Studies on the acetylation and NMR reassignment of indirubin derivatives.
The analysis of 1D- and 2D-NMR spectroscopic data confirmed that the amino N-1' protons of indirubin and indirubin-3'-oxime resonate at a higher frequency than N-1 protons. The amino N-1' protons in both indirubin and indirubin-3'-oxime are not favourable for acetylated reaction due to their intramolecular hydrogen bonding with the amide carbonyl group. The new N-1-acetylindirubin-3'-acetoxime has been synthesised using acetic anhydride. The reassignment of the NMR data of indirubin, indirubin-3'-oxime and N-1-acetylindirubin was confirmed with the aid of DEPT, HSQC, HMBC and NOESY methods.
Cuong
Nguyen Manh
NM
Institute of Chemistry, Vietnam Academy of Science and Technology, Hanoi, Vietnam. nmcuong@ich.vast.ac.vn
Tai
Bui Huu
BH
Hoan
Dang Hoang
DH
D000107:Acetylation; D007211:Indoles / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*
D007211:Indoles; C027185:indirubin