<abstract xmlns="http://www.w3.org/1999/xhtml"><p> Fentanyl [N-(1-phenethyl-4-piperidinyl)propionanilide] is a potent opioid analgesic agent, but a has narrow therapeutic index. We reported earlier on the synthesis and bioefficacy of fentanyl and its 1-substituted analogs (1-4) in mice. Here we report the synthesis and biological evaluation of four additional analogs, viz. N-isopropyl-3-(4-(N-phenylpropionamido)piperidin-1-yl)propanamide (5), N-tbutyl- 3-(4-(N-phenylpropionamido)piperidin-1-yl)propanamide (6), isopropyl 2-[4-(N-phenylpropionamido)piperidin-1-yl]propionate (7) and t-butyl 2-[4-(N-phenylpropionamido)piperidin-1-yl]propionate (8). The median lethal dose (LD50) determined by intravenous, intraperitoneal and oral routes suggests these analogs to be comparatively less toxic than fentanyl. On the basis of observational assessment on spontaneous activities of the central, peripheral, and autonomic nervous systems, all the analogs were found to be similar to fentanyl. Naloxone hydrochloride abolished the neurotoxic effects of these analogs, thereby ascertaining their opioid receptor-mediated effects. All the analogs displayed significant analgesic effects, measured by formalin-induced hind paw licking and tail immersion tests at their respective median effective dose (ED50). They also exhibited 8-12 fold increase in therapeutic index over fentanyl. However, 5 and 6 alone produced lower ED50 (20.5 and 21.0 μg/kg, respectively) and higher potency ratio (1.37 and 1.33, respectively) compared to fentanyl. They could thus be considered for further studies on pain management</p></abstract>

Fentanyl [N-(1-phenethyl-4-piperidinyl)propionanilide] is a potent opioid analgesic agent, but a has narrow therapeutic index. We reported earlier on the synthesis and bioefficacy of fentanyl and its 1-substituted analogs (1-4) in mice. Here we report the synthesis and biological evaluation of four additional analogs, viz. N-isopropyl-3-(4-(N-phenylpropionamido)piperidin-1-yl)propanamide (5), N-tbutyl- 3-(4-(N-phenylpropionamido)piperidin-1-yl)propanamide (6), isopropyl 2-[4-(N-phenylpropionamido)piperidin-1-yl]propionate (7) and t-butyl 2-[4-(N-phenylpropionamido)piperidin-1-yl]propionate (8). The median lethal dose (LD50) determined by intravenous, intraperitoneal and oral routes suggests these analogs to be comparatively less toxic than fentanyl. On the basis of observational assessment on spontaneous activities of the central, peripheral, and autonomic nervous systems, all the analogs were found to be similar to fentanyl. Naloxone hydrochloride abolished the neurotoxic effects of these analogs, thereby ascertaining their opioid receptor-mediated effects. All the analogs displayed significant analgesic effects, measured by formalin-induced hind paw licking and tail immersion tests at their respective median effective dose (ED50). They also exhibited 8-12 fold increase in therapeutic index over fentanyl. However, 5 and 6 alone produced lower ED50 (20.5 and 21.0 μg/kg, respectively) and higher potency ratio (1.37 and 1.33, respectively) compared to fentanyl. They could thus be considered for further studies on pain management

Synthesis and biological evaluation of some novel 1-substituted fentanyl analogs in Swiss albino mice

Pharmacology and Toxicology Division, Defence Research and Development Establishment, Jhansi Road, Gwalior 474 002, (M.P.), India

Synthetic Chemistry Division, Defence Research and Development Establishment, Jhansi Road, Gwalior 474 002, (M.P.), India

School of Studies in Zoology, Jiwaji University, Gwalior 474 011, (M.P.), India

Interdisciplinary Toxicology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fentanyl [N-(1-phenethyl-4-piperidinyl)propionanilide] is a potent opioid analgesic agent, but a has narrow therapeutic index. We reported earlier on the...

Synthesis and biological evaluation of some novel 1-substituted fentanyl analogs in Swiss albino mice

Published Online: Nov 15, 2014

Page range: 93 - 102

Received: Apr 08, 2014

Accepted: Jun 20, 2014

DOI: https://doi.org/10.2478/intox-2014-0013

© Interdisciplinary Toxicology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.