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