Quantitative determination of enzalutamide, an anti-prostate cancer drug, in rat plasma using liquid chromatography-tandem mass spectrometry, and its application to a pharmacokinetic study.

This report details a method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) that allows one to determine the concentration of an atypical anticancer drug, enzalutamide, in rat plasma. Specifically, this method involves the addition of an acetonitrile and bicalutamide (internal standard) solution to plasma samples. Following centrifugation of this mixture, an aliquot of the supernatant was directly injected into the LC-MS/MS system. Separation was achieved using a column packed with octadecylsilica (5 µm, 2.1 × 50 mm) with 10 mM ammonium acetate in acetonitrile as the mobile phase; detection was accomplished using MS/MS by multiple-reaction monitoring via an electrospray ionization source. This method demonstrated a linear standard curve (r = 0.997) over a concentration range of 0.001-1 µg/mL, as well as an intra- and inter-assay precision of 2.7 and 5.1%, respectively, and an accuracy range from 100.8 to 105.6%. The lower limit of quantification was 1.0 ng/mL in 50 µL of rat plasma sample. We also demonstrated that this analytical method could be successfully applied to the pharmacokinetic study of enzalutamide in rats.

Discovery of non-LBD inhibitor for androgen receptor by structure-guide design.

In this study, we synthesized the BF-3 binding small molecules, a series of pyridazinone-based compounds, as a novel class of non-LBP antiandrogens for treating prostate cancer by inhibiting androgen receptor. The new class compound was discovered to inhibitor the viability of AR-dependent human prostate LNCap cells and AR activity combining with the computational method. It showed a good physicochemical and PK property.

In silico identification of poly(ADP-ribose)polymerase-1 inhibitors and their chemosensitizing effects against cisplatin-resistant human gastric cancer cells.

Poly(ADP-ribose)polymerase-1 (PARP-1) enzyme is involved in the repair of DNA damages made by certain anticancer agents. It is suggested that PARP-1 inhibitors potentiate the cytotoxic effects and circumvent the resistance of DNA-modifying anticancer agents such as cisplatin. In this study, we conducted virtual screening of Korea Chemical Bank database targeting PARP-1 and identified several potent PARP-1 inhibitors with submicromolar IC50 values (77-79 nM). We then examined the chemosensitization of cisplatin by pre-treatment of PARP-1 inhibitors in cisplatin-resistant human gastric cancer cells. Our results show that PARP-1 inhibitors suppress the formation of poly(ADP-ribose) and enhance the cytotoxicity of cisplatin.

Synthesis and SAR investigations of novel 2-arylbenzimidazole derivatives as melanin-concentrating hormone receptor 1 (MCH-R1) antagonists.

Compounds containing 2-arybenzimidazole ring systems linked to arylpiperidines were synthesized and evaluated as MCH-R1 antagonists. The results of structure-activity relationship studies led to the identification of compound 4c as a potent MCH-R1 antagonist (IC(50)=1 nM). This compound also has good metabolic stability, and favorable pharmacokinetic and brain penetration properties. However 4c was found to be potent inhibitor of the hERG potassium channel.

One-pot hydrogenation conditions for a sequential process to (+)-monomorine.

(+)-Monomorine has been synthesized under mild hydrogenation conditions initiating deprotection followed by intramolecular, sequential reductive amination reactions. The precursors could be prepared concisely using B-alkyl Suzuki cross coupling of a chiral homoallylamine and a vinyl iodide or an iodofuran derivative.

Identification of a novel antiangiogenic agent; 4-(N-imidazol-2-ylmethyl)amino benzopyran analogues.

A series of 4-(N-imidazol-2-ylmethyl)aminobenzopyran analogues, originally designed as K(ATP) openers for ischemic diseases, showed antiangiogenic properties through the inhibition of HUVEC tube formation. Especially one of p-Cl substituted analogues (4c) completely inhibited HUVEC tube formation at 10 microM. The compound 4c significantly inhibited tumor growth by 52% on A549 (human non small cell lung carcinoma) in nude mice xenografts without any significant side effects.