Production of Mn-Ga Magnets.

Mn-based magnets are known to be a candidate for use as rare-earth-free magnets. In this study, Mn-Ga bulk magnets were successfully produced by hot pressing using the spark plasma sintering method on Mn-Ga powder prepared from rapidly solidified Mn-Ga melt-spun ribbons. When consolidated at 773 K and 873 K, the Mn-Ga bulk magnets had fine grains and exhibited high coercivity values. The origin of the high coercivity of the Mn-Ga bulk magnets was the existence of the D022 phase. The Mn-Ga bulk magnet consolidated at 873 K exhibited the highest coercivity of 6.40 kOe.

Production of (Sm,Zr)(Fe,Co)3 magnets.

This study was aimed at the improvement of SmFe3-based alloys prepared by means of melt-spinning. A systematic study was carried out on (Sm1-xZrx)(Fe0.75Co0.25)3 (x = 0-0.4) alloys melt-spun at a wheel speed of 50 m/s and annealed at 773-1173 K. SmFe3-based melt-spun ribbons with a rhombohedral structure were prepared from the (Sm1-xZrx) (Fe0.75Co0.25)3 (x = 0-0.4) alloys. The addition of zirconium increased the coercivity and enhanced the remanence of the melt-spun ribbons. However, the Curie temperature slightly decreased with increasing zirconium content. The optimally annealed alloys, with a composition of (Sm0.7Zr0.3) (Fe0.75Co0.25)3, achieved a coercivity of 7.8 kOe, a remanence of 6.0 kG, and a Curie temperature of 680K.

A 90-day repeated-dose toxicity study of dietary alpha linolenic acid-enriched diacylglycerol oil in rats.

Diets supplemented with alpha-linolenic acid (ALA)-enriched diacylglycerol (DAG) oil-which mainly consists of oleic and linolenic, linoleic acids-have potential health benefits in terms of preventing or managing obesity. Although safety of DAG oil has been extensively investigated, toxicity of ALA-DAG oil has not been well understood. Hence, the present study was conducted to clarify the potential adverse effects, if any, of ALA-DAG oil in rats (10/sex/group) fed diets containing 1.375%, 2.75%, or 5.5% ALA-DAG oil for 90 days. Compared to control rats fed rapeseed oil or ALA-triacylglycerol oil (flaxseed oil), rats receiving ALA-DAG oil did not reveal any toxicologically significant treatment-related changes as evaluated by clinical signs, functional observational battery, body weight, food consumption, ophthalmology, urinalysis, hematology, clinical chemistry, organ weight, necropsy and histopathology. The no observed adverse effect levels for dietary exposure to ALA-DAG oil for male and female rats were 2916 and 3326 mg/kg body weight/day, respectively, the highest dose tested. The findings from this study suggest that consumption of ALA-DAG oil is unlikely to cause adverse effects.

Pyrrolo[1,2-b]pyridazines, pyrrolo[2,1-f]triazin-4(3H)-ones, and related compounds as novel corticotropin-releasing factor 1 (CRF1) receptor antagonists.

To identify structurally novel corticotropin-releasing factor 1 (CRF(1)) receptor antagonists, a series of bicyclic core analogs pyrrolo[1,2-b]pyridazines and pyrrolo[2,1-f]triazin-4(3H)-ones, which were designed based on a monocyclic core antagonist, was synthesized and evaluated. Among the compounds tested, 2-difluoromethoxy-4-methylpyridin-5-yl analog 27 was found to show efficacy in a dose-dependent manner in an elevated plus maze test in rats. The discovery process and structure-activity relationship is presented.

Pyrazolo[1,5-a]pyrimidines, triazolo[1,5-a]pyrimidines and their tricyclic derivatives as corticotropin-releasing factor 1 (CRF1) receptor antagonists.

To identify structurally novel CRF1 receptor antagonists, a series of bicyclic core antagonists, pyrazolo[1,5-a]pyrimidines, triazolo[1,5-a]pyrimidines, imidazo[1,2-a]pyrimidines and pyrazolo[1,5-a][1,3,5]triazines were designed, synthesized and evaluated as CRF1 receptor antagonists. Compounds 2-27 showed binding affinity (IC(50)=4.2-418 nM) and antagonist activity (EC(50)=4.0-889 nM). Compound 5 was found to show oral efficacy in an Elevated Plus Maze test in rats. Further chemical modification of them led us to discovery of the tricyclic core antagonists pyrazolo[1,5-a]pyrrolo[3,2-e]pyrimidines. The discovery process of these compounds is presented, as is the study of the structure-activity relationship.

6,7-Dihydro-5H-cyclopenta[d]pyrazolo[1,5-a]pyrimidines and their derivatives as novel corticotropin-releasing factor 1 receptor antagonists.

To identify an orally active corticotropin-releasing factor 1 receptor antagonist, a series of 6,7-dihydro-5H-cyclopenta[d]pyrazolo[1,5-a]pyrimidines and their derivatives were designed, synthesized and evaluated. An in vitro study followed by in vivo and pharmacokinetic studies of these heterotricyclic compounds led us to the discovery of an orally active CRF1 receptor antagonist. The results of a structure-activity relationship study are presented.

Further optimization of sulfonamide analogs as EP1 receptor antagonists: synthesis and evaluation of bioisosteres for the carboxylic acid group.

4-{[2-[(2-Furylsulfonyl)(isobutyl)amino]-5-(trifluoromethyl)phenoxy]methyl}benzoic acid analogs 2a and b and a series of the acid analogs, in which the carboxylic acid residue of 2b was replaced with various kinds of carboxylic acid bioisosteres, were synthesized and evaluated as EP1 receptor antagonists. Compound 2b and its monocyclic acid analogs, in which the carboxylic acid residue of 2b was replaced with monocyclic acid bioisosteres, were found to show potent EP1 receptor antagonist activity. Optimization of the linker Y between the phenyl moiety and the carboxylic acid residue of 2b was also carried out (Table 5). Compounds 2b and 16 and 17 possessing conformationally restricted linker Y were found to show the most optimized potency among the tested compounds. Cytochrome P450 inhibition of optimized compounds was also investigated. Details of the structure-activity relationship study are presented.

Discovery of heteroaryl sulfonamides as new EP1 receptor selective antagonists.

4-({2-[Isobutyl(phenylsulfonyl)amino]-5-(trifluoromethyl)phenoxy}methyl)benzoic acid (1) is a functional PGE2 antagonist selective for EP1 receptor subtype. Analogs of 1, in which the phenyl-sulfonyl moiety has been replaced with more hydrophilic heteroarylsulfonyl moieties, exhibited more optimized antagonist activity, while some of them showed in vivo antagonist activity. Structure-activity relationship (SAR) studies are also presented.

Discovery of new chemical leads for selective EP1 receptor antagonists.

A series of 4-([2-[alkyl(phenylsulfonyl)amino]phenoxy]methyl)benzoic acids were identified as functional PGE(2) antagonists with selectivity for the EP1 receptor subtype starting from a chemical lead 1, which was found while screening our in-house compound library. Discovery of the optimized analogs 21-23 is presented here and structure-activity relationships (SAR) are also discussed.