Identification of Antibacterial Sterols from Korean Wild Mushroom Daedaleopsis confragosa via Bioactivity- and LC-MS/MS Profile-Guided Fractionation

Deodeokaloid, a New Indole Alkaloid N-Glycoside and Bioactive Phenolic Compounds from the Roots of Codonopsis lanceolata

Codonopsis lanceolata, commonly known as the bonnet bellflower or deodeok, is primarily found in Eastern Asia. Its roots have been used traditionally across Asia to treat various ailments such as bronchitis, coughs, asthma, and inflammation. In our ongoing efforts to discover bioactive natural products, a phytochemical investigation of the n-BuOH fraction of C. lanceolata root extracts led to the isolation and identification of a new indole alkaloid N-glycoside, deodeokaloid (D-indole-3-lactic acid N-β-D-glucopyranoside) (1), alongside known compounds tangshenoside I (2), tangshenoside IV (3), and chlorogenic acid (4) through HPLC purification. The structure of the new compound 1 was elucidated using 1D and 2D NMR spectroscopy and high-resolution electrospray ionization mass spectrometry (HR-ESIMS). Its absolute configuration was determined through a combination of DP4+ probability analysis and chemical reactions. The isolated compounds 1-4 were evaluated for their anti-Helicobacter pylori and antioxidant activities. In the anti-H. pylori assay, compound 3 showed antibacterial activity similar to that of quercetin as the positive control, inhibiting the bacterial growth by 36.8%. Compound 4 exhibited the most potent antioxidant activity, with an ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate)] radical scavenging activity of 1624.7 mmol TE/mol and a DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging capacity of 707.5 mmol Trolox equivalent (TE)/mol. Compounds 2-4 displayed significant intracellular reactive oxygen species (ROS) scavenging capacity in lipopolysaccharide-stimulated RAW 264.7 macrophage cells. This study highlights C. lanceolata roots as a promising natural source of bioactive compounds with potential therapeutic applications.

Antioxidant, neuroprotective, and neuroblastoma cells (SH-SY5Y) differentiation effects of melanins and arginine-modified melanins from Daedaleopsis tricolor and Fomes fomentarius

BACKGROUND

Microbial melanins possess a broad spectrum of biological activities. However, there is little understanding of their neuroprotective and neuronal cell differentiation properties. This study aimed to extract, purify, and modify melanins from two medicinal fungi (Daedaleopsis tricolor and Fomes fomentarius), and to evaluate their antioxidant activity, as well as their cell protective ability against neurotoxins. In addition, the study also investigated the feasibility of combining melanins or modified melanins with retinoic acid (RA) to induce neuronal differentiation.

METHODS

Melanin was extracted and purified using alkaline acid-based methods. Antioxidant activities and neuroprotective effects were evaluated using the DPPH (1,1-diphenyl-2-picrylhydrazyl) and MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assays, respectively. In addition, morphological changes of SH-SY5Y cells were recorded by using a Pannoramic MIDI scanner.

RESULTS

All melanins and arginine-modified melanins displayed mild DPPH scavenging activities, which were statistically lower than that of ascorbic acid (p < 0.05). In terms of neuroprotection, both melanins and arginine-modified melanins exhibited significant cell protection against H2O2 after 24 h exposure (p < 0.05). Notably, there is no significant difference between F. fomentarius melanin and its modified form as they both increased cell viability by about 20%. Contrarily, while D. tricolor melanin enhanced the cell viability with 16%, its modified form increased the cell viability with 21%. These activities, however, are significantly lower than the positive control (N-acetylcysteine, p < 0.05). Regarding MPTP, only the arginine-modified melanins of the two fungi significantly protected the cells after 24 h exposure to the toxin (p < 0.05). Specifically, F. fomentarius and D. tricolor modified melanins enhanced the cell viability with 10.2% and 11.1%, respectively, whereas that of the positive control was 13.2%. Interestingly, combining RA (10 µM) with 20 µg/mL of either F. fomentarius, or especially D. tricolor arginine-modified melanin, significantly promoted neuroblastoma cell differentiation into mature neuronal cells compared to using RA alone (p < 0.05).

CONCLUSIONS

The arginine-modified melanins of D. tricolor and F. fomentarius have potential for neuroprotection against Parkinsonian neurotoxins. In addition, the arginine-modified melanin of D. tricolor may serve as an excellent material for research in neuroblastoma treatment.

Metabolomic profiling reveals biomarkers for diverse flesh colors in jelly fungi (Auricularia cornea)

Auricularia cornea has garnered attention due to its nutrition, culinary applications, and promising commercial prospects. However, there is little information available regarding the metabolic profiling of various colors strains. In this study, 642 metabolites across 64 classes were identified by LC-MS/MS to understand the metabolic variations between white, pink and dark brown strains. Notably, prenol lipids, carboxylic acids and fatty acyls accounted for 46.8 % of the total. Comparative analysis revealed 17 shared differential metabolites (DMs) among them. ACP vs ACW exhibited 17 unique metabolites, including d-arginine and maleic acid, etc. ACP vs ACB showed 5 unique metabolites, with only PS(18:1(9Z)/0:0) demonstrating up-regulation. ACB vs ACW showed 8 unique metabolites, including 4-hydroxymandelic acid and 5'-methylthioadenosine, etc. KEGG enrichment analysis highlighted pathway variations, and MetPA analysis identified key-pathways influencing DMs accumulation in A. cornea. This pioneering metabolomics study offers insights into A. cornea metabolic profiling, potential applications, and guides further research.

Bioactivity Profiling of Daedaleopsis confragosa (Bolton) J. Schröt. 1888: Implications for Its Possible Application in Enhancing Women's Reproductive Health

This study investigates the bioactivity profile of wood-rotting fungal species Daedaleopsis confragosa (Bolton) J. Schröt. 1888, focusing on its antioxidant, cytotoxic, and genotoxic activities and enzyme modulation properties with respect to its possible application in terms of enhancing women's reproductive health. Two types of extracts, including those based on EtOH extraction (DC) and hydrodistillation (DCHD), were investigated. The results indicate that the radical scavenging capacity against the DPPH radical and reduction potential were stronger in the DC extracts owing to the higher total phenolic content (TPC) and total flavonoid content (TFC) (25.30 ± 1.05 mg GAE/g d.w. and 2.84 ± 0.85 mg QE/g d.w., respectively). The same trend was observed in the protein phosphatase-1 (PP1) activity and in the genotoxic activity against the δ virus since only the DC extract exhibited DNA disintegration regarding a dilution of 1:100. Conversely, the DCHD extract exhibited increased hemolytic and cytotoxic effects (339.39% and IC50 = 27.76 ± 0.89 μg/mL-72 h incubation, respectively), along with greater inhibition of the AChE enzyme (IC50 = 3.11 ± 0.45 mg/mL) and hemolytic activity. These results suggest that terpenoids and steroids may be responsible for the observed activity in DCHD as these compounds could potentially be extracted following the HD procedure. This comprehensive bioactivity profiling offers valuable insights into the potential therapeutic applications of D. confragosa from Serbia and underscores the importance of further investigations for harnessing its pharmacological potential.

An Investigation of Quorum Sensing Inhibitors against Bacillus cereus in The Endophytic Fungus Pithomyces sacchari of the Laurencia sp

Bacillus cereus, a common food-borne pathogen, forms biofilms and generates virulence factors through a quorum sensing (QS) mechanism. In this study, six compounds (dankasterone A, demethylincisterol A3, zinnimidine, cyclo-(L-Val-L-Pro), cyclo-(L-Ile-L-Pro), and cyclo-(L-Leu-L-Pro)) were isolated from the endophytic fungus Pithomyces sacchari of the Laurencia sp. in the South China Sea. Among them, demethylincisterol A3, a sterol derivative, exhibited strong QS inhibitory activity against B. cereus. The QS inhibitory activity of demethylincisterol A3 was evaluated through experiments. The minimum inhibitory concentration (MIC) of demethylincisterol A3 against B. cereus was 6.25 μg/mL. At sub-MIC concentrations, it significantly decreased biofilm formation, hindered mobility, and diminished the production of protease and hemolysin activity. Moreover, RT-qPCR results demonstrated that demethylincisterol A3 markedly inhibited the expression of QS-related genes (plcR and papR) in B. cereus. The exposure to demethylincisterol A3 resulted in the downregulation of genes (comER, tasA, rpoN, sinR, codY, nheA, hblD, and cytK) associated with biofilm formation, mobility, and virulence factors. Hence, demethylincisterol A3 is a potentially effective compound in the pipeline of innovative antimicrobial therapies.