abstract |
A compound of formula l:wherein,R1, R2 and R3 independently represent hydrogen, alkyl, alkenyl,alkynyl, aryl, or aralkyl groups having 1 to 8 carbon atoms;X represents an alkoxyalkyl, alkoxyaryl, alkoxyalkylaryl, aralkylalkoxy, oralkoxyalkylheterocycle; or a pharmaceutically acceptable salt or prodrug thereof. |