Protosteroid

A protosteroid or primordial fat^[1] is a lipid precursor, which can be transformed during subsequent biochemical reactions and finally become steroid.^[2] The protosteroids are biomarkers that are produced by ancient eukaryotes belonged to the microorganisms in the protosterol biota. The intermediate compounds created by these eukaryotes while making crown sterol molecules.^[3]

For the first time, the German biochemist and Nobel laureate Konrad Emil Bloch thought that instead of today's sterols, earlier life forms could have used chemical intermediates in their cells. He called these intermediates protosteroids.^[4] Later researchers synthesized protosteroids called lanosterol, cycloartenol, and 24-methylene cycloartenol. Then researchers from the Australian National University and the University of Bremen^[5] found protosteroids in rocks that formed 1.6 billion years ago in the Barney Creek Formation in Northern Australia. The researchers also found derivatives that matched the pattern produced by 24-methylene cycloartenol in 1.3-billion-year-old rocks.^[6]