Hydroquinone derivatives from the marine-derived fungus Gliomastix sp.

Abstract

Eight new hydroquinone derivatives, gliomastins A-D (1-4), 9-O-methylgliomastin C (5), acremonin A 1-Ob-D-glucopyranoside (6), gliomastin E 1-O-b-D-glucopyranoside (7), and 6together with seven known analogues were isolated from the marine-derived fungus Gliomastix sp. Their structures were elucidated by extensive spectroscopic analysis including 1D and 2D NMR measurements aided by DFT NMR calculations as well as MS data. TDDFT-ECD and OR calculations were performed to determine the absolute configurations of 1 and the aglycones of 6 and 7. Compound 1 features a novel skeleton, biogenetically derived from a Diels-Alder reaction between derivatives of 11 and 13. Compound 2 represents a rare sulfur-containing alkaloid derived from the known hydroquinone 13.Compounds 1, 10 and 12 showed strong cytotoxicity against the L5178Y mouse lymphoma cell line with IC 50 values of 1.8, 1.0 and 1.1 mM, respectively. Compound 3 exhibited moderate antitubercular activity against Mycobacterium tuberculosis with a MIC value of 12.5 mM.

Marine natural products

“…Gliomastin A 445 possesses a novel skeleton which could be biosynthetically derived from a Diels-Alder reaction between the known hydroquinone derivatives acremonin A and F-11334A, both of which were co-isolated, whilst 446 is a rare sulphur containing alkaloid derived from F-11334A. 201 The absolute congurations of 445 and aglycones 450, 451 were determined via Time-Dependent Density Functional Theory-Electronic Circular Dichroism (TDDFT-ECD) and optical rotation (OR) calculations. 201 A Graphostroma species yielded a number of sesquiterpenes 453-461, including xylariterpenoids A and B.…”

“…201 The absolute congurations of 445 and aglycones 450, 451 were determined via Time-Dependent Density Functional Theory-Electronic Circular Dichroism (TDDFT-ECD) and optical rotation (OR) calculations. 201 A Graphostroma species yielded a number of sesquiterpenes 453-461, including xylariterpenoids A and B. The stereochemistry of C-10 in each was revised to that shown in xylariterpeneoids A 463 and B 462 respectively and both were also obtained as rst time MNPs.…”

Bioactive Lactones from the Mangrove-Derived Fungus Penicillium sp. TGM112

“…According to the published procedure [18,19,20,21], compounds 1 – 3 (0.5 mg) were dissolved in a dry solution of the stock Mo 2 (OAc) 4 complex (1.1 mg) in DMSO and then recorded immediately for the first induced ECD spectra, and its time evolution was monitored until stationary (about 30 min after mixing).…”

Bioactivity Potential of Marine Natural Products from Scleractinia-Associated Microbes and In Silico Anti-SARS-COV-2 Evaluation

“…Eight new hydroquinone derivatives, gliomastins A–D ( 65 – 68 ), 9- O -methylgliomastin C ( 69 ), acremonin A 1- O - β -D-glucopyranoside ( 70) , gliomastin E 1- O - β -D-glucopyranoside ( 71 ), and 6′- O -acetyl-isohomoarbutin ( 72 ), together with seven identified analogues ( 73 – 79 ) were spotted in the crude extract of the solid rice culture of the marine-derived fungus Gliomastix sp., which was isolated from the scleractinian coral Stylophora sp. (family: Pocilloporidae), collected from the Red Sea in Egypt ( Figure 11 ) [ 35 ]. This extract displayed cytotoxic potential against the L5178Y mouse lymphoma cell line with an inhibition of 69.1% at a dose of 10 µg/mL.…”