The fungicidal activity of the 3-hydroxy-1,2,3,4-tetrahydroquinazoline-4-one derivatives and simulation of the structure-activity dependence.

Abstract

Hydroxamic acid derivatives exhibit a broad spec- trum of biological activity. They include substances with the fungicidal, antibacterial, insecticidal, acari- cidal, and rodenticidal activities, plant-growth regula- tors, herbicides, animal-growth stimulators, and both inhibitors and reactivators of enzymes. final acetone concentration in the substance-containing and control media was 10 ml/l. The prepared agar was poured into Petri dishes with an internal diameter of 9 cm (15 ml per dish) and cooled. Mycelium pieces of three-day-old fungal cultures were inoculated into the nutrient medium and kept at 25 ∠ 1i C for three days. Then, the diameters of fungal colonies were measured to determine the extent of the mycelium growth inhi- bition as compared to the control. In all series, tri- adimephon (3,3-dimethyl-1-(1H-1,2,4,-triazolyl-1)-1- (4-chlorphenoxy)butanon-2) was used as a reference substance. The results of the tests are shown in Table 2. Synthesis, spectral characteristics, and physico- chemical properties of the compounds used were previ- ously described in detail (7). To study the structure-activity relationships, several types of descriptors were used. The latter were calcu- lated from the molecular mechanical (MMC) and quan- tum-chemical (AM 1) calculations of molecules, the logarithm (log P ) of the coefficient of the compound distribution in the octanol-water system, and the pres- ence of either aliphatic or aromatic substituents.