The purple membrane is an appropriate model system for investigating the effects of anesthetics on the structures and functions of excitable cell membranes. The effects of anesthetically active alcohols (methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, and 1-hexanol) on the structure of bacteriorhodopsin (bR) in the purple membrane were investigated by circular dichroism (CD) and adsorbance measurements. These alcohols increased the 530-nm ellipticity of bR at low concentrations of the alcohols and decreased it at high concentrations. The addition of alcohol at a low concentration in the purple membrane aqueous suspension tended to favor the more folded-compact conformation of the bR by the enhancement of hydrophobic interaction. Alcohols at high concentrations caused the cooperative denaturation of bR due to the access of alcohol to the retinal chromophore. Our attention is mainly focused on the finding that alcohols at low concentrations induce a more folded conformation of bR.

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As a part of elucidating the structural features of a host molecule necessary for the recognition of basic amino acids, the crystal structures of the picrates of DL-arginine (1), L-arginine (2), L-lysine (3), and L-ornitine (4) have been determined by X-ray analyses. The molecular packing pattern is found to be common in these crystal structures.The picric acids themselves form layers perpendicular to a crystallographic axis, and respective basic amino acids are packed into these layers, where the amino acids themselves also form singly or doubly arranged layers in a head-to-tail fashion and are stabilized by hydrogen bonds between the α-carboxyl and guanidyl or terminal amino groups. The picric acid interacts with the amino acid by three to seven NH(amino acid) …O(picric acid) hydrogen bonds. A notable feature of the molecular interaction commonly found in complexes 1-4 is the simultaneous fixation at three portions of the amino acid (α-amino, α-carboxyl and terminal amino or guanidyl groups) by a hydrogen bond and/or electrosatatic interactions. In conclusion, it was shown that both the crystal packing and the molecular interaction modes are important for the complex formation between the basic amino acid and picric acid molecules.

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Condensation of 4-methyl-7-thiocoumarin sodium salt with methyl 5-N-acetyl-4, 7, 8, 9-tetra-O-acetyl-2-chloro-2, 3, 5-trideoxy-D-glycero-D-galacto-2-nonulopyranosonate (2), methyl 5-N-(O-acetylglycolyl)-4, 7, 8, 9-tetra-O-acetyl-2-chloro-2, 3, 6-trideoxy-D-glycero-D-galacto-2-nonulopyranosonate (11), and methyl 4, 5, 7, 8, 9-penta-O-acetyl-2-chloro-2, 3-dideoxy-D-glycero-D-galacto-2-nonulopyranosonate (14) under Williamson reaction conditions gave the corresponding α-glycosides in good yields. Deprotection of these α-glycosides gave three new fluorogenic substrates, the 4-methylcoumarin-7-yl S-glycosides of N-acetylneuraminic acid, N-glycolylneuraminic acid, and 3-deoxy-D-glucose-D-galacto-2-nonulopyranosonic acid (KDN). Furthermore, we have developed a facile method for preparation of benzyl 5-amino-3, 5-dideoxy-α-D-glycero-D-galacto-2-nonulopyranosidonic acid (7), a key intermediate for the synthesis of N-glycolylneuraminic acid.

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Four new minor triterpenoids, 9α, 11α-epoxyfernane (1), 9β, 11β-epoxyfernane (2), 3α, 10α-epoxyfilic-4(23)-ene (3) and 20α, 22-dihydroxyhopane (4) were isolated from fresh leaflets of Cyathea lepifera, together with known triterpenoids, fern-9(11)-ene (5), fern-7-ene (6), filic-3-ene (7), adiantone (8), glaucanone (9), fern-9(11)-en-12-one (10), hydroxyhopane (11), hopan-30-oic acid (12) and cycloartanoid esters (13). The structures of the new compounds were elucidated on the basis of spectral data.

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Five new eunicellin-type diterpenoids, briarellins E-I, along with several known diterpenoids of the asbestinane, briarane and eunicellane classes, were isolated from the Caribbean gorgonian octocoral Briareum asbestinum collected in Puerto Rico. The structures of these compounds were established on the basis of spectroscopic evidence.

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A regioselective bond-cleavage of the cyclopropyl sulfide (2) was performed with mercury(II) salt to supply the homoallyl anion synthon (3) bearing two reactive sites at the α and δ positions. The reaction of 3 with n-Bu₃SnH and I₂ gave α-functionalized products (8 and 9, respectively). On the other hand, recyclization of 3 into δ-functionalized cyclopropyl sulfides (2, 12, 13) was accomplished by treatment with several electrophiles (H⁺, D⁺, allyl iodide).Moreover, the synthesis of δ-oxygenated cyclopropyl sulfide (15) was achieved by the additive Pummerer reaction of the γ, δ-unsaturated γ-sulfinyl alkylmercury chloride (14) which was obtained by m-chloroperbenzoic acid oxidation of 3.

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The instability of Δ² cephem prodrug-type ester (5a) under acidic conditions prompted us to investigate the comparative stability of Δ³ and Δ² cephems at various pHs. The Δ² cephem ester 5a was found to show marked instability under neutral (pH 7) and acidic conditions (1M HCl) compared with the Δ³ cephem ester (4a). A comparative study between Δ³ (4c) and Δ² cephem acid (5c) at pH 7 and in 1M HCl solution showed that the Δ² acid 5c was as stable as the Δ³ acid 4c pH 7, while 5c was less stable than 4c in 1M HCl. Isolation of the degraded compounds demonstrated that the C-4 ester moiety was hydrolyzed in the initial stage to afford 5c, which was further degraded to more polar substances. This instability was observed in other types of Δ² cephem esters (5d-f). Here we report comparative stability studies and elucidation of the degradation products.

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Diisopropylamine (DIPA), N, N-diisopropylethylamine (DIPEA), tributylamine (TNBA) and 7-(1-piperazinyl)-4-quinolone-3-carboxylic acid (2) were titrated in water-dimethylformamide (DMF) mixtures containing 45-98% DMF. Apparent pK_a values in anhydrous DMF (pK_DMF) were calculated by extrapolation from the variation in the half-neutralization pH values in aqueous DMF. The validity of the relative basicity derived from the pK_DMFs was confirmed by examination of the kinetics of esterification of a derivative of 2 with 4-(bromomethyl)-5-methyl-1, 3-dioxol-2-one (DMDO-Br). Relative basicities in DMF were : the carboxylate anion of 2»DIPA>DIPEA>TNBA >the amino group in the piperazinyl part of 2. This order is clearly different from that observed in water.We concluded that DIPEA is a suitable agent to suppress the undesired esterification during the reaction to mask the amino group of 2 with a DMDO group, because it does not remove a proton from the carboxyl group, but only from the protonated amino group.

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Five new saponins named elatosides G, H, I, J, and K were isolated from a garnish foodstuff "Taranome, " the young shoot of Aralia elata SEEM., together with hederagenin-3-O-glucuronopyranoside and elatoside C. Their chemical structures were elucidated on the basis of chemical and physicochemical evidence. Elatosides G, H, and I were found to exhibit potent hypoglycemic activity in the oral glucose tolerance test in rats.

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To investigate a series of new inhibitors of gelatinases based on matlystatin B (1b), extensive structure-activity relationship studies were performed. The new derivatives were evaluated in vitro for the ability to inhibit gelatinases.The inhibitory activities against thermolysin were also assayed to test the compounds' selectivity. Among the compounds modified at the P'₃ moiety, the N-methylamide derivative 5 g was virtually twice as effective on gelatinase B as the parent compound 1b (5g, IC₅₀=0.27μM vs. 1b, IC<50>=0.57μM). Other derivatives, including 1) esters 7a and 7b having the ester portions P'₂ and P'₃, 2) the cyclic amino acids, L-proline or L-pipecolinic acid (13a and 13b) bearing P'₂, and 3) compounds 29a and 29b representing an attachment of the pentyl side chain at C3' (P'₁ side chain)instead of C2', all showed decreased potencies. The key discovery was the observation that the introduction of a nonyl group at the P'₁ position yielded a compound (31f, IC<50>=0.0012μM) with high inhibitory activity against gelatinases and high selectivity over thermolysin. This result suggested that the S'₁ subsites of the gelatinases have a locally deep hydrophobic structure, since on the basis of the optimum inhibitory activity in the alkyl series, the nonyl group seems to fit best into this hydrophobic pocket. Thus 31f exhibited a 475-fold more potent inhibitory activity than 1b towards gelatinase B.

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Lipophilicity of the 1, 2-dithiole-3-thione nucleus was studied by stepwise calculation of log P values of some dithiolethiones from fragmental lipophilic constants of suitable fragments composing the nucleus, and the results were compared with experimental values. Fragmental constants necessary for these calculations were determined from log P values of suitable molecules. The influence of conjugation between the different parts was investigated.Fragmental lipophilic constants of unusual thio-fragments were assessed.

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A new fluorinated analog of vitamin D₂, 24-epi-26, 26, 26, 27, 27, 27-hexafluoro-1α, 25-dihydroxyvitamin D₂, was efficiently synthesized starting from (R)-4-isopropyl-3-propionyl-2-oxazolidinone with high stereochemical control.In all four physiological test systems, the fluorinated vitamin D₂ analog was found to be slightly less active than 1α, 25-dihydroxyvitamin D₃.

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Six novel transition state analogs (TSAs) of cocaine (10-14 and 17) and one non-cocaine, p-aminophenyl-phosphonyl ester of cyclohexanol (19), were synthesized and characterized by ¹H- and ¹³C-NMR and FAB-MS.(1R)-ecgonine methyl ester or cyclohexanol were subjected to phenylphosphonylation in the presence of dicyclohexyl carbodiimde (DCC) and 4-N, N-dimethyl aminopyridine (4-DMAP). TSA-IV (10), however, was synthesized from norcocaine which was protected with dibromoethane to yield 4 before acid hydrolysis, esterification and phenyl-phosphonylation were carried out. TSA-III (11) TSA-I (12) and (19), using various length spacer arms, were coupled with the immunogenic protein, diphtheria toxoid (DT). The TSAs coupled with DT were used to immunize mice and after appropriate boosts their sera were tested for the presence and titer of anti-TSA polyclonal antibodies using ELISA. Preliminary results show that the mice immunized with these TSAs produced high titers of polyclonal catalytic antibodies, except for (19), with the ability to hydrolyze the substrate ¹²⁵I-4'-iodococaine in an in vitro assay, even in the presence of noncatalytic anti-TSA antibodies.

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Our studies on 4-amino-5-chloro-2-ethoxybenzamides led to the discovery that the N-(1, 4-dimethylhexahydro-1H-1, 4-diazepin-6-yl)benzamide 9 and the 1-benzyl-4-methylhexahydro-1H-1, 4-diazepine analogue 10 are potent serotonin-3 (5-HT₃) receptor antagonists. Structure-activity relationship (SAR) studies on the influence of the aromatic nucleus of 9 and 10 upon inhibition of the von Bezold-Jarisch reflex in rats are described. Heteroaromatic rings such as pyrrole, thiophene, furan, pyridine, pyridazine, 1, 2-benzisoxazole, indole, quinoline, and isoquinoline rings showed weak 5-HT₃ receptor antagonistic activity. Within this series, use of the 1H-indazole ring as an aromatic moiety led to a substantial increase of the acitivity; the 1H-indazolylcarboxamides 54, 57, 97, and 102 showed potent 5-HT₃ receptor antagonistic activity. The optimal compound identified via extensive SAR studies was N-(1-benzyl-4-methylhexahydro-1H-1, 4-diazepin-6-yl)-1H-indazole-3-carboxamide (54), whose effect was superior to that of the corresponding benzamide 10 and essentially equipotent to those of ondansetron (1) and granisetron (4).

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The amino group of doxorubicin (DXR) was found to be bound to the carboxyl group of carboxymethylpullulan (CMPul) either directly or through tetrapeptide spacers, including Gly-Gly-Phe-Gly, Gly-Phe-Gly-Gly and Gly-Gly-Gly-Gly. These conjugates had DXR contents of 6.1-7.1%, with the degree of substitution of carboxymethyl groups being 0.6 per sugar moiety. These conjugates associate in phosphate-buffered saline (PBS)(pH 7.4), forming micelles with hydrophobic DXR inside and hydrophilic CMPul on the outside. The amounts of DXR released from the conjugates in the presence of rat liver lysosomal enzymes were determined by HPLC. The rate of the drug release differed among the conjugates tested. CMPul-DXR conjugate bound through Gly-Gly-Phe-Gly released 35% of its DXR over 24 h. On the other hand, CMPul-DXR conjugate without spacer released no free DXR. The antitumor effect of each conjugate in rats bearing Walker 256 was studied by monitoring the tumor weights after a single intravenous injection. Compared with DXR, CMPul-DXR conjugates bound through Gly-Gly-Phe-Gly and Gly-Phe-Gly-Gly spacers significantly suppressed the tumor growth, while CMPul-DXR conjugate bound through Gly-Gly-Gly-Gly showed less antitumor effect than DXR. CMPul-DXR conjugate without spacer showed no in vivo antitumor effect even at a dose equivalent to as much as 20 mg/kg of DXR.

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The constituents of Betula ermanii CHAM. in Japan were identified as follws. Fresh leaves : 20(S), 24(R)-epoxydammmaran-3β, 11α, 25-triol (1), 3-O-β-D-glucopyranoside of 1 (2), 2'-acetate of 2 (3), 11, 2'-diacetate of 2 (4), dammar-24-en-3β-, 11α-20(S)-triol (5), 3-O-β-D-2-O-acetylglucopyranoside of 5 (6). Outer bark : betulin (7), betulin 3-caffeate (8), oleanolic acid (9). Inner bark : (+)-lyoniresinol 3α-O-α-L-rhamnopyranoside (10), (-)-lyoniresinol 3α-O-β-D-xylopyranoside (11), 9, 9'di-O-feruloyl-(-)-secoisolariciresinol (12), acerogenin E (13), 3, 4, 5-trimethoxyphenol β-D-apiofuranosyl(1→6)-β-D-glucopyranoside (14), 4-(4-hydroxyphenyl)-2-butanol 2-O-β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside (15), (+)-catechine 7-O-β-D-xylopyranoside (16), lupeol (17), monogynol A (18). Root outer bark : lupeol caffeate (19), betulin 3-caffeate (8), oleanolic acid caffeate (20), dammarendiol II 3-caffeate (21). Compounds 2, 3, 4, 6, 19 and 21 are new.

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The correlation between in vivo and in vitro dissolution of clarithromycin (CAM) tablets was examined. In vivo dissolution rate constants in the stomach and the intestine were obtained from analysis of the urinary excretion data of CAM following oral administration to humans in the fasting or postprandial state using a pharmacokinetic model including gastrointestinal transit.In the present study, the flow-through cell method with moderate agitation was used, as the in vitro dissolution test related to the in vivo dissolution rate constants. Both the effects of pH of the dissolution medium and the volumetric solvent flow rate on the dissolution rate in the flow-through cell method were examined. The pH of the dissolution medium and the flow rate were related to the in vitro dissolution rate. Therefore, the conditions of the flow-through cell method in correlation with the in vivo dissolution rates in the stomach and intestine were determined by controlling the flow rate at pH 3.0 and 6.8 dissolution medium. The urinary excretion of CAM, simulated by substituting the in vitro dissolution rate constants into the equation, were consistent with the in vivo data. The in vitro tests corresponding to the in vivo dissolution in the stomach and intestine following a single oral administration in the fasting or postprandial state for a CAM tablet were established.

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The binding of xylazine to bovine werum albumin (BSA) was studied by fluorescence quenching, as a function of temperature. The experimental data could be fitted to both the Stern-Volmer equation and the Stern-Volmer equation modified by Lehrer. The temperature dependence of the Stern-Volmer constant, K_SV suggests that the mechanism of the quenching process is mainly dynamic in origin. The thermodynamic parameters were estimated based on such temperature dependence.The positive values found for the enthalpy and entropy changes seem to indicate that the hydrophobic contribution is the predominant intermolecular force stabilizing the xylazine-BSA complex.Fluorescence quenching was also used to calculate the binding constants by the Scatchard procedure. The values of these constants are of the same order of magnitude as the Stern-Volmer constants.These results, together with the spectral changes in the fluorescence emission spectra of BSA induced by xylazine, suggest that the interaction may take place in subdomains IIA and IIIA since these subdomains have been proposed to bind drugs and other hydrophobic materials.

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Micronized samples of lactose monohydrate and salmeterol xinafoate have been used to study the adhesion of micronized particles to compacted powder surfaces. After an initial increase in median adhesion force with increased press-on force no further increase in median adhesion force can be achieved. Thus application of larger press-on forces eventually appears to result in a maximum plastic deformation of the micronized particles. This is in contrast to previous experiments using particles of the same materials in a size range between 20 and 120 μm, where an increase in press-on force always led to an increase in median adhesion force.The adhesion of micronized lactose monohydrate particles to salmeterol xinafoate surfaces is numerically higher than the adhesion of micronized salmeterol xinafoate particles to lactose monohydrate surfaces, although theoretically the same two materials are adhered to each other. This effect could be due to differences in the surface roughness of the compacted surfaces. Hence, if a true estimate of adhesion is required from adhesion studies of any two materials, either material should be used as particlate and as compacted powder material. Otherwise a careful consideration of the practical conditions which are to be modelled has to be made to choose the most appropriate system.The relative autoadhesion force of micronized lactose monohydrate particles could have been predicted from the results obtained using larger particles. This is valid with small limitations also for the relative antoadhesion force of salmeterol xinafoate. The relative adhesion force of salmeterol ximafoate particles to compacted lactose monohydrate surfaces appears independent of particles size even into micronized size range if particles with similar morphology are compared.

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Interactions between water molecules and various pharmaceutical polymers were studied by water vapor sorption and differential scanning calorimetry (DSC). Water-vapor sorption isotherms at 30°C were determined by gravimetric technique and the monolayer values and moisture content at a relative humidity of 79% were estimated for each sample. The state of the water molecules in moistened polymers was investigated using DSC and one or two exothermal peaks of water crystallization were observed in the DSC cooling curves. The content of non-freezing water, which is restricted by hydrophilic groups in polymer molecules, was determined from the amount of freezing and total water in the polymer. The amount of water sorbed at high relative humidity and non-freezing water in DSC measurement correlated to some extent. In hydrophilic polymers having numerous ether linkages, the amount of non-freezing water was larger than that predicted from the small amount of sorbed water in the vapor phase.

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Nondisintegrating single component tablets were dissolved under a non-sink condition, and the applicability of equations derived for the dissolution of particles with optional initial amounts, i.e., the z-law equation, Ln-z equation and Lg-z equation, was examined by comparing the dissolution rate constants and conformity of simulated value to measured value. The z-law equation expressed by a function of the initial amount used for dissolution measurement and solubility was reasonably applicable to the dissolutions of tablets with various initial amounts within solubility.The Ln-z equation well explained the dissolution process with initial amounts within around half of the solubility.The Lg-z equation, an extended application form of the z-law equation, was applicable to the dissolution with an initial amount close to the solubility. These application aspects for dissolutions of nondisintegrating single component tablets were almost the same as those observed for dissolution of particles reported previously, and it was confirmed that the z-law equation, the Ln-z equation and the Lg-z equation appropriately treated dissolutions carried out with optional initial amounts within solubility irrespective of whether particles or tablets. Once the dissolution rate constant was determined in advance, the dissolution process with optional initial amounts within solubility could be approximately predicted. It may become difficult to predict the dissolution process with increase in tablet weight, however.

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We investigated the dissolution behavior of piretanide polymorphs, forms A and B in buffers from pH 1.0-7.0 at a range of temperatures (30-45°C) by a dispersed-amount method. These polymorphs were also tested by the stationary-disk method in pH 5 buffer at 30-45°C. The dissolution of forms A and B compressed into tablets with excipients was also tested in a pH 5 buffer at 37°C by the paddle method.The solubility and the initial dissolution rate of forms A and B were temperature dependent at pH 5. Form B showed higher solubility and a faster initial dissolution rate than form A at various temperatures in pH 5. The solubility of form B calculated from the initial dissolution rate determined by the stationary-disk and the conventional dispersed-amount methods agreed well. Tablets of form B dissolved more quickly than of those form A. The solubility of the two forms suggest that a difference in their initial dissolution rates affect the bioavailability of piretanide preparations.

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Reaction of a lignans precursor, cinnamyl alcohol (2a), with Weitz' aminium salt, tris(4-bromopheny)aminium hexachloroantimonate, in THF gave cinnamaldehyde (4), a coupling product (5), and a furofuran lignan, (±)-sesamin (6). Similar reactions using related precursors 2b, 3a, 3b gave 7, 8a, 9a, 10a, 11a, and 11b.

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(±)-Isopodophyllotoxin (1e) and related lactones 12, 13, 14 were synthesized by a biomimetic procedure from the doubly unsaturated esters 11a and 11b by means of an oxidative free radical cycloaddition reaction utilizing a stable cation radical salt, Weitz' aminium salt, in one step. (±)-Isopicropodophyllin (1g), the trans-fused lactones, 12, 13, and 16, and the cis-fused lactone 17 were also synthesized from the esters 11c and 11b by the reaction with the same reagent.

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To explore the mechanism of the gastric antisecretion activity of ethyl 2-[(1H-benzimidazol-2-yl)sulfinylmethyl]-4-dimethylamino-5-pyrimidinecarboxylate (5), a potential H⁺/K⁺-ATPase inhibitor, in the acid compartment of parietal cells, its reaction with some alkylthiols in the presence of hydrochloric acid was investigated. Upon treatment with 2-mercaptoethanol under acidic conditions, 5 gave a characteristic 1 : 2 adduct, ethyl 4-[2-(2-hydroxyethyldithio)-1-(2-hydroxyethylthio)ethylidenamino]pyrimido[1, 2-α]benzimidazole-3-carboxylate (6), instead of providing a disulfide of type 3, 2-(2-alkyldithiomethylpyridino)benzimidazolide, the product predicted to be formed according to the reaction mechanism of common H⁺/K⁺-ATPase inhibitors, such as omeprazole or lansoprazole, with mercaptans.With a large excess of 2-mercaptoethanol, 5 provided 2-(2-hydroxyethylthio)-1H-benzimidazole (8) and ethyl 4-dimethylamino-2-(2-hydroxyethyldithio)-5-pyrimidinecarboxylate (9) as well as 6. The transformation mechanisms and their implications are discussed.

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The crystal structure of γ-guanidinobutyric acid (GGBA) monohydrate, C₅H<11>O₂N₃·H₂O, was determined by X-ray diffraction. The cryctals are monoclinic, space group P2₁/a, with cell dimensions, a=7.72(2), b=10.188(8), c=10.686(3)Å, β=96.62(5)° and Z=4. The structure was refined to R=0.057. The molecular conformation is characterized by an extended trans planar zig-zag conformation. The GGBA molecule is a zwitter-ion structure, H₂N⁺=C(NH₂)NH(CH₂)₃COO^-, and the molecules are linked by N-H…O and O-H…O intermolecular hydrogen bonds.

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α-Narcotine (1) was treated with ethyl chloroformate by refluxing in dichloromethane to afford six products, which were separated by preparative high-performance liquid chromatography (HPLC). Their stereochemistry and structures were elucidated. This reaction proceeded initially to the chloro-carbamates and successively to the corresponding carbinols. In addition, N-desmethyl-N-carbethoxynarcotine (3), found in the HPLC chromatogram, was identified by direct comparison with synthetic 3; this compound had caused difficulty in our previous mass spectrometric investigations.

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The esterification of Δ³-cephem-4-carboxylic acid sodium salt (1) with 1-iodoethyl isopropyl carbonate always afforded the Δ² cephem ester (3) as an inseparable minor component. However, in the course of formamido cleavage reaction, the 7-amino-Δ²-cephem ester (5) was observed to be less stable than the Δ³ cephem ester (4), which led us to develop a practical synthetic process for Δ³ cephem esters, including a key intermediate of E1101, a new oral cephalosporin.

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[5, 8-¹³C₂]Spermine and [1, 12-¹³C₂]spermine were prepared using [¹³C]KCN as the source of the label. By reaction of the latter with 1, 2-dibromoethane and ethylene chlorohydrin, the corresponding [1, 4-¹³C₂]succinodinitrile and [CN-¹³C]ethylene cyanohydrin were respectively obtained. The reaction conditions were carefully adjusted so as to optimize the yields of the ¹³C-enriched intermediates. The nitrile residues were then reduced using sodium trifluoroacetoxyborohydride in tetrahydrofuran. [1, 4-¹³C₂]Putrescine and [3-¹³C]3-aminopropanol were thus obtained. The latter was transformed into its [3-¹³C]3-carbobenzyloxyamidopropyl bromide derivative. The syntheses of [5, 8-¹³C₂]spermine from the [1, 4-¹³C₂]putrescine precursor and N-(3-bromopropyl)phthalimide, and of [1, 12-¹³C₂]spermine from N, N'-bisbenzylputrescine and the [3-¹³C]3-carbobenzyloxyamidopropyl bromide precursor were then carried out using our previously reported methods, which were modified so as to maximize the yields of the ¹³C-enriched products.

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1-O-Acetyl-2, 5-di-O-p-chlorobenzoyl-3-deoxy-D-ribofuranose (1), derived from the antibiotic cordycepin was coupled with trimethylsilylated derivatives (2a-c) of N⁴-propionylcytosine, N⁴-p-toluoyl-5-fluorocytosine and 5-fluorouracil in the presence of trimethylsilyl trifluoromethanesulfonate (TMS-triflate) to give fully acylated nucleosides (3a-b and 3d, respectively). Selective removal of the N⁴-propionyl group of 3a by treatment with hydrazine hydrate gave 2', 5'-di-O-p-chlorobenzoyl-3'-deoxycytidine (4). Deamination of 4 with sodium nitrite in trifluoroacetic acid afforded 2', 5'-di-O-p-chlorobenzoyluridine (3c) in good yield. Compounds 3a-d were saponified to give free 3'-deoxycytidine (5a), 5-fluoro-3'-deoxycytidine (5b), 3'-deoxyuridine (5c), and 5-fluoro-3'-deoxyuridine (5d), respectively. These 3'-deoxyribonucleosides (5a-d) were then converted to corresponding 5'-monophosphate and further phosphorylated to the 5'-triphosphates by the phosphoroimidazolidate method.The nucleosides (5a-d) were examined for growth-inhibitory effects on mouse leukemic L5178Y cells, and their IC<50> values (μg/ml) were 1.8, 33, 6.5, and 18, respectively. On the other hand, the antiviral activities of these compounds on a rhabdovirus, infectious hematopoietic necrosis virus (IHNV), were moderate (IC<50>=100-500 μg/ml in CHSE-214 cells). The 5'-triphosphates showed remarkable inhibitory effects on DNA polymerase β and DNA polymerase α-primase purified from testes of the cherry salmon, Oncorhynchus masou, but not on common DNA polymerase α from same source.

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A simple and reliable method has been developed for the determination of residual solvents in drug substances by gas chromatography with thermal desorption cold trap injection. Residual solvents in a sample were desorbed by heating at a temperature higher than the melting point of the sample, then trapped in a cold trap cooled at -130°C. After the cold trap was heated, solvents were injected into an analytical column. These operations were performed automatically by the control unit of the injector. This method is useful for the determination of residual solvents in drug substances because of its high sensitivity without the interference of drug substances. As an example of the application of the method, residual solvents in five drug substances were determined.

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The chemical constituents of the wood of Xanthoxylum nitidum (ROXB.) D. C.(Fagara nitida ROXB.) were examined. Two phenylpropanoids, methyl nitinoate (2) and dihydrocuspidiol (3), and a benzodioxane type lignan, nitidanin (4), were newly isolated. The structures of the phenylpropanoids were chemically determined. In addition, the application of a selective insensitive nuclei enhanced by polarization transfer selective (INEPT) technique in the NMR spectrum to the new lignan allowed us to deduce the structure.

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The critical micelle consentration (CMC) values were datermined by surface tensiometry, and the hydrophobicity index (HI) was calculated. The quantitative relation between the minimum inhibitory concentration (MIC) and the CMC, and the HI was calculated.

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With a view to finding more effective antiulcer agents, a series of 2-benzylthio-5, 6, 7, 8-tetrahydro-4(3H)-quinazolinones and related compounds were synthesized and evaluated in a histamine-stimulated gastric secretion model. The sodium salt of the 2-(dimethylamino)benzylthio derivative (8) showed gastric mucosal protection and gastric antisecretion activities, and was also effective against experimantal gastric and duodenal ulcers induced by some ulcerogenic agents. Based on a comparison of the antiulcer properties of 8 with those of the lead compounds (1 and 2) and cimetidine, it appears that, for improvement of antiulcer activity, the reduction of gastric acidity is a more important factor than the reduction of gastric volume output or gastric total acid output.

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The effects of various substitutents in the phenyl moiety of ortho-, meta-, para-, and disubstituted benzoguanamines on the logarithmic 1-octanol/water partition coefficient, log P, were quantitatively examined by multiple regression analysis. The independent variables first used were empirical hydrophobic, electronic, and steric substituent parameters, π, σ, and E_s respectively. Then, semi-empirical molecular orbital calculation was performed with the use of the AM1 Hamiltonian, and the calculated net charges on hydrogen-bondable atoms were used in place of the σ parameters in the analysis. With empirical σ as well as theoretically calculated electronic parameters, not only statistically but also physicochemically highly significant correlation equations were formulated for benzoguanamine derivatives including the multifunctional 2, 6-diamino-1, 3, 5-triazine skeleton.

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The characteristic diagram for refolding of denatured reduced lysozyme was prepared in terms of recovered activity by employing urea and LiCl concentrations as two axes of rectangular coordinates. The diagram obtained will serve as a new tool not only for the optimum design of refolding media but also for the study of the refolding mechanism.

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Eight new sacculatane-type diterpenoids, named 12-deoxy-1β, 11α-dihydroxy-sacculatanolide (1), 11α-hydroxysacculatanolide (2), pellianolactones A, B, (3, 4), 1β, 11α-dihydroxysacculatanolide (5), 1β-hydroxysacculatal (6), 1β-hydroxy-isosacculatal (7), and 1β-hydroxysacculatanolide (8), have been isolated from the liverwort Pellia endiviifolia.

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Camelliatannin D (1), a new complex tannin which inhibits Ca release from mouse calvaria, was isolated from the leaves and fruits of Camellia japonica L. (Theaceae). This tannin is the first example of complex tannin composed of a dimeric hydrolyzable tannin and a flavan-3-ol.

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