New piperazine derivatives helvamides B-C from the marine-derived fungus Penicillium velutinum ZK-14 uncovered by OSMAC (One Strain Many Compounds) strategy.

Four extracts of the marine-derived fungus Penicillium velutinum J.F.H. Beyma were obtained via metal ions stress conditions based on the OSMAC (One Strain Many Compounds) strategy. Using a combination of modern approaches such as LC/UV, LC/MS and bioactivity data analysis, as well as in silico calculations, influence metal stress factors to change metabolite profiles Penicillium velutinum were analyzed. From the ethyl acetate extract of the P. velutinum were isolated two new piperazine derivatives helvamides B (1) and C (2) together with known saroclazin A (3) (4S,5R,7S)-4,11-dihydroxy-guaia-1(2),9(10)-dien (4). Their structures were established based on spectroscopic methods. The absolute configuration of helvamide B (1) as 2R,5R was determined by a combination of the X-ray analysis and by time-dependent density functional theory (TD-DFT) calculations of electronic circular dichroism (ECD) spectra. The cytotoxic activity of the isolated compounds against human prostate cancer PC-3 and human embryonic kidney HEK-293 cells and growth inhibition activity against yeast-like fungi Candida albicans were assayed.

Meroantarctines A-C, Meroterpenoids with Rearranged Skeletons from the Alga-Derived Fungus Penicillium antarcticum KMM 4685 with Potent p-Glycoprotein Inhibitory Activity.

New meroterpenoids, meroantarctines A-C (1-3), with unique 6/5/6/6, 6/5/6/5/6, and 6/5/6/5 polycyclic systems were isolated from the alga-derived fungus Penicillium antarcticum KMM 4685. Their structures were elucidated by spectroscopic methods, X-ray diffraction, and quantum chemical calculations. A biogenetic pathway for 1-3 was proposed. Meroantarctines A-C (1-3) inhibited p-glycoprotein activity and could resensitize drug-resistant cancer cells to docetaxel.

Enhancing Lithium and Sodium Storage Properties of TiO2(B) Nanobelts by Doping with Nickel and Zinc.

Nickel- and zinc-doped TiO2(B) nanobelts were synthesized using a hydrothermal technique. It was found that the incorporation of 5 at.% Ni into bronze TiO2 expanded the unit cell by 4%. Furthermore, Ni dopant induced the 3d energy levels within TiO2(B) band structure and oxygen defects, narrowing the band gap from 3.28 eV (undoped) to 2.70 eV. Oppositely, Zn entered restrictedly into TiO2(B), but nonetheless, improves its electronic properties (Eg is narrowed to 3.21 eV). The conductivity of nickel- (2.24 × 10-8 S·cm-1) and zinc-containing (3.29 × 10-9 S·cm-1) TiO2(B) exceeds that of unmodified TiO2(B) (1.05 × 10-10 S·cm-1). When tested for electrochemical storage, nickel-doped mesoporous TiO2(B) nanobelts exhibited improved electrochemical performance. For lithium batteries, a reversible capacity of 173 mAh·g-1 was reached after 100 cycles at the current load of 50 mA·g-1, whereas, for unmodified and Zn-doped samples, around 140 and 151 mAh·g-1 was obtained. Moreover, Ni doping enhanced the rate capability of TiO2(B) nanobelts (104 mAh·g-1 at a current density of 1.8 A·g-1). In terms of sodium storage, nickel-doped TiO2(B) nanobelts exhibited improved cycling with a stabilized reversible capacity of 97 mAh·g-1 over 50 cycles at the current load of 35 mA·g-1.

New Deoxyisoaustamide Derivatives from the Coral-Derived Fungus Penicillium dimorphosporum KMM 4689.

Seven new deoxyisoaustamide derivatives (1-7) together with known compounds (8-10) were isolated from the coral-derived fungus Penicillium dimorphosporum KMM 4689. Their structures were established using spectroscopic methods, X-ray diffraction analysis and by comparison with related known compounds. The absolute configurations of some alkaloids were determined based on CD and NOESY data as well as biogenetic considerations. The cytotoxic and neuroprotective activities of some of the isolated compounds were examined and structure-activity relationships were pointed out. New deoxyisoaustamides 4-6 at concentration of 1 µM revealed a statistical increase of PQ(paraquat)-treated Neuro-2a cell viability by 30-39%.

Prenylated indole alkaloids from co-culture of marine-derived fungi Aspergillus sulphureus and Isaria felina.

Five new prenylated indole alkaloids, 17-hydroxynotoamide D (1), 17-O-ethylnotoamide M (2), 10-O-acetylsclerotiamide (3), 10-O-ethylsclerotiamide (4), and 10-O-ethylnotoamide R (5) were isolated from a co-culture of marine-derived fungi Aspergillus sulphureus KMM 4640 and Isaria felina KMM 4639. The structures of 1-5 were determined by detailed analysis of spectroscopic data and by comparison with related known compounds. The absolute configurations of 1-5 were determined by time-dependent density functional theory (TD-DFT) calculations of ECD spectra. Compound 2 is able to inhibit the colony formation of human prostate cancer cells 22Rv1 at non-cytotoxic concentration of 10 µM.

Pallidopenillines: Polyketides from the Alga-Derived Fungus Penicillium thomii Maire KMM 4675.

Eleven new polyketides, pallidopenillines 1-11, were isolated from the alga-derived fungus Penicillium thomii. The structures of these compounds were established based on spectroscopic methods. The absolute configuration of pallidopenilline A (1) as 4R, 5S, 8S, 9R, 10R, 13R was established using a combination of the modified Mosher's method, X-ray analysis, and NOESY data. The absolute configurations of 2-5 were determined by time-dependent density functional theory calculations of the ECD spectra and ECD and NOESY data. It was shown that 1-acetylpallidopenilline A (2) and pallidopenilline G (10) inhibit the growth of colonies of 22Rv1 cells by 40% at 2 and 1 µM, respectively.