{TAIL ~ The drug} 6, wherein R1 is {HEAD ~ a n pentyl group} or a 2methylhexyl group 
{ TAIL ~ The drug } 6 , wherein R1 is { HEAD ~ a n pentyl group } or a 2methylhexyl group
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH