A Pair of Chromone Epimers and an Acetophenone Glucoside from the Mangrove Endophytic Fungus Mycosphaerella sp. L3A1

Abstract

Three new compounds, including a pair of chromone derivatives (1 -2), and an acetophenone glucoside (3), together with three known compounds (4 -6), were isolated from the mangrove endophytic fungus Mycosphaerella sp. L3A1. Their structures were elucidated by HR-ESI-MS analysis and extensive spectroscopic data. The absolute configurations of new compounds were determined using single-crystal X-ray diffraction analysis, electronic circular dichroism (ECD) calculations and chemical hydrolysis. In bioassays, compound 4 showed moderate cytotoxic activity against MDA-MB-435, HCT116, and SNB19 with IC 50 values in the range of 18.5-26.29 μM.

Biological and Medicinal Properties of Natural Chromones and Chromanones

“…L3A1. 79 Their structures were elucidated through HR-ESI-MS analysis and spectroscopic data, and the cytotoxicity of the isolated compounds was evaluated against six human cancer cell lines (MDA-MB-435, MDA-MB-231, SNB19, HCT116, A549, and PC-3). Both compounds did not show significant cytotoxic activity against the cancer cell lines tested.…”

“…In continuation of the research work carried out over the past two decades focused on the exploration of new bioactive metabolites, Tan et al isolated two new chromone derivatives ( 121 and 122 , Figure ), from the mangrove endophytic fungus Mycosphaerella sp. L3A1 . Their structures were elucidated through HR-ESI-MS analysis and spectroscopic data, and the cytotoxicity of the isolated compounds was evaluated against six human cancer cell lines (MDA-MB-435, MDA-MB-231, SNB19, HCT116, A549, and PC-3).…”

Antioxidative Indenone and Benzophenone Derivatives from the Mangrove-Derived Fungus Cytospora heveae NSHSJ-2

“…Mangrove-associated fungi are known to be an essential source of natural products for the discovery of new drug leads [ 16 , 17 ]. In our continuing search for structurally diverse and biologically active metabolites from mangrove endophytic fungi [ 18 , 19 , 20 , 21 , 22 ], a chemical investigation for new secondary metabolites from mangrove endophytic fungus Cytospora heveae NSHSJ-2, which was isolated from the fresh stem of the mangrove plant Sonneratia caseolaris , led to the isolation and characterization of seven new polyketides ( Figure 1 ), including four new indenone derivatives, cytoindenones A–C ( 1 , 3 – 4 ), 3′-methoxycytoindenone A ( 2 ), a new benzophenone derivative, cytorhizophin J ( 6 ), and a pair of undescribed tetralone enantiomers, (±)-4,6-dihydroxy-5-methoxy- α -tetralone ( 7 ), together with a known compound, cytosporaphenones E ( 5 ) [ 23 ]. Among them, compound 3 represented the first natural indenone monomer substituted by two benzene moieties at C-2 and C-3.…”