Abstract The organisation of living systems into cellular structures is a characteristic that enables differentiation from the environment. A pivotal step in the development of life is compartmentalisation, achieved through the formation of vesicle-like structures. Fatty acids - or phospholipids - have been used to simulate prebiotic vesicle and protocell formation. However, a process by which amphiphiles are formed from small prebiotically plausible molecules, which spontaneously self-assemble to protocells, is unknown. Here, we demonstrate that an organocatalytic reaction cascade starting from acetaldehyde with prebiotic imidazolidine-4-thione rapidly yields poly(hydroxy)alkenyl aldehydes that spontaneously self-assemble to protocells. In this process, lipid-like molecules (up to C20) develop a membrane, which additionally incorporates the organocatalyst at the liquid-lipid interface. These catalytically active protocells (11 nm – 7 μm) tolerate external influences such as pH value, temperature and salts. This finding unveils an organocatalytic pathway to selective lipid formation and spontaneous compartmentalisation without the necessity of preformed amphiphiles.
Ebeling et al. (Mon,) studied this question.