8 research outputs found
Neuroprotective Activity of Some Marine Fungal Metabolites in the 6-Hydroxydopamin- and Paraquat-Induced Parkinson’s Disease Models
A new melatonin analogue 6-hydroxy-N-acetyl-β-oxotryptamine (1) was isolated from the marine-derived fungus Penicillium sp. KMM 4672. It is the second case of melatonin-related compounds isolation from microfilamentous fungi. The neuroprotective activities of this metabolite, as well as 3-methylorsellinic acid (2) and 8-methoxy-3,5-dimethylisochroman-6-ol (3) from Penicillium sp. KMM 4672, candidusin A (4) and 4″-dehydroxycandidusin A (5) from Aspergillus sp. KMM 4676, and diketopiperazine mactanamide (6) from Aspergillus flocculosus, were investigated in the 6-hydroxydopamine (6-OHDA)- and paraquat (PQ)-induced Parkinson’s disease (PD) cell models. All of them protected Neuro2a cells against the damaging influence of 6-OHDA to varying degrees. This effect may be realized via a reactive oxygen species (ROS) scavenging pathway. The new melatonin analogue more effectively protected Neuro2A cells against the 6-OHDA-induced neuronal death, in comparison with melatonin, as well as against the PQ-induced neurotoxicity. Dehydroxylation at C-3″ and C-4″ significantly increased free radical scavenging and neuroprotective activity of candidusin-related p-terphenyl polyketides in both the 6-OHDA- and PQ-induced PD models
Asperindoles A–D and a p-Terphenyl Derivative from the Ascidian-Derived Fungus Aspergillus sp. KMM 4676
Four new indole-diterpene alkaloids asperindoles A–D (1–4) and the known p-terphenyl derivative 3″-hydroxyterphenyllin (5) were isolated from the marine-derived strain of the fungus Aspergillus sp., associated with an unidentified colonial ascidian. The structures of 1–5 were established by 2D NMR and HRESIMS data. The absolute configurations of all stereocenters of 1–4 were determined by the combination of ROESY data, coupling constants analysis, and biogenetic considerations. Asperindoles C and D contain a 2-hydroxyisobutyric acid (2-HIBA) residue, rarely found in natural compounds. Asperindole A exhibits cytotoxic activity against hormone therapy-resistant PC-3 and 22Rv1, as well as hormone therapy-sensitive human prostate cancer cells, and induces apoptosis in these cells at low-micromolar concentrations
Neuroprotective Metabolites from Vietnamese Marine Derived Fungi of Aspergillus and Penicillium Genera
Low molecular weight secondary metabolites of marine fungi Aspergillus flocculosus, Aspergillus terreus and Penicillium sp. from Van Phong and Nha Trang Bays (Vietnam) were studied and a number of polyketides, bis-indole quinones and terpenoids were isolated. The structures of the isolated compounds were determined by 1D and 2D NMR and HR-ESI-MS techniques. Stereochemistry of some compounds was established based on ECD data. A chemical structure of asterriquinone F (6) was thoroughly described for the first time. Anthraquinone (13) was firstly obtained from a natural source. Neuroprotective influences of the isolated compounds against 6-OHDA, paraquat and rotenone toxicity were investigated. 4-Hydroxyscytalone (1), 4-hydroxy-6-dehydroxyscytalone (2) and demethylcitreoviranol (3) have shown significant increasing of paraquat- and rotenone-treated Neuro-2a cell viability and anti-ROS activity
Biologically Active Echinulin-Related Indolediketopiperazines from the Marine Sediment-Derived Fungus Aspergillus niveoglaucus
Seven known echinulin-related indolediketopiperazine alkaloids (1–7) were isolated from the Vietnamese sediment-derived fungus Aspergillus niveoglaucus. Using chiral HPLC, the enantiomers of cryptoechinuline B (1) were isolated as individual compounds for the first time. (+)-Cryptoechinuline B (1a) exhibited neuroprotective activity in 6-OHDA-, paraquat-, and rotenone-induced in vitro models of Parkinson’s disease. (−)-Cryptoechinuline B (1b) and neoechinulin C (5) protected the neuronal cells against paraquat-induced damage in a Parkinson’s disease model. Neoechinulin B (4) exhibited cytoprotective activity in a rotenone-induced model, and neoechinulin (7) showed activity in the 6-OHDA-induced model
Oxirapentyns F–K from the Marine-Sediment-Derived Fungus <i>Isaria felina</i> KMM 4639
Six new highly oxygenated chromene
derivatives, oxirapentyns F–K (<b>2</b>–<b>7</b>), one new polyketide (<b>8</b>), one new benzofurane
(<b>9</b>), and two known cyclodepsipeptides, isoisariin B and
isaridin E, were isolated from the lipophilic extract of the marine-derived
fungus <i>Isaria felina</i> KMM 4639. The structures of
compounds <b>2</b>–<b>9</b> were determined using
spectroscopic methods. The relative configurations of compounds <b>2</b>–<b>7</b> were established through a combination
of NOE data and spin coupling constants, and these results were confirmed
by X-ray crystallographic analysis of <b>4</b>. The absolute
structures of all oxirapentyns were assumed based on their biogenetic
relationship and confirmed using the modified Mosher’s method
on <b>2</b> and <b>7</b>. Isariketide (<b>8</b>)
showed moderate cytotoxicity toward HL-60 cells