Abstract
In an effort to discover new bioactive anti-tumor lead compounds, a specific tyrosine phosphatase CDC25B and an Erb family receptor EGFR were selected as drug screening targets. This work led to the investigation of the soft coral-derived fungus Talaromyces verruculosus and identification of two new oligophenalenone dimers, verruculosins A–B (1–2), along with three known analogues, bacillisporin F (3), duclauxin (4), and xenoclauxin (5). Compound 1 was the first structure of the oligophenalenone dimer possessing a unique octacyclic skeleton. The detailed structures and absolute configurations of the new compounds were elucidated on the basis of spectroscopic data, X-ray crystallography, optical rotation, Electronic Circular Dichroism (ECD) analysis, and nuclear magnetic resonance (NMR) calculations. Among which, compounds 1, 3, and 5 exhibited modest inhibitory activity against CDC25B with IC50 values of 0.38 ± 0.03, 0.40 ± 0.02, and 0.26 ± 0.06 µM, respectively.
Highlights
Over the past 60 years, a large number of natural products have been discovered from marine fungi, possessing new skeletons, unique structures, and unexpected substituents
Cell Division Cycle 25B (CDC25B), a specific tyrosine phosphatase [12], and epidermal growth factor receptor (EGFR), an Erb family receptor [13], as screening targets. This led to the systematic isolation of soft coral-derived fungus Talaromyces verruculosus and the identification of a novel oligophenalenone dimer verruculosin A (1) with an octacyclic skeleton, which had never been reported in previous literature
The high-resolution electrospray ionization-mass spectrometry (HR-ESI-MS) data recorded at m/z 605.1668 along with the analysis of the nuclear magnetic resonance (NMR) data established the molecular formula of 1 as C32 H28 O12, indicating 19 degrees of unsaturation (DOU)
Summary
Over the past 60 years, a large number of natural products have been discovered from marine fungi, possessing new skeletons, unique structures, and unexpected substituents. Oligophenalenone dimers are a kind of natural metabolite of fungi, with a unique bis(oxaphenalenone) hetero-dimer structure, which have been shown to inhibit the proliferation of several tumor cell lines. A soil fungus Talaromyces stipitatus yielded two novel skelet on products, talaroketals A with a rare benzannulated 5,6-spiroketal ring system, and talaroketals B with a fused bicyclic furano-pyran moiety within the bis(oxaphenalenone) hetero-dimer structure [11]. Cell Division Cycle 25B (CDC25B), a specific tyrosine phosphatase [12], and epidermal growth factor receptor (EGFR), an Erb family receptor [13], as screening targets This led to the systematic isolation of soft coral-derived fungus Talaromyces verruculosus and the identification of a novel oligophenalenone dimer verruculosin A (1) with an octacyclic skeleton, which had never been reported in previous literature. A new analogue verruculosin B (2) along with the known natural products bacillisporin F (3) [8], duclauxin (4) [4], and xenoclauxin (5) [14] were obtained and elucidated
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
