Novel Isoflavone Glucosides in Groundnut (Apios americana Medik) and Their Antiandrogenic Activities

Abstract

Isoflavone glucosides (2'-hydroxy,5-methoxy genistein-7-O-glucoside (1), 2'-hydroxy genistein-7-O-gentibioside (2), 5-methoxy genistein-7-O-glucoside (3), 3',5-dimethoxy genistein-7-O-glucoside (4), 2'-hydroxy genistein-7-O-glucoside (5), genistein-7-O-gentibioside (6), 2'-hydroxy,5-methoxy genistein-4',7-O-diglucoside (7), and 2'-hydroxy genistein-4',7-O-diglucoside (8)) were isolated from the groundnut of Apios americana Medik. Their structures were elucidated on the basis of HR-ESI-MS and 1D- and 2D-NMR analyses. Compounds 1, 2, 4, and 7 are new compounds presented here for the first time. Compounds 2 and 5 were proven to be androgen receptor antagonists due to their binding activities for androgen receptors (IC50 280 and 160 μM, respectively) and the inhibitory activity of androgen-induced expression of prostate-specific antigen (PSA) mRNA in LNCaP (prostate adenocarcinoma) cells (IC50 20 and 18 μM, respectively).

Biological activities of unique isoflavones prepared from Apios americana Medik

“…However, poor relationships were observed between estrogenic activity and antioxidant activity, and between α-glucosidase inhibitory activity and antioxidant activity. One hundred grams of Apios tuber contains approximately 60 mg of genistein (mainly as genistein diglucoside 6,7) ) and 20-40 mg of 1-4 (as their glucosides, 7) ) and 100 g of soy bean contains 80 mg of genistein (mainly as genistin). We usually eat Apios tuber after cooking (boiled or fried), and the reduction of isoflavone glucosides in Apios after cooking was not observed on HPLC analyses (data not shown).…”

“…In our previous study, 7) we identified 7 rare and new isoflavone glucosides other than genistein and genistein glucosides in the tuber of Apios and examined their estrogen receptor (ER) binding activities, androgen receptor (AR) binding activities, and androgen antagonistic activities. Our findings revealed that 2'-OH genistein-7-O-gentibioside and 2′-OH genistein-7-Oglucoside possessed moderate anti-androgenic activities.…”

Recent discoveries and developments of androgen receptor based therapy for prostate cancer

“…Antiandrogenic chemicals also occur naturally in plants. 76 3, 3′-Diindolylmethane (DIM) is an effective anti-androgen that is present in cruciferous vegetables, such as broccoli, Brussels' sprouts, cabbage and kale. Mahanine inhibits the growth and induces apoptosis in both androgen-responsive, LNCaP and androgen-independent, PC3 cells.…”

Soluble Epoxide Hydrolase Inhibitory Activity of Components Isolated from Apios americana Medik

“…The tubers of A. americana grow to a depth of about 100 cm, and form knots in intervals of about 5 and 10 cm [ 1 , 2 ]. Groundnuts have been used as a traditional health food by the North American Indians [ 2 , 3 ]. The nutrients of these roots were previously reported to include fatty acid, amino acid, and carbohydrate compositions, and a high content of protein (over 12%) [ 3 , 4 ].…”

“…Groundnuts have been used as a traditional health food by the North American Indians [ 2 , 3 ]. The nutrients of these roots were previously reported to include fatty acid, amino acid, and carbohydrate compositions, and a high content of protein (over 12%) [ 3 , 4 ]. Recently, isoflavonoids, such as genistein, barpisoflavone A, 2′-hydroxygenistein, 5-methylgenistein, 2′-hydroxy genistein-7- O -gentibioside, 2′-hydroxy,5-methoxy genistein-4′,7- O -diglucoside, and 2′-hydroxy genistein-7- O -glucoside, were isolated from the tubers of A. americana [ 3 , 5 ].…”