Development of a potent and orally active activator of adenosine monophosphate-activated protein kinase (AMPK), ASP4132, as a clinical candidate for the treatment of human cancer

Adenosine monophosphate (AMP)-activated protein kinase (AMPK) plays a key role in maintaining cellular metabolism. AMP or adenosine diphosphate (ADP) levels rise during metabolic stress, such as during nutrient starvation, hypoxia and muscle contraction, and bind to AMPK to induce activity. Recently, activation of AMPK has been considered an attractive therapeutic strategy in the field of human oncology. Structural optimization of lead compound 2, a new type of AMPK activator with potent AMPK activation activity and attractive selective growth inhibition against human cancer cells, improved aqueous solubility, metabolic stability and animal pharmacokinetics (PK) and culminated in the identification of (5-{1-[(6-methoxypyridin-3-yl)methyl]piperidin-4-yl}-1H-benzimidazol-2-yl)(4-{[4-(trifluoromethyl)phenyl]methyl}piperazin-1-yl)methanone ditosylate, ASP4132 (28). Studies on ASP4132 had advanced to clinical trials for the treatment of cancer.

ASP9521, a novel, selective, orally bioavailable AKR1C3 (type 5, 17ß-hydroxysteroid dehydrogenase) inhibitor: In vitro and in vivo characterization

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Background: Aldo–keto reductase 1C3 (AKR1C3), also known as type 5, 17β-hydroxysteroid dehydrogenase, is reported to be highly expressed in human normal prostate and prostate cancer (PC) and the expression increases along with increasing malignancy or grade of PC. Since AKR1C3 converts the adrenal androgen, androstenedione (AD) into testosterone (T), combination with a GnRH analogue and AKR1C3 inhibitor would be expected to provide total androgen blockade in the treatment of castration-resistant prostate cancer (CRPC). We obtained a lead compound having a non-steroidal scaffold by high throughput screening (HTS) approaches for targeting enzyme activity of AKR1C3. After optimization of the lead compound, we found ASP9521 as a potent, selective, and orally bioavailable AKR1C3 inhibitor. Methods: The inhibitory effect of ASP9521 on enzymatic conversion from AD to T by AKR1C3 was evaluated in vitro, and in CWR22R xenograft models. Effect of PSA production and proliferation on LNCaP cells stably expressing AKR1C3 was examined. Pharmacokinetics in various animals were also investigated. Results: ASP9521 showed potent inhibitory effect on enzymatic conversion from AD to T by both human AKR1C3 and cynomolgus monkey homologues in a concentration-dependent manner, with IC50 values of 11 and 49 nmol/L, respectively ASP9521 suppressed both AD-dependent PSA production and cell proliferation in LNCaP cells exogenously expressing AKR1C3 in vitro. The bioavailability of ASP9521after oral administration of 1mg/kg were 30% and 78% in rat and dog, respectively. Furthermore, ASP9521 single oral administration of 3 mg/kg suppressed AD-induced intratumoral T production in CWR22R xenografted castrate nude mice, and this inhibitory effect was maintained for 24 h. In addition, ASP9521 was rapidly eliminated from plasma after oral administration while its intratumoral concentration remained high in tumors expressing AKR1C3. Conclusions: These preclinical in vitro and in vivo data are consistent with a potent inhibition of 17β-hydroxysteroid dehydrogenase. The results suggest that ASP9521 should be investigated further to elucidate its role as treatment for PC.

Effects of biofilm formation on membrane performance in submerged membrane bioreactors

The effects of biofilm formation on membrane performance were evaluated for a submerged membrane bioreactor (sMBR) system with six different types of micro- and ultrafiltration membranes (working volume=19 l). After operation for 24 h the permeability of the membranes with a larger pore size (microfiltration) decreased to that of the membranes with a much smaller pore size (ultrafiltration). Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) confirmed that biofilms could reduce the influence of the membrane surface properties. The chemical oxygen demand (COD) removal efficiency was 95% for the oily wastewater treatment in the sMBR where the filtration process made an important contribution (47% based on feed COD). Significant enhancement in COD removal occurred at the initial filtration stage because of biofilm formation and the dynamic member role of the biofilm layer. Membranes with various pore sizes had approximately the same permeate quality that was attributed to the biofilm on the membrane surfaces. Nevertheless, the ultrafiltration membranes had 43% more COD removal efficiency than the other applied membranes at the beginning of filtration (before biofilm formation) because of the smaller pore sizes and better sieving.

Studies on anti-Helicobacter pylori agents. Part 1: Benzyloxyisoquinoline derivatives

The synthesis and optimization of the anti-Helicobacter pylori activity of a novel series of benzyloxyisoquinoline derivatives that was discovered by a random screening process, are described. In the in vitro assay, compound 10c containing a 3-acetamido-2,6-dichlorobenzyl substituent was found to have extremely potent activity against H. pylori and no activity against other common bacteria. The anti-H. pylori activity of 10c was superior to that of amoxicillin (AMPC) (1) and clarithromycin (CAM) (2). However, 10c did not show in vivo efficacy in a mouse infection model; a feature attributed to the lack of strong bactericidal activity at short contact times.

Synthesis and antibacterial activity of novel 4-pyrrolidinylthio carbapenems. Part III: Novel 2-alkyl substituents containing cationic heteroaromatics linked via a C-N bond

The synthesis and biological activity of a novel series of 2-alkyl-4-pyrrolidinylthio-beta-methylcarbapenems containing a variety of cationic heteroaromatic substituents is described. As a result of these studies, we uncovered a relationship between in vitro antibacterial activity and the length of the alkyl spacer part, and discovered FR20950 (1c), containing a two methylene spacer moiety and an imidazolio group, which possesses a balanced spectrum of antibacterial activity, including Pseudomonas aeruginosa and Methicillin-resistant Staphylococcus aureus (MRSA). Furthermore, FR20950 exhibited excellent urinary recovery, and comparable stability against renal dehydropeptidase-I (DHP-I) to Biapenem. DHP-I stability could be improved by introduction of a substituent on to the imidazole ring.

Discovery of a novel benzyloxyisoquinoline derivative with potent anti-Helicobacter pylori activity

The synthesis and in vitro optimization of the anti-Helicobacter pylori activity of a novel series of benzyloxyisoquinoline derivatives discovered by a random screening process, are described. FR180102 (7f), having a 3-acetamido-2,6-dichlorobenzyl moiety, was found to have extremely potent activity against H. pylori and no effect against a series of common Gram-positive and Gram-negative bacteria.

Synthesis and antibacterial activity of novel 4-pyrrolidinylthio carbapenems--I. 2-Alkoxymethyl derivatives

The synthesis and in vitro antibacterial activity of a novel series of 2-alkoxymethyl-4-pyrrolidinylthio-1 beta-methyl carbapenems are described. As a result of these studies, we discovered that FR27743 (19j) containing a novel 2-fluoroethoxymethyl substituent possesses a broad spectrum of antibacterial activity against both Gram-positive and Gram-negative organisms, including Pseudomonas aeruginosa. Furthermore, FR27743 exhibited excellent stability against renal dehydropeptidase-I (DHP-I), good urinary recovery, and superior in vivo activity compared to that for Meropenem against several systemic infections.

Studies on the synthesis of sesquiterpene lactones, 12. Synthesis of (+)-colartin, (+)-arbusculin A, and their C-4 epimers and their biological activities

Colartin [9] and arbusculin A [11] have been synthesized from alpha-santonin [1] in 14.5% (11 steps) and 9.3% (13 steps) overall yields, respectively. Arbusculin A [11] and compounds 20, 21, and 22, which were derived from intermediate 2, showed significant cell growth inhibitory activity against murine lymphocytic leukemia (P-388) in vitro. Plant growth regulating activity of 11 and its synthetic intermediates 4, 5, 8, and 9 was also studied.