1, 2, 4-Triazine-3, 5 (2H, 4H)-dione (6-azauracil)(I; R =H) and uracil were partially thiated to afford 5-mercapto-1, 2, 4-triazin-3 (2H)-one (II; R H) and 4-mercapto-2 (1H)-pyrimidinone, respectively, in good yields by the use of limited amount of phosphorus pentasulfide. These are the first examples of the success of monothiation in triazine and pyrimidine series. The alkylation of 5-mercapto-1, 2, 4-triazin-3 (2H)-one gave the corresponding alkylthio derivatives (IV and V; R=H) from which 5-amino-1, 2, 4-triazin-3 (2H)-one (6-azacytosine)(III; R=H) was synthesized in an excellent yield.

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6-Azacytidine (IV) was prepared by condensation of mercury salt of 5-methylthio-1, 2, 4-triazin-3 (2H)-one with 1-chloro-2, 3, 5-tri-O-benzoyl-D-ribose in boiling benzene followed by ammonolysis of the condensation product. The synthesis of three isomeric N-glucosides of 6-azauracil is also described.

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5-Aminoimidazole-4-carboxthioamide was synthesized by the phosphorus pentasulfide-pyridine treatment of 5-aminoimidazole-4-carboxamide. The structure was elucidated both by chemical and physical means. 1-β-D-Ribofuranosy1-4-methyl-5-nitroimidazole and 1-β-D-ribofuranosy1-4-nitro-5-methoxycarbonylimidazole were synthesized by the condensation of appropriate imidazole chloro-mercury salt with 2, 3, 5-tri-Obenzoyl-D-ribofuranosyl chloride followed by the removal of protecting groups.

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2, 6-Bis-methylthio-and 2, 6-bis-benzylthio-9-(2', 3', 5'-tri-O-benzoyl)-β-D-ribofuranosylpurines were synthesized by the condensation of chloromercury salt of 2, 6-bisalkylthiopurines with 2, 3, 5-tri-O-benzoyl-D-ribofuranosyl chloride. The transformation to 6-dimethylamino-and 6-methylamino-9-β-D-ribofuranosylpurine by the successive amination and desulfurization was achieved.

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Quaternary salts of 4-azidoquinoline and 4-azidoquinoline 1-oxide were synthesized and their reaction was examined. Their decomposition with alkali afforded 1-methyl-(or methoxy)-4 (1H)-quinolone. Treatment of 1-methoxy-4-azidoquinolinium methosulfate with sodium alkoxides resulted in a reaction at room temperature to form 4-alkoxyquinolines. These compounds reacted with compounds possessing an active methylene to form 1-methyl (or methoxy)-4-aminoquinolinium methosulfate, instead of undergoing triazole cyclization. Thermal decomposition in toluene or catalytic hydrogenation also furnished the same amino compound.

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Condensation of octahydro-4-quinolizinone (I) and ethyl 3-furoate affords (II) which, on being heated with dilute hydrochloric acid, forms a compound (IV) of hexahydroquinolizine series. Reduction of (IV) with sodium borohydride gives (V) which is separated into two kinds of racemate showing infrared absorption band due to trans-quinolizidine.
By the route shown above, (XVII) was obtained from 1, 7-dimethyloctahydro-4-quinolizinone (XII) and (XVII) was separated into three kinds of bases. From the result of infrared spectral measurement, (XVIIa) and (XVIIc) were assumed to be trans-quinolizidine compound and (XVIIb) was assumed to be cis-quinolizidine compound. The infrared spctra (in carbon tetracbloride solution) of (XVIIa) and (-)-deoxynupharidine isolated from Nuphar japonicum DC. were found to be entirely identical and (XVIIa) was concluded to be rac-Deoxynupharidine.

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The preparation of 3-(3, 4-methylenedioxyphenyl)-D-, and -L-alanine (D-and L-(V)) was carried out by the chemical or biological resolution of N-acety1-3-(3, 4-methylenedioxyphenyl)-DL-alanine (DL-(IV)). The N-acetyl-DL-amino acid prepared from 3, 4-methylenedioxybenzyl chloride (H) and diethyl acetamidomalonate (I), via the diester (III), was resolved into two forms, D-and L-(IV), by means of fractional recrystallization of their cinchonine salts from ethanol, followed by the liberation of cinchonine base. Asymmetric hydrolysis of DL-(W) was also smoothly effected by Takadiastase to give the L-amino acid (L-(V)) and N-acetyl-D-amino acid (D-(W)). The latter as well as the one derived from the chemical resolution was converted by boiling it with 10% hydrochloric acid into the D-amino acid (D-(V)) in good yield.

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Asymmetric hydrogenation of l-menthyl α-acetamido-3, 4-methylenedioxycinnamate was carried out by two methods: i) 10% palladium-carbon in ethanol, ii) 10% palladium-carbon in benzene. Hydrogenation products were separated by fractional crystallization, and were converted to optically active 3-(3, 4-methylenedioxyphenyl) alanines by transesterification followed by acid hydrolysis.

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Hydrolyses of the racemate and the optical isomers of 3, 4-methylenedioxyphenylalanine (I), and of their N-acetyl derivatives (DL-, D-, and L-(II)) including the l-menthyl esters (IIIa and IIIb) were smoothly effected by using a mixture of HI, Ac₂O and red phosphorus to furnish the corresponding racemate and optical isomers of 3-(3, 4-dihydroxyphenyl) alanine (Dopa) in fair yields.
This method would be a new and advantageous way for the preparation of DL-, D-, and L-Dopa, when combined with the previously reported preparation of the racemic and optically active intermediates. The absolute configurations of the optical isomers of (I), of their N-acetyl derivatives (D- and L-(I)), and of the l-menthyl esters (IIIa and IIIb) were simultaneously established by the above hydrolyses.

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Kikuba-saponin which had been obtained as an amorphous powder from the rhizome of Dioscorea septemloba THUNB. was isolated in pure state as stals and found to be a diosgenin glycoside in which one mole of D-glucose is attached to gracillin with a β-linkage.
Kikuba-saponin seemed to be a parent saponin of gracillin.

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Three steroid saponins from japanese Dioscoreaceae plants, dioscin, gracillin and kikuba-saponin were proved to have branched-chain oligosaccharide moieties, and assigned structures, diosgenin bis-α-L-rhamnopyranosyl (1→2 and 1→4)-β-D-glucopyranoside (IV), diosgenin -L-rhamnopyranosyl (1→2_G1c.¹)-β-D-glucopyranosyl (1→3_G1c.1)-β-Dglucopyranoside (V) and diosgenin β-D-glucopyranosyl (1→X_G1c.2)-β-D-glucopyranosyl (1→_3G1c.¹)-α-L-rhamnopyranosyl (1→2_G1c.¹)-β-D-glucopyranoside (VI), respectively.

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An enzyme system in rabbit liver homogenate oxidizes MHB to yield 3-OH-MHB and 3-keto-MHB.
MHB is at first oxidized to 3-OH-MHB by a TPNH-dependent microsomal enzyme system. 3-Keto-MHB are then produced from 3-OH-MHB and both metabolites are interconvertible in the soluble fraction of the liver.

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Nous avons confirmé qu'il y a de quelques moyens d'obtenir de l'éthano-4, 7 polyhydro substituée-2 isoindoline, à partir de l'éthano-4, 7 tetrahydro-3a, 4, 7, 7a isoindolinedione-1, 3. Les methodes de la synthàse se constituent d'une série de combinaisons de l'alcoylation en position-2, de la hydrogénation d'un groupe insature, et de l'élimination de deux oxygànes des imides.

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The structure of cynanchogenin was investigated. The locations of four hydroxyl groups, double bond and ester linkage were clarified, and total constitution was proposed as H-I (Chart I).

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A new aglycone, penupogenin, was isolated from Cynanchum caudatum MAX. and its structure was decided as a cinnamic acid ester of sarcostin.

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1. Two types of equations expressing the velocity of acid neutralizing reaction of antacids were discussed. One was the calcium carbonate type, for which the initial increase of pH, (dx/dt)_t=0, was convenient to compare the velocity of reaction. The other was DAHG type, for which the apparent order of reaction, n, the finished time, t∞, and the pH flexional time, tυ, were convenient to compare the antacid reactivity quantitatively.
2. The activation energy of reaction between powdered marble and hydrochloric acid was estimated to be about 6, 400 calories.
3. The velocity of reaction between DAHG and acid depended upon the kind of samples or acids used.
4. The activation energy of reaction between DAHG and acid was estimated to be about 20, 000 colories.
5. The rapid increase of pH at the initial stage of reaction between DAHG and acid was considered to be due primarily to the absorption of acid by the test sample.
6. The change of pH at the final stage of reaction between DAHG and acid was considered to be dependent upon the hydrolysis of aluminum ion produced and the adsorption effect of the test sample.

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1. The velocity of reaction between DAHG and acid showed the additivity with respect to the composition of mixed test samples of DAHG, i. e., the linear function of the composition.
2. In the reaction between DAHG and hydrochloric acid mixed with sulfuric acid or nitric acid mixed with sulfuric acid, the finished time, t_∞, and the pH flexional time, t_v, became maximum at a certain mixing ratio, R_m, between the two original acids. R_m, was different with regard to the kind of test samples and the total amount of electrolytes and/or DAHG. The estimated activation energies were not remarkably changed near R_m, i. e., 20, 000 calories and almost the same as the values of different R.
3. The examinations of hydrochloric acid mixed with sulfates and of nitric acid mixed with sulfates gave about the same results as described above. The velocity of reaction between DAHG and acid mixed with salt was dependent upon the kind of anions, but fairly independent of the kind of cations.

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The reaction between dried aluminum hydroxide gel (DAHG) and acid was represented by_??_where n is nearly zero is both cases of hydrochloric acid and nitric acid, and 0<η<1 in the case of sulfuric acid by thermal analysis.
2. In the reaction between DAHG and hydrochloric acid mixed with sulfuric acid or nitric acid mixed with sulfuric acid, the order of the reaction, n, changed remarkably at the ratio of about 5% sulfuric acid (in gram-equivalent) and the reaction velocity was minimum at this ratio.
3. The activation energy of the reaction between DAHG and acid was found to be about 20, 000 calories.
4. These facts mentioned above were in good agreement with the results of the pH measurement described in previous papers.
5. The heat of reaction, which agreed well with the values given in a critical table, was measured.

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