RG7834, a dihydroquinolizinone (DHQ) candidate developed by Roche Pharma, was expected to realize the “functional cure of HBV”. However, it was dismissed in phase I clinical trial due to its neurotoxicity. In this study, a series of new DHQ derivatives containing a cyclic ether or benzo-fused (cyclic) ether moiety were designed, synthesized and evaluated for their in vitro activity. Many of them exhibited potent inhibition activity against HBsAg, HBeAg and HBV DNA. More importantly, in the in vitro neurotoxicity evaluation, most of the PC12 cells treated with RG7834 became round and even shrunken with the disappearance of neurites; in contrast, most of the cells treated by (2ʹS, 6S)-1a, showed similar morphological structures to the control group with clearly visible neurites, indicating that (2ʹS, 6S)-1a could have improved neurotoxicity. The first study of the structure-neurotoxicity relationship of DHQs paves the way for the future development of DHQs.

罗氏制药研发的二氢喹啉酮（DHQ）候选药物RG7834有望实现“HBV的功能性治愈”。然而，由于其神经毒性，它在 I 期临床试验中被驳回。在这项研究中，设计、合成了一系列含有环醚或苯并稠合（环）醚部分的新型 DHQ 衍生物，并对其体外活性进行了评估。其中许多对 HBsAg、HBeAg 和 HBV DNA 表现出有效的抑制活性。更重要的是，在体外神经毒性评价中，RG7834处理的PC12细胞大部分变圆，甚至萎缩，神经突消失；相比之下，大多数用( 2ʹS, 6S )-1a处理的细胞，显示出与对照组相似的形态结构，具有清晰可见的神经突，表明( 2ʹS, 6S )-1a可以改善神经毒性。对DHQs结构-神经毒性关系的首次研究为DHQs的未来发展铺平了道路。