These "organic" compounds are not necessarily dependent on living things for their formation. Many of them can already be formulated in labrotories.
Compounds like humic acids - common soil constituents - haven't even all been well characterized in the lab as of now, let alone synthesized. Many are derived from lignin which was once part of a living plant. The plant dies and bacteria and fungi digest or degrade the organics from it to leave this stuff behind. A fiendishly complicated material, in short, made up of probably thousands of different compounds.
Wikipedia treats this subject, too.
™ Version 4.2
