2-hexaprenyl-6-methoxyphenol (HMPhOH) aka 2-methoxy-6-hexaprenylphenol is enzymatically converted to 2-hexaprenyl-6-methoxy-1,4-benzoquinol (MDMQ6H2) (Gin et al. 2003, Ozeir et al. 2011). It was thought at one time that the flavin-dependent monooxygenase, Coq6, was the enzyme that catalysed this reaction, however, it has been subsequently shown that Coq6 is not essential for this reaction (Ozeir et al. 2011). However, it is still believed that another member of the Coq family catalyses this event.