Polyketides with α-Glucosidase Inhibitory Activity from a Mangrove Endophytic Fungus, Penicillium sp. HN29-3B1

Abstract

Five new compounds, pinazaphilones A and B (1, 2), two phenolic compounds (4, 5), and penicidone D (6), together with the known Sch 1385568 (3), (±)-penifupyrone (7), 3-O-methylfunicone (8), 5-methylbenzene-1,3-diol (9), and 2,4-dihydroxy-6-methylbenzoic acid (10) were obtained from the culture of the endophytic fungus Penicillium sp. HN29-3B1, which was isolated from a fresh branch of the mangrove plant Cerbera manghas collected from the South China Sea. Their structures were determined by analysis of 1D and 2D NMR and mass spectroscopic data. Structures of compounds 4 and 7 were further confirmed by a single-crystal X-ray diffraction experiment using Cu Kα radiation. The absolute configurations of compounds 1-3 were assigned by quantum chemical calculations of the electronic circular dichroic spectra. Compounds 2, 3, 5, and 7 inhibited α-glucosidase with IC50 values of 28.0, 16.6, 2.2, and 14.4 μM, respectively, and are thus more potent than the positive control, acarbose.

Perylenequione Derivatives with Anticancer Activities Isolated from the Marine Sponge-Derived Fungus, Alternaria sp. SCSIO41014

“…The single compound 6 ([ α ${]}_{\mathrm{normalD}}^{25}$ +3.1, c 0.1, MeOH) and 7 ([ α ${]}_{\mathrm{normalD}}^{25}$ −7.2, c 0.1, MeOH) were isolated, and they had opposite ECD spectra (Figure 5). The optical rotation of 6 was consistent with that of 4′-( S )-(3,5-dihydroxyphenyl)-4′-hydroxy-6′-methylcyclopent-1′-en-5′-one [21], indicating that they had the same S configuration at C-4′, opposite to that of 7 . Thus, the absolute structure of 6 was determined as 4′-( S )-(3-Methoxy-5-hydroxyphenyl)-4′-hydroxy-6′-methylcyclopent-1′-en-5′-one and named ( S )-alternariphent A1, while the absolute structure of 7 was determined as 4′-( R )-(3-Methoxy-5-hydroxyphenyl)-4′-hydroxy-6′-methylcyclopent-1′-en-5′-one and named ( R )-alternariphent A2.…”

“…The 1 H NMR and 13 C NMR data (Table 2) of 6/7 were almost identical to those of 4′-( S )-(3,5-dihydroxyphenyl)-4′-hydroxy-6′-methylcyclopent-1′-en-5′-one isolated from Penicillium sp. HN29-3B1 [21], indicating that 6/7 were a structural analog, except for the presence of a methoxy group ( δ C/H 55.7, C-7). The deduction was confirmed by the HMBC correlation (Table 2) from H 3 -7 to C-3.…”

Active Metabolites from Endolichenic Fungus Talaromyces sp.

“…Other known compounds, 3 (colorless crystals), 4 (oil), 5 (colorless crystals), 6 (colorless crystals), and 7 (white solid), were identified as 6-methylbiphenyl-3,3',4,5'-tetraol, [13] desmethylaltenusin, [14] ergone, [15] ergosterol, [16] and palmitic acid by using spectroscopic analysis, respectively.…”

Bioactive Chaetoglobosins from the Mangrove Endophytic Fungus Penicillium chrysogenum

“…Endophytes are fungi or bacteria that live in the healthy tissues of living plants without causing discernible disease to the host [20]. Among them, marine mangrove endophytic fungi have attracted significant attention for their notable ability to produce metabolites with novel structures and biological activities [21,22]. …”