Efficient preparative isolation and identification of walnut bioactive components using high-speed counter-current chromatography and LC-ESI-IT-TOF-MS.

Preparative isolation of complex mixtures of compounds from walnut polar extracts was established by a combination of high-speed counter-current chromatography (HSCCC) and electrospray ionization-ion trap-time of flight mass spectrometry (ESI-IT-TOF-MS). Compounds were isolated after a solvent optimisation selection based on solute distribution in a biphasic solvent system. Isolation was achieved through one or two successive HSCCC runs, and final purification on Sephadex LH-20.

Aflaquinolones A-G: secondary metabolites from marine and fungicolous isolates of Aspergillus spp.

Seven new compounds (aflaquinolones A-G; 1-7) containing dihydroquinolin-2-one and terpenoid units have been isolated from two different fungal sources. Two of these metabolites (1 and 2) were obtained from a Hawaiian fungicolous isolate of Aspergillus sp. (section Flavipedes; MYC-2048 = NRRL 58570), while the others were obtained from a marine Aspergillus isolate (SF-5044) collected in Korea.

Biological activity of peanut (Arachis hypogaea) phytoalexins and selected natural and synthetic Stilbenoids.

The peanut plant (Arachis hypogaea L.), when infected by a microbial pathogen, is capable of producing stilbene-derived compounds that are considered antifungal phytoalexins. In addition, the potential health benefits of other stilbenoids from peanuts, including resveratrol and pterostilbene, have been acknowledged by several investigators.

Pterocarpenes elicited by Aspergillus caelatus in peanut (Arachis hypogaea) seeds.

The substituted pterocarpenes named aracarpene-1 (1) and aracarpene-2 (2) were isolated from wounded peanut seeds challenged by a strain of Aspergillus caelatus. The structures of these putative phytoalexins were determined by interpretation of NMR and MS data. The aracarpenes were investigated for their antifungal and antibacterial activities as well as antioxidant, anti-inflammatory, and cytotoxic activities in mammalian cells.

New dimeric stilbenoids from fungal-challenged peanut ( Arachis hypogaea) seeds.

The peanut plant can resist fungal attacks by producing stilbene-derived phytoalexins. Once understood, such a natural phytoalexin-based mechanism of peanut resistance could be potentially manipulated to obtain fungal-resistant peanut breeding lines. Several simple stilbenoid phytoalexins from peanuts have been reported.

New stilbenoids from peanut ( Arachis hypogaea ) seeds challenged by an Aspergillus caelatus strain.

Four new stilbene derivatives, termed arahypins, have been isolated from peanut seeds challenged by an Aspergillus caelatus strain, along with two known stilbenoids that have not been previously reported in peanuts. The structures of these new putative phytoalexins were determined by analysis of NMR, MS, and UV data. Together with other known peanut stilbenoids that were also produced in the challenged seeds, these new compounds may play a defensive role against invasive fungi.