R6 and R9 are each, independently, hydrogen, alkyl of 1 6 carbon atoms, or {HEAD ~ aralkyl} of {TAIL ~ 7 10 carbon atoms} 
R6 and R9 are each , independently , hydrogen , alkyl of 1 6 carbon atoms , or { HEAD ~ aralkyl } of { TAIL ~ 7 10 carbon atoms }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL