| 中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
|---|---|---|---|---|
| —— | N-Benzyloxycarbonyl-glycyl-glycyl-L-phenylalanyl-L-leucin-methylester | 68835-85-8 | C28H36N4O7 | 540.616 |
| —— | L-phenylalanyl-L-leucine methyl ester | 38155-19-0 | C16H24N2O3 | 292.378 |
| N-{[(2-甲基-2-丙基)氧基]羰基}苯丙氨酰亮氨酸甲酯 | methyl (S)-2-((S)-2-(tert-butoxycarbonylamino)-3-phenylpropanamido)-4-methylpentanoate | 64152-76-7 | C21H32N2O5 | 392.495 |
| —— | Z-Gly-Gly-L-Phe-OMe | 15027-03-9 | C22H25N3O6 | 427.457 |
| —— | (2S)-2-(2-[2-[(tert-butoxycarbonyl)amino]acetamido]acetamido)-3-phenylpropanoic acid | 39621-73-3 | C18H25N3O6 | 379.413 |
| —— | Z-Gly-Gly-Phe-OH | 13171-93-2 | C21H23N3O6 | 413.43 |
Opioids account for 69,000 overdose deaths per annum worldwide and cause serious side effects. Safer analgesics are urgently needed. The endogenous opioid peptide Leu-Enkephalin (Leu-ENK) is ineffective when introduced peripherally due to poor stability and limited membrane permeability. We developed a focused library of Leu-ENK analogs containing small hydrophobic modifications. N-pivaloyl analog KK-103 showed the highest binding affinity to the delta opioid receptor (68% relative to Leu-ENK) and an extended plasma half-life of 37 h. In the murine hot-plate model, subcutaneous KK-103 showed 10-fold improved anticonception (142%MPE·h) compared to Leu-ENK (14%MPE·h). In the formalin model, KK-103 reduced the licking and biting time to ~50% relative to the vehicle group. KK-103 was shown to act through the opioid receptors in the central nervous system. In contrast to morphine, KK-103 was longer-lasting and did not induce breathing depression, physical dependence, and tolerance, showing potential as a safe and effective analgesic.