Abstract: Provision of a novel combined therapy with ECyd, which therapy exhibits remarkable antitumor effect and gives less adverse effects. The invention provides an antitumor agent containing, in combination, 1-(3-C-ethynyl-?-D-ribopentofuranosyl)cytosine or a salt thereof and carboplatin.

Abstract: A novel pyrimidine nucleoside compound represented by the following formula (1): (wherein one of X and Y represents a cyano group, and the other represents a hydrogen atom; one of R1 and R2 represents a hydrogen atom, a carbonyl group having a C1-C6 alkyl group which has been mono-substituted by an amino group, or a group represented by (R3)(R4)(R5)Si—, and the other represents a silyl group represented by (R6)(R7)(R8)Si—, or R1 and R2 together form a 6-membered cyclic group represented by —Si (R9)(R10)—; R3, R4, R5, R6, R7, and R8 each represent an alkyl group, a cyclic alkyl group, an aryl group, or an alkyl group which has been substituted by one or two aryl groups; and R9 and R10 each represent an alkyl group) or a salt thereof. The novel pyrimidine nucleoside compound exhibits excellent anti-tumor effect as compared with existing pyrimidine nucleoside compounds.

Abstract: Disclosed is a compound of formula I: [wherein B is a nucleobase selected from the group consisting of adenine, guanine, cytosine, uracil and hypoxanthine], a compound of formula II: [wherein B? is a nucleobase selected from the group consisting of adenine, guanine, cytosine, thymine, uracil and hypoxanthine], a method for synthesizing these nucleoside triphosphates, and a process for producing an oligonucleotide using these nucleoside triphosphates.

Abstract: The invention relates to a 3'-substituted nucleoside derivative represented by the following general formula (1): ##STR1## wherein B means a nucleic acid base which may have a substituent, Z represents a lower alkynyl or lower alkenyl group which may be substituted by a group represented by the formula: ##STR2## in which R.sup.a, R.sup.b and R.sup.c are individually a lower alkyl group or a phenyl group, or an oxiranyl group which may have at least one lower alkyl group, R.sup.1 and R.sup.2 individually represent H or an ester-forming residue capable of easily leaving in a living body, and R.sup.3 is H, a mono- or polyphosphoric acid residue, or an ester-forming residue capable of easily leaving in a living body, with the proviso that the sugar moiety is ribose, or a pharmaceutically acceptable salt thereof. The 3'-substituted nucleoside derivative according to the invention has an excellent antitumor activity and is hence useful for treatment for and prevention of cancers.

Abstract: Novel 2'-methylidenenucleotide compounds of the formula (I) ##STR1## wherein R is a hydrogen or a halogen, R.sup.1 and R.sup.2 are the same or different and each is a fatty acid residue or a hydrocarbon residue, and R.sup.3 and R.sup.4 are the same or different and each is a hydrogen, a halogen or an alkyl; salts thereof; methods for production thereof; and pharmaceutical use thereof. The compounds and salts thereof show an excellent antitumor effect in mammals. More specifically, they show a remarkable activity of inhibiting growth of mouse tumors, cultured human tumor cells, and human tumors transplanted to nude mice, and are useful for the treatment and prevention of recurrence of lung cancer, gastrointestinal cancer, breast cancer, cervical cancer, gynecological cancer, urinological cancer, leukemia, melanoma, lymphogenous metastatic tumor and the like in mammals. They are also useful as antitumor agents since they have an increased bioavailability and low toxicity.