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Development of antitumor agents targeting energy metabolism pathways of cancer cells has attracted much attention in recent days. In general, most cancer cells are known to display Warburg effect. Recently, it has been reported that cancer cells exist as heterogeneous groups in the microenvironment surrounding cancer cells and that not only glycolysis but also mitochondrial oxidative phosphorylation (OXPHOS) is important for cancer growth. In addition, many research groups have reported that the acquisition of anticancer drug resistance is caused by metabolic reprogramming from glycolysis to OXPHOS. Therefore, OXPHOS inhibitors could be useful antitumor agents. OPB-111077 is an orally active novel antitumor agent and has the inhibitory effect on mitochondrial OXPHOS. OPB-111077 had the inhibitory effect on mitochondrial respiratory chain complex I which led to the inhibition of energy production and activation of AMPK-mTOR energy stress sensor pathway. In in vitro growth inhibition studies, OPB-111077 showed potent inhibitory effects on the growth of various human blood tumor cell lines derived from leukemia, multiple myeloma and lymphoma with IC 50 values between 18.6 and 525.3 nM, and on the growth of human solid tumor cell lines derived from liver cancer, lung cancer, gastric cancer and breast cancer with IC 50 values ranging from 92.6 to 1727.7 nM. In in vivo studies using SCID mice bearing tumors from human tumor cell lines, daily oral administration of OPB-111077 demonstrated significant antitumor effects against leukemia, lymphoma, liver, gastric and breast cancer cell line-derived tumor, dose-dependently. Here, we report the combination therapy strategy based on the cancer energy metabolism of OPB-111077. We found that OPB-111077 combined with alkylating agent, cyclophosphamide or bendamustine, showed the synergistic effect on xenograft mice model using human diffuse large B-cell lymphoma (DLBCL) cell line. To clarify this mechanism, we examined the effect of alkylating agents on mitochondrial respiration in vitro using flux analyzer and found that alkylating agents induced OXPHOS nature in the DLBCL cell line. Furthermore, the administration of alkylating agents to DLBCL cell line xenograft model mice followed by mRNA expression analysis of their tumor tissue confirmed that expression of OXPHOS-related markers was induced. These results suggest the administration of alkylating agents induced reprogramming to OXPHOS predominant nature in tumor. The tumor environment is actively reprogrammed to OXPHOS by alkylating agents, and it is changed to a state in which the antitumor effect of OPB-111077 can be more exerted. Thus, alkylating agents enhance the effect of OPB-111077 by tilting glycolytically dominant tumors to OXPHOS dominant. The alkylating agents, cyclophosphamide and bendamustine, are used as standard therapies for lymphoma. OPB-111077 could be treated in a wide range of applications as a combination therapy with the alkylating agents for lymphoma. In clinical, we have confirmed that OPB-111077 has tolerable and controllable toxicity profile of single agent in some advanced cancer patients including DLBCL. Bendamustine and rituximab (BR) therapy is indicated for the treatment of patients who are ineligible for transplantation of relapsed / refractory (R/R) DLBCL. However, there is still a high unmet need for patients with R/R DLBCL due to no standard treatment for transplant-ineligible patients. We are conducting combination therapy of OPB-111077 with bendamustine and rituximab in Phase 1 clinical trial for R/R DLBCL in Japan. Disclosures Ohi: Otsuka Pharmaceutical Co.,Ltd.: Current Employment. Okuno: Otsuka Pharmaceutical Co.,Ltd.: Current Employment. Tanaka: Otsuka Pharmaceutical Co.,Ltd.: Current Employment. Ohtani: Otsuka Pharmaceutical Co.,Ltd.: Current Employment. OffLabel Disclosure: Compound: OPB-111077 Purpose: Development of novel antitumor agent

Lactococcus strain 20–92 is a bacterium that produces equol directly from daidzein under anaerobic conditions. In this study, we reveal that the transcription of the gene encoding daidzein reductase in Lactococcus strain 20–92 (L-DZNR), which is responsible for the first stage of the biosynthesis of equol from daidzein, is regulated by the presence of daidzein. We analyzed the sequence surrounding the L-DZNR gene and found six novel genes, termed orf-US4, orf-US3, orf-US2, orf-US1, orf-DS1 and orf-DS2. These genes were expressed in Escherichia coli, and the resulting gene products were assayed for dihydrodaidzein reductase (DHDR) and tetrahydrodaidzein reductase (THDR) activity. The results showed that orf-US2 and orf-US3 encoded DHDR and THDR, respectively. DHDR in Lactococcus strain 20–92 (L-DHDR) was similar to the 3-oxoacyl-acyl-carrier-protein reductases of several bacteria and belonged to the short chain dehydrogenase/reductase family. THDR in Lactococcus strain 20–92 (L-THDR) was similar to several putative fumarate reductase/succinate dehydrogenase flavoprotein domain proteins. L-DHDR required NAD(P)H for its activity, whereas L-THDR required neither NADPH nor NADH. Thus, we succeeded in identifying two novel enzymes that are related to the second and third stages of the biosynthetic pathway that converts daidzein to equol.

The optical isomers of 5-dimethylamino-1-[4-(2-methylbenzoylamino)benzoyl]-2,3,4,5-tetrahydro-1H-1-benzazepine (OPC-31260, 1) and its metabolites (2, 3, 4, 5 and 6) were enantioselectively synthesized. The chiral acetate 8b and alcohol 7a were prepared via the resolution of the racemic alcohol (±)-7 using the lipase-mediated transesterification in vinyl acetate. The compounds 8b and 7a were converted to the hydroxy metabolites (2a and 2b), the methylamine metabolites (3a and 3b), the dimethylamines (1a and 1b), and the amine metabolites (4a and 4b) in several steps while maintaining their absolute configurations. The 4,5-diol metabolites (5a, 5b, 6a and 6b) were synthesized from the key intermediates obtained by the lipase-catalyzed transesterification.

The optically active metabolites of (S)-3,4-dihydro-6-[3-(1-o-tolyl-2-imidazolyl)sulfinyl-propoxy]-2(1H)-quinolinone (OPC-29030, 1), which is a new anti-platelet agent (platelet adhesion inhibitor), were effectively synthesized by the enzyme-catalyzed enantioselective transesterification of the racemic sulfinyl metabolites. The enzymes can recognize a stereogenic sulfur atom remote from the reaction site.

A metabolite of Aripiprazole (1), 7-[4-[4-(2,3-dichloro-4-hydroxyphenyl)-1-piperazinyl]butoxy]-3,4-dihydro-2(1H)-quinolinone (2), was prepared by the coupling reaction of 1-(4-benzyloxy-2,3-dichlorophenyl)-piperazine (11) with 7-(4-chlorobutoxy)-3,4-dihydro-2(1H)-quinolinone (16). The palladium-catalyzed amination of contiguous tri- and tetra-substituted benzenes with piperazine derivatives was investigated. The key intermediate 11 was efficiently prepared using the palladium-catalyzed amination of phenyl bromide 15 with piperazine.

Optically active 2-[(3-hydroxypropyl)sulfinyl]-1-( o -tolyl)imidazole (S)- 2 was synthesized by kinetic resolution of (±)- 2 with lipase and hydrolysis of the acetate (S)- 3 with potassium carbonate. The reaction mixture of the lipase-catalyzed transesterification was converted to the phthalic acid derivative (R)- 4 , and this (R)- 4 and the unreacted acetate (S)- 3 were fractionated without use of column chromatography. The unrequired recovered alcohol (R)- 2 was also racemized and (±)- 2 was repeatedly submitted to the lipase-catalyzed transesterification.

A hydroxylated metabolite (5a) of 7-hydroxy-1-[[[4-(3-methoxyphenyl)-1-piperazinyl]acetyl]amino]-2,2,4,6-tetramethylindan (OPC-14117), which is a novel cerebroprotective agent with central nervous system-stimulating activity, was synthesized by use of a model cytochrome P-450 system. In order to confirm the structure of this compound it was prepared by another route. Tile structures of several metabolites (5a, 7 and 8) were identified by means of comparisons with the synthetic compounds.

An efficient and highly enantioselective synthesis of ( S )-(−)-5,6-difluoro-2-methyl-1,2,3,4-tetrahydroquinoline (4b) , a key intermediate in the synthesis of ( S )-(−)-nadifloxacin ( 2 ), was carried out by using a cross-coupling reaction. Also α,β-acetylenic ketones 14a,b underwent an asymmetric reduction using various chiral reagents to afford the corresponding propargylic alcohols 8a,b in good yield and excellent enantiomeric excess, which can be easily converted to butanol 9 .

Grepafloxacin (1-cyclopropyl-1,4-dihydro-6-fluoro-5-methyl-7-(3-methyl-1-piperazinyl )-4-oxo-3-quinoline-carboxylic acid, OPC-17116) (1) exhibits potent and broad-spectrum in vitro and in vivo antibacterial activity. In order to identify the structures of the metabolites of grepafloxacin, 17 possible metabolites were prepared. Among them, 6 compounds were found to be actual metabolites (2a, b, 4a, b and 6a, b) of grepafloxacin in rats, dogs and/or humans. The antibacterial activities of these metabolites were found to be weaker than that of grepafloxacin.

The enantiomers of 7-fluoro-1-methyl-3-(methylsulfinyl)-4(1H)-quinolinone [(±)-1, flosequinan], a new drug for the treatment of heart failure, were synthesized from the optically active (R)-α-methylbenzylamine derivatives of quinoline. The key intermediates, (R)-α-methylbenzylamine derivatives, were prepared by diastereomeric separation. The configuration of (+)-1 was assigned on the basis of an X-ray crystallographic analysis of the synthetic precursor (4a). The absolute configuration was found to be (R)-(+)-1 and (S)-(-)-1.

An efficient and highly enantioselective synthesis of ( S )-(−)-5,6-difluoro-2-methyl-1,2,3,4-tetrahydroquinoline (4b) , a key intermediate in the synthesis of ( S )-(−)-nadifloxacin ( 2 ), was carried out by using a cross-coupling reaction. Also α,β-acetylenic ketones 14a,b underwent an asymmetric reduction using various chiral reagents to afford the corresponding propargylic alcohols 8a,b in good yield and excellent enantiomeric excess, which can be easily converted to butanol 9 .

In a search for inhibitors of gastric H+/K+ATPase, 4-(phenylamino)quinoline-3-carboxamides were synthesized and evaluated for antisecretory activity against histamine-induced gastric acid secretion in rats. These compounds were synthesized by condensation of aniline derivatives with N-substituted 4-chloroquinoline-3-carboxamides, which were obtained from treatment of 4(1H)-quinolinone-3-carboxylic acid with thionyl chloride. Most of the compounds inhibited histamine-induced gastric acid secretion in rats. Among them, N-allyl-4-(2-ethylphenylamino)quinoline-3-carboxamide (4h) was the most potent inhibitor and had the best profile as a candidate antiulcer agent. This compound showed reversible, K+-competitive gastric H+/K+-ATPase inhibitory activity.

The enantiomers of 7-fluoro-1-methyl-3-(methylsulfinyl)-4(1H)-quinolinone [(±)-1, flosequinan], a new drug for the treatment of heart failure, were synthesized from the optically active (R)-α-methylbenzylamine derivatives of quinoline. The key intermediates, (R)-α-methylbenzylamine derivatives, were prepared by diastereomeric separation. The configuration of (+)-1 was assigned on the basis of an X-ray crystallographic analysis of the synthetic precursor (4a). The absolute configuration was found to be (R)-(+)-1 and (S)-(-)-1.

A hydroxylated metabolite (5a) of 7-hydroxy-1-[[[4-(3-methoxyphenyl)-1-piperazinyl]acetyl]amino]-2,2,4,6-tetramethylindan (OPC-14117), which is a novel cerebroprotective agent with central nervous system-stimulating activity, was synthesized by use of a model cytochrome P-450 system. In order to confirm the structure of this compound it was prepared by another route. Tile structures of several metabolites (5a, 7 and 8) were identified by means of comparisons with the synthetic compounds.

Optically active 2-[(3-hydroxypropyl)sulfinyl]-1-( o -tolyl)imidazole (S)- 2 was synthesized by kinetic resolution of (±)- 2 with lipase and hydrolysis of the acetate (S)- 3 with potassium carbonate. The reaction mixture of the lipase-catalyzed transesterification was converted to the phthalic acid derivative (R)- 4 , and this (R)- 4 and the unreacted acetate (S)- 3 were fractionated without use of column chromatography. The unrequired recovered alcohol (R)- 2 was also racemized and (±)- 2 was repeatedly submitted to the lipase-catalyzed transesterification.

A metabolite of Aripiprazole (1), 7-[4-[4-(2,3-dichloro-4-hydroxyphenyl)-1-piperazinyl]butoxy]-3,4-dihydro-2(1H)-quinolinone (2), was prepared by the coupling reaction of 1-(4-benzyloxy-2,3-dichlorophenyl)-piperazine (11) with 7-(4-chlorobutoxy)-3,4-dihydro-2(1H)-quinolinone (16). The palladium-catalyzed amination of contiguous tri- and tetra-substituted benzenes with piperazine derivatives was investigated. The key intermediate 11 was efficiently prepared using the palladium-catalyzed amination of phenyl bromide 15 with piperazine.

As an efficient and enantioselective synthesis of the 4,5-dihydroxy-benzazepine compounds, the syntheses of optically active 5-0-protected trans-4,5-dihydroxybenzazepine derivatives were accomplished. The trans-7-chloro-4-hydroxy-5-methoxymethoxy-1 -(p-toluenesulfonyl)-2,3,4,5-tetrahydro-1H-1-benzazepine [(±)-4] was kinetically resolved by lipase-catalyzed transesterification. The optically active 4* was isomerized into the cis compound (6*) utilizing the Mitsunobu esterification followed by hydrolysis. The chiral compounds (4* and 6*) were converted to the 4,5-bismethoxymethoxy compounds (7*-10*), which were the intermediates for the compounds (2a, b and 3a, b).

The 5-hydroxy-2,3,4,5-tetrahydro-1H-benzazepine derivative (2), which is a typical metabolite of mozavaptan (1) having the 2,3,4,5-tetrahydro-1H-benzazepine skeleton, was synthesized by utilizing the intramolecular Mitsunobu reaction of the corresponding 2-(4-hydroxybutyl)aniline derivative. In the intramolecular Mitsunobu reaction, effect of the substituent group on nitrogen atom, influence of the functional group applying to synthesis of the other metabolites (3, 4 and 5) and utilization of synthesis of 2-substituent benzazepine derivatives were investigated.

The optical isomers of 5-dimethylamino-1-[4-(2-methylbenzoylamino)benzoyl]-2,3,4,5-tetrahydro-1H-1-benzazepine (OPC-31260, 1) and its metabolites (2, 3, 4, 5 and 6) were enantioselectively synthesized. The chiral acetate 8b and alcohol 7a were prepared via the resolution of the racemic alcohol (±)-7 using the lipase-mediated transesterification in vinyl acetate. The compounds 8b and 7a were converted to the hydroxy metabolites (2a and 2b), the methylamine metabolites (3a and 3b), the dimethylamines (1a and 1b), and the amine metabolites (4a and 4b) in several steps while maintaining their absolute configurations. The 4,5-diol metabolites (5a, 5b, 6a and 6b) were synthesized from the key intermediates obtained by the lipase-catalyzed transesterification.

In a search for inhibitors of gastric H+/K+ATPase, 4-(phenylamino)quinoline-3-carboxamides were synthesized and evaluated for antisecretory activity against histamine-induced gastric acid secretion in rats. These compounds were synthesized by condensation of aniline derivatives with N-substituted 4-chloroquinoline-3-carboxamides, which were obtained from treatment of 4(1H)-quinolinone-3-carboxylic acid with thionyl chloride. Most of the compounds inhibited histamine-induced gastric acid secretion in rats. Among them, N-allyl-4-(2-ethylphenylamino)quinoline-3-carboxamide (4h) was the most potent inhibitor and had the best profile as a candidate antiulcer agent. This compound showed reversible, K+-competitive gastric H+/K+-ATPase inhibitory activity.

The unstable 2-pyrrolidinol derivative (2), as a metabolite of a new vasopressin V 2 receptor agonist OPC-51803 (1), was synthesized by the cytochrome P-450 model reaction of 1 with the Fe-salen complex and iodosobenzene.

The optically active enantiomers of 7-chloro-5-hydroxy-1-[2-methyl-4-(2-methylbenzoylamino)benzoyl]-2,3,4,5-tetrahydro-1H-1-benzazepine (OPC-41061, 1) were enantioselectively synthesized. The asymmetric transfer hydrogenation of the ketone (2), which is the precursor of 1, gave the corresponding secondary alcohols in good yield and excellent enantiomeric excess.

An efficient and enantioselective synthesis of (R)-[1-(p-toluene-sulfonyl)-2,3,4,5-tetrahydro-1H-1-benzazepin-5-yl]acetic acid (2), a key intermediate in the synthesis of (R)-2-{1-[2-chloro-4-(1-pyrrolidinyl)benzoyl]-2,3,4,5-tetrahydro-1H-1-benzazepin-5-yl}-N-isopropylacetamide (OPC-51803, 1), was accomplished. The chiral alcohol [(S)-3], the precursor of (R)-2, was separated from the racemic alcohol [(′)-3] using the lipase mediated transesterification in vinyl acetate. The obtained (S)-3 was fractionated without using column chromatography and it was converted to 2 without a decrease in the enantiomeric excess.