- Prodrugs of vitamin E. 1. Preparation and enzymatic hydrolysis of aminoalkanecarboxylic acid esters of d-α-tocopherol
-
Nine aminoalkanecarboxylic acid esters of d-α-tocopherol were synthesized and evaluated as potential water-soluble prodrugs suitable for parenteral administration. The hydrochloric acid salts of the esters were soluble in water. The kinetics of hydrolysis of the esters was studied in isotonic phosphate buffer, rat plasma, human plasma, and rat liver homogenate at 37 °C. The hydrolysis of the esters was proved to be catalyzed by fiver esterases. The susceptibility of the esters to undergo liver esterase hydrolysis was affected by the structure of the amino functionality and size of the acyl moiety on the promoiety. The N-methylaminoacetyl and N,N- dimethylaminoacetyl esters of d-α-tocopherol were more rapidly hydrolyzed than d-α-tocopheryl acetate, a commercially available d-α-tocopheryl ester. These results suggested that the salts of the N-methylaminoacetyl and N,N- dimethylaminoacetyl esters are promising prodrug candidates of d-α- tocopheryl for parenteral use.
- Takata,Karube,Nagata,Matsushima
-
-
Read Online
- Screening of ligands for the Ullmann synthesis of electron-rich diaryl ethers
-
In the search for new ligands for the Ullmann diaryl ether synthesis, permitting the coupling of electron-rich aryl bromides at relatively low temperatures, 56 structurally diverse multidentate ligands were screened in a model system that uses copper iodide in acetonitrile with potassium phosphate as the base. The ligands differed largely in their performance, but no privileged structural class could be identified.
- Otto, Nicola,Opatz, Till
-
supporting information; experimental part
p. 1105 - 1111
(2012/09/07)
-
- N,N-dimethyl-β-alanine as an inexpensive and efficient ligand for palladium-catalyzed Heck reaction
-
N,N-Dimethyl-β-alanine was found to be a more powerful phosphine-free ligand than the previously reported ligand, N,N-dimethylglycine, in the Pd-catalyzed Heck reaction for a variety of aryl bromides, aryl iodides, and activated aryl chlorides with a practical turnover number of 103. Both kinetic and theoretical studies suggested that N,N-dimethyl-β-alanine led to faster oxidative addition of an aryl halide to Pd than N,N-dimethylglycine.
- Cui, Xin,Li, Zhe,Tao, Chuan-Zhou,Xu, Yu,Li, Juan,Liu, Lei,Guo, Qing-Xiang
-
p. 2467 - 2470
(2007/10/03)
-
