TOPOLOGICAL INDEXES AND R(M) VALUES OF ISOMERIC METHYLPHENOLS IN STRUCTURE - BIOLOGICAL-ACTIVITY STUDIES .9.

Selected isomeric methylphenols have been separated bf TLC on silanize d silica gel. R(M) and toxicological log 1/C values have been correlat ed with the hydrophobic constant pi, with pK(a) values, and with numer ical values of the topological indexes M, (0) chi(v), (1) chi(v), (2) chi(v), 3 chi(v), W, I-B, A, B-0, B-1, B-2, B-2(q), B-3, B-3(q), C, D, and chi(012). A series of monoparametric equations with high correlat ion coefficients was obtained; these equations enabled prediction of R (M) and log 1/C values for the methylphenols investigated. Multiparame tric equations used for prediction of R(M) and log 1/C values were cha racterized by smaller values of standard errors than were monoparametr ic: equations. The best correlation was found for use of the topologic al indexes (0) chi(v), (1) chi(v), (2) chi(v), A, B-3, B-3(q), C, D, a nd chi(012). These results testify to the special significance of topo logical indexes for estimating the physico-chemical and biological pro perties of selected organic compounds. These investigation had semi-qu antitative character.