activity.

Five unusual alkaloids featuring a pyrrolo[1,2-a]quinolone skeleton (pyrroloquinolones B-F, 1-5) were isolated from the ethanol extract of the whole plant of Vernonia glabra (Steetz) Vatke, along with sixteen known compounds. Their structures were established by means of spectroscopic (1D and 2D NMR, UV, IR, and ECD) and high resolution mass spectrometric techniques as well as by comparison of their spectroscopic data with those reported in the literature. The ethanol extract and some isolated compounds were assessed for their antibacterial activity against four bacterial strains. The extract was significantly active against Staphylococcus aureus ATCC1026 and S. epidermidis ATCC35984 (MIC = 64 μg/mL). All the tested compounds showed moderate activity against S. epidermidis (16 ≤ MIC ≤ 64 μg/mL). Furthermore, this is the first report on tricyclic pyrrolo[1,2-a]quinolone alkaloids from a plant source. A biosynthetic pathway for the formation of these compounds is also proposed., Competing Interests: Declaration of competing interest The authors declare that they have no competing interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)