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