posted on 2021-11-17, 15:12authored byXiao-Zhen Wu, Wen-Jun Huang, Wei Liu, Attila Mándi, Qingbo Zhang, Liping Zhang, Wenjun Zhang, Tibor Kurtán, Cheng-Shan Yuan, Changsheng Zhang
Penicisteckins A–D (1–4), two pairs of atropodiastereomeric
biaryl-type hetero- and homodimeric
bis-isochromans with 7,5′- and 7,7′-linkages and a pair
of atropodiastereomeric 2-(isochroman-5-yl)-1,4-benzoquinone derivatives
[penicisteckins E (5) and F (6)], were isolated
from the Penicillium steckii HNNU-5B18. Their structures
including the absolute configuration were determined by extensive
spectroscopic and single-crystal X-ray diffraction analysis and TDDFT-ECD
calculations. Both the bis-isochromans and the isochroman/1,4-benzoquinone
conjugates represent novel biaryl scaffolds containing both central
and axial chirality elements. The monomer anserinone B (8) exhibited potent antibacterial activities against Staphylococcus
aureus ATCC 29213 and methicillin-resistant Staphylococcus
aureus with minimal inhibition concentration values ranging
from 2 to 8 μg mL–1. Plausible biosynthetic
pathways of 1–6 are proposed, which
suggest how the absolute configurations of the isolates were established
during the biosynthetic scheme.