Chemical investigation of a peanut-associated fungal strain Aspergillus niger IMBC-NMTP01 resulted in isolation and identification of 14 secondary metabolites, including two new, epi-aspergillusol (1) and aspernigin (3), and 12 known compounds: pyrophen (2), 2-(hydroxyimino)-3-(4-hydroxyphenyl)propanoic acid (4), aspergillusol A (5), rubrofusarin B (6), nigerasperone A (7), fonsecin (8), TMC-256C1 (9), pyranonigrin A (10), orlandin (11), nigerasperone C (12), asperpyrone A (13), and 5-(hydroxymethyl)-2-furancarboxylic acid (14). Compounds 9, 12-14 showed cytotoxicity toward all six human cancer cell lines, including HepG2, KB, HL-60, MCF-7, SK-Mel2, and LNCaP, with IC₅₀ values ranging from 8.4 to 84.5 µM, compounds 3-5 were cytotoxic against five cancer cell lines except HepG2, whereas 1 exhibited cytotoxicity toward HepG2, KB, and MCF-7 cells. All of the compounds, except 2 and 13, inhibited NO overproduction in LPS-induced RAW264.7 cells. In addition, all of the compounds displayed antimicrobial effects against Enterococcus faecalis, whereas 13 compounds, except 10, significantly inhibited the growth of the yeast Candida albicans. Graphical Abstract

The roots of Polygala tenuifolia Wild (Polygalaceae), which is among the most important components of traditional Chinese herbal medicine, have been widely used for over 1000 years to treat a variety of diseases. In the current investigation of secondary metabolites with anti-inflammatory properties from Korean medicinal plants, a phytochemical constituent study led to the isolation of 15 compounds (1–15) from the roots of P. tenuifolia via a combination of chromatographic methods. Their structures were determined by means of spectroscopic data such as nuclear magnetic resonance (NMR), 1D- and 2D-NMR, and liquid chromatography-mass spectrometry (LC-MS). As the obtained results, the isolated compounds were divided into two groups—phenolic glycosides (1–9) and triterpenoid saponins (10–15). The anti-inflammatory effects of crude extracts, fractions, and isolated compounds were investigated on the production of the pro-inflammatory cytokines interleukin (IL)-12 p40, IL-6, and tumour necrosis factor-α in lipopolysaccharide-stimulated bone marrow-derived dendritic cells. The IC₅₀ values, ranging from 0.08 ± 0.01 to 21.05 ± 0.40 μM, indicated potent inhibitory effects of the isolated compounds on the production of all three pro-inflammatory cytokines. In particular, compounds 3–12, 14, and 15 showed promising anti-inflammatory activity. These results suggest that phenolic and triterpenoid saponins from P. tenuifolia may be excellent anti-inflammatory agents.