A pharmaceutical compositions comprises a compound of formula (I):
or a pharmaceutically acceptable salt thereof: wherein
R
1
═R
2
═H; or R
1
and R
2
together form a moiety represented by the formula
R
3
represents a substituted or unsubstituted alkyl having 4-30 carbon atoms, or a substituted or unsubstituted aryl group having 3-30 carbon atoms; and
R
4
represents a substituted or unsubstituted aryl group having 3-30 carbon atoms;
with the proviso that R
3
is not butyl, pentyl, tetrahydropyranyloxymethyl, tetrahydropyranyloxypropyl or phenyl when R
1
═R
2
═H and R
4
is o-cyanophenyl,; and with the proviso that R
3
is not butyl when R
1
═R
2
═H and R
4
is phenyl.
The pharmaceutical composition may be used to treat a subject afflicted with a tumor/cancer by inhibiting topoisomerase I activities or blocking the S phase or G
2
/M phase of the tumor/cancer cells.
This invention provides aryl-substituted acyclic enediyne compounds of formula (I):
or a pharmaceutically acceptable salt or solvate thereof, wherein
R
1
═R
2
═H; or R
1
and R
2
together form a moiety represented by the formula
R
3
represents a substituted or unsubstituted alkyl having 4-30 carbon atoms, or a substituted or unsubstituted aryl group having 3-30 carbon atoms; and R represents a substituted or unsubstituted aryl group having 3-30 carbon atoms;
with the proviso that R
3
is not butyl, pentyl, tetrahydropyranyloxymethyl, tetrahydropyranyloxypropyl or phenyl when R
1
═R
2
═H and R
4
is o-cyanophenyl,; and with the proviso that R
3
is not butyl when R
1
═R
2
═H and R
4
is phenyl. The compounds of formula (I) are found to have inhibitory activities against topoisomerase I or act as a S phase or G2/M phase blocker.