A method of treating male erectile dysfunction comprising administering to a male human in need of such treatment an effective amount of a compound of formula : ##{HEAD ~ STR6}## wherein R1 is methyl or ethyl {TAIL ~ R2} is ethyl or n propyl 
wherein
A method of treating male erectile dysfunction comprising administering to a male human in need of such treatment an effective amount of a compound of formula : # # { HEAD ~ STR6 } # # wherein R1 is methyl or ethyl { TAIL ~ R2 } is ethyl or n propyl
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH