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'.

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 cytosporone derivatives isolated from the mangrove-derived fungus Dothiorella sp. ML002.

Three new cytosporone derivatives dothiorelones K-M (1, 2 and 7), together with six known ones (3-6, 8 and 9) were isolated from the mangrove-derived fungus Dothiorella sp. ML002. Their structures were determined by comprehensive 1D, 2D NMR spectroscopic and HR-ESI-MS spectroscopic data. Compounds 1, 2 and 5 displayed inhibitory activities against α-glucosidase with the IC50 values of 22.0, 77.9 and 5.4 µg/mL, respectively. Additionally, compounds 1, 2, and 5 also exhibited antibacterial activities against Staphylococcus aureus (ATCC 6538) with the same MIC values of 50 µg/mL, respectively. The results indicated that cytosporone derivatives will be useful to as diabetes control agents.

Bioactive Secondary Metabolites from the Culture of the Mangrove-Derived Fungus Daldinia eschscholtzii HJ004.

Two new polyketides, 8-O-methylnodulisporin F (1) and nodulisporin H (2), two new naphthoquinones, 5-hydroxy-2-methoxy-6,7-dimethyl-1,4-naphthoquinone (3) and 5-hydroxy-2-methoxynaphtho[9-c]furan-1,4-dione (4), and a new naphthofuran 1,3,8-trimethoxynaphtho[9-c]furan (5), along with five known compounds 4-O-methyl eleutherol (6), 2-acetyl-7-methoxybenzofuran (7), (-)-orthosporin (8), diaporthin (9), and 6-hydroxymellein (10), were obtained from the EtOAc extract of the mangrove-derived fungus Daldinia eschscholtzii HJ004. The structures of the isolated compounds were elucidated by extensive NMR and MS analyses, while the absolute configurations of the stereogenic carbons were established based on experimental and calculated electronic circular dichroism spectra. Compounds 4 and 7 displayed a potent inhibitory activity against α-glucosidase with the IC50 values of 5.7 and 1.1 µg/mL, respectively. Compounds 1 and 2 showed a moderate antibacterial activity against Staphylococcus aureus, methicillin-resistant S. aureus (MRSA) and Bacillus cereus, with minimum inhibitory concentration (MIC) values ranging from 6.25 to 12.5 µg/mL. Compound 3 exhibited antibacterial activity against B. cereus with the MIC value of 12.5 µg/mL.

Bioactive Lactones from the Mangrove-Derived Fungus Penicillium sp. TGM112.

Three new lactones penicilactones A-C (1-3) were obtained from the mangrove-derived fungus Penicillium sp. TGM112. Their structures and absolute configurations were determined by detailed NMR, MS spectroscopic data, Mo2(OAc)4-induced electronic circular dichroism (ECD), and circular dichroism (CD) spectroscopy. Compound 1 showed antibacterial activity against Staphylococcus aureus with an MIC value of 6.25 µg/mL. Compound 2 showed insecticidal activity against newly hatched larvae of Culex quinquefasciatus with the LC50 value of 78.5 (±0.58) µg/mL.

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.[Formula: see text].

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

A new α,ß-unsaturated 7-ketone sterol, 5ß,6ß-epoxy-3ß, 15α-dihydroxy-(22E,24R)-ergosta-8(14),22-dien-7-one (1), along with five known sterone derivatives, 5ß,6ß-epoxy-3ß,7α-dihydroxy-(22E,24R)-ergosta-8(14),22-dien-15-one (2), 5ß,6ß-epoxy-3ß,7α,9α-trihydroxy-(22E,24R)-ergosta-8(14),22-dien-15-one (3), 3ß,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.

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,ß-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.