A nonlinear QSAR study was conducted on a series of 4-phenylpiperidine derivatives (4PPs) acting as μ opioid agonists by three-layer backpropagation neural network (NN) method. At first a variety of molecular descriptors were calculated and then selected with two-stage least squares combining partial least squares (PLS) method. The selected four molecular descriptors, out of 292 ones, were correlated with the known analgesic activities of 38 4PPs by NN method. The established QSAR model was further validated by five additional 4PPs, as an external testing set. Moreover, a pharmacophore model was hypothesized based on the results, which would be helpful for structural optimization of 4PPs.

Three meptazinol benzoyl esters (1-3) were synthesized as prodrugs to minimize the first-pass effect of meptazinol and improve the bioavailability. Among these three esters, compound 3 showed better bioavailability than the parent meptazinol. Further, the relative regional bioavailability of prodrug 3 was evaluated using in situ closed loop study in rats, which showed that prodrug 3 has higher absorption efficacy in rat intestine. Thusly, prodrug 3 may be worth for further development.

Based on the known coumarin-based prodrug system, a new meptazinol (Z)-3-[2-(propionyloxy) phenyl]-2-propenoic ester (3) was designed and synthesized as prodrug to minimize the first-pass effect of meptazinol (1) and improve the oral bioavailability. The prodrug (3) showed a 4-fold increase in oral bioavailability over the parent drug meptazinol in rats.

Molecular modeling and 3D-QSAR studies were performed on 31 indolomorphinan derivatives to evaluate their antagonistic behaviors on jopioid receptor and provide information for further modification of this kind of compounds. Best predictions were obtained with CoMFA standard model (q2=0.693, N=4, r2=0.900) and CoMSIA combined model (q2=0.617, N=4, r2=0.904). Both models were further validated by an external test set of eight compounds with satisfactory predictions: r2=0.607 for CoMFA and r2=0.701 for CoMSIA. In addition, the 3D structure of human j opioid receptor was constructed based on the crystal structure of bovine rhodopsin, and the CoMSIA contour plots were then mapped into the structural model of j opioid receptor-GNTI complex to identify key residues, which might account for jantagonist potency and selectivity. The roles of nonconserved Glu297 and conserved Lys227 of human jopioid receptor were then discussed.

对具有很高kappa受体亲和性和选择性的依那朵林进行了合成研究。以1，4环己二酮为原料，经缩合、环合、还原、环氧化等16步反应得到关键中间体1-[8-甲氨基-1-氧杂螺[4，5]癸烷-7-基]吡咯烷（16），再和4苯并呋喃乙酸在偶合剂CDI催化下得到目标化合物依那朵林。