[Relation between the chemical structure of substances and their antimicrobial action against atypical strains. II. 6-acycloamido-2-alkylthiobenzothiazoles, quantitative relation to their effectiveness spectrum].
Forty-six 6-acylamido-2-alkylthiobenzothiazoles were tested in vitro for antimicrobial activity towards Mycobacterium avium. The values of logarithms of the minimal inhibitory concentrations (log MIC) are shown in Table 1. The relationships between chemical structure and the activity under study were studied by the Free-Wilson method. The results, contributions of the substituents in positions 2 and 6 and the contribution of the common benzothiazole part (marked C) to the activity (delta log MIC) are shown in Table 2. Regression equation correlating the contributions and fragmental hydrophobic constants (f) belonging to the unbranched alkyl groups bound to the sulphur atom in position 2 (see Table 2) are not statistically significant (equation 8). The initial data for a complex analysis of the structure--antimycobacterial activity relationships with regard to the equipotency of the activity towards the species mentioned below form the values of log MIC and the derived values delta log MIC towards Mycobacterium tuberculosis, M. kansasii (see ref.9) and M. avium (see above). According to it, to each drug, each molecular fragment, the vector of activities A is attributed (equation 1), or the vector of contributions a (equation 7). Complex analysis is based on the idea of comparison (similarity) of the drug under study with an "ideal" drug, which possesses the required profile of activities. The vector uk corresponding to it is given for the above-considered case (of wide spectrum) by relation 5, for the case of selectivity with regard to the 1st activity by relation 4. The fundamental concepts of vector algebra, particularly the scalar product of vectors (A, uk) (relation 3) are used as the criteria of decision.(ABSTRACT TRUNCATED AT 250 WORDS)
Machácek
M
M
Kunes
J
J
Sidóová
E
E
Odlerová
Z
Z
Waisser
K
K
D055598:Chemical Phenomena; D002621:Chemistry; D009162:Mycobacterium avium / Q000187:drug effects*; D013329:Structure-Activity Relationship; D013844:Thiazoles / Q000494:pharmacology*
D013844:Thiazoles
Vztahy mezi chemickou strukturou látek a jejich antimykobakteriální aktivitou vůci atypickým kmenům. II. 6-acylamido-2-alkylthiobenzothiazoly, kvantitativní vztahy ke spektru úcinků.