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