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