STRUCTURE-BIOLOGICAL ACTIVITIES RELATIONSHIPS AMONG LEUCOMYCINS AND THEIR DERIVATIVES

Abstract

The relationship between chemical structure and biological activity of leucomycins and their derivatives was examined in vivo and in vitro. The biological activity of Fr-group was higher than that of Ac-group in vitro, but the latter showed higher blood level and lower toxicity than Fr-group. Lengthening of the carbon chain in the O-acyl group at C-4 in mycarose resulted in a marked increase in the biological activity in vitro, with the isovaleryl group having the highest activity. The aldehyde group in the lactone was related to antibiotic activity, but α, β, γ, δ-unsaturated alcohol system at C₉- to C₁₂-positions was not important.