For the RNA world hypothesis, the direct condensation between nucleobase and ribose to afford canonical nucleoside has been a formidable challenge in terms of regioselectivity. In this report, we demonstrate that cavitation, a frequently occurring energy-intensive phenomenon upon the collapse of bubbles, could be a plausible driving force to form the purine nucleosides directly from nucleobase and ribose with the desired regioselectivity. Under cavitation, the overall yield of N9 nucleosides increases compared with non-cavitation conditions, whereas the amount of the undesired ribosylamino isomers decreases. Plausible geochemical scenarios on primordial Earth are proposed that could facilitate enrichment of the desired N9 nucleosides. Under salt-free dry-wet conditions, much improved yield (7.2%) and selectivity (N9/ribosylamino = 0.45) of the N9 isomers are achieved compared with the classical routes.

对于RNA世界的假设，就区域选择性而言，核碱基与核糖之间的直接缩合以提供规范的核苷一直是一项艰巨的挑战。在这份报告中，我们证明了空化（气泡破裂时经常发生的能量密集现象）可能是直接从核苷碱基和核糖形成具有所需区域选择性的嘌呤核苷的合理驱动力。在空化条件下，与非空化条件相比，N 9核苷的总产量增加，而不需要的核糖基氨基异构体的数量减少。提出了原始地球上可能存在的地球化学情景，可以促进所需氮的富集9个核苷。在无盐干湿条件下，与传统方法相比，N 9异构体的收率（7.2％）和选择性（N 9 /核糖基氨基= 0.45）大大提高。