Five new pyridone alkaloids Citridones H-L (1-5) along with one new natural product ent-Citridone A (6) were isolated from the marine-derived fungus Penicillium sp. XZD3-3, which came from the gut of a marine shrimp. The structures and absolute configurations of these compounds were elucidated on the basis of NMR, HRESIMS, UV, modified Mosher′s method, single-crystal X-ray diffraction, and ECD calculation. Compounds 1 and 3 contained unprecedented polycyclic systems of phenyl-pyranopyridone and phenyl-spiro[cyclopentene-furopyridone], respectively. Compound 2 showed moderate inhibition activity against nitric oxide production with IC₅₀ value of 52.5μM. All tested compounds were inactive in neither antibacterial nor cytotoxicity assays.

从海洋真菌Penicillium sp。中分离出5种新的吡啶酮生物碱Citridones HL（1-5）和一种新的天然产物ent- Citridone A（6）。XZD3-3，来自海虾的肠道。根据NMR，HRESIMS，UV，改进的Mosher方法，单晶X射线衍射和ECD计算，阐明了这些化合物的结构和绝对构型。化合物1和3分别包含空前的苯基-吡喃并吡啶酮和苯基-螺环[环戊烯-呋喃啶酮]多环系统。化合物2表现出对一氧化氮产生的中等抑制活性，IC ₅₀值为52.5μM。所有测试的化合物在抗菌和细胞毒性试验中均无活性。