AUTHOR=Wei Pan-Pan , Ai Hong-Lian , Shi Bao-Bao , Ye Ke , Lv Xiao , Pan Xiao-Yan , Ma Xu-Jun , Xiao Dan , Li Zheng-Hui , Lei Xin-Xiang 

TITLE=Paecilins F–P, new dimeric chromanones isolated from the endophytic fungus Xylaria curta E10, and structural revision of paecilin A

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.922444

DOI=10.3389/fmicb.2022.922444

ISSN=1664-302X

ABSTRACT=<p>A total of eleven new dimeric chromanones, paecilins F-P (<bold>2</bold>–<bold>12</bold>), were isolated from the endophytic fungus <italic>Xylaria curta</italic> E10, along with four known analogs (<bold>1</bold>, <bold>13</bold>–<bold>15</bold>). Their structures and absolute configurations were determined by extensive experimental spectroscopic methods, single-crystal X-ray diffraction, and equivalent circulating density (ECD) calculations. In addition, the structure of paecilin A, which was reported to be a symmetric C8-C8′ dimeric pattern, was revised by analysis of the nuclear magnetic resonance (NMR) data, and single-crystal X-ray diffraction. Compound <bold>1</bold> showed antifungal activity against the human pathogenic fungus <italic>Candida albicans</italic> with a minimum inhibitory concentration of 16 μg/mL, and Compounds <bold>8</bold> and <bold>10</bold> showed antibacterial activity against the gram-negative bacterium <italic>Escherichia coli</italic> with the same minimum inhibitory concentration of 16 μg/mL.</p>