Yiyi Liu, Haixin Chen, Guang‐Ying Chen, Xu‐Hua Nong, Zhuang Han
Three previously undescribed indole alkaloids, candindoles A–C ( 1 – 3 ), along with five known analogues ( 4 – 8 ), were isolated from the marine-derived fungus Aspergillus candidus HNNU0546. Structurally, 1 and 2 represent the first terphenyl-indole piperazine alkaloid hybrids featuring unprecedented backbones. Their structures including absolute configurations were elucidated by extensive spectroscopic methods, DP4+ probability analysis, and electronic circular dichroism (ECD) calculations. A plausible biosynthetic pathway for 1 is proposed. Compound 1 exhibited moderate growth-inhibitory activity against the plant pathogenic fungus of Alternaria sp. with an EC 50 value of 19.21 ± 0.26 μM, while compounds 1 and 2 showed significant cytotoxicity toward human rhabdomyosarcoma cells A673 with IC 50 values of 7.72 and 8.89 μM, respectively, comparable to the positive control cisplatin.