Abstract: A breast cancer resistance protein (BCRP/ABCG2) inhibitor. The BCRP inhibitor contains, as an active ingredient, an acrylonitrile derivative or a salt thereof.

Abstract: The present invention is directed to a breast cancer resistance protein (BCRP/ABCG2) inhibitor. The BCRP inhibitor contains, as an active ingredient, an acrylonitrile derivative represented by formula (1): wherein one of R1 and R2 represents a cyano group and the other represents a hydrogen atom; Ar1 represents a group selected from among the groups represented by formulas (2) to (4): and Ar2 represents an aromatic hydrocarbon group having a condensed ring which may be substituted by a halogen atom, or a group selected from among the groups represented by the following formulas (5) to (15): or a salt thereof.

Abstract: The invention provides a cancer cell useful in screening BCRP-inhibitors, and a BCRP-inhibitor. The BCRP-inhibitor contains, as the active ingredient, a flavonoid represented by any of the following formulae (1), (2), (3), (4), and (5): and glycosides, esters, or salts thereof; and an anticancer agent containing the BCRP-inhibitor together with an anticancer agent available as the substrate of BCRP.

Abstract: The invention provides a drug which inhibits BCRP. A breast cancer resistance protein inhibitor containing, as an active ingredient, a diphenylacrylonitrile derivative represented by the following formula (1): [wherein, each of 8 R's, which are the same or different from one another, represents a hydrogen atom, a hydroxyl group, a nitro group, an amino group, an acetylamino group (—NHCOCH3 group); a cyano group (—CN group); a formyl group (—CHO group), —COOR1 (R1 is hydrogen or C1-C4 alkyl), —O(CH2)nCOOR2 (n=1?7: R2 is hydrogen or C1-C4 alkyl), —OOCCH2CH2COOR3 (R3 is hydrogen, C1-C4 alkyl, (Z)-2-(3,4-dimethoxy-phenyl)-3-(4-hydroxy-phenyl)-acrylonitrile, or glycopyranosyl), a C1-C8 alkoxy group, a C1-C4 alkyl group, a halogen atom, a C1-C4 alkoxy C1-C4 alkoxy C1-C4 alkoxy group, a C2-C8 acyloxy group, a C2-C8 halogenoacyloxy group, a methylenedioxy group, a trifluoromethyl group, a phosphate group (i.e., —OP(O) (OH)2) or a salt thereof, a sulfate group (i.e.

Abstract: The invention provides a cancer cell useful in screening BCRP-inhibitors, and a BCRP-inhibitor. The BCRP-inhibitor contains, as the active ingredient, a flavonoid represented by any of the following formulae (1), (2), (3), (4), and (5): and glycosides, esters, or salts thereof; and an anticancer agent containing the BCRP-inhibitor together with an anticancer agent available as the substrate of BCRP.

Abstract: The invention provides a drug which inhibits BCRP. A breast cancer resistance protein inhibitor containing, as an active ingredient, a diphenylacrylonitrile derivative represented by the following formula (1): [wherein, each of 8 R's, which are the same or different from one another, represents a hydrogen atom, a hydroxyl group, a nitro group, an amino group, an acetylamino group (—NHCOCH3 group); a cyano group (—CN group); a formyl group (—CHO group), —COOR1 (R1 is hydrogen or C1-C4 alkyl), —O(CH2)nCOOR2 (n=1?7: R2 is hydrogen or C1-C4 alkyl), —OOCCH2CH2COOR3 (R3 is hydrogen, C1-C4 alkyl, (Z)-2-(3,4-dimethoxy-phenyl)-3-(4-hydroxy-phenyl)-acrylonitrile, or glycopyranosyl), a C1-C8 alkoxy group, a C1-C4 alkyl group, a halogen atom, a C1-C4 alkoxy C1-C4 alkoxy C1-C4 alkoxy group, a C2-C8 acyloxy group, a C2-C8 halogenoacyloxy group, a methylenedioxy group, a trifluoromethyl group, a phosphate group (i.e., —OP(O) (OH)2) or a salt thereof, a sulfate group (i.e.

Abstract: The present invention relates to new camptothecin derivatives shown by the below formula, which are water-soluble and excellent in an anti-tumor activity, and to salts thereof. In the formula, R1 represents a hydrogen atom or an alkyl group with 1-6 carbon atoms, R2 represents identically or differently 0-4 alkyl groups with 1-6 carbon atoms, a halogen atom, an alkoxyl or hydroxyl group, R3 represents a lower alkylamino, di-lower alkylamino, arylamino, cyclicamino or lower alkoxyl group, and salts thereof.

Abstract: New camptothecin derivatives of the general formula (1): ##STR1## wherein R.sup.1 represents a hydrogen atom or a C.sub.1 -C.sub.6 alkyl group, R.sup.2 represents a hydrogen or a C.sub.1 -C.sub.6 alkoxy group, R.sup.3 represents a hydrogen or halogen atom or a C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 alkoxy, hydroxyl, C.sub.2 -C.sub.6 acyloxy or methoxyethoxymethoxy group, R.sup.4 represents a hydrogen or halogen atom, and R.sup.5 represents a C.sub.1 -C.sub.6 alkyl, C.sub.3 -C.sub.6 unsaturated alkyl, alkylthioalkyl, alkoxyalkyl, pyridyl or substituted phenyl group, with the proviso that all of the R.sup.2, R.sup.3 and R.sup.4 substituents should not be a hydrogen atom, and a process for preparing the new camptothecin derivatives by subjecting the camptothecin derivatives of the general formula (2): ##STR2## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.