{HEAD ~ The oxygenated hydrocarbons} may originate from any source, but are preferably derived from {TAIL ~ biomass} 
are preferably derived from
{ HEAD ~ The oxygenated hydrocarbons } may originate from any source , but are preferably derived from { TAIL ~ biomass }
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL REL REL REL TAIL TAIL TAIL TAIL TAIL