| 摘要 |
<p>A compound which is biologically active in maintaining calcium and phosphorous metabolism in animals, selected from the group consisting of formula (IA) and (IB): wherein the bond between carbons C-22 and C-23 is single or double; Y is hydrogen, F, -CH3 or -CH2CH3; Z is F, H or X; Y' is H, -CH3 or CH2CH3; Z' is F or H; Qa is CF¿3? or CH2X; Q?b¿ is CF¿3? or CH3; X is selected from the group consisting of hydrogen and -OR?1¿, wherein R1 is hydrogen or an orthoester glycoside radical of the formula (II) where A represents a glucofuranosyl or glucopyranosyl ring; R2 is hydrogen, lower alkyl, aralkyl, or aryl; and R3 is hydrogen or a straight or branched chain glycosidic residue containing 1-100 glycosidic units per residue; with the proviso that at least one of the R1 is an orthoester glycoside moiety of formula (II).</p> |
