Selected phenolic compounds in cultivated plants: ecologic functions, health implications, and modulation by pesticides.

Phenolic compounds are widely distributed in the plant kingdom. Plant tissues may contain up to several grams per kilogram. External stimuli such as microbial infections, ultraviolet radiation, and chemical stressors induce their synthesis. The phenolic compounds resveratrol, flavonoids, and furanocoumarins have many ecologic functions and affect human health. Ecologic functions include defense against microbial pathogens and herbivorous animals. Phenolic compounds may have both beneficial and toxic effects on human health. Effects on low-density lipoproteins and aggregation of platelets are beneficial because they reduce the risk of coronary heart disease. Mutagenic, cancerogenic, and phototoxic effects are risk factors of human health. The synthesis of phenolic compounds in plants can be modulated by the application of herbicides and, to a lesser extent, insecticides and fungicides. The effects on ecosystem functioning and human health are complex and cannot be predicted with great certainty. The consequences of the combined natural and pesticide-induced modulating effects for ecologic functions and human health should be further evaluated.

Preparation and characterization of the fullerene diols 1,2-C(60)(OH)(2), 1,2-C(70)(OH)(2), and 5,6-C(70)(OH)(2).

The simple fullerene diols C(60)(OH)(2) and C(70)(OH)(2) were prepared by addition of RuO(4) followed by acid hydrolysis. The 1,2-C(60)(OH)(2) isomer was formed from C(60), and two isomers (1,2 and 5,6) of C(70)(OH)(2) were formed in the RuO(4) hydroxylation of C(70). These compounds are much more soluble in THF and dioxane than the parent fullerenes. More highly hydroxylated materials are formed as well.

[Studies on the metabolism of inorganic sulfate (author's transl)]. / Untersuchungen über den Stoffwechsel des anorganischen Sulfates.

The blood serum fasting levels of inorganic sulfate increase with age, other differences are largely due to diet. The serum sulfate shows a circadian rhythm with a minimum before noon and a maximum in the afternoon and evening. Urinary excretion of sulfate disappears during a low-protein diet. The serum sulfate levels rise temporarily if oral intake of protein, water or inorganic sulfate in non-laxative doses is increased. From the decomposition of protein, sulfate is first excreted with alkali cations and sooner than other catabolites. Drinking water mobilizes sulfate from its tissue pool, which can be blocked by the addition of sodium chloride. The subsequent excretion of an oral sulfate dose is prolonged over one day.

Chromatographic purification and properties of soluble single-walled carbon nanotubes.

We report an improved chromatographic purification of soluble single-walled carbon nanotubes (s-SWNTs) using gel permeation chromatography. Three fractions are separated by gel permeation chromatography, and the first fraction contains 74% of the s-SWNTs as detected by atomic force microscopy and UV and near-infrared spectroscopy.