Abstract: Aziridines may be subjeted to a cyclooligomerization reaction to produce polyazacycloalkane compounds useful for example in the preparation of chelating agents for use in diagnostic imaging contrast agents. N-benzyl-aziridine in particular is useful as it can be cyclotetramerized and debenzylated to yield cyclen, a key intermediate in chelating agent preparation. The invention provides a particularly attractive route to production of N-benzyl and other N-arylmethyl aziridines of formula (I) where each R1 is independently hydrogen or a group AR and Ar is an optionally substituted phenyl group. The process comprises reacting a purified N-arylmethylethanolamine-sulphonate sulphonate ester with a base. N-aryimethyl-ethanolamine sulphonate ester of the formula R′NHCH2CH2OSO3H, wherein the N-arylmethyl group R′ is an N-(bisarylmethyl) or N-(triarylmethyl) group, as intermediates.

Abstract: Aziridines may be subjected to a cyclooligomerization reaction to produce polyazacycloalkane compounds useful for example in the preparation of chelating agents for use in diagnostic imaging contrast agents. N-benzyl-aziridine in particular is useful as it can be cyclotetramerized and debenzylated to yield cyclen, a key intermediate in chelating agent preparation. The invention provides a particularly attractive route to production of N-benzyl and other N-arylmethyl aziridines of formula (I) where each R.sub.1 is independently hydrogen or a group AR and Ar is an optionally substituted phenyl group. The process comprises reacting a purified N-arylmethylethanolaminesulphonate ester with a base. N-arylmethyl-ethanolamine sulphonate ester of the formula R'NHCH.sub.2 CH.sub.2 OSO.sub.3 H, wherein the N-arylmethyl group R' is an N-(bisarylmethyl) or N-(triarylmethyl) group, as intermediates. In a further aspect, the invention provides compounds of formula (II) ##STR1## where Ar and R.sub.

Abstract: The invention provides a blood pool contrast agent having an overall molecular weight of at least 10KD comprising a macrostructure which has bound thereto a plurality of opsonization inhibiting moieties and carries chelated ionic paramagnetic or heavy metal moieties, the chelant groups for said chelated moieties being macrocyclic where said macrostructure is liposomal.

Abstract: The invention provides polychelant compounds which are useful for example in diagnostic imaging procedures and which are degradable in vivo to release excretable fragments. Such compounds conveniently are of the formula (I): R.sup.1 (X.sup.1 R.sup.2 ((X.sup.2).sub.p L).sub.n).sub.m (where X.sup.1 is a linker moiety metabolically cleavable to release R.sup.1 X.sup.3.sub.m and X.sup.4 R.sup.2 ((X.sup.2).sub.p L).sub.n fragments where X.sup.3 and X.sup.4 are the cleavage residues of X.sup.1 ; R.sup.1 X.sup.3.sub.m is a biotolerable polymer, preferably a substantially monodisperse polymer and especially one with a molecular weight below 40,000 D, particularly below 30,000 D and especially below 20,000 D, for example a first to sixth generation dendrimer; X.sup.4 R.sup.2 ((X.sup.2).sub.p L).sub.n is a polychelant fragment having a molecular weight below 40,000 D, preferably below 30,000 D, especially below 20,000 D, each such moiety preferably being the same; p is 0 or 1; X.sup.

Abstract: The invention provides a dendrimeric compound comprising a dendrimeric bioactive moiety with linked thereto a plurality of diagnostically or therapeutically active moieties characterized in that the molecular skeleton of said compound contains at least one biodegradable cleavage site such that on cleavage thereof said active moieties are released in renally excretable form.

Abstract: There are provided vanadium compositions for use in the treatment of hypertension, obesity and diabetes, in particular improved oral compositions comprising oxovanadium (IV) chelates of monoprotic, bidentate oxygen, oxygen and oxygen, nitrogen coordinating ligands especially kojic acid and maltol.