Isolation and difference in anti-Staphylococcus aureus bioactivity of curvularin derivates from fungus Eupenicillium sp.
With the anti-microbial and anti-tumor composite screening model, bioassay-guided fractionation led to the isolation of two structurally related bioactive compounds, curvularin and alphabeta-dehydrocurvularin, from ethyl acetate extract of Eupenicillium sp. associated with marine sponge Axinella sp. Further study on the structure-activity relationship demonstrated that both compounds exhibited differences in bioactive profiles which are highly associated with their minor structural differences. Both curvularin and alphabeta-dehydrocurvularin have similar level of anti-fungal and anti-tumorous activity, while alphabeta-dehydrocurvularin is active against Staphylococcus aureus with a minimal inhibitory concentration of 375 microg/ml but curvularin does not. No detectable activity against Gram-negative bacteria such as Escherichia coli and Pseudomonas aeruginosa exists for both compounds. It is suggested that the partial planar backbone structure, due to the conjugation of pi electrons in the presence of a 3,4-double bond and the carbonyl group at position C-2 in alphabeta-dehydrocurvularin, acts as a key factor for the inhibition of S. aureus, a Gram-positive low G + C bacteria that are often the hospital-acquired and/or community-acquired pathogen.
Xie
Lian Wu
LW
Key Laboratory of Marine Bio-resources Sustainable Utilization (LMB-CAS), Guangdong Key Laboratory of Marine Materia Medica (LMM-GD), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, People's Republic of China.
Ouyang
Yong Chang
YC
Zou
Kun
K
Wang
Guang Hua
GH
Chen
Min Jie
MJ
Sun
Hui Min
HM
Dai
Shi Kun
SK
Li
Xiang
X