Shengrong Liao

Arthpyrones A–C, Pyridone Alkaloids from a Sponge-Derived Fungus Arthrinium arundinis ZSDS1-F3

Three new 4-hydroxy-2-pyridone alkaloids, arthpyrones A-C (1-3), were isolated from the sponge-derived fungus Arthrinium arundinis ZSDS1-F3. Their structures were elucidated on the basis of spectroscopic analysis, CD spectra, quantum chemical calculation, and X-ray single-crystal diffraction analysis. Compounds 1 and 2 possessed a 2-pyridone core featured with a decalin moiety linked via a carboxide bridge bearing a novel oxabicyclo[3.3.1]nonane ring system rarely discovered in nature. A possible biosynthetic pathway for them was proposed.

New prenylxanthones from the deep-sea derived fungus Emericella sp. SCSIO 05240.

Four new prenylxanthones, emerixanthones A–D (1–4), together with six known analogues (5–10), were isolated from the culture of the deep-sea sediment derived fungus Emericella sp. SCSIO 05240, which was identified on the basis of morphology and ITS sequence analysis. The newstructures were determined by NMR (1H, 13C NMR, HSQC, HMBC, and 1H-1H COSY), MS, CD, and optical rotation analysis. The absolute configuration of prenylxanthone skeleton was also confirmed by the X-ray crystallographic analysis. Compounds 1 and 3 showed weak antibacterial activities, and 4 displayed mild antifungal activities against agricultural pathogens.

Chrysamides A–C, Three Dimeric Nitrophenyl trans-Epoxyamides Produced by the Deep-Sea-Derived Fungus Penicillium chrysogenum SCSIO41001

Three dimeric nitrophenyl trans-epoxyamides, chrysamides A-C (1-3), were obtained from the deep-sea-derived fungus Penicillium chrysogenum SCSIO41001. Their structures were characterized by spectroscopic analysis, electronic circular dichroism computations, and X-ray single-crystal diffraction analysis. Notably, compound 1 possesses a novel centrosymmetric dimer skeleton featuring an unprecedented 7-oxa-2,5-diazabicyclo[2.2.1]heptane ring system, which represents the first example of dimeric nitrophenyl trans-epoxyamide in nature. Compound 3 suppresses the production of proinflammatory cytokine interleukin-17. A possible biosynthetic pathway of 1-3 was proposed.

Naturally occurring organoiodines

This review, with 290 references, presents the fascinating area of iodinated natural products over the past hundred years for the first time. It covers literature published from 1896 to 2014 and refers to compounds isolated from both biogenic and abiotic sources. In total, 182 naturally-occurring organoiodine compounds are recorded. The emphasis is on the compounds together with the relevant biological activities, sources, collection places, countries of origin, biosynthetic studies, and first total syntheses.

Antifungal New Oxepine-Containing Alkaloids and Xanthones from the Deep-Sea-Derived Fungus Aspergillus versicolor SCSIO 05879

Phytopathogenic fungi remain a continuous and huge threat in the agricultural fields. The agrochemical industry has made great development of the use of microbial natural products, which has been regarded as an effective strategy against phytopathogenic fungi. Antifungal bioassay-directed fractionation was used to isolate two new oxepine-containing alkaloids (1 and 2), two new 4-aryl-quinolin-2-one alkaloids (3 and 4), and four new prenylated xanthones (5-8) from the deep-sea-derived fungus Aspergillus versicolor SCSIO 05879. Extensive NMR spectroscopic analysis, quantum mechanical calculations, and X-ray single-crystal diffraction were used to elucidate their structures, including their absolute configurations. Versicoloids A and B, versicone A, and cottoquinazoline A showed antifungal activities against three phytopathogenic fungi. The antifungal activities of these bioactive compounds strongly depend on the fungal species. Especially versicoloids A and B showed strong fungicidal effect (MIC of 1.6 μg/mL) against Colletotrichum acutatum, compared with that of the positive control cycloheximide (MIC of 6.4 μg/mL). The results of antifungal experiments indicated that versicoloids A and B may be regarded as candidate agents of antifungal agrochemicals.

Sesquiterpenoids and xanthones derivatives produced by sponge-derived fungus Stachybotry sp. HH1 ZSDS1F1-2

A new (2) and four known (1, 8–10) sesquiterpenoids, two new (3 and 4) and eight known (5–7, 11–15) xanthone derivatives were isolated from the cultures of sponge-derived fungus Stachybotry sp. HH1 ZDDS1F1-2. The structure of the compounds 1–15 was determined mainly by analysis of the one-dimensional and two-dimensional NMR spectroscopic data and by analogy with the data of those reported. Compound 1 was confirmed by X-ray crystallography. All the compounds were tested for their cytotoxic, antiinflammatory and antiviral (EV71) effects. Compounds 5, 7 and 11 showed significant cytotoxicity against selected human tumor cell lines. Compounds 3, 4 and 11 also displayed significant inhibitory activity against cycloooxygenase (COX-2). Compounds 4, 5 and 11 showed activities against intestinal virus EV71.

Cytotoxic Cytochalasins from Marine-Derived Fungus Arthrinium arundinis

Four new cytochalasins, arthriniumnins A-D (1-4), a new natural product, ketocytochalasin (5), as well as five known cytochalasin analogues (6-10) were isolated and identified from the fungus Arthrinium arundinis ZSDS1-F3 from the sponge Phakellia fusca. Their structures were elucidated by NMR spectroscopic and mass spectrometric analyses, as well as single crystal X-ray diffraction. Compounds 6 and 9 showed cytotoxicity against K562, A549, Huh-7, H1975, MCF-7, U937, BGC823, HL60, Hela, and MOLT-4 cell lines, with IC50 values ranging from 1.13 to 47.4 µM.

New Sinularianin Sesquiterpenes from Soft Coral Sinularia sp.

Four new sesquiterpenes, sinularianins C–F (3–6), together with known sinularianins A (1) and B (2) were identified from a South China Sea soft coral Sinularia sp. Compounds 1–6 were evaluated for inhibition of NF-κB activation using the cell-based HEK293 NF-κB luciferase reporter gene assay. Compounds 1 and 4 were exhibited a potent effect with inhibitory rates of 41.3% and 43.0% at the concentration of 10 µg/mL, respectively.

Three new indolyl diketopiperazine metabolites from the antarctic soil-derived fungus Penicillium sp. SCSIO 05705

Three new indolyl diketopiperazine derivatives, penillines A and B (1 and 3), isopenilline A (2), together with seven known alkaloid compounds (E)-3-(1H-imidazole-4-yimethylene)-6-(1H-indl-3-ylmethyl)-2,5-piperazinediol (4), penilloid A (5), meleagrin (6), neoxaline (7), questiomycin A (8), N-(2-hydroxyphenyl)-acetamide (9), 2-benzoxazolinone (10), were isolated from the Antarctic soil-derived fungus Penicillium sp. SCSIO 05705. The new structures of 1–3 were elucidated on the basis of 1D and 2D NMR, mass spectra, CD spectra, and quantum chemical calculations. All the isolated compounds were tested for their antiviral (H1N1 and H3N2), antituberculosis, antibacterial, and cytotoxic activities. Among them, compounds 6–8 had significant in vitro cytotoxicities against the K562, MCF-7, A549, U937, Hela, DU145, HL60, and HT29 cell lines, with IC50 values ranging from 2.73 to 17.7 μM. In addition, compound 8 showed potent antituberculosis activity with an MIC value of 3.91 μM, and the inhibition effect was close to the positive control INH (isoniazid, MIC 2.04 μM). A possible biogenesis pathway for compounds 1–7 was proposed.

New Meroterpenoids from the Endophytic Fungus Aspergillus flavipes AIL8 Derived from the Mangrove Plant Acanthus ilicifolius

Four new meroterpenoids (2–5), along with three known analogues (1, 6, and 7) were isolated from mangrove plant Acanthus ilicifolius derived endophytic fungus Aspergillus flavipes. The structures of these compounds were elucidated by NMR and MS analysis, the configurations were assigned by CD data, and the stereochemistry of 1 was confirmed by X-ray crystallography analysis. A possible biogenetic pathway of compounds 1–7 was also proposed. All compounds were evaluated for antibacterial and cytotoxic activities.