| abstract |
Novel 1.alpha.-hydroxy vitamin D derivatives and their 20-epi analogues, comprising compounds of general formula (I) where R1 and R2, which may be the same or different, each represents a hydrogen atom or an aliphatic, cycloaliphatic, araliphatic or aryl group or together with the nitrogen atom to which they are attached form a heterocyclic group; R3 represents a methyl group having .alpha.- or .beta.-configuration; X represents a valence bond or a C1-2 alkylene group; Y represents -O-, -S-, CH2- or -NR- where R is a hydrogen atom or an organic group; Z represents a valence bond or a C1-3 alkylene group; and A = represents a cyclohexylidene moiety characteristic of the A-ring of a 1.alpha.-hydroxylated vitamin D or analogue thereof, with the proviso that when -X-Y-Z together represent an alkylene group containing up to 4 carbon atoms A = does not carry an exocyclic methylene group at the 10-position. Active compounds of the invention exhibit cell modulating activity while exhibiting a substantial lack of calcaemic effect. |