Page 167 - 2025中醫藥與天然藥物聯合學術研討會-中醫藥與天然藥物的挑戰Ｘ機遇與未來大會手冊

PC-49

Discovery and characterization of N-substituted azaphilones from the

algicolous fungus Penicillium sclerotiorum

#,1
2
1
Tzu-Yi Ke, Shih-Wei Wang, Tsong-Long Hwang, Govindarajan Ganesan, Yuan-Bin
3
,1
Cheng*

1 Department of Marine Biotechnology and Resources, National Sun Yat-sen University,
Kaohsiung 80424, Taiwan
2 Institute of Biomedical Sciences, MacKay Medical College, New Taipei City 25245,
Taiwan
3 Graduate Institute of Health Industry Technology and Research Center for Chinese Herbal
Medicine, College of Human Ecology, Chang Gung University of Science and Technology,
Taoyuan 333324, Taiwan
* E-mail: jmb@mail.nsysu.edu.tw

Abstract
The secondary metabolites of the algicolous fungus P. sclerotiorum were analyzed using
genomic and metabolomic approaches. After meticulous separation, two novel polyketide
derivatives 1–2, five new azaphilone analogues 3–7, and 11 new N-substituted azaphilones 8–
18, along with 22 known azaphilone derivatives, were identified. Structural elucidation of these
compounds was performed using ECD, HR-ESI-MS, and NMR spectroscopy. Furthermore, the
absolute configurations of compounds 1, 2, and 10 were determined by X-ray single-crystal
diffraction. Structurally, compounds 1 and 2 represent novel polyketide derivatives, while
compound 10 is a unique N-substituted azaphilone characterized by the presence of a medium-
chain fatty acid. Additionally, a plausible biosynthetic pathway for the new compounds 1–9 was
proposed based on analysis of the Azp gene cluster. The biosynthesis of azaphilones is initiated
by the action of AzpA, AzpB1, and AzpB2, which catalyze the formation of the initial precursor
moiety. This intermediate subsequently undergoes hydroxylation and chlorination, followed by
cyclization and dehydration, resulting in the formation of the characteristic azaphilone core
structure. Further structural diversification is accomplished through a series of enzymatic
modifications, including oxidation, reduction, methylation, and acetylation. The anti-
lymphangiogenic potential of selected compounds was evaluated in vitro using human
lymphatic endothelial cells (LECs). In particular, nitrogenated azaphilones 9 and 22 exhibited
significant inhibitory activity, with IC50 values of 5.8 ± 0.2 and 5.7 ± 0.2 μg/mL, respectively.
The medium-chain fatty acid-substituted azaphilones 10, 11, and 14‒16 were assessed for their
in vitro anti-inflammatory activities. The results showed that compound 10 significantly
inhibited elastase release in human neutrophils, with an IC50 value of 2.16 ± 0.44 μg/mL.

Keywords: Penicillium sclerotiorum; Azaphilones; Anti-lymphangiogenesis activity; Anti-
inflammatory activity