Diverse Ring-seco Limonoids from Munronia unifoliolata and Their Biological Activities

Comprehensive Summary Twenty-two new limonoids, mufolinoids A-V (1-22), including six rings A, B-seco limonoids (1-6), twelve ring A-seco limonoids (7-18), four ring-intact limonoids (19-22), together with thirteen known compounds (23-35) were isolated from Munronia unifoliolata. Their structures including absolute configurations were elucidated by combination of NMR, HR-MS, single-crystal X-ray diffraction and calculations of ECD and NMR technologies. Compounds 24, 25, 33, 34 could be significantly reversed the multidrug resistance of MCF-7/doxorubicin (DOX) cells, and the reversal fold (RF) was much higher than that of positive drug Verapamil. Compounds 24, 28, and 29 exhibited significant anti-inflammatory activity with the IC50 values in the range of 17.7-39.4 mu mol/L. Furthermore, compound 29 could markedly inhibit the release of IL-1 beta by inhibiting the initiation and assembly of NLRP3 inflammasome, which demonstrates the great potential of limonoids as an anti-inflammatory agent.

Automated summary

Twenty-two new limonoids were isolated from Munronia unifoliolata, with compounds 24, 25, 33, and 34 showing significant reversal of multidrug resistance and compounds 24, 28, and 29 exhibiting strong anti-inflammatory activity. Compound 29 was particularly effective in inhibiting IL-1 beta release by inhibiting the NLRP3 inflammasome, highlighting the potential of limonoids as anti-inflammatory agents.