Parasiticol, a metabolite structurally related to the aflatoxins, has been isolated and characterized. The compound is elaborated by several strains of the Aspergillus jiaDus series previously shown to be aflatoxin producers. The metabolite was separated and purified by chromatography Oll three columns (silicic acid, silica gel, and alumiua) followed by recrystallization from chlorofom,-bexane....

Phosphatidyl inositol and a cardiolipin-like phospholipid survive the autolysis which is induced in yeast by treating it with toluene, whereas other phospholipids are extensively degraded. Lipid from autolyzed yeast was suspended in isopropanol to extract lecithin and neutral lipid. The insoluble phosphatidyl inositol and cardiolipin were then separated by chromatography on silicic acid.

1. To gain insight into a putative role for mitochondria in silicon metabolism, mitochondrial uptake (by which it is meant the removal from the medium) of silicic acid [Si(OH)4] was studied under conditions minimizing SI(OH)4 polymerization. 2. Measurements of mitochondrial respiration and swelling indicated indirectly a significant uptake of Si(OH)4 as a weak acid, but this was not confirmed w...

Diamond, the hardest of all minerals, was classed as an inert material, similar to anthracite and corundum, by Gardner (1938) on the basis of intravenous injection experiments in rabbits. By intraperitoneal injection into mice Bovet (1952) produced collagenous nodules in places where much diamond dust was accumulated. But it took six months to one year for such nodules to form as against a few ...

Two in situ iron-enrichment experiments were conducted in the Pacific sector of the Southern Ocean during summer 2002 (SOFeX). The ‘‘north patch,’’ established within the Subantarctic Zone ( 561S), was characterized by high nitrate ( 21mmolm ) but low silicic acid (2mmolm ) concentrations. North patch iron enrichment increased chlorophyll (Chl) by 12-fold to 2.1mgm 3 and primary productivity (P...

Diatoms are known to fractionate silicon isotopes during the formation of their frustules causing isotopic composition biogenic silica track degree silicic acid consumption in surface waters. Despite a growing body work that uses this proxy reconstruct past changes utilization, understanding benthic cycle, particularly identification and quantification processes potentially alter early diagenes...