Chienhainanins A-L, polyacetylenes from Chieniodendron hainanense and their antimicrobial activities

Twelve new C₂₁ polyacetylenes (1-12) together with five known analogues (13-17) featuring three structural classes, were isolated from the twigs and leaves of Chieniodendron hainanense. Their structures were elucidated by spectroscopic data analyses combined with electronic circular dichroism and optical rotation calculations. Antimicrobial activity evaluation revealed that compounds 7-12 exhibited significant antibacterial activity against Enterococcus faecalis and methicillin-resistant Staphylococcus aureus (MRSA), with MIC values ranging from 2 to 16 μg/mL. Additionally, compounds 7 and 11 displayed moderate antifungal activity against Crytococcus neoformans, with MICs of 64 and 32 μg/mL, respectively. RNA sequencing analysis indicates that compound 9 may disrupt ribosomal function and induce a stress response in MRSA.