Asymmetric Total Synthesis and Stereochemical Revision of Gymnangiamide
摘要:
The asymmetric total synthesis of the originally proposed structure of gymnangiamide, a cytotoxic pentapeptide isolated from the marine hydroid Gymnangium regae Jaderholm, has been achieved. Key to the synthesis was the use of asymmetric hydrogenation of alpha-substituted, beta-ketoesters through dynamic kinetic resolution for the preparation of nonproteinogenic chiral amino acids. The disparity of the NMR spectra between the synthetic material containing the L-serine residue and the natural product required a revision of the proposed structure.
A conjugation of a cytotoxic drug to a cell-binding molecule with a bis-linker (dual-linker) as shown in Formula (I). Bis-linkage methods of making a conjugate of a cytotoxic drug/molecule to a cell-binding agent in a specific manner are also described, as well as application of the conjugates for the treatment of a cancer, or an autoimmune disease, or an infectious disease.
wherein “
” is an optional bond; X, Y, Z
1
, and Z
2
are a functional group; m
1
and n are a integer; L
1
and L
2
are a linker.
Asymmetric Total Synthesis and Stereochemical Revision of Gymnangiamide
The asymmetric total synthesis of the originally proposed structure of gymnangiamide, a cytotoxic pentapeptide isolated from the marine hydroid Gymnangium regae Jaderholm, has been achieved. Key to the synthesis was the use of asymmetric hydrogenation of alpha-substituted, beta-ketoesters through dynamic kinetic resolution for the preparation of nonproteinogenic chiral amino acids. The disparity of the NMR spectra between the synthetic material containing the L-serine residue and the natural product required a revision of the proposed structure.