article · Applied Biological Chemistry
Phytochemical analysis of Erythrina caffra leaf extracts led to the isolation of four compounds, including a novel sterol glycoside and lutein, alongside the identification of 22 secondary metabolites using liquid chromatography tandem mass spectrometry. Biological evaluations focused on cytotoxicity, antioxidant capacity, and viral enzyme inhibition. Cytotoxicity tests against human skin and kidney cell lines demonstrated that lutein noticeably reduced cell viability and density, whereas the crude leaf extract and ethyl acetate fraction showed no notable cytotoxic impact. In antioxidant assays, the methanol fraction showed the highest peroxyl-radical scavenging activity, with all isolated compounds also exhibiting significant antioxidant capacity. Furthermore, testing against the SARS-CoV-2 papain-like protease revealed weak to moderate inhibitory potential across extracts, with only the methanol fraction showing limited activity. These findings outline the chemical profile and baseline bioactivities of the plant material.
Exploring the chemical constituents of medicinal plants provides a foundation for identifying natural antioxidants and bioactive molecules. By profiling the secondary metabolites of Erythrina caffra and assessing their cytotoxicity and enzymatic activities, this research clarifies the plant's safety profile and baseline biological effects, supporting the search for natural compounds that combat oxidative stress or target specific cellular mechanisms.
This study represents early-stage laboratory research into the chemical components and bioactivities of Erythrina caffra leaves. The identified antioxidant capacity and cytotoxicity profiles may interest natural product chemists and pharmaceutical or cosmetic developers looking for plant-derived leads. However, because the viral inhibition was weak and active antioxidant constituents require further isolation and characterisation, practical applications remain distant from real-world use and will require substantial downstream testing.
AI-generated from the published abstract. Always read the original work before citing.
From the crude ethanol extract of Erythrina caffra leaves, a new compound, stigmasta-5,22-diene 3-O-(6’-tridecanoate)-β-D-glucopyranoside (1), along with stigmasta-5,22-diene (2), lutein (3), and triacontanol (4), was isolated. Their structures were elucidated using spectroscopic (1D and 2D NMR) and spectrometric [High-Resolution Electrospray Ionization Mass Spectrometry, (HRESIMS)] analyses. RP-LC-MS/MS profiling of the ethyl acetate and methanol fractions further identified 22 secondary metabolites, whose proposed structures were consistent with reported fragmentation patterns and literature data. The cytotoxic effects of the crude extract, fractions, and isolated compounds were evaluated on human keratinocytes (HaCaT), melanocytes (NHEM-Ad), and embryonic kidney cells (HEK293) via resazurin and crystal violet assays. Lutein (3) at 100 µg/mL significantly reduced cell viability to 39.19 ± 9.27%, 61.39 ± 3.26%, and 71.29 ± 7.82%, and cell density to 24.35 ± 4.29%, 35.96 ± 1.44%, and 39.16 ± 6.17%, respectively, for HaCaT, NHEM-Ad, and HEK293. In contrast, the crude extract and ethyl acetate fraction did not notably affect cell viability. Antioxidant evaluation revealed that the methanol fraction possessed the strongest activity (5.52 ± 0.14 µmol TE/mg) in the ORAC assay, while all isolated compounds and the crude extract exhibited significant peroxyl-radical scavenging activity. Plant-derived extracts and compounds showed weak to moderate inhibition of SARS-CoV-2 PLpro, with only the methanolic fraction exhibiting limited activity (IC₅₀<100 µg/mL), significantly lower than the reference inhibitor. Overall, these findings highlight the phytochemical diversity and biological potential of E. caffra leaves, emphasizing their antioxidant capacity and selective cytotoxicity. Future work should isolate and characterize the bioactive constituents responsible for the observed antioxidant effects. Graphical abstract
This page summarises published work. The authoritative version sits with the publisher.
DOI: 10.1186/s13765-026-01126-w
Is something wrong with this record? Report it or request removal.
Discussion
Have you built on this work, tried to replicate it, or seen it applied in practice? Share what you know. Verified researchers and MARATTO™ domain experts can open a discussion, and any member can reply. Contributions are reviewed before they appear.
No discussion yet. Open the first thread.
New to MARATTO™? Create a free account.
