Molecular structure and biochemical toxicity of four halogeno-benzenes on the unicellular green alga Selenastrum capricornutum

Comparative toxicity of hexachlorobenzene, 1,2,3-trichlorobenzene, bromobenzene, and chlorobenzene on the growth, protein concentration, ATP content and relevant enzyme activities of the unicellular green alga Selenastrum capricornutum was studied. Five typical molecular descriptive parameters: E-homo, (1)chi(v), K-ow, E-s, pi(x) of these organic chemicals were selected to study the structure and bio-activities of the four halogeno-benzenes. The results indicated that the protein concentration, activities of G6PDH and AP, and ATP content were more sensitive to halogeno-benzenes than dry weight. Among the four halogeno-benzenes, the order of toxicity on the alga was: hexachlorobenzene > 1,2,3-trichlorobenzene > bromobenzene > chlorobenzene. There was a good correlation between the molecular structure of halogeno-benzenes and their biochemical toxicity. (C) 1998 Elsevier Science B.V. All rights reserved.