R10 is independently selected from {HEAD ~ the group} consisting of H, alkyl, and {TAIL ~ arylalkyl} 
consisting of
R10 is independently selected from { HEAD ~ the group } consisting of H , alkyl , and { TAIL ~ arylalkyl }
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL