Isobenzofuranone monomer and dimer derivatives from the mangrove endophytic fungus Epicoccum nigrum SCNU-F0002 possess α-glucosidase inhibitory and antioxidant activity

Isolation, Structural Characterization and Antidiabetic Activity of New Diketopiperazine Alkaloids from Mangrove Endophytic Fungus Aspergillus sp. 16-5c

“…Investigation on the biological activities of prenylated DKP alkaloids disclosed antioxidant activity in the literature [ 27 , 28 ]. It is reported that excessive accumulation of free radical and synchronous reduced the antioxidant defense mechanisms and can induce complications of diabetes mellitus [ 15 ]. In order to find potent antidiabetic natural products, all the compounds ( 1 – 16 ) were screened for the enzyme inhibitory activities against α-glucosidase and PTP1B ( Table 3 ).…”

“…In conclusion, chemical investigation of the mangrove endophytic fungus Aspergillus sp. 16-5c led to isolation and identification of six new alkaloids, aspergiamides A-F (1-6), with ten known analogs (7)(8)(9)(10)(11)(12)(13)(14)(15)(16). The potential of DKPs alkaloids as antidiabetic agents was evaluated by α-glucosidase inhibition and PTP1B inhibition assay.…”

“…16-5c were investigated. Chemical investigation yielded six new diketopiperazine alkaloids, including five indole diketopiperazine alkaloids, aspergiamides A-E (1-5) and one 4-quinazolinone like diketopiperazine alkaloids aspergiamide F (6), together with ten known alkaloids (7)(8)(9)(10)(11)(12)(13)(14)(15)(16) from the culture extracts of the fungus 16-5c (Figure 1). These compounds were evaluated the antidiabetic potential by screening the enzyme inhibition of α-glucosidase and PTP1B.…”

“…As part of our aims for exploring biological active natural products [ 15 ], the secondary metabolites from fungus Aspergillus sp. 16-5c were investigated.…”

Fused multicyclic polyketides with a two-spiro-carbon skeleton from mangrove-derived endophytic fungus Epicoccum nigrum SCNU-F0002

“…The intricate polycyclic skeleton of 1 is unique in natural sources, and has been reported in only three literatures up to date. [18][19][20] From the pathway analysis, we know that (AE)-isoepicolactone via intermolecular [5 + 2] cycloaddition reaction complete the cascade and obtains a complex dimmer compound. Our rst time characterize isoepicolactone from natural source proved the priediction of Prof. Trauner, 21 who accomplished the elegant total synthesis of epicolatone using intermolecular [5 + 2] cycloaddition strategy, in that work (AE)-isoepenolides are reported as by-products in racemates.…”