Candindoles A and B, heterozygous terphenyl-indole alkaloids with antifungal and cytotoxic activities 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 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 EC50 value of 19.21 ± 0.26 µM, while compounds 1 and 2 showed significant cytotoxicity towards human rhabdomyosarcoma cells A673 with IC50 values of 7.72 and 8.89 µM, respectively, comparable to the positive control cisplatin.