Patent ID: 8053583

Claim:
A compound of the structure: wherein n=1 and R is selected from the group consisting of: NHCH 2 CO 2 CH 3 (3a), NHCH(CH 2 CH 2 SCH 3 )CO 2 CH 3 (3b), (NCH 2 CH 2 CH 2 CH)CO 2 CH 3 (3c), | —————— | (L)-NHCH(CH(CH 3 ) 2 )CO 2 CH 3 (3d), (D)-NHCH(CH(CH 3 ) 2 )CO 2 CH 3 (3c) N(CH 3 )CH 2 CO 2 CH 3 (3f) (L)-NHCH(CH 2 CH)(CH 3 ) 2 )CO 2 CH 3 (3g), (D)-NHCH(CH 3 )CO 2 CH 3 (3i), NHCH(C 6 H 5 )CO 2 CH 3 (3j), 3-(CF 3 )C 6 H 4 CH 2 NH (3q) and NHCH(CH 2 OCH(CH 3 ) 3 )CO 2 CH 3 (3t); and wherein n=2, R is selected group consisting of: 3,5-F 2 C 6 H 3 CH 2 NH (4c), NH(CH 2 ) 3 NHCO 2 C(CH 3 ) 3 (4d), NH(CH 2 ) 2 N(CH 3 ) 2 (4e) and NHCH 2 CH 2 CH 2 N(CH 3 ) 2 (4j).