Synthesis of the Quinoline-Linked Triazolopyrimidine Analogues and Their Interactions with the Recombinant Tobacco Acetolactate Synthase

• Published in: Biochemical and biophysical research communications Vol. 258; no. 3; pp. 797 - 801
• Main Authors: Namgoong, Sung Keon, Lee, Hyun Jung, Kim, Young Sook, Shin, Jung-Hyu, Che, Jong-Khn, Jang, Do Young, Kim, Gun Sung, Yoo, Jae Won, Kang, Moon-Kyeong, Kil, Mee-Wha, Choi, Jung-Do, Chang, Soo-Ik
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 19.05.1999
• Subjects: acetolactate synthase; Acetolactate Synthase - chemistry; Acetolactate Synthase - genetics; herbicides; Herbicides - chemistry; Mutation; Nicotiana - enzymology; Plants, Toxic; Quinolines - chemistry; Recombinant Proteins - chemistry; tobacco; Triazoles - chemical synthesis; Triazoles - chemistry; triazolopyrimidine sulfonamide; tobacco; acetolactate synthase; triazolopyrimidine sulfonamide; herbicides
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1006/bbrc.1999.0708

Acetolactate synthase (ALS) is the first common enzyme in the biosynthesis of L-leucine, L-isoleucine, and L-valine. Triazolopyrimidine sulfonamide (TP) is a mixed-type inhibitor of ALS with respect to both pyruvate and thiamine pyrophosphate. In this study, we synthesized new substituted quinoline-linked TP analogues and several TP analogues which contained either unsubstituted aminoquinolines or amino isoquinolines. In addition, we examined the interactions of both the wild-type and the sulfonylurea-resistant recombinant tobacco ALS enzymes in a highly pure and active form with the quinoline-linked TP analogues, respectively. The wild-type tobacco ALS was extremely sensitive to inhibition by the quinoline-linked TP analogues. In contrast, the mutant tobacco ALS was insensitive to both the quinoline-linked triazolopyrimidine and the sulfonylurea herbicides. The results indicate that the ability of the quinoline-linked TP analogues to inhibit ALS is highly sensitive to substitution at the ortho position (C-7) and to the position of the ring nitrogen around the sulfonamide functionality (C-8).