Abstract: A pharmaceutical composition for use as a nephrotoxicity alleviator for alleviating the nephrotoxicity caused by a drug administered into the living organism, which composition contains S-adenosyl-L-methionine or a salt thereof as an active ingredient is provided. Also provided is a pharmaceutical composition for use as an agent for potentiating the antitumor activity of platinum complex compounds, which composition contains S-adenosyl-L-methionine as an active ingredient.

Abstract: A novel process for producing derivatives of the anti-tumor agent N.sup.4 -acyl-5'-deoxy-5-fluorocytidine using the novel 5'-deoxy-5-fluoro-N.sup.4, 2'-0,3'-0-triacylcytidine derivatives as intermediates is provided.5-Deoxy-1,2,3-tri-0-acyl-.beta.-D-ribofuranoside is reacted with 5-fluorocytosine to produce 5'-deoxy-2',3'-di-0-acyl-5-fluorocytidine, followed by acylation, to produce the novel intermediate 5'-deoxy-5-flouro-N.sup.4,2'-0,3'-0-triacylcytidine. The acyl radicals of this intermediate are selectively de-0-acylated to obtain N.sup.4 -acyl-5'-deoxy-5-fluorocytidine derivatives. From fluorocytosine, N.sup.4 -acyl-5'-deoxy-5-fluorocytidine derivatives can be obtained through few steps in high yield, an in satisfactory purity.

Abstract: Novel S-adenosylmethionine derivatives useful as medicament are provided which are represented by the following general formula (I): ##STR1## wherein R.sub.1 and R.sub.2 each represent straight or branch alkyl or alkenyl having 1-10 carbon atoms; m is 1-3; and A is an anion of inorganic or organic acids.

Abstract: New 5-fluorouridine compounds of the general formula: ##STR1## wherein n is an integer of 1 to 3, R' stands for a straight or branched chain alkyl group having 1 to 4 carbon atoms or a benzyl group, and R stands for an amino acid residue selected from the group consisting of alanyl, phenylalanyl, valyl, tyrosyl, 3,4-dihydroxyphenylalanyl and lysyl groups. These compounds possess excellent anti-malignant tumor, anti-viral and immunosuppressive activities.

Abstract: New nucleoside derivatives possessing strong anti-tumor activity with low toxicity, represented by the general formula: ##STR1## wherein (A-CO-- is a residue of a saturated straight or branched chain fatty acid, B is a nitrogen-containing group, Q is a substituent of the fatty acid, Z and Z' each is H or OH with the proviso that both of Z and Z' are not OH, and n is zero or an integer of at least 1, as well as physiologically acceptable salts thereof. These nucleoside derivatives are prepared by introducing the nitrogen-containing acyl group directly in one step or indirectly in two steps into the 5'-position of 5-fluorouridine, 2'-deoxy-5-fluorouridine or 1-.beta.-D-arabinofuranosyl-5-fluorouracil and splitting off any protective group and optionally converting the free compound into a physiologically acceptable salt thereof or vice versa.