Azaphilones and p-Terphenyls from the Mangrove Endophytic Fungus Penicillium chermesinum (ZH4-E2) Isolated from the South China Sea

Eight secondary metabolites, including three new azaphilones (chermesinones A–C, 1–3), three new p-terphenyls (6′-O-desmethylterphenyllin, 4; 3-hydroxy-6′-O-desmethylterphenyllin, 5; 3′′-deoxy-6′-O-desmethylcandidusin B, 7), and two known p-terphenyls (6, 8), were isolated from the culture of the mangrove endophytic fungus Penicillium chermesinum (ZH4-E2). Their structures were established by spectroscopic analysis. The absolute configuration of 1 was determined by X-ray crystallography. Terphenyls 4, 5, and 6 exhibited strong inhibitory effects against α-glucosidase with IC50 values of 0.9, 4.9, and 2.5 μM, respectively. Terphenyls 7 and 8 showed inhibitory activity toward acetylcholinesterase with IC50 values of 7.8 and 5.2 μM.

自红树林内生真菌Penicillium chermesinum (ZH4-E2)的培养物中分离得到八种次生代谢产物，其中包括三种新型氮杂菲酮类化合物（chermesinones A-C, 1-3），三种新型对苯三酚（6'-O-去甲基对苯三酚林，4；3-羟基-6'-O-去甲基对苯三酚林，5；3''-去氧-6'-O-去甲基candidusin B，7），以及两种已知对苯三酚（6，8）。通过光谱分析确定了其结构。化合物1的绝对构型通过X射线晶体学测定。对苯三酚4、5和6对α-葡萄糖苷酶表现出显著的抑制作用，其IC50值分别为0.9、4.9和2.5 μM。对苯三酚7和8对乙酰胆碱酯酶也显示出抑制作用，其IC50值分别为7.8和5.2 μM。