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Kenji INAGAKI, Kimie SAWAKI
1995 Volume 43 Issue 2 Pages
183-188
Published: February 15, 1995
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Reaction products of calf thymus DNA with (1R, 2S, 3S)-3-methylcyclohexanediamineplatinum (abbreviated as Pt(RSS-dach)Cl
2) were investigated by enzymatic degradation of the platinated DNA and subsequent HPLC analysis.Five platinated adducts involving d(GpG), d(ApG) and (dG)
2 residues were identified by HPLC after complete digestion using deoxyribonuclease I, nuclease P1, and alkaline phosphatase. The adducts with d(GpG) and d(ApG)consisted of two geometrical isomers, because Pt(RSS-dach)Cl
2 lacks a C
2 symmetry element. The d(GpG) and d(ApG) adducts were intrastrand compounds crosslinked between the N7 atoms of the adjacent purine bases. The two d(GpG) adducts were most abundant and comprised more than 65% of all the platinated adducts. The relative ratio of the two d(GpG) isomers was 3 : 2 for reaction with DNA, whereas the ratio was 1 : 1 for reaction with a single stranded oligonucleotide. The detailed structure of the two d(GpG) adducts is also described based on NMR spectroscopic data.
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Kaori ANDO, Fumiaki KOIKE, Fumihiro KONDO, Hiroaki TAKAYAMA
1995 Volume 43 Issue 2 Pages
189-192
Published: February 15, 1995
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An improved synthesis of a highly potent vitamin D
3 analog, 24, 24-difluoro-1α, 25-dihydroxyvitamin D
3 (1b)has been accomplished via vitamin D
2-SO
2 adducts. The introduction of fluorine atoms was performed by treating the α-keto ester (11) with diethylaminosulfur trifluoride. The total yield was 12.5% from inexpensive vitamin D
2 in 11 steps. This sequence is sufficiently straightforward to be conducted on a gram scale.
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Tetsuaki TANAKA, Kazuo MURAKAMI, Osamu OKUDA, Tetsuya INOUE, Takeshi K ...
1995 Volume 43 Issue 2 Pages
193-197
Published: February 15, 1995
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A formal total synthesis of (±)-aphidicolin (1) was accomplished starting from the tricyclic ketone (2)corresponding to the B/C/D ring system. The quaternary carbon center adjacent to the spirocarbon was constructed stereoselectively by conjugate addition of a methyl group to the enone (7) obtained from 2 in a four-step sequence.The tetracyclic enone (3) was obtained via acid-catalyzed intramolecular aldol condensation of the tricarbonyl compound (10) followed by 1, 3-carbonyl transposition, in which Pd(0)-catalyzed reductive deacetoxylation of γ-acetoxy-α, β-enone (15) was a crucial step. The A-ring manipulation was performed by a similar procedure to the Ireland method to give the keto-acetonide (4), a degradation product of 1, which has already been efficiently reconverted to 1.
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Hiroyuki AGETA, Yoko ARAI, Hideki SUZUKI, Tamiko KIYOTANI, Miyoe KITAB ...
1995 Volume 43 Issue 2 Pages
198-203
Published: February 15, 1995
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The
1H- and
13C-NMR signals of nine triterpenoid hydrocarbons belonging to the oleanene and migrated oleanene groups together with friedelin were completely assigned by the application of modern NMR techniques, and the conformations of rings D and E are discussed on the basis of Chem3D Plus and MM2 calculations, and nuclear Overhauser effect spectroscopy spectra.
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Shinya KOHRA, Kazuo UEDA, Yoshinori TOMINAGA
1995 Volume 43 Issue 2 Pages
204-209
Published: February 15, 1995
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Reaction of 1-methyl-2-[methylthio(trimethylsilylmethylimino)methylimino]-1, 2-dihydropyridine (1), prepared from 2-amino-1-methyl-pyridinium iodide in 3 steps, with carbonyl compounds in the presence of 2 eq of cesium fluoride in acetonitrile afforded 2-(1-methyl-1, 2-dihydropyridylidene)aminooxazoline derivatives (12), which correspond to formal [3+2] cycloadducts of the aminonitrile ylid. Further, compound 1 reacted with carbonyl compounds in the presence of a catalytic amount of tetra-n-butylammonium fluoride (TBAF) to give corresponding cycloadducts.
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Tomomi IKEMOTO, Akira HAZE, Hiroyuki HATANO, Yoshifumi KITAMOTO, Masat ...
1995 Volume 43 Issue 2 Pages
210-215
Published: February 15, 1995
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The reaction of guanosine and triethyl phosphate at 50°C for 15 min produced the guanosine-triethyl phosphate complex in which triethyl phosphate is coordinated to guanosine of high-anti form in a 1 : 1 molar ratio. During the conversion of guanosine to guanosine 5'-monophosphate with phosphorus oxychloride, the guanosine-triethyl phosphate complex showed excellent selectivity and high reactivity toward phosphorus oxychloride compared with those of guanosine. The rate of selective phosphorylation of guanosine into guanosine 5'-monophosphate was markedly improved by preheating the mixture of guanosine and triethyl phosphate at 50°C, followed by adding phosphorus oxychloride to the mixture at 0°C. Thus, the 5'-phosphorylation of guanosine with phosphorus oxychloride in triethyl phosphate is considered to progress via the guanosine-triethyl phosphate complex as the reaction intermediate.
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Takashi MATSUMOTO, Takashi ISHIDA, Yoshio TAKEDA, Kimiko SOH, Ikumi KU ...
1995 Volume 43 Issue 2 Pages
216-222
Published: February 15, 1995
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1-Isopropylnaphthalene (1) was administered orally to rabbits and the following eight metabolites, 2-(1-naphthyl)-2-propanol (7), 2-(1-naphthyl)-1-propanol (8 : R/S=83 : 17), 2-(1-naphthyl)-1, 2-propanediol (9 : R/S=40 : 60), 4-isopropyl-1, 2-naphthoquinone (10), 4-isopropyl-1-naphthol (11), 4-isopropyl-2-naphthol (12), 5-isopropyl-2-naphthol (13), and 2-(1-naphthyl)propanoic acid (14') as its methyl ester (14 : R/S=52 : 48), were isolated from urine. Among them, three metabolites (8, 9, and 14), possessing an asymmetric carbon atom in the molecule, were formed enantioselectively and five metabolites (7, 10, 11, 12, and 13) were formed regioselectively.The presumed metabolic pathways of 1-isopropylnaphthalene (1) in rabbits leading to these metabolites are discussed.
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Qing HUANG, Yasuhiro TEZUKA, Tohru KIKUCHI, Arasuke NISHI, Keisuke TUB ...
1995 Volume 43 Issue 2 Pages
223-229
Published: February 15, 1995
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Four peptaibols, named trichokonins (TKs) V, VI, VII, and VIII, were isolated from the culture broth of Trichoderma koningii OUDEMANS. Primary structures of these peptaibols were elucidated by electrospray ionization mass spectrometry (ESI-MS), FAB-MS and collision-induced dissociation (CID) techniques along with nuclear Overhauser enhancement spectroscopy (NOESY).
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Fumio ITOH, Koichi YUKISHIGE, Megumi WAJIMA, Koichiro OOTSU, Hiroshi A ...
1995 Volume 43 Issue 2 Pages
230-235
Published: February 15, 1995
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Either the α- or γ-carboxyl group of the glutamic acid moiety of N-[4-[3-(2, 4-diamino-7H-pyrrolo[2, 3-d]pyrimidin-5-yl)propyl]benzoyl]-L-glutamic acid (1b, TNP-351) and its related compound (1a) was replaced with a 1H-tetrazle ring, and the inhibitory effects of the resulting compounds on dihydrofolate reductase (DHFR) and the growth of murine fibrosarcoma Meth A cells were examined. The γ-tetrazole analogs (2) were found to be much more potent DHFR inhibitors than TNP-351, and strongly inhibited the growth of Meth A cells. On the other hand, the α-tetrazole analogs (3) were much less active against Meth A cells, even though their DHFR-inhibitory activity was comparable to that of TNP-351. These findings suggest that the α-carboxyl group plays an important role in effective uptake via the reduced folate carrier, and a novel DHFR inhibitor could be obtained by chemically modifying the γ-carboxyl moiety while leaving the α-carboxyl group intact.
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Masahisa YAMAGUCHI, Noriaki MARUYAMA, Takaki KOGA, Kenshi KAMEI, Michi ...
1995 Volume 43 Issue 2 Pages
236-240
Published: February 15, 1995
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Synthesis and pharmacological evaluation of novel thienopyridazinones and related compounds are described.A thiophene ring was found to be able to replace the benzene ring of a phthalazinone without loss of biological activities. This observation supports our hypothesis that the benzene ring plays an important role in both thromboxane A
2 (TXA
2) synthetase-inhibitory and bronchodilatory activities. Further, it was shown that the carbonyl moiety of a phthalazinone is not necessary for these activities.
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Yutaka NOMURA, Tomio YAMAKAWA, Koichiro NISHIOKA, Tomohiro OMURA, Nori ...
1995 Volume 43 Issue 2 Pages
241-246
Published: February 15, 1995
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A series of 2-(4-benzhydryl-1-piperazinyl)-1-phenylethanols (4) was synthesized and evaluated for calcium entry-blocking activity, assessed as inhibitory activity on calcium current in rat hippocampal pyramidal neurons by using a patch-clamp technique (10
-5 M), and cerebral visodilating activity, assessed in terms of increase of vertebral blood flow after intravenous administration (1 mg/kg) in anesthetized dogs. Alkoxy substituents on the phenyl ring of the phenylethanol moiety conferred potent calcium entry-blocking activity and potent cerebral vesodilating activity.Among these compounds, 4i (NC-1100) was selected as the best analog. Some pharmacological properties of 4i are presented.
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Toshimi SEKI, Takayuki TAKEZAKI, Rikio OHUCHI, Hiroshi OHUYABU, Yoshit ...
1995 Volume 43 Issue 2 Pages
247-255
Published: February 15, 1995
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A series of phenoxypropanolamines having a hydrazinopyridazinyl moiety was synthesized. Their hypotensive and β-blocking activities were evaluated after intravenous administration of the compounds to anethetized rats.Some of them exhibited both activities. In particular, compound 20k is a candidate for clinical use due to its hypotensive activity, equal to that of hydralazine, and its β-blocking activity, 2.7-fold more potent than that of propranolol.
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Kazuyoshi ASO, Takenori HITAKA, Koichi YUKISHIGE, Koichiro OOTSU, Hiro ...
1995 Volume 43 Issue 2 Pages
256-261
Published: February 15, 1995
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Novel pyrrolo[2, 3-d]pyrimidine antifolates (1a, b and 2a, b) with a nitrogen atom in the bridge chain between the 2, 4-diaminopyrrolo[2, 3-d]pyrimidine and phenylene rings were designed and efficiently synthesized. These compounds exhibited more potent inhibitory activities than methotrexate (MTX) against the proliferation of human epidermoid carcinoma KB cells and human non-small cell lung carcinoma A549 cells despite their modest dihydrofolate reductase (DHFR)-inhibitory potency.
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Yoshihiro ABE, Tomoko SHOJI, Michi KOBAYASHI, Qing WANG, Naoko ASAI, H ...
1995 Volume 43 Issue 2 Pages
262-265
Published: February 15, 1995
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Racemic amino-alcohols such as pindolol, propranolol, alprenolol and bucumolol enantiomers exhibited different distribution behaviors in a two-phase system consisting of a chloroform solution of didodecyl L-tartrate and an aqueous solution of boric acid. It seemed that a borate complex of the 1, 2-diol group of the tartrate and the amino-alcohol was formed in the system. In the case of pindolol, one enantiomer was preferentially extracted into the organic phase (×2.20) at equilibrium.
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Kouichi KASAI, Kiyoshi OKADA, Nobuyuki YAMAJI
1995 Volume 43 Issue 2 Pages
266-270
Published: February 15, 1995
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Four N-acetyl-β-D-glucosaminides, 4-amino-2, 6-dibromophenyl (1a), 4-amino-2, 6-dichlorophenyl (1b), 4-amino-2-chlorophenyl (1c) and 4-aminophenyl N-acetyl-β-D-glucosaminides (1d) were synthesized. Substrates 1a-c were hydrolyzed by N-acetyl-β-D-glucosaminidase and the released aglycones reacted with N-ethyl-N-(3-methylphenyl)-N'-succinylethylenediamine to produce indoaniline dyes in the presence of bilirubin oxidase under weakly acidic rate-assay conditions (pH 5.0). The K
m values for 1a-c were 1.97, 1.65 and 1.39 mM, respectively. Among these compounds, 1b is considered to be the substrate with most potential for the rate-assay of N-acetyl-β-D-glucosaminidase, since it showed the largest V
max value and the strongest color generation from colorless to green (λ
max 302→718 nm)following enzyme hydrolysis and the coupling reaction. Furthermore, 1b was moderately soluble and stable in aqueous solution and exhibited about a 5.9-fold higher sensitivity to the enzyme than 2-chloro-4-nitrophenyl N-acetyl-β-D-glucosaminide.
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Hiroshi MORITA, Shinji NAGASHIMA, Koichi TAKEYA, Hideji ITOKAWA
1995 Volume 43 Issue 2 Pages
271-273
Published: February 15, 1995
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A new peptide called astin J (1) was isolated from the roots of Aster tataricus. The structure was elucidated by spectroscopic methods and chemical transformation from a cyclic pentapeptide, astin C, isolated from A. tataricus to the analogous acyclic peptide, 2. Antileukemic activities of the series of acyclic peptides are also described.
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Kyung Soo KO, Yutaka EBIZUKA, Hiroshi NOGUCHI, Ushio SANKAWA
1995 Volume 43 Issue 2 Pages
274-278
Published: February 15, 1995
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Hairy root cultures of three Cassia plants, Cassia torosa, C. occidentalis and C. obtusifolia were induced by infection with Agrobacterium rhizogenes and were esteblished to investigate their production and biosynthesis of phenolic pigments of polyketide origin. The hairy root cultures produced pigments similar to those of the mother plants; however, the contents of each pigment was varied by growth conditions. Incorporation experiments using stable isotopes in C. torosa hairy root cultures revealed the high biosynthetic activity of germichrysone.
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Akiko KUSANO, Kei SHIMIZU, Mayumi IDOJI, Makio SHIBANO, Katsuhiko MINO ...
1995 Volume 43 Issue 2 Pages
279-283
Published: February 15, 1995
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Three new cycloartane xylosides were isolated from the aerial parts of Cimicifuga simplex, and their structures were elucidated as 23-O-acetyl-1α-hydroxyshengmanol 3-O-β-D-xylopyranoside, 25-O-acetyl-1α-hydroxycimigenol 3-O-β-D-xylopyranoside and 1α-hydroxycimigenol 3-O-β-D-xylopyranoside.
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Takehisa HANAWA, Atsushi WATANABE, Takanori TSUCHIYA, Rieko IKOMA, Mas ...
1995 Volume 43 Issue 2 Pages
284-288
Published: February 15, 1995
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The pharmaceutical utility of silk fibroin as a possible material for an oral dosage form for elderly patients was investigated. Silk fibroin gel (SFG) was prepared from its aqueous solution. The gel formation was studied as a function of adjusted pH and concentration of silk fibroin (SF). On the basis of Fourier transform infrared spectroscopy of SFG, the transition from the random coil to the β-structure was observed. The rate of gelation was sufficiently accelerated by the addition of glycerol to the SF aqueous solution. The glycerol content also affected the rate of gelation of the SF solution. Rheological properties of SFG were evaluated using a creep meter. The SF content and/or glycerol content affected the breaking stress of SFG. Moisture desorption from SFG was retarded with an increase in glycerol content. It was found that SFG was able to be prepared at room temperature (20±5°C), and the SF content and glycerol content affected the formation and physicochemical properties of SFG.
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Mei-Lin GO, Tong-Lan NGIAM, James A. ROGERS
1995 Volume 43 Issue 2 Pages
289-294
Published: February 15, 1995
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The thermodynamics of the partitioning of 7-chloro-4-(4'-methoxy)anilinoquinoline (I) and its cyclized analogue, 3-chloro-8-methoxy-11H-indolo[3, 2-c]quinoline (II) have been determined in octanol-buffer and liposome systems.Under the conditions of partitioning, the protonated forms of compounds I and II were predominant, but partitioning involved only the non-ionized species. The van't Hoff plots for both compounds were linear in the octanol-buffer system from 11° to 35°C. The log P of compound I increased with temperature, and partitioning was entropically controlled.In contrast, the partitioning of compound II decreased with temperature and was enthalpically driven. The van't Hoff plots of compounds I and II in the dimyristoyl-L-α-phosphatidylcholine (DMPC) liposome-buffer were biphasic.A decrease in log P was observed from 13°C to approximately the T
c of the phospholipid, followed by a subsequent increase in log P as temperature increased to about 32°C. In the case of compound I, partitioning was entropically controlled at temperatures below and above T
c. In contrast, the partitioning of compound II was enthalpically controlled below T
c but entropically driven above T
c. The thermodynamics of the partitioning of compounds I and II in octanol and gel phase phospholipid (below T
c) are similar. This may be attributed to their conformational differences. The planarity and rigidity of compound II allows it to interact well with the ordered matrices of octanol and phospholipid with an expected loss of enthalpy. In contrast, the twisted conformation of compound I would have disrupted the ordered matrices of the octanol and phospholipid phases, resulting in an entropy gain upon partitioning.This study shows that the molecular shape and conformational characteristics of solute molecules are important determinants in the partitioning process.
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Xian-Rong QI, Yoshie MAITANI, Naoto SHIMODA, Kumiko SAKAGUCHI, Tsuneji ...
1995 Volume 43 Issue 2 Pages
295-299
Published: February 15, 1995
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We encapsulated erythopoietin (Epo) in dipalmitoylphosphatidylcholine (DPPC) liposomes with soybean-derived sterols (SS-liposomes) and its glucoside (SG-liposomes) by reverse-phase evaporation vesicle method, and evaluated them by subcutaneous administration in rats. With 4 min of sonication, the damage to Epo activity was observed mainly in the non-encapsulated Epo in the liposomes. This study indicated that the bilayer of liposomes had the ability to protect the Epo activity, by reducing the aggregation that was caused by interaction between Epo molecules. The SG-liposomes had a higher retention of the Epo activity than SS-liposomes. 25.3% or 33.6% of activity was retained by SS-liposomes under the conditions of 4 min or 1 min of sonication, while 53.3% or 58.3% of the activity was retained by SG-liposomes under the same conditions. Shorter sonication was available to minimize the loss of the Epo activity. Epo in SG-liposomes appeared to increase the activity.
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Yukio ASO, Sumie YOSHIOKA, Tomoko OTSUKA, Shigeo KOJIMA
1995 Volume 43 Issue 2 Pages
300-303
Published: February 15, 1995
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The applicability of isothermal microcalorimetry to evaluation of the physical stability of amorphous nifedipine was examined. Amorphous nifedipine was obtained by fusion and subsequent rapid cooling, and its crystallization heat at a constant temperature was measured using a heat-conductive microcalorimeter. The heat production due to crystallization of amorphous nifedipine and the transformation of its metastable crystalline form into a stable crystalline one was detected at a temperature above its glass transition temperature T
g). The time required for half an amorphous nifedipine sample to be crystallized (t
50) was calculated from the heat production time profile, and the reciprocal of t
50 (1/t
50) was used as a measure of the crystallization rate, which increased as the temperature increased. The Williams, Landel and Ferry (WLF) plot of 1/t
50 was linear, indicating that the crystallization rate was affected by the nifedipine matrix viscosity, which decreased as the temperature increased. Moisture decreased the T
g of the fused nifedipine and increased its crystallization rate. The effects of temperature and humidity can be interpreted by changes in the matrix viscosity, which is related to the molecular motion of nifedipine.
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Yorinobu YONEZAWA, Shuichi KAWASE, Midori SASAKI, Itaru SHINOHARA, His ...
1995 Volume 43 Issue 2 Pages
304-310
Published: February 15, 1995
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The derivation of equations available for the treatment of a dissolution process of a monodisperse system with an optional initial amount within solubility was attempted. Two kinds of dissolution equations were derived as a function of the initial amount used in the dissolution test by using MacLaurin's expansion. When the initial amount is equal to one-third of the solubility, a semilogarithm form dissolution equation was deduced as was abbreviated as the Ln-z equation. When the initial amount is an amount other than one-third of the solubility, the derived equation was expressed by a form which included the cube root law and negative two-thirds law equations, and was abbreviated as the z-law equation. Also, the Langmuir form dissolution equation was obtained as an extended application form of the z-law equation, and was abbreviated as the Lg-z equation.Since the applicability or validity of the z-law equation was examined in a previous paper, the applicabilities of the Ln-z equation and the Lg-z equation were examined in this paper. As a result, it was suggested that the dissolution rate constant of a substance can be determined by dissolution measurement with an optional initial amount, and once the dissolution rate constant is determined in advance, the dissolution process of the substance with any optional initial amount within solubility can be approximately predicted.
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Mitsuyuki MATSUO, Chizuko NAKAMURA, Kazuhiko ARIMORI, Masahiro NAKANO
1995 Volume 43 Issue 2 Pages
311-314
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Delayed-release tablets of diltiazem hydrochloride (DIL) were prepared by using AL-15 type hydroxyethycellulose(HEC) as a matrix material. The tablet consisted of a core tablet containing 30 mg of DIL and an outer shell formed by compressing HEC. The lag time to start the rapid release of DIL was more prolonged in the tablets consisting of a smaller particle size (20-53 and 53-106 μm) of HEC than those of the larger particle size(106-250 and 250-355 μm). However, there was little difference in the release rate of DIL among the two kinds of tablets. The rate of water uptake was greater in the tablets prepared with the larger particle size than those with the smaller particle size. These results suggest that the rate of water uptake seems to be a rate limiting process in setting the lag time. Observation of the surface of the tablets by electron micrograph showed that with the larger the particle size the cavity grows larger and with the smaller the particle size the cavity grows smaller.The lag time was also prolonged with an increase in the amount of HEC. Consequently, the lag time can be controlled optionally by changing the particle size and/or the amount of HEC forming the outer shell. This delayed-release system using HEC will be useful for time-related symptoms which need time-controlled or site-specific delivery in the gastrointestinal tract.
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Yoshimasa KAMIKAWAJI, Ryozo SAKODA, Kiyotomo SETO
1995 Volume 43 Issue 2 Pages
315-317
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On hydrolysis of the calcium antagonist, 2-(N-benzyl-N-phenylamino)ethyl 5-(5, 5-dimethyl-2-oxo-1, 3, 2-dioxaphosphorinan-2-yl)-1, 4-dihydro-2, 6-dimethyl-4-(3-nitrophenyl)pyridine-3-carboxylate hydrochloride ethanol (NZ-105 1·HCl·EtOH) in 35% hydrochloric acid, the 1, 4-dihydropyridine ring was transformed to a cyclohexeone ring, affording the cyclohexenonephosphonates 2 and 3.
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Masaru KIHARA, Takashi OZAKI, Shigeru KOBAYASHI, Tetsuro SHINGU
1995 Volume 43 Issue 2 Pages
318-320
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Two new alkaloids, 3-O-acetylnarcissidine (4) and 3-O-acetylnarcissidine N-oxide (5), were isolated from Leucojum autumnale L. (Amaryllidaceae) together with the known alkaloids narcissidine (3) and lycorine (6).
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Tozo FUJII, Kazuo OGAWA, Tohru SAITO, Taisuke ITAYA, Tadamasa DATE, Ki ...
1995 Volume 43 Issue 2 Pages
321-324
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Oxidation of 1-benzyladenine (12) with m-chloroperoxybenzoic acid in MeOH or in MeOH-0.5 M phosphate buffer (pH 6.6) has been found to afford 1-benzyladenine 7-oxide (13) as the main product. Nonreductive debenzylation of 13 gave adenine 7-oxide (14) in 63% yield. The structure of 13 was unequivocally established by an X-ray crystallographic analysis.
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Tozo FUJII, Yasutaka TAKADA, Kazuo OGAWA, Taisuke ITAYA, Satoshi MATSU ...
1995 Volume 43 Issue 2 Pages
325-327
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Treatment of N
6-benzyladenine (2) with 15% aqueous H
2O
2 in trifluoroacetic acid at 65-70°C for 1 h was found to give the N(3)-oxide (3) and the N(7)-oxide (4) in 4% and 4% yields, respectively. The structure of 3 was established by its identity with a sample prepared from 6-chloropurine 3-oxide (6) and benzylamine, and the structure of 4 by its identity with a sample obtained from 1-benzyladenine 7-oxide (8) by Dimroth rearrangement. The N-oxides 3 and 4, together with previously reported N
6-benzyladenine 1-oxide (1), were tested for cytokinin activity in the tobacco callus bioassay. Each of the three N-oxides was active at 4 μM concentration, being less active than the parent base 2 by a factor of 40.
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Tozo FUJII, Kazuo OGAWA, Tohru SAITO, Taisuke ITAYA
1995 Volume 43 Issue 2 Pages
328-331
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In contrast to the N(3)-selectivity in N-alkylation, N-oxidation of 7-benzyladenine (17) with m-chloroperoxybenzoic acid in MeOH has been found to give 7-benzyladenine 1-oxide (18) in 76% yield. Alternatively, the same N-oxide (18) has been synthesized in 81% yield from 1-benzyl-4-(ethoxymethyleneamino)imidazole-5-carbonitrile(19) and hydroxylamine. Treatment of 1-benzyl-4-(hydroxyamino)imidazole-5-carbonitrile (24), obtained in 63% yield from the corresponding 4-nitro drivative (20) by catalytic hydrogenation (Pt/H
2), with formamidine acetate in boiling EtOH furnished 7-benzyladenine 3-oxyde (23) in 78% yield. A UV spectroscopic approach indicated that the neutral species of 18 exists in H
2O in the N(1)-oxide form rather than the N(1)-OH form (27).
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Masahisa YAMAGUCHI, Noriaki MARUYAMA, Takaki KOGA, Kenshi KAMEI, Michi ...
1995 Volume 43 Issue 2 Pages
332-334
Published: February 15, 1995
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Synthesis and pharmacological evaluation of novel indazole derivatives are described. These compounds were found to exhibit both thromboxane A
2 (TXA
2) synthetase-inhibitory and bronchodilatory activities. This observation supports the idea that the partial structure of the 3-pyridyl and phenyl groups with a methylene insertion is an important component for well-balanced activities.
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Hisatoshi YOSHIDA, Noriyuki USAMI, Yasumasa OHISHI, Kazuhito WATANABE, ...
1995 Volume 43 Issue 2 Pages
335-337
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Eight halogenated drivatives of cannabinol (CBN) substituted on the aromatic ring at the 2 and/or 4 position were synthesized and their pharmacological effects were evaluated by intracerebroventricular injection (50 μg/mouse)in mice, using hypothermia, pentobarbital-induced sleep prolongation, catalepsy and anticonvulsant effect as indices.The hypothermic effects of monohalogenated drivatives of CBN were comparable to that of CBN, whereas the effects of dihalogenated derivatives of CBN except for the fluorinated derivative were attenuated. In the interaction with pentobarbital, two monochlorinated derivatives exhibited a significant prolongation of sleeping time, although other derivatives did not significantly affect the sleeping time. The cataleptogenic effects of monofluoro- and 4-bromo-CBN were stronger than that of CBN. 4-Bromo-CBN exhibited a significant prolongation of seizure latency induced by pentylenetetrazol. These data suggest that halogenation of CBN modifies the pharmacological profile of the cannabinoid.
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John DE BRITTO, Visuvasam Soosai MANICKAM, Subbarayan GOPALAKRISHNAN, ...
1995 Volume 43 Issue 2 Pages
338-339
Published: February 15, 1995
Released on J-STAGE: March 31, 2008
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Three dihydroflavonol glycosides, 3-O-α-L-rhamnosides of (2S, 3S)-, (2R, 3R)- and (2R, 3S)-5, 7, 3', 4'-tetrahydroxydihydroflavonol, were isolated from Sphaerostephanos arbuscula as the first example of dihydroflavonols from ferns. Aglycone chirality was determined by
1H-NMR data.
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Hiraku ONISHI, Yoshiharu MACHIDA, Tsuneji NAGAI
1995 Volume 43 Issue 2 Pages
340-343
Published: February 15, 1995
Released on J-STAGE: March 31, 2008
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The mixture of 2'-O-(4-carboxybutyryl)-5-fluorouridine (2'-glu-FUR) and 3'-O-(4-carboxybutyryl)-5-fluorouridine (3'-glu-FUR), named (glu-FUR(I)), and 5'-O-(4-carboxybutyryl)-5-fluorouridine (5'-glu-FUR), named glu-FUR(II), were easily obtained from the reaction of 5-fluorouridine (FUR) with glutaric anhydride. In addition, the chitosan-glu-FUR(I) conjugate and the chitosan-glu-FUR(II) conjugate were prepared. The obtained compounds were investigated regarding their in vitro characteristics. Equilibrium between 2'-glu-FUR and 3'-glu-FUR was suggested to be attained quickly in a 1/15 M phosphate buffer of pH 7.4. Glu-FUR(II) was found to be introduced into chitosan more easily than glu-FUR(I). For every compound, chemical hydrolysis was accelerated at weakly basic pH and a gradual regeneration of FUR was observed at physiological pH.
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Kazuo NAGASAWA, Asami YAMASHITA, Satoru KATOH, Keiichi ITO, Kohji WADA
1995 Volume 43 Issue 2 Pages
344-346
Published: February 15, 1995
Released on J-STAGE: March 31, 2008
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N-(Coumarin-4-yl)-L-proline[CPRO-1], readily prepared from commercially available Cbz-L-proline and 4-hydroxycoumarin, was proved to be an efficient and useful chiral derivatizing agent by
1H NMR inspection of the resulting diastereomeric esters and amides.
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Hiroyuki MINAMI, Emi TAKAHASHI, Yoshiyasu FUKUYAMA, Mitsuaki KODAMA, T ...
1995 Volume 43 Issue 2 Pages
347-349
Published: February 15, 1995
Released on J-STAGE: March 31, 2008
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Two new xanthones, garciniaxanthone D (1) containing a dihydrobenzofran ring and 1, 4, 5-trihydroxyxanthone (2), have been isolated from Garcinia subelliptica as superoxide anion scavengers. Their structures have been determined mainly by spectroscopic methods and some chemical reactions.
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Masayuki YOSHIKAWA, Toshiyuki MURAKAMI, Takahiro UENO, Masashi KADOYA, ...
1995 Volume 43 Issue 2 Pages
350-352
Published: February 15, 1995
Released on J-STAGE: March 31, 2008
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New inhibitors of ethanol absorption, E-senegasaponins a and b, Z-senegasaponins a and b, Z-senegins II and III, were isolated from Senegae Radix, the roots of Polygala senega L. var latifolia TORREY et GRAY, together with senegins II and III. Their chemical structures have been elucidated on the basis of chemical and physicochemical evidence, and the geometrical isomeric structures of methoxycinnamoyl moiety in each saponin were found to show tautomer-like behavior. The inhibitory effects of senegasaponins, senegins, and their related compounds have been examined, and some structure-activity relationships have been found.
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Yasushi MATSUMURA, Tomoyuki ASAI, Toyomichi SHIMADA, Toshiaki NAKAYAMA ...
1995 Volume 43 Issue 2 Pages
353-355
Published: February 15, 1995
Released on J-STAGE: March 31, 2008
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Novel fluoroprostacyclin analogs (1a-f) have been synthesized and pharmacologically evaluated. Compounds 1a-c given intravenously or orally showed potent and long-lasting anti-anginal activities in an animal model.
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Hideo TANAKA, Hiroyuki KAGECHIKA, Koichi SHUDO
1995 Volume 43 Issue 2 Pages
356-358
Published: February 15, 1995
Released on J-STAGE: March 31, 2008
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Treatment of retinoic acid (1a) or its methyl ester (2a) with hydrochloric acid in methanol gave methyl 4-oxo-retinoates (4a-c). Similar oxidation proceeded when 2a was treated with trifluoromethanesulfonic acid in the presence of lithium chloride in methanol.
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Jun-ichi UEDA, Akira HANAKI, Terumi NAKAJIMA
1995 Volume 43 Issue 2 Pages
359-361
Published: February 15, 1995
Released on J-STAGE: March 31, 2008
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The copper ions in the imidazole-clusters of histidine-oligopeptide, His(His)
nGly(n=18) and N-acetyl-His(His)
nGly(n=8 and 18), showed the d-d transition bands at 520 nm and 630 nm and oxidase-like activities. Those with the d-d bands at 480 nm and 550 nm did not have the activity.
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Masataka IHARA, Fumihito SETSU, Yuji TOKUNAGA, Keiichiro FUKUMOTO, Yos ...
1995 Volume 43 Issue 2 Pages
362-364
Published: February 15, 1995
Released on J-STAGE: March 31, 2008
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Indirect electroreductive cyclization of η-bromo-α, β-unsaturated esters 1-6 using Co(III) or Ni(II)complex as an electron-transfer catalyst provided the six membered compounds 7-12, which are useful synthetic intermediates of several indole and ipecac alkaloids.
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Isao KITAGAWA, Taifo MAHMUD, Motomasa KOBAYASHI, ROEMANTYO, Hirotaka ...
1995 Volume 43 Issue 2 Pages
365-367
Published: February 15, 1995
Released on J-STAGE: March 31, 2008
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Through bioassay-guided separation of the chemical constituents of the needles of Taxus sumatrana, taxol (1), cephalomannine (2), and a new taxoid 19-hydroxy-13-oxobaccatin III (8) have been isolated together with 7-epi-10-deacetyltaxol (3), 7-epi-10-deacetylcephalomannine (4), baccatin III (5), 19-hydroxybaccatin III (6), and 10-deacetyl-13-oxobaccatin III (7). The chemical structure of 8 has been elucidated on the bases of its chemical and physicochemical properties.
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