np9b00563_si_001.pdf (3.5 MB)
Cholinesterase Inhibitory Arisugacins L–Q from a Penicillium sp. Isolate Obtained through a Citizen Science Initiative and Their Activities in a Phenotype-Based Zebrafish Assay
journal contribution
posted on 2019-08-21, 13:58 authored by Wentao Dai, Imelda T. Sandoval, Shengxin Cai, Kaylee A. Smith, Richard Glenn C. Delacruz, Kevin A. Boyd, Jessica J. Mills, David A. Jones, Robert H. CichewiczPhenotype-based screening of a fungal
extract library yielded an
active sample from a Penicillium sp. isolate that
impaired zebrafish motility. Bioassay-guided purification led to the
identification of 14 meroterpenoids including six new metabolites,
arisugacins L–Q (4, 5, 8, and 12–14), seven known arisugacins
(1–3, 6, 7, 9, and 10), and one known terreulactone
(11). Their structures were determined using a combination
of NMR and HRESIMS data, evidence secured from theoretical and experimental
ECD spectra, and the modified Mosher’s method. The purified
compounds were tested in zebrafish embryos, as well as in vitro for
cholinesterase inhibition activities. Compound 12 produced
defects in myotome structure (metameric muscle, which is critical
for locomotion) in vivo and showed the most potent and selective acetylcholinesterase
inhibitory activity with an IC50 of 191 nM in vitro. The
phenotype assay was also used to reveal bioactivities for several
previously reported arisugacins, which had failed to show activity
in prior cell-based and in vitro testing. This study demonstrates
that utilization of the zebrafish phenotype assay is an effective
approach for the identification of bioactive extracts, is compatible
with the bioassay-guided compound purification strategies, and offers
a valuable tool for probing complex natural product sources to detect
bioactive small molecules with potential therapeutic or other commercial
applications.