Dehai Li

Alkaloids from a deep ocean sediment-derived fungus Penicillium sp. and their antitumor activities.

Four new alkaloids, including two new meleagrin analogs, meleagrin D (1) and E (2), and two new diketopiperazines, roquefortine H (3) and I (4), were isolated from a deep ocean sediment-derived fungus Penicillium sp. Meleagrin D (1) and E (2) possess unprecedented acetate–mevalonate-derived side chains on the imidazole moiety. These new meleagrins showed weak cytotoxicity against the A-549 cell line, whereas meleagrin B (5) and meleagrin (6), which were isolated previously from the same strain, induced HL-60 cell apoptosis or arrested the cell cycle through G2/M phase, respectively. The results indicate that the distinct substitutions on the imidazole ring significantly influence the cytotoxicity of the meleagrin alkaloids.

Antiviral isoindolone derivatives from an endophytic fungus Emericella sp. associated with Aegiceras corniculatum.

Chemical investigation of the endophytic fungus Emericella sp. (HK-ZJ) isolated from the mangrove plant Aegiceras corniculatum led to isolation of six isoindolones derivatives termed as emerimidine A and B and emeriphenolicins A and D, and six previously reported compounds named aspernidine A and B, austin, austinol, dehydroaustin, and acetoxydehydroaustin, respectively. Their structures were elucidated on the basis of NMR spectroscopic evidence while the anti-influenza A viral (H₁N₁) activities of eight compounds were also evaluated using the cytopathic effect (CPE) inhibition assay.

Cytotoxic Metabolites from the Antarctic Psychrophilic Fungus Oidiodendron truncatum

Two new epipolythiodioxopiperazines, named chetracins B and C (1 and 2), and five new diketopiperazines, named chetracin D (4) and oidioperazines A-D (5, 10, 12, and 13), were isolated from the fungus Oidiodendron truncatum GW3-13, along with six known compounds (3, 6, 7, 8, 9, and 11). Their structures were elucidated by extensive NMR, MS, and CD analyses, as well as chemical transformation. An in vitro MTT cytotoxicity assay revealed potent biological activity for 1 in the nanomolar range against a panel of five human cancer lines.

Antiviral alkaloids produced by the mangrove-derived fungus Cladosporium sp. PJX-41.

Six new indole alkaloids including five new glyantrypine derivatives (1, 2a, 2b, 3, 4) and a new pyrazinoquinazoline derivative (5), together with eight known alkaloids (6-13), were isolated from the culture of the mangrove-derived fungus Cladosporium sp. PJX-41. Their structures were elucidated primarily by spectroscopic and physical data. The absolute configurations of compounds 1-9 were established on the basis of CD, NOESY data, and single-crystal X-ray diffraction analysis. Compounds 2b, 5, 7-9, and 11 exhibited significant activities against influenza virus A (H1N1), with IC50 values of 82-89 μM.

Phenylspirodrimanes with Anti-HIV Activity from the Sponge-Derived Fungus Stachybotrys chartarum MXH-X73

Seven new phenylspirodrimanes, named stachybotrins D-F (1, 3, 4), stachybocins E and F (5, 6), and stachybosides A and B (7, 8), and four known compounds (2, 9-11), were isolated from the sponge-derived fungus Stachybotrys chartarum MXH-X73. Their structures were determined by detailed analysis of spectroscopic data. The absolute configurations of 1-8 were determined by chemical hydrolysis and modified Moshers and Marfeys methods. All compounds were tested in an anti-HIV activity assay, and compound 1 showed an inhibitory effect on HIV-1 replication by targeting reverse transcriptase. Further study exhibited that 1 could block NNRTIs-resistant strains (HIV-1RT-K103N, HIV-1RT-L100I,K103N, HIV-1RT-K103N,V108I, HIV-1RT-K103N,G190A, and HIV-1RT-K103N,P225H) as well as wild-type HIV-1 (HIV-1wt) with EC50 values of 7.0, 23.8, 13.3, 14.2, 6.2, and 8.4 μM, respectively.

Aspulvinones from a mangrove rhizosphere soil-derived fungus Aspergillus terreus Gwq-48 with anti-influenza A viral (H1N1) activity.

A new butenolide isoaspulvinone E (1), together with two known butenolides aspulvinone E (2) and pulvic acid (3) were isolated from the marine-derived fungus, Aspergillus terreus Gwq-48. They showed significant anti-influenza A H1N1 virus activities, with IC50 values of 32.3, 56.9, and 29.1μg/mL, respectively. Moreover, only compound 1 exhibited effective inhibitory activity against H1N1 viral neuraminidase (NA), and docking of two isomers (1-2) into the active sites of NA showed that the E double bond Δ(5(10)) was essential to achieve activity.

Pyronepolyene C-glucosides with NF-κB inhibitory and anti-influenza A viral (H1N1) activities from the sponge-associated fungus Epicoccum sp. JJY40

A new pyronepolyene C-glucoside, named iso-D8646-2-6 (1) together with the known related compound D8646-2-6 (2), was isolated from the sponge-associated fungus Epicoccum sp. JJY40. They showed NF-κB inhibitory and anti-influenza A viral (H1N1) activities.

Two New Bisorbicillinoids Isolated from a Deep-sea Fungus, Phialocephala sp. FL30r

Two new bisorbicillinoids, named oxosorbiquinol (1) and dihydrooxosorbiquinol (2), were isolated from a deep-sea fungus, Phialocephala sp., and their structures established using spectroscopic methods. The absolute configurations of 1 and 2 were determined by their biosynthesis route and analysis of the CD spectrum. Their cytotoxic effects on P388, A-549, HL60, BEL7402 and K562 cell lines were examined by the MTT method.

Four New Chloro-Eremophilane Sesquiterpenes from an Antarctic Deep-Sea Derived Fungus, Penicillium sp. PR19N-1

A new chloro-trinoreremophilane sesquiterpene 1, three new chlorinated eremophilane sesquiterpenes 2–4, together with a known compound, eremofortine C (5), were isolated from an Antarctic deep-sea derived fungus, Penicillium sp. PR19N-1. Structures were established using IR, HRMS, 1D and 2D NMR techniques. In addition, the plausible metabolic network of these isolated products is proposed. Compound 1 showed moderate cytotoxic activity against HL-60 and A549 cancer cell lines.

Hybrid isoprenoids from a reeds rhizosphere soil derived actinomycete Streptomyces sp. CHQ-64.

Indotertine A (1), a hybrid isoprenoid with a condensed pentacyclic skeleton, together with two related hybrid isoprenoids, drimentines F (2) and G (3), were isolated from a reeds rhizosphere soil derived actinomycete Streptomyces sp. CHQ-64. Their structures including absolute configurations were elucidated by spectroscopic methods, X-ray single crystal diffraction analysis, and TDDFT ECD calculations. Drimentines G (3) showed strong cytotoxicity against human cancer cells lines with IC(50)s down to 1.01 μM, while 1 and 2 showed no significant activity.