Three new depsidones, botryorhodines E-G (1-3), and two new isoindolinones, meyeroguillines A and B (7 and 9), along with five known compounds were isolated from an endophytic fungus Meyerozyma guilliermondii, derived from the mangrove plant Kandelia obovata. Their structures were elucidated by 1D and 2D NMR spectroscopy and high resolution mass spectrometry (HREIMS). Compounds 1-6 exhibited st...

Nocardiopsis sp. K-290 was found to produce novel metabolites, designated K-252b, c and d, which were structurally related to K-252a. These compounds were isolated from the culture broth and the physico-chemical and biochemical properties were examined. The compounds strongly inhibited protein kinase C. IC50 values (the concentrations causing 50% inhibition) for the effects of K-252b, c and d o...

The chemical investigation of the mangrove endophytic fungus Aspergillus sp. 085242 afforded eight isocoumarin derivatives 1-8 and one isoquinoline 9. Asperisocoumarins A and B (1 and 2) were new furoisocoumarins, and asperisocoumarins E and F (5 and 6) were new isocoumarins. Their structures were established by analysis of their spectroscopic data and the absolute configuration of compound 2 w...

Cholinesterases are important biological targets responsible for regulation of cholinergic transmission, and their inhibitors are used for the treatment of Alzheimer's disease. To design new cholinesterase inhibitors, of different structure-based design strategies was followed, including the modification of compounds from a previously developed library and a fragment-based design approach. This...

Halofantrine is a newer antimalarial drug which has not been approved for clinical use in Papua New Guinea. We assessed 21 Central Province isolates of Plasmodium falciparum for their in vitro susceptibility to halofantrine. The concentration required to inhibit 50% of parasite growth (IC50) ranged from 0.05 to 7.0 nM with a mean of 1.90 nM and a median of 1.50 nM. The minimum inhibitory concen...

The phytochemical investigation on 1 g of materials from Gypsoplacamacrophylla (Zahlbr.) Timdal resulted in the discovery of gypmacrophin A, a rare pentacyclic sesterterpenoid; brialmontin III, a new polysubstituted depside and two known ones, brialmontins I and II. The structure and absolute configurations of gypmacrophin A were elucidated by spectroscopic analyses and computational methods. G...

Acquired resistance of Helicobacter pylori to metronidazole and clarithromycin has been reported, with metronidazole resistance being very common. This has an important clinical impact on dual therapies, as well as on the standard triple therapies. However, when antisecretory drug based triple therapies with amoxycillin or clarithromycin and metronidazole are used, the resistance can be overcom...

A new indolyl-6,10b-dihydro-5aH-[1]benzofuro[2,3-b]indole derivative, varioloid A (1), was isolated from the marine alga-derived endophytic fungus Paecilomyces variotii EN-291. Its structure was elucidated on the basis of extensive analysis of 1D and 2D NMR data and the absolute configuration was determined by time-dependent density functional theory-electronic circular dichroism (TDDFT-ECD) ca...

A new methylated flavonol, 5,7,2',4'-tetrahydroxy-3-methoxyflavone (1), had been isolated from the methanol extract of the wood of Morus australis, along with nine known compounds, kuwanon C (2), morusin (3), morachalcone A (4), oxyresveratrol (5), 4'-(2-methyl-2-buten-4-yl)oxyresveratrol (6), moracins M (7) and C (8), alboctalol (9), and macrourin B (10). The structures of these compounds were...

The inactivation gating of hERG channels is important for the channel function and drug-channel interaction. Whereas hERG channels are highly selective for K+, we have found that inactivated hERG channels allow Na+ to permeate in the absence of K+. This provides a new way to directly monitor and investigate hERG inactivation. By using whole cell patch clamp method with an internal solution cont...