A QUANTITATIVE STRUCTURE-ACTIVITY RELATIONSHIP FOR THE EFFECT OF ALCOHOLS ON NEUTRAL RED RETENTION BY THE MARINE MACROALGA ENTEROMORPHA-INTESTINALIS

The effect of alcohols on the retention of neutral red, a vital stain, was investigated for the marine macroalga Enteromorpha intestinalis. The algae were incubated for 24 hrs in a series of non-specific narcot ic alcohols, and subsequently exposed to a neutral red solution for 3 hrs. On removal, the stain was extracted into a solvent and the result ant absorbance measured spectrophotometrically. EC50 values for the in hibition of neutral red uptake were used to establish a quantitative s tructure-activity relationship (QSAR). This technique is reproducible and sensitive enough for laboratory testing. Comparisons are made betw een this assay and others.