Embryo phenolic compounds

Microspectrofluorometry was employed for mapping the location of phenolic substances in maize kernels. Autofluorescence due to phenolic acids was detected mainly in the embryo, aleurone and pericarp of maize kernel cross sections. Boric acid (H3BO3) reagent enhanced the fluorescence due to flavonoids in the aleurone layer. The amides of phenolic acids required derivatization with Ehrlich s reagent (168) to reveal fluorescence in the embryo and aleurone. The localization of phenolic amines was conflrmed by HPLC analysis. Phenolic compounds are important in the resistance of maize kernels to pests. Resistant maize types showed higher intensities of phenolic fluorescence but no unusual distributions of these compounds. ... 

The question then arises of the extent to which any nonlethal effect is reversible after removal of the toxicant. The answer seems to be that in the few cases which have been examined, this may indeed be the case all of them have examined phenolic compounds, one (McCahon et al. 1990) using the crustacean Asellus aquaticus, one assessing respiratory/cardiovascular effects on rainbow trout (Bradbury et al. 1989), and the third (Neilson et al. 1990) using the embryo/larvae assay with zebra fish (Brachydanio rerio). The last of these has been developed into a protocol that is modeled on the standard bioconcentration procedure in which a period of depuration is included after exposure to the toxicant. 

Chlorinated organic compounds are formed when chlorine used in bleaching the pulp reacts with phenols of the wood and humic substances during the pulping step. These pollutants are discharged with the effluents into the aquatic environment. It has been found that some of these effluents are lethal even at concentrations as low as 3.2% of the effluent. Chronic effects, including gross deformities, embryo and larval mortalities, behavioral modifications, and reproductive abnormalities, have been documented even at very low concentrations of effluent. 

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