摘要
Vitamin B 12 model molecule, dicyano cobyric mono acid hexamethylester 2f was synthesized from Vitamin B 12 by alcoholysis and acidic hydrolysis. Dicyano-a,b,c,d,e,g-α-f-N-(3-imidazoly) propylamido cobyrinate 3f was synthesized by the reaction between 2f and 3-imidazolylpropylamine hydrochloride. Compound 3f was treated with trifluoroacetic acid to give dimer-vitamin B 12 model molecule 5f. Compound 5f was treated with acidic buffers in methanol and the ring of 5f was opened to give compounds 6f. UV-Vis spectra were determined in buffers with different pH values. The equilibrium constants of Co-N bonds were calculated. K-value of 5f was 552×10 3, which is much greater than that of monomer vitamin B 12 4f. The strength of coordination bonds between the N atom in the side chain of cobyrinate and the Co atom in 5f was much weaker than that in monomer-vitamin B 12 4f.
Vitamin B 12 model molecule, dicyano cobyric mono acid hexamethylester 2f was synthesized from Vitamin B 12 by alcoholysis and acidic hydrolysis. Dicyano-a,b,c,d,e,g-α-f-N-(3-imidazoly) propylamido cobyrinate 3f was synthesized by the reaction between 2f and 3-imidazolylpropylamine hydrochloride. Compound 3f was treated with trifluoroacetic acid to give dimer-vitamin B 12 model molecule 5f. Compound 5f was treated with acidic buffers in methanol and the ring of 5f was opened to give compounds 6f. UV-Vis spectra were determined in buffers with different pH values. The equilibrium constants of Co-N bonds were calculated. K-value of 5f was 552×10 3, which is much greater than that of monomer vitamin B 12 4f. The strength of coordination bonds between the N atom in the side chain of cobyrinate and the Co atom in 5f was much weaker than that in monomer-vitamin B 12 4f.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2003年第6期1031-1033,共3页
Chemical Journal of Chinese Universities
基金
国家教育部优秀青年教师基金资助
