Guangxi Normal University

Nine previously undescribed phenylspirodrimane dimers, distachydrimanes G-O (1-6 and 8-10), along with one known analogue (7), were isolated from the fermentation culture of the coral-derived endophytic fungus Stachybotrys chartarum. Their structures were elucidated through comprehensive spectroscopic analyses, including NMR and HRESIMS, comparison of experimental and calculated ECD data, and single-crystal X-ray diffraction analysis. Compounds 1-6 comprise three isomeric pairs linked via a 6/7-membered oxygen heterocycle. Compounds 2, 4, and 6 possess the first-reported 22S,23R,23'R configuration, whereas compounds 1, 3, and 5 feature the rare 22R,23S,23'S configuration. Compound 10 represents the first C-18-C-23'-linked dimer with a furan-deficient monomer. Bioactivity assays demonstrated that compound 3 potently inhibited MSU-induced IL-1β secretion and pseudopodia formation in THP-1 cells. It attenuated oxidative stress by suppressing ROS generation, thereby blocking NF-κB p65 nuclear translocation and subsequent cascade of inflammatory responses, cellular senescence, and DNA damage. These findings highlight compound 3 as a promising lead for anti-gouty arthritis therapeutics.

Nanozymes have been widely applied in the field of biosensing due to their enzyme-like catalytic activity and unique properties of nanomaterials. The activity of nanozymes is a key factor influencing sensor performance including detection sensitivity and analysis time. Therefore, developing new strategies to effectively improve the catalytic performance of the nanozyme is highly anticipated. This study takes Co₃O₄ nanozyme as an example, using low-cost and enzyme-free ovalbumin (OVA) as the template, generates additional pore structures within metal-organic frameworks, thereby increasing surface area and accelerating mass transfer rates. Meanwhile, OVA serves as both the nitrogen and carbon sources to promote electron transfer and further regulate the activity of nanozyme. Based on the above strategies, a N/C-Co₃O₄ nanozyme with efficient oxidase-like activity was successfully synthesized and applied in colorimetric detection of magnesium ascorbyl phosphate. The developed sensing system exhibited linear response across concentrations ranging from 0.50 to 70 μM, with calculated detection limit of 0.36 μM. These results demonstrate an innovative approach for regulating nanozyme activity through the integration of multiple methodological strategies.

This study employed Raman spectroscopy combined with characteristic-peak-intensity-ratio analysis and a novel difference-spectral-statistical-mapping (DSSM) method to elucidate dynamic functional group transformations in flaxseed oil during various frying temperatures (100-185 °C) and repeated frying frequencies (1-5 times). The multiple linear regression models of I₉₆₉/I₁₂₆₆ with I₉₆₉/I₁₃₀₀ and I₉₆₉/I₁₄₄₁ exhibit high correlation coefficients (R²) between 0.93 and 0.94, suggesting that the changes in trans-CC are closely related to the variations in cis-CC and methylene (CH₂), which provides key insights for optimizing industrial detection models and fundamental oxidation kinetics research. DSSM identified hidden oxidation features, including epoxy groups and conjugated trienes, visualizing their evolution trends, offering critical spectroscopic evidence for assessing the quality degradation of frying oils. These methods provide theoretical support for real-time and rapid monitoring of the dynamic changes of functional groups in frying oil, taking a key step towards industrial level real-time monitoring of Raman spectroscopy technology.