Vanoxonin, a new inhibitor of thymidylate synthetase, was found in cultured broths of the strain MG245-CF2 classified as Saccharopolyspora hirsuta. Vanoxonin, C18H25N3O9, was obtained as colorless powder. Vanoxonin forms a vanadium complex which exhibits a strong inhibition against thymidylate synthetase. The concentration for 50% inhibition of the enzyme (IC50) was 0.7 micrograms/ml.

Cyclothiazomycin is a novel renin inhibitor produced by Streptomyces sp. NR0516. It was isolated from fermentation broth by extraction with butyl alcohol, QAE-Toyopearl column chromatography and preparative HPLC. Cyclothiazomycin, which was determined to be a unique polythiazole-containing bicyclic peptide, exhibited inhibitory activity against human plasma renin with IC50 being 1.7 microM.

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...

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...