Page - (000315) - in Biomedical Chemistry: Current Trends and Developments

28 > 10 000 29 18.5 ± 1.7 30 540 ± 20 31 64 ± 2 32 175 ± 13 a S configuration = l configuration and R configuration = d configuration. 3.3.2.2.3 Effects of SP1–7 and its Analogs As mentioned in the introduction, SP1–7 has been shown to influence opioid withdrawal symptoms and possess antinociceptive properties. Consequently, the synthesized compounds 15 and 26 were evaluated in different in vivo models. The amidated C-terminal analog SP1–7-NH2 (15) was demonstrated to attenuate the expression of naloxone-precipitated withdrawal in morphine-dependent rats when administered intracerebroventricularly (Zhou, 2009; Zhou, 2003). In agreement with the binding affinities obtained in the SAR study, the C-terminal amide analog is more efficient in reducing opioid withdrawal symptoms than SP1–7.