Analysis, synthesis and metabolic studies of sterols from harmful algae and fungi.

摘要

A series of analyses of the sterol compositions of several harmful algae were carried out. 24-Propylidenecholesterol was found in the Northeast brown tide alga Aureococcus anophagefferens as well as other species of Pelagophyte algae. Using the 24-E and 24-Z isomers of this sterol as biomarkers, analysis of a sediment core from Peconic Bay indicated that A. anophagefferens has been present in Long Island waters for about 100 years. Analysis of the ichytocidal Pfiesteria piscicida detected a novel sterol and a synthesis of this sterol was completed. Detailed lipid analysis was used in a chemotaxonomic study for two other harmful algae, Chloromorum toxicum and Chattonella verruculose, confirmed that these algae do not belong to the genus Chattonella (Raphidophyceae).; Metabolism of harmful algal sterols by bay scallops (Argopecten irradiens) and brine shrimps (Artemia salina) were investigated in feeding experiments using 13C-labeled sterols. The brown tide sterols E- and Z-24-propylidenecholesterol were partially converted to cholesterol by the test animals, while other sterols from harmful algae were not metabolized.; A detailed study of the sterol compositions of two species of the opportunistic fungal parasite Pneumocystis was carried out by HPLC and NMR analysis. Of the 28 sterols isolated from the AIDS pneumonia species P. jirovecii, most contained the 14alpha-methyl groups, indicating the a mutation of 14alpha-demethylase possibly caused by the use of anti-fungal drugs. Analysis of two closest related plant pathgenic rust fungi, Gymnosporangium juniperi-virginianae and Gymnosporangium clavipes, found similar sterols as for Pneumocystis.