An initial attempt of protection by {TAIL ~ acylation} of sulfhydryl group resulted in maintaining duration of the activity to {HEAD ~ some extent} 
An initial attempt of protection by { TAIL ~ acylation } of sulfhydryl group resulted in maintaining duration of the activity to { HEAD ~ some extent }
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD