Patent ID: 8227425

Claim:
A compound of structural formula (I): wherein: X is —CH 2 —or —O—; a single or double bond links C 2 to C 3 of the ring; R 1 denotes —OH, a halogen or —B/moiety, but with the proviso that R 1 is absent when a double bond linking C 2 to C 3 of the ring is present; R 2 is —OH, —O—CH(C 2 H 5 ) 2 , —NH 2 , —NHC(═NH)NH 2 or —NH—OH; R 3 is —NH 2 , —NHCO—CH 3 or —NH—CO-CH 2 —OH ; and R 4 is —CHOH—CHOH—CH 2 —OH, —CHOH—CH 2 B/moiety, —CH 2 —B/moiety or —B/moiety; with the proviso that at least one of R 1 or R 4 contains a —B/moiety, or both R 1 and R 4 contain a —B/moiety; wherein said —B/moiety is: and wherein: R 5 is —NH—, —CH 2 —NH—, —CH(CH 3 )—NH—, —NH—CH(CH 3 )—NH—, —C(CH 3 ) 2 —CH 2 —NH—, —NH—CO—CH 2 —O—CH 2 —CH 2 —NH—, R 6 is —H, —CH 3 or —C 2 H 5 ; R 7 is —H, —CH 3 or —C 2 H 5 ; and R 8 is —NH—, —CO—NH— or —C(NH)—NH—; and addition salts, resolved enantiomers or purified diastereomers thereof.