Adpressins A–G: Oligophenalenone Dimers from <i>Talaromyces adpressus</i>
Meijia Zheng, Qin Li, Hong Liao, Yongqi Li, Chenxi Zhou, Xinyi Zhao, Chunmei Chen, Weiguang Sun, Yonghui Zhang, Hucheng Zhu
Abstract
Nine new oligophenalenone dimers, adpressins A–G ( 1 – 9 ), together with nine known compounds ( 10 – 18 ), were isolated from the fungus Talaromyces adpressus . Their chemical structures were determined on the basis of spectroscopic and mass spectral analyses. Their relative and absolute configurations were identified by 1 H and 13 C NMR calculations followed by DP4+ analyses, electronic circular dichroism (ECD) calculations, and ECD spectra comparison with related compounds. Compound 1 is the first example of a duclauxin derivative featuring an unusual 6/6/6/5/6/6/6 ring system, while compounds 6 and 7 contained a novel pyrrolidine ring. Compounds 5, 9, and 18 exhibited moderate inhibition against LPS-induced B lymphocyte proliferation with IC 50 values ranging from 1.6 to 8.6 μ M. Additionally, compounds 9 and 18 exhibited moderate inhibition against Con A-induced T lymphocyte proliferation with IC 50 values of 9.3 and 2.6 μ M, respectively.