Title
A new aquatic pathogen inhibitor produced by the marine fungus Aspergillus sp. LS116
Author
Peng Xu, Lijian Ding, Jiaxin Wei, Qiang Li, Minjie Gui, Xiaoping He, Dengquan Su, Shan He, Haixiao Jin
Year
2019
Journal
Aquaculture
Abstract
In this study, a fungal strain LS116 with antibacterial activity against aquatic pathogen Vibrio harveyi was screened out from sponge-associated fungi by Oxford cup method. According to its morphological characteristics and internal transcribed spacer (ITS) analysis, the active strain belonged to the genus Aspergillus. A bioactivity-guided approach was conducted to identify the antibacterial substances in the culture extract of strain LS116, a new C23 steroid with bicyclo[4.4.1]A/B ring, named aspergillsteroid A (1), and a known C25 steroid with the same structure skeleton, neocyclocitrinol B (2), were isolated and purified by column chromatographs and HPLC (high-performance liquid chromatography) for the first time. Their chemical structures were determined by HRESIMS (high-resolution electrospray ionization mass spectroscopy) spectrometry, NMR (nuclear magnetic resonance) spectroscopy, and CD (circular dichroism). Among them, compound 1 displayed significant antibacterial activity against V. harveyi with a MIC value of 16 μg/mL. The study demonstrated that compound 1 can be considered as a new promising agent for the control of aquatic disease in the future.
Instrument
J-1500
Keywords
Circular dichroism, Absolute configuration, Pharmaceutical, Agriculture and environmental