New analogues of anti-
cancer drugs atamestane (1), drostanolone enanthate ((3), and
exemestane (6) were synthesized through
biotransformation. New derivatives, 14α-hydroxy-1-methylandrosta-1,4-
diene-3,17-dione ((2) (IC50, 9.7±0.72 nM) of 1 (IC50, 13.8±0.2 nM), and 2-methylandrosta-12β,17β-dihydroxy-1,4-
diene-3-one (4) (IC50, 4.23±0.133 nM) of 3 (IC50, 6.4±0.06 nM) showed a potent inhibition against human
aromatase enzyme and thus have the potential to treat ER+ breast-cancers and other related diseases. New metabolites, 2α-methyl-9α,17β-dihydroxy-5α-androstan-3-one ((5) (IC50=793.0±29.9 nM) of 3, 6-
methylene-3α,7β,17β-trihydroxy-5β-
androstane (7) (IC50, 46.1±0.81 nM), and 11α,17β-dihydroxy-6-
methylene-androsta-1,4-
diene-3-one (8) (IC5O=12797.0±844 nM) of
exemestane (6) (IC50=232.0±31 nM) also showed a remarkable anti-
aromatase activity.
Aromatase is an
enzyme, involves in the synthesis of
estrogen (ER). Increased amount of ER due to overexpression of
aromatase in the body, promotes cancerous cells growth in breast. Therefore, aromatase
enzyme is a key target for the discovery of chemotherapeutic agents against ER+ breast-cancers.