From the root of Momordica cochinchinensis SPRENG. (Cucurbitaceae), three saponins named momordins I, II and III have been isolated. Their structures were determined on the basis of chemical and spectral evidence as oleanolic acid 3-O-α-L-arabinopyranosyl (1→3)-β-D-glucuronopyranoside (momordin I), 28-O-β-D-glucopyranoside of momordin I (momordin II) and 3β-hydroxy-11α, 12α-epoxy-olean-28, 13-olide 3-O-α-L-arabinopyranosyl (1→3)-β-D-glucuronopyranoside (momordin III). Momordin II was proved to be identical with hemsloside Ma₁ isolated from the tubers of Hemsleya macrosperma and H. chinensis.

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3, 5-Bis (methoxycarbonyl)-4-phenyl-2-isoxazoline-2-oxides (1) were readily transformed into 2-methoxycarbonyl-1-oxido-3H-indole-3-acetates (2) in the presence of Lewis acids such as titanium tetrachloride in dichloromethane. The reaction may occur via initial N-O bond fission to form an ionic intermediate (B), which cyclizes to 3H-indole-1-oxide (2) through an intramolecular aromatic substitution, on the basis of deuterium incorporation experiments as well as stereochemical considerations. With regard to the substituent effect, the reaction of meta-substituted phenylisoxazolines (1f-h) having an o, p-orientating group such as halogen was facilitated to provide 5-substituted 3H-indole-1-oxides (2f-h) in good yield. In contrast, the reaction of para-substituted compounds (1b-e) having the same substituents gave benzofuro-[3, 3a-d] isoxazoles (7b-e) preferentially, rather than 6-substituted 3H-indole-1-oxides (2b-e).

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Two water-soluble glucans (A and B) were isolated from the rhizomes of Crinum latifolium. The final preparations were each homogeneous as determined by glass-fiber electrophoresis, gel chromatography, and thin-layer chromatography. Glucan A was composed of 12 glucose units, while glucan B had about 110 glucose residues. Methylation, periodate oxidation, nuclear magnetic resonance, and enzymic degradation studies showed that both glucans are mainly composed of α-1→4 linked D-glucopyranose residues having branches linked through position 6. Glucan A had one side chain composed of a hexasaccharide. The average length of the unit chain in glucan B was about 11, and glucan B had various polymerized side chains. O-Acetyl groups were identified in glucan A, and they were located at positions 2 and 3 of a glucose unit.

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Seven polyphenyls, including four new compounds, 2, 2', 6'- (2) and 3, 2', 6'-triphenyl-p-terphenyl (3), 3', 5'-diphenyl-p-quaterphenyl (4), and 2-phenyl-3'-(2-biphenylyl)-p-terphenyl (7), were synthesized by the Ullmann coupling reaction of aryl iodide (s) or by the Kharash-type coupling reaction of aryl Grignard reagent with an aryl iodide catalyzed by bis (acetylacetonato)-nickel (II). Infrared spectral studies of the polyphenyls showed that the range of 730-770 cm^-1, generally accepted as the position of the out-of-plane C-H bending bands of the phenyl ring, should be widened slightly to 730-786 cm^-1. The high frequency bands were confirmed to be correlated closely to the overcrowding by terminal rings in the complex structures. Proton magnetic resonance spectral studies indicated that the characteristic spectral features of the branched polyphenyls were fully consistent with their conformational aspects deduced from stereomodels. In the ultraviolet spectral studies the polyphenyls containing highly branched p-phenylene ring (s) showed intense K-bands or shoulders at locations very similar to those of the corresponding linear polyphenyls containing the same number of p-phenylene rings.

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N-(5, 6-Dihydro-4-benzo [h] quinazolinyl) amino acids (III and VII) were synthesized by condensation of 4-chloro-5, 6-dihydrobenzo [h] quinazoline (II) with several amino acids and were cyclized to 4, 5-dihydrobenz [h] imidazo [1, 2-c] quinazoline derivatives, i.e., 11, 13, 15-triazasteroidal compounds (IV, V, VI, VIII, and IX) using phosphoryl chloride or acetic anhydride. An oxygen function could be introduced at C-1 of 4, 5-dihydrobenz [h] imidazo [1, 2-c] quinazoline, i.e., C-17 of the 11, 13, 15-triazasteroidal compounds.

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No diterpene glycoside was isolated from the roots of Rubus suavissimus S. LEE, in contrast to its leaves, which taste sweet and contain a large amount of the sweet diterpene glucoside named rubusoside. Instead, a new 28-β-gluchopyranosyl ester of 2α, 3β, 19α-trihydroxyurs-12-ene-23, 28-dioic acid named suavissimoside F1 was isolated from the roots of this plant, along with niga-ichigoside F1 (28-β-glucopyranosyl ester of 19α-hydroxyasiatic acid) which has already been obtained from leaves of other Rubus spp.

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The reaction of allylmetal (group IVb) compounds with aromatic compounds and iodosylbenzene in the presence of BF₃-Et₂O afforded the corresponding allylation products. Allylation of alcohols was also carried out to give allyl ethers. The activation of iodosylbenzene by the coordination of BF₃-Et₂O was assumed to be one of the most important factors for the reaction. The involvement of the reactive allyliodine (III) compounds in these reactions is discussed.

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A mucous polysaccharide, named Hippeastrum-H-glucomannan, was isolated from the bulbs of Hippeastrum hybridum HORT. The final preparation was homogeneous as determined by ultracentrifugal analysis, glass-fiber electrophoresis, and gel chromatography. It was composed of D-mannose and D-glucose in the molar ratio of 5 : 2, and its molecular weight was estimated to be 331000. O-Acetyl groups were identified and their content amounted to 13.2%. They were located at positions 2, 6 of some of the D-mannose units. Methylation and partial acid hydrolysis studies showed that the glucomannan is mainly composed of β-1→4-linked aldohexopyranose residues, and that it contains about eighty-three aldohexose units per six non-reducing groups on average. Both D-mannose and D-glucose units occupy non-reducing terminal positions and branching points linked through position 3.

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The title chiral hydride was found to reduce various achiral cyclic ketones, giving the corresponding optically active cyclic (R)-alcohols in high optical (73-98%ee) yields. The development of the improved chiral hydride and some characteristics of the reagent are also described.

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An alternative method for the synthesis of 4-alkyl-2 (5H)-furanones is described. Intramolecular carbene addition reaction of α-diazo compounds (4) in the presence of rhodium acetate or copper acetylacetonate furnished the bicyclic compounds (5), which were subjected to cyclopropane ring-opening reaction to give the 4-alkyl-4, 5-dihydrofuran-2 (3H)-ones (6) regioselectively. These compounds (6) were further converted into 4-alkyl-2 (5H)-furanones (14) in several steps.

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Two new steroidal alkaloid glycosides, tentatively named SL-c (1) and SL-d (2), were obtained from the stems of Solanum lyratum THUNB. The chemical structures of 1 and 2 were characterized respectively as β-lycotrioside and β-lycotetraoside, both having a mixture of (25ζ)-solanidan-3β, 23β-diol and (25ζ)-Δ⁵-solaniden-3β, 23β-diol as the aglycone moiety. These compounds markedly inhibited the growth of a human cervical cancer cell line, JTC-26.

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Symmetrical disulfides (2a-m, 9, 13) were synthesized by oxidation or by a new reaction using ethyl α-bromomalonate from the corresponding thiazolidinecarboxylic acids containing a sulfhydryl group (1a-m, 8, 12). Mixed disulfides (14a-g) were synthesized by reaction of thiols (1a, c) with Bunte salt. Stereoselective acylation of the thiazolidinecarboxylic acid 5a gave the symmetrical disulfide 2c or the dicarboxylic acid 15, depending on the conditions. The absolute configurations of these disulfides were decided to be (2R, 2'R, 4R, 4'R) by comparison of nuclear magnetic resonance spectra and specific rotation with those of the (2S, 2'S, 4R, 4'R)-disulfide (4). The disulfides were tested for aldose reductase inhibitory activity in vitro. The symmetrical disulfide 2j and dicarboxylic acid 15 showed remarkably high potency.

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Stereoselective reductions of (S)-4-isopropyl-3-phenacyl-1, 3-oxazolidin-2-one (2) with several complex metal hydrides gave 2-4'-isopropyl-2'-oxo-1', 3'-oxazolidinyl-1-phenylethanol (3) and 2-N-1'-isopropyl-2'-hydroxyethyl-N-methylamino-1-phenylethanol (4) in good yields. These products were diastereomeric mixtures and the diastereomer ratios were estimated to be ca. 75 : 25. The asymmetric 2-amino-1-phenylethanols (major products of 3 and 4) were easily isolated by recrystallization. The absolute configuration of (1S, 4'S)-3 was determined by X-ray analysis. The reductions of (S)-4-isopropyl-1-phenacyl-1, 3-oxazolidine (6) with complex metal hydrides gave 2-4'-isopropyl-1', 3'-oxazolidinyl-1-phenylethanol (7) and 4 as diastereomeric mixtures (ca. 70 : 30).

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Reaction of 2-chloro-N, N-dimethyl-2-(phenylthio) acetamide (1a) with styrene in the presence of stannic chloride gave 3, 4-dihydro-N, N-dimethyl-4-phenyl-2H-1-benzothiopyran-2-carboxamide. The same benzothiopyran was also obtained from N, N-dimethyl-2-(phenylsulfinyl) acetamide and styrene under the Pummerer reaction conditions, but in lower yield. Similarly, α-chlorosulfides derived from ethyl 2-(phenylthio) acetate, 2-(phenylthio) acetonitrile, 1-(phenylthio)-2-propanone, and thioanisole reacted with styrene to give the corresponding 4-phenylbenzothiopyrans in variable yields. The reaction of 1a with trans-stilbene gave the expected benzothiopyran derivative, but the reaction of 1a with 1, 1-diphenylethylene and phenylacetylene showed some variation of the reaction course. This cycloaddition reaction was extended to the intramolecular case. A possible mechanism for the formation of the benzothiopyran is discussed.

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A homologous series of (-)-shikimic acid gallates (I-V) has been isolated, together with 1, 6-di-O-galloyl-β-D-glucopyranoside (VI), 5-O-galloyl-D-hamamelose (VII), 2, 5-di-O-galloyl-D-hamamelose (VIII) and 2', 3, 5-tri-O-galloyl-D-hamamelose (IX), from the leaves of Castanopsis cuspidata var. sieboldii NAKAI. On the basis of spectroscopic analysis, enzymatic hydrolysis and methanolysis, their structures have been established as 3-O-gallate (I), 3-O-digallate (II), 3-O-trigallate (III), 3, 5-di-O-gallate (IV) and 3, 4-di-O-gallate (V) of (-)-shikimic acid.

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Treatment of the β-D-ribofuranosyl cyanide 5 with sodium methoxide, followed by reaction with diketene, gave the spiro 1, 3-oxazine 6, which underwent the ring transformation with ammonia and phenylhydrazine to give the protected pyrimidine (8) and 1, 2, 4-triazole (13) C-nucleosides, respectively. Deprotection of 8 with 90% trifluoroacetic acid gave the pyrimidine C-nucleoside 9. Passage of hydrogen chloride gas over a solution of the cyanide 1 and benzyl hydrosulfide gave the fully protected ribofuranosylthioformimidate 15. Treatment of 15 with triethylamine, followed by reaction with diketene gave the dihydrofuran derivative 16. Compound 16, on treatment with ammonia, hydroxylamine, and phenylhydrazine, was transformed into the corresponding furan derivatives 17-19.

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The solvolytic behavior of 3-ethoxycarbonyl-2-phenyl-Δ²-pyrroline-4, 5-diones 7 depends on the N-substituents. On treatment with ethanol or methanol, the NH derivative 7a afforded the corresponding keto ester 9, a product of C₅-lactam carbonyl attack, while the N-alkyl derivatives 7b-d gave the enols 8b-d, products of C₂-attack. Kinetic analysis based on time dependent ultraviolet spectra of 7 in ethanolic solution revealed that the C₂-center of the compound is the most electrophilic and that N-alkylation enhances the C₂-electrophilicity. This increase in the electrophilicity can be rationalized in terms of the restricted rotation of the C₂-phenyl group resulting from N-substitution, which prevents the phenyl-dioxopyrroline conjugation, thus destabilizing the dioxopyrroline form. In the solvolytic reaction of 7 in the presence of potassium hydroxide, the products were dependent on the solvent used. In methanol, 7a-b afforded the enolate 18a-b, while in water the carboxylate 19a-b was formed.

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Novel isomerizations of isostegane (6) into the three other possible isomers, namely, isopicrostegane (7), picrostegane (8), and stegane (9) are described. All the possible enantiomers were synthesized.

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The prosapogenins from the fruits of Xanthoceras sorbifolia BUNGE (Sapindaceae) were examined. On the basis of chemical and spectral analyses, the structures of three minor prosapogenins, obtained by acid hydrolysis of crude saponin fraction, were characterized as 21-O-(3, 4-di-O-angeloyl)-β-D-fucopyranosyl theasapogenol B (1), 21-O-(4-O-acetyl-3-O-angeloyl)-β-D-fucopyranosyl theasapogenol B (2) and 21-O-(4-O-acetyl-3-O-angeloyl)-β-D-fucopyranosyl-22-O-acetyl protoaescigenin (3), respectively.

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Two new secobisbenzylisoquinoline alkaloids, secocepharanthine (base J) (3) and O-methylpunjabine (base K) (4), were isolated from Stephania sasakii HAYATA (Menispermaceae). Their structures were established and the structures of two other alkaloids [base B (1) and base C (2)] were also established as dihydrosecocepharanthine (1) and O-methyldeoxopunjabine (2). In addition, two known bisbenzylisoquinoline alkaloids, obaberine (5) and thalrugosine (6), were newly isolated from the same plant.

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With the aim of establishing the structure of the Alangium alkaloid desmethylpsychotrine, stereospecific syntheses of two alternative structures, (±)-9-demethylpsychotrine (1) and (±)-10-demethylpsychotrine (2), have been achieved through a"lactim ether route."The synthesis of (±)-1 started with an initial condensation of the lactim ether 6, derived from the translactam ester 5, with 3-benzyloxy-4-methoxyphenacyl bromide (7a) and proceeded through the intermediates 8a, 9a, 10c, 10a, 11a, 12a, 13a, 14a, and 15a. A parallel sequence of conversions starting with 6 and 4-benzyloxy-3-methoxyphenacyl bromide (7b) produced (±)-2. The ¹³C nuclear magnetic resonance spectra of (±)-1 and (±)-2 confirmed their endocyclic double bond structure in the dihydroisoquinoline moiety. Spectral comparison of (±)-1 and (±)-2 with natural desmethylpsychotrine suggested formula 1 to be the most likely structure of this alkaloid.

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Three new ent-kaurane-type diterpenes, I, II and III, were isolated from the fronds of Dipteris conjugata REINW. Their structures were elucidated as 16β, 17-dihydroxy-ent-kauran-19-oic acid, 16β, 17-dihydroxy-19-nor-ent-kauran-18-oic acid and 16β, 17, 18-trihydroxy-ent-kauran-19-oic acid, respectively.

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The crystal and molecular structure of (+)-epigriseofulvin were elucidated by X-ray structure analysis. The crystal belongs to a triclinic space group P1, with the unit cell parameters of a=11.718 (4), b=9.870 (3) Å, α=103.49 (3), β=102.38 (3), γ=96.26 (3)°, V=1061 (1) ų. The unit cell contains two crystallographically independent (+)-epigriseofulvin molecules and two chloroform molecules. The structure was solved by the direct method and refined to an R-value of 0.093 for 3971 non-zero reflections. No significant conformational differences between the two molecules were observed. The cyclohexenone rings take half-chair conformations with planar conjugated enone systems.

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Methyl 3-O-benzyl-4, 6-O-benzylidene-2-O-(trifluoromethanesulfonyl)-β-D-mannopyranoside (7) was examined as a substrate for the preparation of 2-deoxy-2-fluoro-D-glucose (1) by fluoride ion treatment. The triflate (7) reacted rapidly with tetraalkylammonium fluorides in acetonitrile or tetrahydrofuran to give methyl 3-O-benzyl-4, 6-O-benzylidene-2-deoxy-2-fluoro-β-D-glucopyranoside (10) in 52-57% yield. Removal of the protecting groups from 10 by the use of 50% methanesulfonic acid afforded the required 1 in good yield. This synthetic sequence may provide an effective alternative to known methods for preparing ¹⁸F-labeled 1.

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As a starting material for the synthesis of mouse epidermal growth factor, a half of the molecule, the protected tetracosapeptide ester (positions 30-53), was synthesized by successive condensations of eight peptide fragments : (positions 51-53), (49-50), (46-48), (42-45), (39-41), (37-38), (34-36), (30-33).

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The tripentacontapeptide corresponding to the entire linear sequence of epidermal growth factor was synthesized by assembling 15 peptide fragments and one His residue (position 22), followed by deprotection with trifluoromethanesulfonic acid-thioanisole in trifluoroacetic acid. The deprotected peptide was subjected to air-oxidation. After purification by ion-exchange chromatography on diethyl aminoethyl cellulose followed by high performance liquid chromatography, a peptide with powerful anti-gastric activity was obtained.

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Antihemorrhagic principles were isolated from Hypericum erectum THUNB. (Hypericaceae) by a combination of countercurrent distribution and Sephadex LH-20 column chromatography, and identified as wedelolactone [5', 5, 6-trihydroxy-7'-methoxycumarino-(3', 4' : 3, 2)-coumaronel (1, 8, 9-trihydroxy-3-methoxy-6-oxo-6H-[z] benzofuro [3, 2-c] [z] benzopyran) and desmethylwedelolactone [5', 7', 5, 6-tetrahydroxyl-cumarino-(3', 4' : 3, 2)-coumarone] (1, 3, 8, 9-tetrahydroxy-6-oxo-6H-[z]-benzofuro [3, 2-c] [z] benzopyran).

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The present paper describes the isolation of an antihemorrhagic principle in Biota orientalis (L.) ENDL. (Cupressaceae) by a combination of partition, Sephadex LH-20 and silica gel column chromatographies, and its identification as quercitrin.

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In a survey of intestinal bacteria capable of metabolizing glycyrrhizin (GL), Ruminococcus sp. PO1-3 and Clostridium innocuum ES24-06 were isolated from human feces. The former strain had the ability to hydrolyze GL to glycyrrhetic acid (GA) and to reduce 3-dehydroglycyrrhetic acid (DGA) to GA while the latter strain had the ability to reduce DGA to 3-epiglycyrrhetic acid (EGA). A mixture of the two strains could not only reduce DGA to both GA and EGA, but also epimerize GA to EGA and vice versa, possibly through a 3-dehydro intermediate.

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The degradation of potassium clavulanate in a weakly alkaline aqueous solution has been investigated. Potassium clavulanate was degraded in 0.1 M Na₂HPO₄ solution at various temperatures. Four degradation products were isolated and their structures were elucidated as 2, 5-bis-(2-hydroxyethyl) pyrazine (I), 3-methyl-2, 5-bis-(2-hydroxyethyl) pyrazine (II), 3-(2-carboxyethyl)-2, 5-bis-(2-hydroxyethyl) pyrazine (III). and 3-ethyl-2.5-bis-(2-hydroxyethyl) pyrazine (IV) by mass spectroscopy and nuclear magnetic resonance spectroscopy. High-performance liquid chromatographic analysis of the reaction solution indicated that the reaction at 60°C yielded all four pyrazine derivatives, whereas II was not formed at 35°C and III was not formed at 100°C. A reaction mechanism is proposed which involves 4-amino-3-oxobutanol (IX) as a key intermediate.

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Molecular species of N-(2-thiazolyl) thioureas and their Cu (II) chelates present in solution were estimated by analysis of the absorption spectra in the ultraviolet region obtained under various conditions. The N-(2-thiazolyl) thioureas studied were 1, 1-dimethyl-3-(4-methyl-2-thiazolyl) thiourea (1a), 1, 1-dimethyl-3-[3, 4-dimethyl-2 (3H)-thiazolylidene] thiourea (2a), 1, 1-dimethyl-3-(4-methyl-2-thiazolyl)-S-methylisothiourea (3a). 1, 1, 3-trimethyl-3-(4-methyl-2-thiazolyl) thiourea (4a), 1-monomethyl analogs of 1a, 2a, 3a, and 4a (1b, 2b, 3b, and 4b, respectively), 1-unsubstituted analogs of 1a and 2a (1c and 2c, respectively), 1, 3-dimethyl-3-(4-methyl-2-thiazolyl)-S-methylisothiourea (5b), 1-methyl-3-[3, 4-dimethyl-2 (3H)-thiazolylidene]-S-methylisothiourea (6b), and their derivatives, in which some of the methyl groups were replaced by ethyl groups or the 4-position and/or 5-position of the thiazole moiety were substituted. The thiazole nitrogen atom was more basic than the thiourea nitrogen and sulfur atoms in 1a, and the predominant species in neutral solvents was the thiazolinylidenethiourea form (II). The predominant species of 1b and 1c in neutral media were the thiazolylthiourea (I) form, probably stabilized by an intramolecular hydrogen bond. There was also a difference in the predominant species between 3a and 3b. In methanol, 1a, 1b, and 1c formed Cu (II) chelates, which were extracted with chloroform. Cu (II) chelates were also formed from 2a, 2c, 3a, and 3b, but they were not soluble in chloroform.

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The fabrication and performance characteristics of quinine-sensitive membrane electrodes based on the ion-association complex of quinine with tetraphenylborate are described. The electrodes showed a near-Nernstian response over the range of about 5×10^-5-1×10^-1M quinine concentration. The potentiometric response of the electrodes was satisfactorily fast above a concentration of 1×10^-5M, though below this level a longer time was required to attain the steady state-potential. The effects of ion-association complex concentration in the membrane and the membrane thickness on the potentiometric response were small. The electrodes showed good selectivity for quinine relative to several inorganic and organic ions, though the response was interfered with alkaloids. The electrodes can be used in the pH range of 5.3-7.3. Direct potentiometry and potentiometric titration were applicable for the determination of quinine concentration.

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A color reaction involving a keto acid or hydroxy acid, a metal ion such as Al (III). and a xanthene dye was studied. A method for the spectrophotometric determination of keto acids or hydroxy acids (e.g., β-phenylpyruvic acid, PPA) with 9-(2'-carboxyphenyl)-4, 5-dibromo-2, 3, 7-trihydroxy-6-fluorone (bromohydroxyhydroquinonephthalein. Br. Qn. Ph.) and Al (III) was established. A detection test for PPA on a spot plate was also examined. This method is based on the formation of the Br. Qn. Ph. -Al (III)-PPA complex, which has an absorption maximum at around 570nm. The present method could be used to determine up to 20 μg/10ml PPA, and the apparent molar absorptivity was calculated to be 8.4×10⁴ dm³ cm^-1 mol^-1. This method is superior to the other spectrophotometric methods in sensitivity. Recovery of PPA added to human urine was good.

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Enzyme labeling of a steroid with horseradish peroxidase by the N-succinimidyl ester method has been investigated in comparison with that with β-galactosidase. The reaction of the activated ester of 4-hydroxytestosterone 4-hemiglutarate with horseradish peroxidase provided a labeled antigen showing high immunoreactivity with an anti-testosterone antiserum in the enzyme immunoassay procedure. The effect of steroid/enzyme molar ratio, ranging from 2 to 60, in the labeling on the assay sensitivity was then examined. It was found that, in contrast to the case of β-galactosidase, the sensitivity of the assay using horseradish peroxidase-labeled antigen is not significantly influenced by the molar ratio. Dose-response curves with high sensitivities could be obtained by the use of these labeled antigens at an appropriate dilution of the antiserum. The active ester method proved to be useful for the preparation of enzymelabeled antigens because of its simplicity and excellent reproducibility.

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β-Mannosidase was purified to electrophoretic homogeneity from the 20000g supernatant of guinea pig liver homogenate. A highly purified enzyme preparation was also obtained from the acetone powder. This enzyme had a pH optimum of 4.0 and molecular weights of ca. 120000 as determined by gel filtration and 110000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. It was free from other glycosidase activities, as far as was tested. The enzymatic hydrolysis of o- and p-nitrophenyl β-mannosides exhibited an unusual relationship of rate to substrate concentration, indicative of the involvement of two molecules of substrate in the reaction. The rate of hydrolysis was enhanced markedly by several p-nitrophenyl compounds including p-nitrophenyl glycosides, and also by Triton X-100 and chlorinated pesticides such as aldrin.

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The effects of rhatannin, Chinese gallotannin and tannin fractions isolated from Arecae Semen, Cinnamomi Cortex, Ephedrae Herba, Epimedii Herba. Moutan Cortex, Polygoni avicularis Herba, Potentillae Herba and Rhei Rhizoma on the activities of angiotensin-converting enzyme (ACE) and other six proteases were investigated. These tannin samples had no significant effect on the activity of kallikrein, but all of them inhibited the activities of carboxypeptidase B, leucine aminopeptidase, trypsin and chymotrypsin although to lesser extents as compared to the effects on ACE. On the other hand, all the samples except for Chinese gallotannin and the fraction from Moutan Cortex, enhanced the activity of carboxypeptidase A. All the samples showed non-competitive inhibition patterns with ACE. Rhatannin and the tannin samples obtained from Arecae Semen, Ephedrae Herba, Epimedii Herba, Polygoni avicularis Herba, and Rhei Rhizoma showed more potent inhibitory effects on ACE than the other samples, and their I₅₀ values were 3.7, 1.0, 1.9, 2.9, 1.1, and 1.2 μg/ml, respectively. The apparent K_i value of rhatannin for ACE was 5×10^-7M with Bz-Gly-His-Leu as the substrate, and this value is 5 times and 300 times higher than those of SQ 20881 (K_i=1×10^-7M) and SQ 14225 (K_i=1.7×10^-9M). respectively. Thus, it is suggested that rhatannin and some of the tannin samples obtained from the above crude drugs (which are believed to have hypotensive effects) show high specificity as ACE inhibitors.

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A polysaccharide, [α]²⁰_D-35.8° in water, was isolated from the tubers of Dioscorea japonica THUNB. The polysaccharide was homogeneous as judged by ultracentrifugal analysis and gel chromatography. It was mainly composed of D-mannose and D-glucose in a molar ratio of 6 : 1, and contained 8.8% O-acetyl groups. Its molecular weight was estimated to be 3.7×10⁵ by gel chromatography. The O-acetyl groups were located at position 2, at position 6, at position 3, and at positions 2 and 6, of some of the mannopyranosyl residues. From the results of methylation analysis, periodate oxidation, Smith degradation, and carbon-13 nuclear magnetic resonance spectroscopy, it was concluded that the polysaccharide, a linear glucomannan, was composed of β-1→4 linked D-aldohexopyranosyl units.

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Three forms of glucoamylase [EC 3. 2. 1. 3] of a Rhizopus sp., Gluc₁ (M. W. 74000), Gluc₂ (M. W. 58600) and Gluc₃ (M. W. 61400), were compared by circular dichroism (CD) spectroscopy and kinetic studies. The CD spectra of the enzymes indicated that Gluc₂ and Gluc₃. which lack fragments from the N-terminal part of Gluc₁, resembled Gluc₁ in protein backbone conformation, although with some differences in the states of aromatic amino acid side chains. Therefore, the N-terminal part of Gluc₁ appears not to have a critical effect on the gross conformation of the remaining domain of Gluc₁, though two glycopeptides, presumably released from the N-terminal part of Gluc₁, fragments H (M. W. 16700) and L (M. W. (14400), had different conformations from that of Gluc₁. The three enzymes each contained 1 SH in a buried form, as well as 1 S-S bridge, and had similar susceptibility to denaturants. On the other hand, Gluc₂ and Gluc₃ differed markedly from Gluc₁ in the K_m values for large substrates, but differed little in the K_m and V_max values for small substrates or in the V_max values for large substrates, except for pullulan, which is highly branched. Gluc₁, but not Gluc₂ or Gluc₃, may have an additional site (s) interacting with large substrates, besides the active center.

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The promoting effects of sodium salts of N-acyl-L-phenylalanines, p-substituted benzoic acids, saturated straight-chain fatty acids, saturated straight-chain α-bromofatty acids and N-acyl-N-methylglycines on the rectal absorption of sodium ampicillin (ABPC Na) were investigated in rats. The absorption-promoting effect of each carboxylic acid sodium salt was found to be parabolically correlated with its lipo-hydrophilic character (log P). The optimal log P value (log P₀) of carboxylic acids exerting the maximum rectal absorption-promoting effect was in the range of 4.2-4.8. Among these carboxylic acids, sodium caprate was selected for examination of its rectal absorption-promoting action on four penicillins (ampicillin, sulbenicillin, piperacillin and mezlocillin) and eight cephalosporins (cephacetrile, ceftizoxime, cephalothin, cefazolin, cefmetazole, cefotiam, cefoperazone and cefpiramide). The extents of rectal absorption of the β-lactam antibiotics coadministered with sodium caprate were found to correlate well with the permeability of the drugs to cellulose membrane.

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A mathematical optimization technique was applied to obtain a formulation of indomethacin (IMC)/polyvinylpolypyrrolidone/methyl cellulose solid dispersion with a high dissolution rate and high stability of IMC. Model formulations were prepared according to a composite spherical experimental design based on the simplex method. The dissolution rate and chemical stability of IMC were determined as response variables for deciding an optimum formulation. These response variables were predicted by the second-order polynomial regression model of formulation and process factors. In order to optimize the formulation, regression equations of each response were mathematically structured as a constrained nonlinear optimization problem. The solution was obtained by application of the sequential unconstrained minimization technique. Experimental results obtained for the optimum formulation agreed well with the predictions.

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The activity of porcine liver esterase towards diesters of 5-fluoro-2'-deoxyuridine with saturated aliphatic acids including acetic, propionic, butyric, hexanoic, octanoic, decanoic and dodecanoic acids was investigated. The susceptibility of the 3', 5'-diesters increased as the acyl chain was lengthened up to octanoyl, but further increase in the acyl chain length resulted in a sharp decrease in the susceptibility. The susceptibility of 3'-and 5'-monoesters increased as the chain was lengthened to decanoyl and slightly decreased on going to dodecanoyl. These results suggest that the higher antitumor activity of longer alkyl chain diesters of 5-fluoro-2'-deoxyuridine is partly due to their slow rates of hydrolysis by non-specific esterase.

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The plasma-induced instability of reverse-phase evaporation vesicles (REV) was successfully evaluated by measuring chloride leakage. The chloride efflux could be followed by using a silver chloride electrode without interference from coexisting substances such as liposomal lipid, plasma or bovine serum albumin (BSA). The permeability of REV was increased by incubation with human plasma or BSA ; the effect of plasma was estimated to be approximately 50 times larger than that of a corresponding amount of albumin. The difference of protein-lipid interaction in the cases of plasma and isolated albumin is discussed on the basis of the leakage pattern and the activation energy of the permeation process.

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Polylactic acid microspheres containing doxorubicin were prepared by a solvent evaporation process and release patterns of the drug from the microspheres were examined in vitro. Microspheres with greater drug contents released more drug. The release rate of the drug after the initial burst was found to be small, so that prolonged release was obtainable. It was also found that the wettability of the microspheres might influence the release rate. Venous plasma levels of the drug following intra-arterial administration into dog liver were considerably lower than those following administration of the drug solution. Microangiography revealed embolization due to the microspheres in peripheral arteries in the liver.

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The potential influence of the transverse heterogeneity in the sinusoidal enzyme contents and the capillary transit times on the elimination from the liver sinusoids was evaluated by using distributed models. Moreover, the predictions of the undistributed model (the parallel tube model), the venous equilibration model (the well-stirred model), the new distributed models presented in this study and the distributed model by Bass et al. (J. Theor. Biol., 72, 161 (1978)) for the hepatic drug clearance were compared. Data on lidocaine kinetics reported by Pang and Rowland (J. Pharmacokinet. Biopharm., 5, 655 (1977)) were employed. The steady state output concentration of lidocaine in the blood leaving the liver was predicted better by the well-stirred and distributed models than by the parallel tube model. Because both the parallel tube and well-stirred models ignore the anatomic and metabolic heterogeneities in the liver lobule, they may be refuted experimentally and theoretically, as reported by Goresky et al. (J. Clin. Invest., 52, 991 (1973)). It is considered that the distributed model taking account of the transverse heterogeneity in the sinusoidal enzyme contents and the capillary transit time, based on anatomical evidence, can well accommodate the experimental data on lidocaine.

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2, 4-Dinitrotoluene (2, 4-DNT), which is an industrial chemical of importance in the production of urethane foams and elastomers, is a hepatocarcinogen in rats. 2, 4-Diaminotoluene (2, 4-DAT), one of the urinary and hepatic metabolites of 2, 4-DNT, is also carcinogenic in rats. We have studied the pathways of metabolism of 2, 4-DNT in the cecal microflora of rats. 2, 4-DNT was not metabolized by this preparation in the presence of oxygen. Under anaerobic conditions, an ordered sequence of reductive metabolism was observed. 2, 4-DNT was reduced to 2-amino-4-nitrotoluene (2A4NT) and 4-amino-2-nitrotoluene (4A2NT) via 2-hydroxylamino-4-nitrotoluene (2HA4NT) and 4-hydroxylamino-2-nitrotoluene (4HA2NT), which were identified by mass spectral (MS) comparison with authentic materials. The two aminonitrotoluenes were then reduced to 2, 4-DAT. No intermediates in this sequence could be isolated. These findings indicate that rat intestinal microflora catalyze the reductive metabolism of 2, 4-DNT and suggest that the reduction of 2, 4-DNT to 2, 4-DAT may play a role in the carcinogenicity of 2, 4-DNT.

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In our earlier studies, the Klebsiella O3 lipopolysaccharide (LPS) isolated from culture supernatant of Klebsiella pneumoniae strain Kasuya (O3 : K1) or its decapsulated mutant strain LEN-1 (O3 : K1^-) was shown to exhibit a much stronger adjuvant effect than other known adjuvants, including LPS of Escherichia coli and Salmonella. The O3 LPS isolated from culture supernatant of Klebsiella strain LEN-1 was degraded into 59-66% neutral sugars and 25-27% lipids by hydrolysis with 1% acetic acid at 100°C for 1 h. The polysaccharide moiety (OPS) obtained by the hydrolysis was homogeneous on gel filtration. It contained 92.4% mannose, 0.15% 2-keto-3-deoxyoctonate and less than 0.1% P. The molecular weight values of OPS determined by gel filtration analysis and by the Somogyi-Nelson method were 14000 and 16200, respectively. The specific rotation of OPS was +88° and its infrared spectrum showed no β-configuration of mannopyranose. Methylation analysis indicated that OPS contained (1→2)-and (1→3)-linkages in a ratio of 3 : 2. Smith degradation and partial acid hydrolysis of OPS liberated mannosyl-(1→3)-mannose. We postulate that OPS consists of a mannan which has α-mannosyl-(1→3)-α-mannosyl-(1→2)-α-mannosyl-(1→2)-α-mannosyl-(1→2)-α-mannose units joined through α-mannosyl-(1→3)-linkages.

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Cyclization of N-methyl-3, 4-dimethoxyphenylacetamide (1) with paraformaldehyde in formic acid afforded 6, 7-dimethoxy-3-isochromanone (2b). In contrast, the same reaction of α, α-disubstituted phenylacetamides (5a, b, d) gave the corresponding 4, 4-disubstituted isoquinolin-3-ones (7a-c). However, the α-allylphenylacetamide (5c) gave the azepinone (8) as the main product. On the other hand, the carbamate (6e) afforded the 4-allylisoquinoline (10).

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The optical rotation of optically pure (S)-(-)-4-phenyl-3 (E)-buten-2-ol ((S)-(-)-2) was determined on the basis of nuclear magnetic resonance (NMR) spectral measurements of the acetate in the presence of a chiral shift reagent. Our former result on the asymmetric reduction of 4-phenyl-3 (E)-buten-2-one (1) had to be corrected. The title chiral hydride prepared by using diphenylamine or 2-anilinopyridine as an achiral additive was found to reduce 1, affording (S)-(-)-or (R)-(+)-2 in 66% or 53% optical yield.

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Five- and six-membered ring systems containing a nitrogen atom at the bridgehead position were prepared via [3+2] dipolar cycloaddition of 1-pyrroline 1-oxide (5) with 2-aryl-3-butenoates. Cycloaddition of 5 with methyl 4, 4-dichloro-2-[4-(tosyloxy) phenyl]-3-butenoate (4) gave 3 (and 2)-dichloromethyl-2 (and 3)-methoxycarbonyl-2 (and 3)-[4-(tosyloxy) phenyl]-2, 3, 3a, 4, 5, 6-hexahydropyrrolo [1, 2-b] isoxazole (6 and 7) in a ratio of 52 : 10. Compound 6 was converted to 1-aza-3-r-hydroxy-4-c-methyl-3-t-[4-(tosyloxy) phenyl] bicyclo [3.3.0] octan-2-one (12) by treatment with zinc in aqueous acetic acid in one step or via the 4-chloromethyl analog of 12 (i.e., 11). On the other hand, cycloaddition of 5 with methyl 2-phenyl-3-butenoate (15) afforded methyl 2, 3, 3aα, 4, 5, 6-hexahydropyrrolo [1, 2-b] isoxazol-2α-yl phenyl acetate (16) and 2-methoxycarbonyl-3-methyl-2-phenyl-2, 3, 3a, 4, 5, 6-hexahydropyrrolo [1, 2-b] isoxazole (17) and its regioisomer (18) in a ratio fo 17 : 31 : 32. Treatment of 16 with zinc in aqueous acetic acid furnished 1-aza-4β-hydroxy-3α-phenyl-5aαH-bicyclo [4.3.0] nonan-2-one (20).

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The resolution of (±)-trans-1-benzyl-5-ethyl-2-oxo-4-piperidineacetic acid [(±)-1] was effected with (R)-(+)-α-phenylethylamine through formation of the diastereomeric salts (+)-2 and (-)-3. Conversion of (+)-1 into the (3R, 4R)-(+)-enantiomer [(+)-6] of the title compound proceeded via a route involving debenzylation of (+)-1 with Na in liquid NH₃, esterification of the resulting (+)-4 to give (+)-5, and ethylation of (+)-5 with triethyloxonium fluoroborate. A parallel sequence of reactions starting from (-)-1 produced (-)-6 through (-)-4 and (-)-5.

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