Given an abstract from a research paper, your task is to identify and label relationships between chemical compounds and genes mentioned in the abstract.

The relationship type must be one of ['DOWNREGULATOR', 'SUBSTRATE', 'INDIRECT-REGULATOR', 'PART-OF', 'MODULATOR-ACTIVATOR', 'REGULATOR', 'INHIBITOR', 'COFACTOR', 'UPREGULATOR', 'ACTIVATOR', 'ANTAGONIST', 'NOT', 'INDIRECT-DOWNREGULATOR', 'SUBSTRATE_PRODUCT-OF', 'INDIRECT-UPREGULATOR', 'AGONIST', 'PRODUCT-OF', 'MODULATOR', 'DIRECT-REGULATOR', 'UNDEFINED', 'AGONIST-INHIBITOR', 'AGONIST-ACTIVATOR', 'MODULATOR-INHIBITOR'].

Please format your output as a JSON array. Each entry in the array should express a single relation, formatted as ["<Entity_A>", "<RELATION_A_B>", "<Entity_B>"]. If no relations can be found, please output an empty JSON array [].

Abstract:

Inhibitory effect of synthetic progestins, 4-MA and cyanoketone on human placental 3 beta-hydroxysteroid dehydrogenase/5----4-ene-isomerase activity. Human placental 3 beta-hydroxysteroid dehydrogenase/5----4-ene isomerase (3 beta-HSD) purified from human placenta transforms C-21 (pregnenolone and 17 alpha-hydroxy pregnenolone) as well as C-19 (dehydroepiandrosterone and androst-5-ene-3 beta, 17 beta-diol) steroids into the corresponding 3-keto-4-ene-steroids and is thus involved in the biosynthesis of all classes of hormonal steroids. Trilostane, epostane and cyanoketone are potent inhibitors of 3 beta-HSD with Ki values of approximately 50 nM. 4-MA, a well known 5 alpha-reductase inhibitor, is also a potent inhibitor of 3 beta-HSD with a Ki value of 56 nM. Synthetic progestin compounds such as promegestone and RU2323 show relatively strong inhibitory effects with Ki values of 110 and 190 nM, respectively. Cyproterone acetate, a progestin used in the treatment of hirsutism, acne and prostate cancer as well as norgestrel and norethindrone that are widely used as oral contraceptives also inhibit 3 beta-HSD activity at Ki values of 1.5, 1.7 and 2.5 microM, respectively.
[["androst-5-ene-3 beta ", "17 beta-diol", "SUBSTRATE", "3 beta-HSD"], ["3-keto-4-ene-steroids", "PRODUCT-OF", "3 beta-HSD"], ["androst-5-ene-3 beta ", "17 beta-diol", "SUBSTRATE", "Human placental 3 beta-hydroxysteroid dehydrogenase/5 - ---4-ene isomerase"], ["progestin", "INHIBITOR", "3 beta-HSD"], ["epostane", "INHIBITOR", "3 beta-HSD"], ["progestins", "INHIBITOR", "human placental 3 beta-hydroxysteroid dehydrogenase/5 - ---4-ene-isomerase"], ["4-MA", "INHIBITOR", "5 alpha-reductase"], ["Trilostane", "INHIBITOR", "3 beta-HSD"], ["cyanoketone", "INHIBITOR", "3 beta-HSD"], ["dehydroepiandrosterone", "SUBSTRATE", "Human placental 3 beta-hydroxysteroid dehydrogenase/5 - ---4-ene isomerase"], ["pregnenolone", "SUBSTRATE", "Human placental 3 beta-hydroxysteroid dehydrogenase/5 - ---4-ene isomerase"], ["3-keto-4-ene-steroids", "PRODUCT-OF", "Human placental 3 beta-hydroxysteroid dehydrogenase/5 - ---4-ene isomerase"], ["cyanoketone", "INHIBITOR", "human placental 3 beta-hydroxysteroid dehydrogenase/5 - ---4-ene-isomerase"], ["norethindrone", "INHIBITOR", "3 beta-HSD"], ["dehydroepiandrosterone", "SUBSTRATE", "3 beta-HSD"], ["pregnenolone", "SUBSTRATE", "3 beta-HSD"], ["Cyproterone acetate", "INHIBITOR", "3 beta-HSD"], ["17 alpha-hydroxy pregnenolone", "SUBSTRATE", "3 beta-HSD"], ["4-MA", "INHIBITOR", "human placental 3 beta-hydroxysteroid dehydrogenase/5 - ---4-ene-isomerase"], ["17 alpha-hydroxy pregnenolone", "SUBSTRATE", "Human placental 3 beta-hydroxysteroid dehydrogenase/5 - ---4-ene isomerase"], ["4-MA", "INHIBITOR", "3 beta-HSD"], ["norgestrel", "INHIBITOR", "3 beta-HSD"]]