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