The culinary medicinal mushroom Hericium erinaceus holds significant global esteem and has garnered heightened interest within increasingly ageing societies due to its pronounced neuroprotective and anti-neuroinflammatory properties. Within this study, two novel diterpenes, 16-carboxy-13-epi-neoverrucosane (1) and Erinacine L (2); three known xylosyl cyathane diterpenoids, Erinacine A (3), Erinacine C (4), and Erinacine F (5); and four lanostane-type triterpenoids, and three cyclic dipeptides (10–12), in addition to orcinol (13), were isolated from the rice-based cultivation medium of H. erinaceus. Their structures were determined by NMR, HR-ESI-MS, ECD, and calculated NMR. Compound 1 marks a pioneering discovery as the first verrucosane diterpene originating from basidiomycetes, amplifying the scope of fungal natural product chemistry, and the intricate stereochemistry of Compound 5 has been comprehensively assessed for the first time. Compounds 2–5 not only showed encouraging neurotrophic activity in rat adrenal pheochromocytoma PC-12 cells, but also significantly inhibited lipopolysaccharide (LPS)-induced nitric oxide (NO) production in BV2 microglia cell cultures with IC₅₀ values as low as 5.82 ± 0.18 μM. To elucidate the mechanistic underpinnings of these bioactivities, molecular docking simulation was used to analyze and support the interaction of 1 and 2 with inducible NO synthase (iNOS), respectively. In particular, compound 2, a cyathane-xyloside containing an unconventional hemiacetal moiety, is a compelling candidate for the prevention of neurodegenerative diseases. In summation, this investigation contributes substantively to the panorama of fungal diterpene structural diversity, concurrently furnishing additional empirical substantiation for the role of cyathane diterpenes in the amelioration of neurodegenerative afflictions.

A novel glucomannan, named ATSW-1, was obtained from Allii Tuberosi Semen by ion and gel permeation chromatography purification. Its structure was characterized using high-performance chromatography, Fourier transform infrared spectroscopy, gas chromatography-mass spectrometry, and nuclear magnetic resonance spectroscopy. The in vitro immune activities of ATSW-1 were examined using the Cell Counting Kit-8, the neutral red phagocytosis assay, and the secretion of related cytokines. The results showed that the molecular weight of ATSW-1 was 35.9 kDa and mainly constituted of mannose, glucose, and arabinose with a molar ratio of 1:0.72:0.04. Its main backbone was composed of →4)-β-D-Glcp-(1→, →4)-β-D-Manp-(1→, and →4,6)-α-D-Manp-(1→, with the branches β-D-Glcp-(1→, α-L-Araf-(1→ and →5)-α-L-Araf-(1→ linkage substituted at C-6 position of →4)-α-D-Manp-(1 → . ATSW-1 significantly enhanced immune responses, increasing the phagocytic activity of RAW264.7 cells by 1.52 times compared to the blank control group. Further investigations revealed that ATSW-1 promotes immune activity by upregulating the NO, TNF-α, and IL-6 secretion. These findings provide a foundation for the potential development and application of Allii Tuberosi Semen polysaccharides in functional foods or immune-related therapeutics.