Abstract: A compound of formula (II), and a method of preparation thereof, for use as a smooth muscle cell (SMC) proliferation-inhibiting drug: wherein: R1 to R6 are —H, —F, —CH3, —CF3, —CF2CH3, —OCH3, —COCH3, —C4H9, —COOC2H5, or —C6H5, or two vicinal residues from R1 to R6 form a saturated or unsaturated carbocyclic ring together with the two carbon atoms to which they are attached; R7 is OH, allyloxy, propargyl-oxy, 2,2-dimethylpropanoyloxy (pivaloyloxy), butanoyloxy, 3-methylbutanoyloxy, 2-buten-oyloxy, 2-methyl-2-butenoyloxy, 3-methyl-2-butenoyloxy, isopentanoyloxy, 2-ethylbutanoyl-oxy, 3,3-dimethylbutanoyloxy, cyclopropylcarbonyloxy, cyclobutylcarbonyloxy, cyclo-pentylcarbonyloxy, cyclopentenylcarbonyloxy, cyclohexylcarbonyloxy, cyclo-hexenylcarbonyloxy, adamantylethanoyloxy, 3-phenylpropenoyloxy (cinnamyloyloxy), 2-methylbenzoyloxy, or naphthoyloxy; wherein, in ring A and/or B, one or more carbon ring atoms are optionally replaced by heteroatoms; wherein the compounds of formula (II) are obtained by combining