Two New Meroterpenes from the Mangrove Endophytic Fungus Aspergillus sp. 085241B

Abstract

Two new meroterpenes, acetoxydehydroaustin B (1) and 1,2-dihydro-acetoxydehydroaustin B (2) were isolated in the form of a mixed crystal from the mangrove endophytic fungus Aspergillus sp. 085241B. Their structures and absolute configurations were determined by extensive analysis of their spectra and X-ray diffraction data. In a preliminary bioassay, the mixed crystal did not exhibit activities against cancer cell lines of MDA-MB-435, SKBR3, HepG2, HEP3B, PC-3, and A549, as well as against aglucosidase and tyrosinase.

Induction of Diverse Bioactive Secondary Metabolites from the Mangrove Endophytic Fungus Trichoderma sp. (Strain 307) by Co-Cultivation with Acinetobacter johnsonii (Strain B2)

“…In continuing the search for novel and bioactive natural products from mangrove endophytic fungi [ 17 , 18 , 19 , 20 ], we recently turned to our interest in microorganism co-culture in order to obtain new bioactive compounds. After analyzing the high-performance liquid chromatography (HPLC) profiles of the co-cultivation extracts of 616 strains of mangrove endophytic fungi and Acinetobacter johnsonii B2, together with their monoculture extracts, we found that the co-cultivation of Trichoderma sp.…”

Acetylcholinesterase Inhibitory Meroterpenoid from a Mangrove Endophytic Fungus Aspergillus sp. 16-5c

“…The above spectroscopic features suggested that 1 belonged to the austin analogue [ 16 ], whose planar structure is similar to the 1,2-dihydro-acetoxydehydroaustin B. However, the carbon chemical shifts values of C-1 (δ C 37.1) and C-2 (δ C 64.8) were different from those of 1,2-dihydro-acetoxydehydroaustin B.…”

“…Although meroterpenoids have a wide range of biological activities [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ], few biological activities have been reported for austin and austin analogues. In this work, Compounds 1 – 10 were evaluated for their acetylcholinesterase (AChE) inhibitory activity using Huperzine A as a control ( Table 2 ).…”

“…and Penicillium sp. have been reported [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. As part of our ongoing investigations on novel bioactive compounds from mangrove endophytic-derived fungi [ 17 , 18 , 19 , 20 ], ten meroterpenoids, including one new meroterpenoids named 2-hydro-acetoxydehydroaustin ( 1 ), together with nine known meroterpenoids, 11-acetoxyisoaustinone ( 2 ), isoaustinol ( 3 ), austin ( 4 ), austinol ( 5 ), acetoxydehydroaustin ( 6 ), dehydroaustin ( 7 ), dehydroaustinol ( 8 ), preaustinoid A2 ( 9 ), and 1,2-dihydro-acetoxydehydroaustin B ( 10 ), were isolated from the fungus Aspergillus 16-5c, which was isolated from the leaves of the mangrove plant Sonneratia apetala collected on the coastal saltmarsh of the South China Sea ( Figure 1 ).…”

“…As part of our ongoing investigations on novel bioactive compounds from mangrove endophytic-derived fungi [ 17 , 18 , 19 , 20 ], ten meroterpenoids, including one new meroterpenoids named 2-hydro-acetoxydehydroaustin ( 1 ), together with nine known meroterpenoids, 11-acetoxyisoaustinone ( 2 ), isoaustinol ( 3 ), austin ( 4 ), austinol ( 5 ), acetoxydehydroaustin ( 6 ), dehydroaustin ( 7 ), dehydroaustinol ( 8 ), preaustinoid A2 ( 9 ), and 1,2-dihydro-acetoxydehydroaustin B ( 10 ), were isolated from the fungus Aspergillus 16-5c, which was isolated from the leaves of the mangrove plant Sonneratia apetala collected on the coastal saltmarsh of the South China Sea ( Figure 1 ). Compound 10 was reported as a mixture previously [ 16 ], but it is reported as a single compound here. The absolute configurations of stereogenic carbons for Compounds 3 , 7 , 8 , and 9 are determined here for the first time ( Figure 2 ).…”