Bioactive isocoumarins isolated from a mangrove-derived fungus Penicillium sp. MGP11

Two new isocoumarins penicimarins L-M (1-2), along with seven known analogues (3-9) were isolated from the mangrove-derived fungus Penicillium sp. MGP11. Compounds 1-2 were established by spectroscopic methods and comparison of their circular dichroism (CD) spectra with the literature. All isolated compounds were evaluated for antioxidant and α-glucosidase inhibitory activities. Compound 8 had better antioxidant activity (IC₅₀ = 4.6 μM) than positive control trolox (IC₅₀ = 12.9 μM). Compounds 5, 8 and 9 exhibited α-glucosidase inhibitory activity with the IC₅₀ values of 776.5, 683.7 and 868.7 μM, respectively.

One new α,β-unsaturated 7-ketone sterol from the mangrove-derived fungus Phomopsis sp.MGF222

A new α,β-unsaturated 7-ketone sterol, 5β,6β-epoxy-3β, 15α-dihydroxy-(22E,24R)-ergosta-8(14),22-dien-7-one (1), along with five known sterone derivatives, 5β,6β-epoxy-3β,7α-dihydroxy-(22E,24R)-ergosta-8(14),22-dien-15-one (2), 5β,6β-epoxy-3β,7α,9α-trihydroxy-(22E,24R)-ergosta-8(14),22-dien-15-one (3), 3β,9α,15α-trihydroxy-(22E,24R)-10(5→4)-abeo-ergosta-6,8(14),22-trien-5-one (4), 3,15-dihydroxyl-(22E,24R)-ergosta-5,8(14),22-trien-7-one (5) and (22E,24R)-ergosta-4,6,8(14),22-tetraen-3,15-dione (6) were isolated from the mangrove-derived fungus Phomopsis sp. MGF222. Their structures were established on the basis of extensive spectroscopic data and comparison with the data of literature. Compound 2 showed weak antibacterial activity against Micrococcus tenuis with the MIC value of 28.2 (±0.52) μM. Compound 5 exhibited moderate antibacterial activity against Staphylococcus aureus with the MIC value of 14.6 (±0.47) μM.

A new phenol derivative isolated from mangrove-derived fungus Eupenicillium sp. HJ002

A new phenol derivative, 3-chloro-5-hydroxy-4-methoxyphenylacetic acid methyl ester (1), along with five known compounds methyl 4-hydroxyphenylacetate (2), cytosporone B (3), (R)-striatisporolide A (4), (R)-butanedioic acid (5) and ergosterol (6) were isolated from the mangrove-derived fungus Eupenicillium sp. HJ002. Their structures were established by spectroscopic methods, GIAO based ¹³C NMR chemical shift calculations and comparison with the data of literature. Compounds 1-5 were isolated from Xylocarpus granatum Koening-derived fungus for the first time.

Bioactive Polyketide Derivatives from the Mangrove-Derived Fungus Daldinia eschscholtzii HJ004

Five new tetralones, daldiniones A-E (1-5), three new chromones, 7-hydroxy-5-methoxy-2,3-dimethylchromone (9), 5-methoxy-2-propylchromone (10), and 7-ethyl-8-hydroxy-6-methoxy-2,3-dimethylchromone (11), and two new lactones, helicascolides D and E (16 and 17), together with nine known metabolites (6-8, 12-15, and 18-19) were isolated from the mangrove-derived fungus Daldinia eschscholtzii HJ004. The structures and absolute configurations of the new compounds were determined by analyzing MS and NMR data and utilizing GIAO based ¹³C NMR chemical shift calculations and quantum chemical electronic circular dichroism (ECD) calculations. Compounds 9, 13, and 18 showed inhibitory activities against α-glucosidase with IC₅₀ values of 13, 15, and 16 μM, respectively.

Bioactive Meroterpenoids and Isocoumarins from the Mangrove-Derived Fungus Penicillium sp. TGM112

Two new meroterpenoids, penicianstinoids A and B (1 and 2), and eight new isocoumarins, peniciisocoumarins A-H (3-10), together with 10 known analogues (11-20) were obtained from the mangrove-derived fungus Penicillium sp. TGM112. The structures and absolute configurations of 1-10 were determined by interpretation of detailed NMR, MS spectroscopic data, X-ray diffraction analyses, modified Mosher's method, and calculated electronic circular dichroism data. Compounds 1-4, 7, 8, 10, 12, 13, and 16 showed growth inhibition activity against newly hatched larvae of Helicoverpa armigera Hubner with IC₅₀ values ranging from 50 to 200 μg/mL, respectively. Compounds 1, 2, and 11-15 displayed activity against Caenorhabditis elegans with EC₅₀ values ranging from 9.4 (± 1.0) to 38.2 (± 0.6) μg/mL, respectively. Compound 1 represents an austinoid-like meroterpenoid that is reported here for the second time, in which a carbon-carbon double bond was oxidized to a carbonyl group at C-1'-C-2'.

Two new benzophenones and one new natural amide alkaloid isolated from a mangrove-derived Fungus Penicillium citrinum

Two new compounds penibenzophenones A-B (1-2), and the synthetic α,β-unsaturated amide alkaloid (E)-tert-butyl(3-cinnamamidopropyl)carbamate (4), newly identified as a natural product, alone with three known ones (3, 5-6) were isolated from the EtOAc extract of the endophytic fungus Penicillium citrinum HL-5126 isolated from the mangrove Bruguiera sexangula var. rhynchopetala collected in the South China Sea. Compound 1 was a chlorinated benzophenone. The structures of 1-6 were elucidated by extensive NMR spectral interpretation, MS data and X-ray analysis. The new compound 2 displayed cytotoxic activity against human A549 cell lines with an IC₅₀ value of 15.7 μg/mL, and 1 showed antibacterial activity against Staphylococcus aureus with a MIC value of 20 μg/mL.