Copper-rich deep-sea hydrothermal vent minerals facilitate hydrogen cyanide formation from glycine

In prevailing origin of life scenarios, hydrogen cyanide (HCN) is a key molecule for forming life’s essential building blocks, as demonstrated by HCN-centric prebiotic chemistry. However, whether HCN can be in-situ generated in deep-sea hydrothermal vents (HVs) has remained unexplored. Here, we show that a natural HV mineral consisting of chalcopyrite, pyrite and sphalerite facilitates HCN formation through the anaerobic oxidation of glycine. Using 13C-isotopic labeled glycine under alkaline conditions, free HCN formation reached at 3.2 μM at 25 °C, with the yield increasing threefold at 10 °C. Copper leaching during the reaction, together with the model experiment showing glycine-to-HCN conversion in the presence of CuCl2, indicates that copper(II) functions as an oxidant in this process. Because glycine can be generated through multiple pathways, our findings integrate cyanide chemistry into deep-sea HVs, expanding the chemical diversity accessible within alkaline vent environments and potentially analogous systems beyond Earth.