Qian Che

Genome scanning inspired isolation of reedsmycins A–F, polyene-polyol macrolides from Streptomyces sp. CHQ-64

Genome scanning of the reed rhizosphere soil-derived Streptomyces sp. CHQ-64 revealed a partial gene cluster, putatively encoding a polyene-polyol compound. Inspired by this finding, six new polyene-polyol macrolides, reedsmycins A–F (1–6), were isolated guided by the characteristic NMR signals. Their structures were elucidated using mass spectrometry and extensive NMR spectroscopy. Among them, reedsmycin F (6) possessed a rare 31-membered macroring containing a tetrahydrofuran motif, and reedsmycin A (1) exhibited promising activity against Candida albicans with a MIC of 25–50 μM, in a comparable level to that of the positive control nystatin.

Peniphenylanes A-G from the Deep-Sea-Derived Fungus Penicillium fellutanum HDN14-323.

Seven new 6-methylsaligenin derivatives, including the trimeric peniphenylanes A-B (1-2) and dimeric peniphenylanes C-G (3-7), together with four known biogenetically related compounds (8-11) were discovered from the extract of the deep-sea-derived fungus Penicillium fellutanum HDN14-323. The structures of the new compounds were established through extensive analysis. Their cytotoxic activity against HeLa, HL-60, and HCT-116 cell lines was evaluated, with compound 4 exhibiting the best activity against the HeLa cell line (IC50 = 9.3 µM).

Clindanones A and B and cladosporols F and G, polyketides from the deep-sea derived fungus Cladosporium cladosporioides HDN14-342

Four new tetralone derivatives, clindanones A and B (1 and 2) and cladosporols F and G (3 and 4), together with three known biogenetically related polyketides (5–7), were isolated from the deep-sea derived fungus Cladosporium cladosporioides HDN14-342. The structures of 1–4, including absolute configurations, were deduced based on MS, NMR and TD-DFT calculations of specific ECD spectra. The absolute configurations of the known cladosporols C (5) and E (6) were also revised. Compounds 1 and 2 possessed new dimeric forms of the skeleton composed by coupling of indanone and 1-tetralone units, and 4 showed the best cytotoxic activity against HeLa cells with an IC50 value of 3.9 μM.

Lipid-Lowering Polyketides from the Fungus Penicillium Steckii HDN13-279

Seven new polyketides, named tanzawaic acids R–X (1–6, 11), along with seven known analogues (7–10 and 12–14), were isolated from Penicillium steckii HDN13-279. Their structures, including the absolute configurations, were elucidated by NMR, MS, X-ray diffraction, circular dichroism (CD) analyses and chemical derivatization. Five compounds (2, 3, 6, 10 and 12) significantly decreased the oleic acid (OA)-elicited lipid accumulation in HepG2 liver cells at the concentration of 10 μM, among which, four compounds (3, 6, 10 and 12) significantly decreased intracellular total cholesterol (TC) levels and three Compounds (3, 6, and 10) significantly decreased intracellular triglyceride (TG) levels. Moreover, the TG-lowering capacities of compounds 6 and 10 were comparable with those of simvastatin, with the TG levels being nearly equal to blank control. This is the first report on the lipid-lowering activity of tanzawaic acid derivatives.

Lipid-lowering polyketides from a soft coral-derived fungus Cladosporium sp. TZP29.

Two new C12 polyketides, cladospolides E and F (1 and 2), together with four known derivatives seco-patulolides A and C (3 and 4), 11-hydroxy-γ-dodecalactone (5) and iso-cladospolide B (6), were isolated from a soft coral-derived fungus Cladosporium sp. TZP-29. Their structures, including the absolute configurations, were elucidated by spectroscopic analysis, modified Moshers method, and the analysis of their biogenesis. All compounds were non-cytotoxic while compounds 1 and 3-5 showed potent lipid-lowering activity in HepG2 hepatocytes.

Exopisiod B and farylhydrazone C, two new alkaloids from the Antarctic-derived fungus Penicillium sp. HDN14-431

Abstract Two new compounds, exopisiod B (1) and farylhydrazone C (2), together with two known compounds (3–4), were isolated from the Antarctic-derived fungus Penicillium sp. HDN14-431. Their structures including absolute configurations were elucidated by spectroscopic methods and TDDFT ECD calculations. The cytotoxicity and antimicrobial activities of all compounds were tested.

Chetracins E and F, cytotoxic epipolythiodioxopiperazines from the marine-derived fungus Acrostalagmus luteoalbus HDN13-530

Two new epipolythiodioxopiperazines, named chetracins E and F (1 and 2), along with the known chetracin C (3), were isolated from the fungus Acrostalagmus luteoalbus HDN13-530. Their structures were elucidated based on the NMR, MS and CD data, as well as chemical conversion. All of the compounds exhibited cytotoxicity against the tested five cancer lines in low-micromolar or nanomolar IC50 values. The computational docking indicated that compounds 1–3 could bind to the C-terminal of heat shock protein 90 (Hsp90), which was in line with the experimental observation of decreases in levels and active forms of Hsp90 client proteins.

Determination of Taichunamide H and Structural Revision of Taichunamide A

A new indole alkaloid, named taichunamide H (1), was obtained from cultures of the fungus Aspergillus versicolor. With observation of a carbon resonance with a chemical shift of 190.4 ppm, generally thought to be a carbonyl, the structure of 1 was initially proposed to be a diastereomer of taichunamide A that contains a unique spiro-azetidine moiety. Further analysis of compound 1 using X-ray diffraction showed that the spiro-azetidine moiety should be revised as a fused-imine-containing pyrrole ring, with the resonance at 190.4 ppm assigned as an imine carbon. Accordingly, the structure of taichunamide A was also revised.

α-Pyrone derivatives with cyto-protective activity from two Takla Makan desert soil derived actinomycete Nocardiopsis strains recovered in seawater based medium

Abstract In this paper, we described the discovery of two Nocardiopsis strains HDN154-146 and HDN154-168 from Takla Makan desert soil samples using seawater based medium. Chemical investigation of these two strains led to the discovery of eight new α-pyrone derivatives named nocahypyrones A-H (1–8), together with one known analogue germicidin G (9). The structures of these compounds, including absolute configurations, were elucidated by extensive NMR, MS, and CD analyses. Compounds 1–9 were tested for their cyto-protective activities and for the first time we found α-pyrones 5 and 8 exhibited capabilities to induce expression of phase II detoxifying enzymes.

Sorbicillasins A–B and Scirpyrone K from a Deep-Sea-Derived Fungus, Phialocephala sp. FL30r

Two new nitrogen-containing sorbicillinoids named sorbicillasins A and B (1 and 2) and a new 3,4,6-trisubstituted α-pyrone derivative, scirpyrone K (3), together with two known biosynthetically related polyketides (4–5), were isolated from the deep-sea-derived fungus Phialocephala sp. FL30r by using the OSMAC (one strain-many compounds) method. The structures of 1–3, including absolute configurations, were deduced based on MS, NMR, and time-dependent density functional theory (TD-DFT) calculations of specific ECD (electronic circular dichroism) spectra. Compounds 1 and 2 possessed a novel hexahydropyrimido[2,1-a] isoindole moiety, and compound 3 exhibited weak radical scavenging activity against DPPH (2,2-diphenyl-1-picrylhydrazyl) with an IC50 value of 27.9 μM.