The crystal and molecular structures of carbon-bridged 6, 5'-cyclo-5'-deoxy-4-thiouridine (6, 5'-Cs⁴U), 6, 5'-cyclo-5'-deoxy-2', 3'-O-isopropylideneuridine (6, 5'-CiU) and 6, 6'-cyclo-5', 6'-dideoxy-allofuranosyluracil (6, 6'-CU) have been determined by X-ray diffraction. The molecular conformations of 6, 5'-Cs⁴U and 6, 5'-CiU are very similar; the conformation about the glycosidic bond is anti (low region), the torsion angle O(4')-C(1')-N(1)-C(2)being -150.0° for 6, 5'-Cs⁴U and -145.5° for 6, 5'-CiU, and the sugar puckering being both O(4')-exo. On the other hand, 6, 6'-CU takes the glycosidic torsion angle of -116.9(4)° (middle anti region) and the sugar conformation of C(4')-endo. The cyclization causes little alteration in the geometry of the base moiety. 6, 5'-Cs⁴U and 6, 5'-CiU exhibit the similar base-base interactions between adjacent molecules, although their molecular packings are quite different; the 4-thiouracil or uracil moiety interacts with adjacent base moieties through hydrogen bonding and stacking interactions. In 6, 6'-CU, cyclonucleosides were connected by hydrogen bondings between the hydroxyl and sugar ring oxygen atoms and between the hydroxyl groups and the base nitrogen and oxygen atoms. As the 2', 3'-cyclic phosphates of these carbon-bridged cyclonucleosides are hydrolyzed by ribonuclease A, it is suggested that the conformers found in these cyclonucleosides are recognized by the enzyme.

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Four new oleanane-type triterpene saponins named aster saponins A, B, C and D were isolated from the root of Aster tataricus L.f. (Compositae). Their structures were elucidated based on chemical and spectral evidence as follows.Aster saponin A : a 28-[O-β-D-xylopyranosyl-(1→3)-O-α-L-arabinopyranosyl-(1→4)-[O-β-D-apiofuranosyl-(1→3)]-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosyl]ester of 3-O-[O-α-L-arabinopyranosyl-(1→6)-β-D-glucopyranosyl]-2β, 3β, 16α-trihydroxyolean-12-en-28-oic acid (asterogenic acid).Aster saponin B : an echinocystic acid (3β, 16α-dihydroxyolean-12-en-28-oic acid) glycoside corresponding to aster saponin A.Aster saponin C : a 28-[O-β-D-xylopyranosyl-(1→3)-O-α-L-arabinopyranosyl-(1→4)-[O-β-D-apiofuranosyl-(1→3)]-O-α-L-rhamnopyranosyl-(1→2)-[O-α-L-rhamnopyranosyl-(1→3)]-β-D-xylopyranosil]ester of 3-O-[O-α-L-arabinopyranosyl-(1→6)-β-D-glucopyranosyl]asterogenic acid.Aster saponin D : an echinocystic acid glycoside corresponding to aster saponin C.

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The reactions of pyridine N-oxide (1) with hydroxypyrimidine derivatives (2-7) in the presence of platinated palladium-carbon (Pd-Pt/C) catalyst were studied. 5-Hydroxypyrimidine (2), 4-hydroxypyrimidines(3 and 4) and 1-methyl-2-pyrimidinone (6) gave the corresponding dimers and 2-pyridyl derivatives by this condensation with high regioselectivity at the dehydrogenative position, while 2-hydroxypyrimidine (5) gave only the 2-pyridyl derivative. 2, 4-Dihydroxypyrimidine (7) did not react under similar reaction conditions. All products obtained these reactions are new compounds.These dimerization reactions may be useful for the synthesis of the dimers of N-heteroaromatic compounds.

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Dimerization reactions of six π-rich N-heteroaromatic compounds (2-7) and five xanthine derivatives (8-12) in the presence of platinated palladium-carbon (Pd-Py/C) catalyst were investigated. N-Methylimidazole (2), benzimidazole (4) and N-methylbenzimidazole (5) condensed dehydrogenatively to afford the corresponding symmetric dimers when heated in the presence of Pd-Pt/C catalyst and pyridine N-oxide (1). On the other hand, imidazole (3), pyrazole (6) and N-methylpyrazole (7) did not dimerize under the same conditions. The same reactions using caffeine (10), 1, 7-dimethylhypoxanthine (9) gave the corresponding dimers.

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Cyclization of 6-octen-1-als with Rh(I) (Wilkinson) complex was examined. In all cases with methyl substituents at the C₂- or C₃-position, a mixture of cis- and trans-cyclohexanol derivatives was obtained, but 7-methyl-6-octen-1-al without any substituents instead underwent a decarbonylation reaction. 4-Oxa-analogues also afforded a similar result. In Rh(I)-catalyzed cyclization, the formation of cis-cyclohexanols is in remarkable contrast to Lewis acid-catalyzed cyclization to afford the trans products.

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This paper describes the preparation of the polyfunctionalized cyclopentane ((±)-5) by silica gel-catalyzed air-oxidation, and its kinetic resolution by means of microbial reduction with Rhodotorula rubta to afford optically pure (-)-5 (>99% ee). Starting with (-)-5, a new route to prostaglandin E₁ was established.

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Cycloadditions reaction of 3-vinylindoles, generated by the alkylation of 3-thioacetylindole, with dienophiles to give functionalized carbazoles were explored.

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The stereochemistry of 1, 3-addition of ketene acetals (1a, b) to the chiral nitrones (4a-d) derived from 2, 3-O-isopropylidene-D-glyceraldehyde was examined. The reaction of ketene methyl tert-butyldimethylsilyl acetal (1a) with the N-benzylnitrone (4a) produced a syn-1, 3-adduct (5a) predominantly, while the reaction of ketene tert-butyl tert-butyldimethylsilyl acetal (1b) with the N-diphenylmethylnitrone (4d) gave an anti-1, 3-adduct (5h) predominantly. These adducts were readily transformed into the corresponding 3-benzoylamino-2, 3-dideoxypentoses (10a, b).

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Treatment of 5-cyano-1-phenyluracil derivatives (1) with ammonia and alkylamines afforded 6-amino-5-iminomethyluracils (2) via rearrangement involving ring-opening and ring-closure processes. Upon reaction of 3-unsubstituted 5-cyano-1-phenyluracil (1d) with ammonia and methylamine, ring-opening products, 3-acryloyl-1-phenylureas (5a and 5b) were isolated and recyclized with ease to 6-aminouracils (2j and 2k). Employment of sodium hydroxide instead of amines caused analogous rearrangement to give 6-amino-5-formyluracils (7a-c).

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Naturally occurring 5-carbonylmethyl-7-hydroxy-2-methyl-chromones, -chromanone and analogue 1, 2, 3, and an 4 were synthesized by two routes from a self condensation product 6 of dimethyl acetonedicarboxylate, and the pyrone 10.

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The scavenging effects of twenty-five tannins including low-molecular polyphenols on the superoxide anion radical (O₂^-) generated in the hypoxanthine-xanthine oxidase system were estimated by electron spin resonance (ESR) measurements of the adducts formed by 5, 5-dimethyl-1-pyrroline-N-oxide (DMPO) and the radical. The scavenging effects of tannins and related polyphenols having ortho-trihydroxyl (pyrogallol) structure [galloyl, hexahydroxydiphenoyl (HHDP) groups in hydrolyzable tannins, galloyl group in acylated proanthocyanidins, and the B-ring of some flavan-3-ols] were stronger than the effects of unacylated proanthocyanidins. The effects of tannins and related polyphenols on the superoxide anion radical were also compared with those on the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical. Each tannin in an ethanol solution of DPPH radical reduced the intensity of the signal of the DPPH radical, and gave a weak signal assignable to a radical derived from that tannin, in a similar way to the appearance of the signal of dl-α-tocopherol radical, accompanied with reduction of the signal of DPPH radical, in a mixture of dl-α-tocopherol and the DPPH radical. In contrast to the case of the superoxide anion radical, the effects of unacylated proanthocyanidins on DPPH radical were comparable with those of the other types of tannins. The scavenging effects of all of the tannins and related polyphenols tested in the experiments on DPPH radical were stronger than that of dl-α-tocopherol.

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The biosynthesis of chaetochromin A, a metabolite of Chaetomium gracile, has been studied using [¹³CH₃]methionine, sodium [1-¹³C]acetate, sodium [1, 2-¹³C₂]acetate, sodium [1-¹³C, 2, 2, 2-²H₃]acetate, and sodium [1-¹³C, 1, 1-¹⁸O₂]acetate as precursors. The folding pattern of the polyketide chain in chaetochromin A, biosynthesized from sodium [1, 2-¹³C₂]acetate as the precursor, was determined to be the same as that of rubrofusarin by carbon-13 nuclear magnetic resonance (¹³C-NMR) analysis. By using [¹³CH₃]methionine as a precursor, the source of 2-CH₃ was determined. When sodium [1-¹³C, 2, 2, 2-²H₃]acetate was fed, a β-isotope-shifted peak was observed only for carbon 2. In the ¹³C-NMR spectra of chaetochromin A and of its hexamethyl ether derived from sodium [1-¹³C, 1, 1-¹⁸O₂]acetate, isotope-shifted peaks were observed for carbons 4, 5, 6, 8 and 10a, but not for carbon 2. These results showed that oxygen 1 originated from the same unit of acetate as carbon 10a.

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The reactions of 3, 6-dimethyl [6-methyl-3-phenyl and 3-(4-chlorophenyl)-6-methyl]-1, 3-oxazine-2, 4(3H)-diones (1a, 1b, and 1c) with various amines were investigated under various conditions. Several reaction products were obtained such as the pyrimidines (3a, 3b, 3c, and 3d), the acetoacetamides (4a, 4b, and 4c), (4-chlorophenyl)urethane (5a), and ethyl acetoacetate (4d) with primary amines, and the acetoacetamides (4e and 4f), the urethanes (5a and 5b), the carboxamides (5c, 5d, 5e, and 5f), and the butenamides (7a, 7b, and 7c) with secondary amines. In the case of 1c with amine, alcohol used as a solvent reacted as a nucleophile to give the urethane (5a or 5b).

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A chemical examination of the leaves of Quercus phillyraeoides A. GRAY (Fagaceae) has led to the isolation of five new tannins, phillyraeoidins A-E (27-31), together with twenty-six structurally known tannins and related compounds including gallotannins (1, 2), ellagitannins (3-14), proanthocyanidins (15-17), complex tannins (18-21) and simple phenol glucoside gallates (22-26). On the basis of spectroscopic and chemical evidence, the structures of phillyraoidins A-D have been established as dimeric hydrolyzable tannins in which two glucose units are linked through a valoneayl ester bond, while phillyraeoidin E was characterized as 1, 2, 3, 6-tetra-O-galloyl-4-valoneayl(lactone)-β-D-glucose.

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Benzyl (4-methylcoumarin-7-yl 5-acetamido-3, 5-dideoxy-α-D-glycero-D-galacto-2-nonulopyranosid)onate was prepared as a starting compound for the syntheses of the title compounds. The 9-O-, 4-O-, 7-O-, and 7, 8-di-O-acetylated 4-methylcoumarin-7-yl 5-acetamido-3, 5-dideoxy-α-D-glycero-D-galacto-2-nonulopyranosidonic acids were prepared without migration of the O-acetyl groups. The structures of these compounds were confirmed by analysis of the proton nuclear magnetic resonance (¹H-NMR) spectra.

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A minor saponin, asernestioside C (1), was isolated from the roots of Astragalus ernestii COMB. (Leguminosae) and its structure was determined from the two-dimensional nuclear magnetic resonance spectra and nuclear Overhauser effect (NOE) difference spectra. In this case, negative NOE was observed between the 3-H and the anomeric proton of 3-O-sugar moiety and between the 24-H and the 26-H₃. Examples of negative NOE were also found in some other saponins.

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Reduction of the chiral α-keto-β, γ-unsaturated acetals (1) derived from (-)-(2S, 3S)-1, 4-dimethoxy-2, 3-butanediol was studied. Extremely high stereoselectivity was attained with LiAlH₄ and two epimeric allyl alcohols (2aA-2cA and 2aB-2cB) were prepared selectively by a proper choice of additive. As an application of this methodology, total syntheses of (R)-(-)-3'-methoxy-4'-O-methyljoubertiamine [(R)-(-)-4] and its enantiomer [(S)-(+)-4] were achieved from the single chiral enone acetal (3) through a highly stereocontrolled reduction followed by the Claisen-Eschenmoser rearrangement.

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The structures of six cembranoids, sarcophytol P (3a), sarcophytol R (4), sarcophytol S (5), sarcophytol Q (8a), sarcophytol K (11a), and sarcophytol F (14a), isolated from the soft coral Sarcophyton glaucum, were determined from the spectroscopic properties and by synthesis, or by analyses of their derivatives formed on storage in CHCl₃. Sarcophytol P (3a) was shown to be the 20-hydroxy derivative of the major component sarcophytol A (1a), and afforded the transannular cyclization product 6 on storage in CHCl₃ at room temperature, in the same way as 1a. Sarcophytol R (4) and sarcophytol S (5) were correlated to 1a by conversion of its 7R, 8R (7a) and 7S, 8S (7b) epoxide derivatives. Sarcophytol Q (8a) was shown to be a 1, 4, 14-trihydroxycembranoid, and was converted to the known ring-cleaved aldehyde 9. Sarcophytol K (11a) was a 13, 14-dihydroxycembranoid having a 1E, 3Z-diene moiety. The absolute configurations of 11a and its 1Z, 3E- and 1Z, 3Z-isomers sarcophytols B (2a) and J (13a) were determined by a circular dichroism study of their bis-p-dimethylaminobenzoate derivatives. Sarcophytol F (14a) was a 1E isomer of 1a and showed characteristic proton nuclear magnetic resonance spectral properties due to the restricted conformational interconversion. The structure was derived by characterizing two decomposition products, the same pentaene (15) and dihydrofuran (17) derivatives as those derived from 1a.

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A convenient synthesis of 19-nor steroids 4a, 4b, 12a, and 12c is described. Oxygenation of 2, 4-dibromoestrogens 1a, 1b, 8a, and 8b with nitric acid in acetic acid gave the corresponding 2, 4-dibromo-10β-hydroxy-1, 4-dien-3-one derivatives 2a, 2c, 9a, and 9d in excellent yields. These 10β-hydroxy-dienones were subjected to catalytic hydrogenation over palladium-on-charcoal to afford the saturated 5ξ-3-oxo derivatives 3a, 3b, 10a, and 10b, respectively, in very high yields. These saturated products were then converted into the corresponding 19-nor steroids 4a, 4b, 12a, and 12c by treatment with acid, perchloric acid, p-toluenesulfonic acid or Nafion-H.

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A chemical examination of the bark of Mallotus japonicus (THUNB.) MUELLER-ARG. (Euphorbiaceae) has led to the isolation of five new hydrolyzable tannins (16-20), together with fourteen known tannins (1-14). On the basis of chemical and spectroscopic evidence, the structures of compounds 16 and 17 were established as 1, 2-di-O-galloyl -3, 6-(R)-hexahydroxydiphenoyl-β-D-glucose and 1-O-digalloyl-3, 6-(R)-hexahydroxydiphenoyl-β-D-glucose, respectively, while compounds 18 (mallojaponin) and 19 (mallonin) were shown to be 1-O-galloy-2, 4-elaeocarpusinoyl-3, 6-(R)-valoneayl-β-D-glucose and 1-O-galloyl-2, 4-elaeocarpusinoyl-β-D-glucose. Compound 20 (mallotusinin) was characterized as a novel ellagitannin which possesses a unique 1, 1'-(3, 3', 4, 4'-tetrahydroxy)dibenzofurandicarbozyl group. On the other hand, examination of the leaves revealed the presence of hydrolyxable tannins (8-10, 12-15) all containing a β-D-glucopyranose core with ¹C₄-conformation. Furthermore, the orientation of the valoneayl group in mallotinic acid (13) and mallotusinic acid (14), which had remained unclarified, was determined on the basis of ¹H-¹³C shift correlation spectral analysis and chemical correlations.

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The structures of three hydrolyzable tannins, i.e., grandinin (3) (isolated from various species of Myrtaceae, Fagaceae and Lythraceae), pterocarinin A (4) (from Pterocarya steroptera C.DC. and Eucalyptus viminalis LABILL.) and pterocarinin B (6) (from P. stenoptera), have been established on the basis of chemical and spectroscopic evidence as novel C-glycosidic ellagitannins in which a C₅-polyalcohol unit with lyxose-type configuration is linked through a carbon-carbon bond to the C-1 position of the C-glycosyl moiety. Successful biomimetic synthesis of 3 and 4 suggests that the C₅-polyalcohol unit is biosynthetically derived from L-ascorbic acid.

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Two new scalarane-type bishomosesterterpenes, dehydrofoliaspongin (17) and phyllofoliaspongin (18), were isolated together with foliaspongin (4) and scalardysin-B (15) from the Okinawan marine sponge Phyllospongia foliascens. On the basis of chemical and physicochemical evidence including the X-ray crystallographic analysis of a methylated derivative (16) of 15, the structures of 17 and 18 were determined and the previously proposed structure (3) of foliaspongin was revised to 4, having a 4β-ethyl moiety. Phyllofoliaspongin (18) showed cytotoxic, anti-thrombocyte, and vasodilative activities.

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Cornusiin A (1), cornusiin B (2) and cornusiin C (3), new dimeric monomeric and trimeric hydrolyzable tannins, were isolated from the fruits of cornus officinalis (Cornaceae). Their structures, including the orientation of the valoneoyl group in 1 and 3, were established on the basis of chemical and spectroscopic data. 2, 3-Di-O-galloyl-D-glucose (7), 1, 2, 3-tri-O-galloyl-β-D-glucose, 1, 2, 6-tri-O-galloyl-β-D-glucose, 1, 2, 3, 6-tetra-O-galloyl-β-D-glucose, gemin D (5), isoterchebin, tellimagrandin I (6) and tellimagrandin II were also isolated from the fruits. The orientation of the valoneoyl group in camptothin A (14) and that in camptothin B (15), which had been isolated from Camptotheca acuminata (Nyssaceae), were also determined based on that in 1.

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A practical preparation of various 2, 3-dihydro-5H-oxazolo[3, 2-a]thieno[3, 2-d]-, [3, 4-d]-, and [2, 3-d]pyrimidin-5-one derivatives was developed starting from the corresponding aminothiopheneesters in two steps, and their chloro-substituted derivatives were prepared. These compounds were evaluated for gastric antisecretory activity in pylorus-ligated rats, compared to the anti-ulcer standard, cimetidine, and their structure-activity relationships are discussed.

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A series of substituted 6, 7-dihydro-1-oxo-1H, 5H-benzo[i, j]quinolizine-2-carboxylic acids was synthesized and tested for antibacterial activities. Among them, 9-fluoro-6, 7-dihydro-5-methyl-8-(4-methyl-1-piperazinyl)-1-oxo-1H, 5H-benzo[i, j]quinolizine-2-carboxylic acid (OPC-7241) exhibited potent antibacterial activity against gram-positive and -negative bacteria, including Staphylococcus aureus and Pseudomonas aeruginosa, and 9-fluoro-6, 7-dihydro-8-(4-hydroxy-1-piperidyl)5-methyl-1-oxo-1H, 5H-benzo[i, j]quinolizine-2-carboxylic acid (OPC-7251) showed potent activity characteristically against Propionibacterium acnes.

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Many 8-[(2-benzimidazolyl)sulfinylmethyl]-1, 2, 3, 4-tetrahydroquinoline derivatives were synthesized and tested for their (H⁺ + K⁺)adenosine triphosphatase (ATPase)-inhibitory and antisecretory activities against histamine-induced gastric acid secretion in rats. These sulfinyl compounds were synthesized by the oxidation of the corresponding sulfides, which were obtained from the reaction of 8-chloromethyl-1, 2, 3, 4-tetrahydroquinolines and 2-mercaptobenzimidazoles in the presence of potassium carbonate. All compounds tested were potent inhibitors of (H⁺ + K⁺)ATPase. Most of the compounds showed antisecretory activity. Among them, 8-[(2-benzimidazolyl)sulfinylmethyl]-1-ethyl-1, 2, 3, 4-tetrahydroquinoline (IXa) was found to have the most potent activity. The structure-activity relationships are discussed.

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Novel 2-chloro-1, 4-dihydropyridine derivatives were synthesized by chlorination of 2-hydroxy-1, 4-dihydropyridines with POCl₃. The dihydropyridines chlorinated at position 2 exhibited more potent vasodilative and hypotensive activities than the dihydropyridines (nicardipine and nitrendipine) with a methyl group at position 2.

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Thiazolo[3, 2-a]thieno[3, 2-d]-, [3, 4-d]- and [2, 3-d]pyrimidin-5-one derivatives (6, 11, and 16), and polymethylene condensed thieno[3, 2-d]-, [3, 4-d]- and [2, 3-d]pyrimidin-5-one derivatives (19-21), in which the oxygen atom of the oxazolidine moiety in 3 was replaced by a sulfur atom or methylene groups, were synthesized and evaluated for gastric antisecretory activity in pylorus-ligated rats. The structure-activity relationships of these compounds are discussed.

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Minor new withanolides, daturametelins C, D, E, F and G-Ac, have been isolated from the methanolic extract of the fresh aerial parts of Datura metel L. (Solanaceae) and their structures have been determined mainly by spectroscopic means. Daturametelins E anf F are the first withanolides having a 1-one-3β-O-sulfate structure in ring A.

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Two new triterpenoid glycosides, 3-O-α-L-rhamnopyranosyl-(1→2)-β-D-galactopyranosyl-(1→2)-β-D-glucuronopyranosiduronic acids (2 and 3) of 3β, 22β-dihydroxyolean-12-en-29-oic acid and 3β, 21β, 22β-trihydroxyolean-12-en-29-oic acid, along with a known glycoside, kaikasaponin III (1), were isolated from the bark of Dalbergia hupeana HANCE. Their structures were determined by chemical and spectral methods.

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Nine novel triterpenoid saponins, named crocosmiosides A-I, were isolated from the corms of montbretia (Crocosmia crocosmiiflora N. E. BR., Iridaceae). Among those saponins, the structures of crocosmiosides A (1), B (2) and H (3) were determined on the basis of spectral and chemical evidence. They are unique acylated saponins which have 2, 9, 16-trihydroxypalmitic acid glycoside as the acyl moiety, and their structures were elucidated as polygalacic acid-3-{α-L-arabinopyranosyl-(1→6)-β-D-glucopyranosido}-28-{2-O-[β-D-apio-D-furanosyl-(1→4)-β-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl]-4-O-(9-hydroxy-16-α-L-rhamnopyranosyloxy-2-β-D-xylopyranosyloxyhexadecanoyl)-β-D-fucopyranoside} (1), polygalacic acid-3-{α-L-arabinopyranosyl-(1→6)-β-D-glucopyranosido}-28-{2-O-[β-D-apio-D-furanosyl-(1→4)-β-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl]-4-O-(9, 16-dihydroxy-2-β-D-xylopyranosyloxyhexadecanoyl)-β-D-fucopyranoside} (2) and polygalacic acid-3-{α-L-arabinopyranosyl-(1→6)-β-D-glucopyranosido}-28-{2-O-[β-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl]-4-O-(9-hydroxy-16-α-L-rhamnopyranosyloxy-2-β-D-xylopyranosyloxyhexadecanoyl)-β-D-fucopyranoside} (3), respectively.

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Anti glyco-3β, 12α-dihydroxy-5-cholen-24-oic acid antisera were prepared by immunizing rabbits with haptenbovine serum albumin (BSA) conjugates coupled at the C-3, C-15α, and C-24 positions on the bile acid molecule, and their properties were investigated by heterologous combination assay using ¹²⁵I-labeled tracer. The antiserum raised against the C-3 BSA conjugate showed poor titer and specificity, while the antisera from the other two conjugates showed satisfactorily high affinity constants (K_a = 5.0×10⁸ and 7.0×10⁸ M^-1) and reasonable specificity, exhibiting negligible cross-reactivities with other major human bile acids and cholesterol. Among the unsaturated bile acids tested, high reactivity was observed with tauro-3β, 12α-dihydroxy-5-cholen-24-oic acid, which suggested that bridge phenomena were significant in this assay system.

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Ion-selective electrodes (ISEs) responsive to the antitussives dextromethorphan and dimemorfan were constructed by the fixation of an ion-exchanger, ammonium tetraphenylborate, on a Millipore membrane by means of a plasma-polymerization technique. The electrodes showed a Nernstian response over the range of 10^-5-10^-2 M dextromethorphan and dimemorphan, and the working pH range was 5-7. The interference from common cations such as Na⁺, K⁺ and Ca²⁺ was negligible but some organic cations interfered weakly. The electrodes were applied successfully for the determination of the drugs in pharmaceutical preparations.

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Commercially available heparin preparations slightly enhanced the rate of thrombin/antithrombin (AT) III reaction at pH 6.05 in the absence of NaCl. However, this accelerative activity was significantly lower than that induced by heparin with high affinity for AT III (HA-heparin), probably due to the formation of the binary complexes of HA-heparin-AT III as well as that composed of thrombin and heparin with low affinity for AT III (LA-heparin). The HA-heparin-catalyzed thrombin/AT III reaction was faster in the presence of 0.1 M NaCl at pH 6.05 than that in the absence of the salt.LA-heparin and dextran sulfate (DS) were also found to accelerate the thrombin/AT III reaction rate, but neither substance catalyzed the formation of the complex in the presence of 0.1 M NaCl at pH 7.4. LA-heparin was also confirmed to compete with HA-heparin for enhancement of the thrombin/AT III reaction. Thus, it appears that AT III tends to form a ternary complex with the thrombin-DS or thrombin-LA-heparin complex, even in the presence of 0.1 M NaCl, whereas factor X_a reacts with the AT III-DS or AT III-LA-heparin complex.These results indicate that HA-heparin is the only substance having the ability to catalyze the thrombin/AT III reaction, and that its turnover rate is markedly elevated in the presence of strongly electropositive and electronegative ions because of the decreased affinity of the enzyme for heparin under such conditions.

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When recombinant human interleukin 2 (rIL-2) was stored for a long period in aqueous solutions, its methionine residues were spontaneously oxidized the corresponding methionine sulfoxides. To clarify the oxidation process, rIL-2 was treated with hydrogen peroxide, and three oxidation products were separated by reversed-phase high-performance liquid chromatography. By means of amino acid analyses after cyanogen bromide cleavage of these products, we found that Met¹⁰⁴, Met²³, and Met³⁹ were consecutively oxidized in this order; Met⁴⁶ was not oxidized easily. The substances generated by extended storage of rIL-2 in aqueous solutions were identified by comparison of their peptide maps with those of the chemically oxidized products. The protein-chemical properties of these products, except for the modifications of the methionine residues, were similar to those of intact rIL-2; their biological activities were almost the same.

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The effects of neuraminidase treatment on the dynamic properties of the porcine intestinal brush-border membranes have been examined by using a fluorogenic thiol reagent, N-(1-pyrene)maleimide (NPM). Desialylation of the membranes by treatment with neuraminidase resulted in changes in the fluorescence parameters of NPM-labeled membranes, i.e. a decrease of the fluorescence lifetime and a suppression of the temperature-dependent decrease of the fluorescence intensity. These results suggest that the environmental properties around NPM-labeled SH groups in the membrane proteins were modified by neuraminidase treatment. Perturbation of the microenvironment around NPM-labeled SH groups associated with desialylation by the enzyme treatment was also determined by measuring the increase of fluorescence anisotropy and decrease of quenching efficiency with acrylamide or CH₃COOTl of the complex. Based on the results it is suggested that the dynamic properties of the conformation around NPM-labeled SH groups in the membrane proteins are sensitively influenced by neuraminidase treatment.

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Modification of lysine, tyrosine, histidine, aspartic acid and glutamic acid residues did not affect the agglutinating activity of the Tulipa gesneriana lectin (TGL). Modification of two arginine residues per subunit in the lectin with either 2, 3-butanedione or phenylglyoxal led to an almost complete loss of activity. An inactive lectin modified with 2, 3-butanedione recovered a full activity on dialysis against Tris-HCl buffer. The presence of 0.1 M (α-1→6) linked mannotriose, a potent inhibitor of the lectin, protected all the arginine residues from modification and the lectin was fully active. Circular dichroism spectroscopy showed that no significant conformational change of TGL occurred following arginine modification.A treatment of the lectin solution with N-bromosuccinimide or 2-hydroxy-5-nitrobenzyl bromide, chemical reagents for tryptophan modification, caused turbidity of the solution, . accompanied with complete loss of activity. The fluorescence emission spectrum of the lectin showed a characteristic tryptophan emission with a maximum centered at 336 nm. Upon addition of manno-oligosaccharides a decrease of the fluorescence intensity was observed, indicating that the environment of tryptophan residues altered.These results suggest that arginine and tryptophan residues are importantly involved in the sugar binding of TGL.

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The hot water extract of sclerotia of Sclerotinia sclerotiorum IFO 9395 (TSHW) was divided into representative fractions by ammonium sulfate and ethanol precipitations, and (1→3)-β-D-glucanase treatment. The ammonium sulfate and ethanol precipitations gave a (1→3)-β-D-glucan fraction (TSG) and a mannan fraction (TSM). After the degradation of (1→3)-β-D-glucan in TSHW by (1→3)-β-D-glucanase treatment, a water-isoluble protein fraction (EDP) and supernatant (EDS) were obtained. Among these fractions, the mitogenic and antitumor activities were mainly observed in EDP and TSG, respectivety. On the other hand, the stimulatory effect on the reticuloendothelial system was mainly found in EDP and EDS, and a weak effect was observed in TSG. These findings suggest that the mitogenic and antitumor activities of TSHW were mainly due to the protein and (1→3)-β-D-glucan, respectively, and that the mitogenic substance (EDP) is tightly bound to (1→3)-β-D-glucan (TSG) in TSHW, accounting for its solubility in aqueous solution.

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A novel cytolytic factor, dolabellanin P, was purified to apparent homogeneity from the purple fluid of the sea hare, Dolabella auricularia. Purified dolabellanin P is a single polypeptide of 60 kDa. The amino acid composition and the N-terminus of the factor were also determined. This factor nonspecifically lysed all the cells tested at 50-200 ng protein/ml. Dolabellanin P caused complete cytolysis within 2 h. The factor is distinct from antineoplastic glycoproteins previously isolated from eggs (aplysianin E) or albumen gland (aplysianin A) of Aplysia kurodai in terms of certain cytolytic properties. These results suggest that dolabellanin P, found in the sea hare, a marine invertebrate, is a new cytolytic factor.

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Tolbutamide (TBM) was agglomerated by several methods of spherical crystallization technique. A mixture of an ethanolic solution of TBM (II) and isopropyl acetate (III : bridging liquid) was added to water (I : crystallization solvent), and crystals were allowed to form. Agglomeration was then allowed to proceed while this system was stirred at 600 rpm. Next, I was added to a mixture of II and III; that is, the order of addition in the initial procedure was reversed, and crystallization-agglomeration was carried out. In addition, after adding I to II and causing the crystallization of TBM, III was added to the system to bring about agglomeration.These different crystallization-agglomeration techniques yielded TBM agglomerates having different crystalline forms, with a mixture of form A and form B obtained in the mixed solution of ethanol /water /isopropyl acetate (the first 2 methods described above) and form B obtained in the mixed solution of ethanol/water (the 3rd method). The composition ratio of the mixture of form A and form B crystals also differed as a function of the crystallization process. The findings of these experiments indicated that the causes of this difference in the composition ratio differ as a function of the course of changes in the composition of the TBM solution up to the point of agglomeration due to difference in the crystallization method. That is, it was elucidated that the crystalline form of the TBM agglomerate depends on the solvent environment (composition) at the time of formation of the crystal nuclei.

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Rat gastric mucosal cells were isolated with the aid of 0.1% collagenase and Disase^[○!R]. Pepsinogen secretion from these cells was stimulated by carbachol, cholecystokinin octapeptide (CCK(S)-8) and pentagastrin, but not by histamine. Attempts to obtain a sufficient number of cells using a higher concentration of Dispase resulted in disappearance of the responses to secretagogues. However, when gastric mucosal cells thus prepared were cultured for 24 h in a CO₂ incubator, they were found to respond not only to carbachol, CCK(S)-8 and pentagastrin, but also to histamine, resulting in an increase in pepsinogen secretion. The secretagogue-induced pepsinogen secretion was inhibited by its antagonist in a dose-dependent manner. These results suggest that the receptor present in chief cells for pepsinogen secretion was destroyed during the isolation procedure and regenerated during culture.

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Two neoclerodane diterpenoids, clerodinins A and B, together with three known compounds, clerodin, stigmasta-5, 22, 25-trien-3β-ol and 3-epi-glutinol, have been isolated from the hexane extract of the leaves of Clerodendron brachyanthum, and their structures determined.

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The crystal structure of the title compound (1b), which is the acetyl derivative of one of the oxygenated dimers of 3-methylindole, has been determined by single-crystal X-ray analysis. The crystals are monoclinic, space group P2₁/a, with a=13.980 (3), b=12.340 (3), c=10.021 (4) Å, β=92.51 (3)°, and Z=4. The bond lengths and angles in 1b are not much different from those in the stereoisomer of 1b with inverted configuration at the C₁₂ position, indicating the rigidity of the five successive ring structures of 6H-oxazolo[3, 2-a : 4, 5-b']diindole. The molecular stereochemistries of these isomers are discussed.

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5-Amino-6-mercapto-1, 3-dimethyluracil (2) was prepared by the treatment of 5, 6-diamino-1, 3-dimethyluracil (1) with liquid H₂S and pyridine in a sealed steel tube at 60°C for 20 h. Thiazolo[5, 4-d]pyrimidinediones 3a, b were obtained from 2 by cyclization with HCO₂H and AcOH.Under stringent conditions, however, 1 was converted into the 5, 9-dihydrodipyrimido[4, 5-b : 5', 4'-e][1, 4]thiazine derivtive 4a.The structure of 4a was confirmed by spectral (nuclear magnetic resonance and mass spectra) data and by comparison with a sample which was prepared from 2 and 5-hydroxy-1, 3-dimethyluracil.Benzylation of 4a gave 1, 3, 7, 9-tetramethyl-5-benzyl (or p-bromobenzyl)-5, 9-dihydrodipyrimido[4, 5-b : 5', 4'-e][1, 4]thiazine-2, 4, 6, 8-(1H, 3H, 7H)-tetrone (4b, c) and 1, 3, 7, 9-tetramethyl-5-benzyl (or p-bromobenzyl)-5, 9-dihydropyrrolo[3, 2-d : 4, 5-d']dipyrimidine-2, 4, 6, 8-(1H, 3H, 7H)-tetrone (6a, b).

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An asymmetric synthetic route to 2-substituted-3-aminocarbonyl propionic acid, which is the significant component of low-molecular-weight renin inhibitors, is described. The key step of this synthesis is diastereoselective alkylation by using chiral oxazolidinone and benzyl bromoacetate.

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A method for analysis of 3-deoxy-D-glycero-D-galacto-2-nonulopyranosonic acid (KDN) by high-performance liquid chromatography (HPLC) with a strongly basic anion-exchange resin was developed. The method was applied to detect free KDN in water used to rinse of fertilized eggs of chum salmon, Oncorhynchus keta. Furthermore, KDN was isolated from the water as a fully protected derivative.

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A practical synthetic route to optically active 6, 6'-dichloro-2, 2'-diphenic acid (III) and its dimethyl ester (IV) was developed.

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Newly developed β-1- and β-2-adamantylaspartates [H-Asp(O-1-Ada)-OH and H-Asp(O-2-Ada)-OH] were applied to the sythesis of a C-terminal octapeptide of the β-subunit of human chorionic gonadotropin (hCG) by a conventional solution method and a hexacosapeptide of the α-subunit of insulin receptor (30-55) by a solid-phase method with the objective of suppressing aspartimide formation during the synthesis of aspartylpeptides. The 1-Ada and 2-Ada groups were confirmed to be useful protecting groups for the β-carboxyl function of the Asp residue.

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The proton and carbon-13 nuclear magnetic resonance signals of cytochalasin E (1) were assigned with the aid of ¹H-¹H, ¹H-¹³C and ¹H-¹³C long-range chemical shift correlation spectroscopy spectra, and the structure of the decomposition product (2) generated under neutral conditions was determined.

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Erbstatin dimethyl ether (12) was synthesized by Friedel-Crafts reaction of chloro(methyl- or phenyl-thio)acetonitrile (5a or 5b) with hydroquinone dimethyl ether, followed by reduction to the amine, formylation, and oxidative desulfenylation. By using a similar sequence of reactions, N-acetyl-1, 2-didehydrodopamine dimethyl ether (13) was prepared from veratrole and 5a, b.

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