I was just reading about pyruvate to build my biochemistry literacy (the molecule is relevant to an NMR project I’m helping out on). Wikipedia describes pyruvate, which is the product of breaking down glucose, as a key intersection in several metabolic pathways, aerobic and anaerobic. Being at the heart of the chemistry of metabolism makes a molecule a candidate for being a very old player in biochemistry. Here’s how the Pyruvate article puts the molecule in the context of the origin of life:

Main article: iron-sulfur world theory

Current evolutionary theory on the origin of life posits that the first organisms were anaerobic because the atmosphere of prebiotic Earth was, in theory, almost barren of diatomic oxygen. As such, requisite biochemical materials must have preceded life. In vitro, iron sulfide at sufficient pressure and temperature catalyzes the formation of pyruvate. Thus, argues Günter Wächtershäuser, the mixing of iron-rich crust with hydrothermal vent fluid is suspected of providing the fertile basis for the formation of life.