Synthesis and antimetastatic properties of stereoisomeric tricyclic bis(dioxopiperazines) in the Lewis lung carcinoma model
摘要:
Synthesis of trans- and cis-tetrahydrodipyrazino[1,2-a:1',2'-d] pyrazine-1,3,7,9(2H,4H,8H,10H)-tetrone analogues 10 and 11 belonging to the bis(dioxopiperazine) class of antitumor agents and their bis(morpholinomethyl) derivatives 12 and 13 are described with use of 2,5-dimethylpyrazine as the starting material. Synthetic studies utilizing 3,6-disubstituted 2,5-dioxopiperazine precursors are included. Evaluation of 10-13 in the Lewis Lung carcinoma model indicated the bis(morpholinomethyl) analogue cis-13 to be antimetastatic, whereas the trans isomer 12 was toxic at a similar dose effecting a decrease in the life span of treated mice. The parent bis(dioxopiperazines) 10 and 11 were ineffective as antitumor or antimetastatic drugs.
Several cyclic dipeptides were synthesized by refluxing methanolic solution of dipeptide methyl esters in high yield and purity. Cyclic dipeptides prepared by the Fischer method, the Nitecki method, and the present methanol-reflux method were compared with respect to yield and optical purity. The methanol-reflux method usually gave good results. High-performance liquid chromatography was effectively applied to detect racemization.