Abstract: Novel sterol derivatives of formula (I), in which: R1 represents a hydroxyl group or protected hydroxyl group, R2 represents a hydrogen atom and a double bond is present at c, or R1 and R2 together represent an oxo group and a double bond is present at b or double bonds are present at a and b; R3 represents a methyl group having ?- or ?-configuration; R4 and R5, which may be the same or different, are selected from hydrogen atoms and aliphatic, cycloaliphatic, araliphatic and aryl groups, or together with the nitrogen atom to which they are attached form a heterocyclic group; and X represents a polymethylene group containing 2–5 carbon atoms, an oxa group-containing analogue thereof in which a methylene group other than that attached to the —CO.NR4R5 moiety is replaced by an oxygen atom, or an unsaturated analogue thereof containing up to two double bonds.

Abstract: Formula (I) in which: R1 and R2, which may be the same or different, each represents a lower alkyl, alkenyl or alkynyl group; R3 represents a methyl group having ?- or ?-configuration; R4 represents a hydrogen atom or an etherifying or esterifying group; R5 represents a hydrogen atom, a hydroxyl group or a lower alkoxy group; X represents a group OR4, or a group NR6R7 wherein R6 represents a hydrogen atom, an aliphatic or araliphatic group, or an acyl group comprising an aliphatic, araliphatic or aryl group linked to the nitrogen atom by way of a carbonyl group; and R7 is a hydrogen atom or a lower alkyl group; Y represents a lower alkylene, alkenylene or alkynylene group optionally substituted by a hydroxyl, etherified hydroxyl or esterified hydroxyl group; exhibit potent effects on modulation of cell growth and differentiation, while having low calcaemic activity.

Abstract: Compounds of Formula (I) in which: R1 and R2, which may be the same or different, each represents a lower alkyl, alkenyl or alkynyl group; R3 represents a methyl group having ?- or ?-configuration; R4 represents a hydrogen atom or an etherifying or esterifying group; R5 represents a hydrogen atom, a hydroxyl group or a lower alkoxy group; X represents a group OR4, wherein R4 is as defined above, or a group NR6R7 wherein R6 represents a hydrogen atom, an aliphatic or araliphatic organic group, or an acyl group comprising an aliphatic, araliphatic or aryl organic group linked to the nitrogen atom by way of a carbonyl group; and R7 is a hydrogen atom or a lower alkyl group; Y represents a lower alkylene, alkenylene or alkynylene group optionally substituted by a hydroxyl, etherified hydroxyl or esterified hydroxyl group; and the dotted lines signify that double bonds may be present at the 16(17)-position and/or either at the 6(7)- and 8(9)-positions or at the 7(8)-position exhibit potent effects on modulation of

Abstract: The present invention relates to novel 1.alpha.-hydroxy vitamin D derivatives in which the 17-position side chain carries an azide or optionally substituted 1,2,3-triazole group, including compounds of general formula (I) where R.sup.1 represents a methyl group having .alpha.- or .beta.-configuration; W represents a valence bond or a C.sub.1-5 alkylene group; X represents azide or an optionally substituted triazole group; and A.dbd. represents a cyclohexylidene moiety characteristic of the A-ring of a 1.alpha.-hydroxylated vitamin D or analogue thereof. Active compounds of the invention exhibit cell modulating activity while exhibiting a substantial lack of calcaemic effect.

Abstract: The present invention relates to novel 1.alpha.-hydroxy vitamin D derivatives in which the 17-position side chain carries an azide or optionally substituted 1,2,3-triazole group, including compounds of general formula (I) where R.sup.1 represents a methyl group having .alpha.- or .beta.-configuration; W represents a valence bond or a C.sub.1-5 alkylene group; X represents azide or an optionally substituted triazole group; and A=represents a cyclohexylidene moiety characteristic of the A-ring of a 1.alpha.-hydroxylated vitamin D or analogue thereof. Active compounds of the invention exhibit cell modulating activity while exhibiting a substantial lack of calcaemic effect.

Abstract: The invention relates to vitamin D amine and amide derivatives of general formula ##STR1## where R represents a hydrogen atom, an aliphatic, cycloaliphatic or araliphatic group, or an acyl group comprising an aliphatic, cycloaliphatic, arylaliphatic or aryl group linked to the nitrogen atom by way of a carbonyl group; R.sup.1 and R.sup.2 are each selected from lower alkyl and cycloalkyl groups or together with the carbon atom to which they are attached form a lower cycloalkyl group; R.sup.3 represents a methyl group having .alpha.- or .beta.-configuration; Y represents a lower alkylene, alkenylene or alkynylene group optionally substituted by a hydroxyl, etherified hydroxyl or esterified hydroxyl group; and A.dbd. represents a cyclohexylidene moiety characteristic of the A-ring of a 1 .alpha.-hydroxylated vitamin D or analogue thereof. Active compounds of the invention exhibit cell modulating activity and in certain cases may also have an effect on calcium metabolism.

Abstract: The invention relates to novel 1.alpha.-hydroxy vitamin D derivatives and their 20-epi analogues, comprising compounds of general formula (I) ##STR1## where R.sup.1 and R.sup.2, 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; R.sup.3 represents a methyl group having .alpha.- or .beta.-configuration; X represents a valence bond or a C.sub.1-2 alkylene group; Y represents --O--, --S--, --CH.sub.2 -- or --NR-- where R is a hydrogen atom or an organic group; Z represents a valence bond or a C.sub.1-3 alkylene group; and A.dbd. 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.dbd. does not carry an exocyclic methylene group at the 10-position.