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Volume 48, Issue 5
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Yueh-Hsiung KUO, Yi-Ming CHIANG2000 Volume 48 Issue 5 Pages 593-596
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFour new ursane-type triterpenes, 3β-acetoxy-11α-methoxyl-12-ursene (1), 3β-acetoxy-11α-ethoxy-12-ursene (2), 3β-acetoxy-11α-hydroperoxy-12-ursene (3), 3β-hydroxy-11α-hydroperoxy-12-ursene (4), and two new oleanane-type triterpenes, 3β-acetoxy-11α-ethoxy-12-oleanene (5), 3β-acetoxy-11α-hydroperoxy-12-oleanene (6), together with 3β-acetoxy-11α-hydroxy-12-ursene (7), 3β, 11α-diacetoxy-12-ursene (8), 3β-acetoxy-11α-hydroxy-12-oleanene (9), were isolated from the aerial roots of Ficus microcarpa L. f. Their structures were elucidated by spectroscopic and chemical methods.View full abstractDownload PDF (654K) -
Yueh-Hsiung KUO, Chi-I CHANG, Ching-Kuo LEE2000 Volume 48 Issue 5 Pages 597-599
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSix podocarpane-type trinorditerpenes were isolated from the bark of Taiwania cryptomerioides. Thier structures, 14-hydroxy-13-methoxy-8, 11, 13-podocarpatrien-7-one (1), 13-hydroxy-12-methoxy-8, 11, 13-podocar-patriene (2), 12-hydroxy-13-methoxy-8, 11, 13-podocarpatriene (3), 14-hydroxy-13-methoxy-8, 11, 13-podocarpatriene (4), 13-hydroxy-8, 11, 13-podocarpatriene (5), and 13, 14-dihydroxy-8, 11, 13-podocarpatrien-7-one (6), were determined principally from spectral evidence.View full abstractDownload PDF (595K) -
Abd-Elgawad RADI, Amira HASSANEIN2000 Volume 48 Issue 5 Pages 600-602
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSCyclic voltammetry was used to explore the adsorption behavior of secnidazole on a hanging mercury drop electrode (HMDE). The effects of various operational parameters on the accumulation behavior of the adsorbed species were tested. Thus, a sensitive stripping voltammetry procedure for the determination of secnidazole with an adsorptive accumulation on the surface of HMDE has been developed. Measurements were taken by differential-pulse voltammetry after determination of the optimum conditions. The linear concetration range was 1×10-8-1×10-7M when using a 120 s preconcentration at -0.1 V vs. Ag/AgCl in acetate buffer of pH 4.0. The detection limit of secnidazole was 5×10-9M. The precision, expressed by the coefficient of variation, was 2.5% (n=10) at a concentration of 1×10-7M. The method was successfully applied to the analysis of secnidazole in urine.View full abstractDownload PDF (504K) -
Shigeki HASHIMOTO, Takahiro INUI, Yushin NAKAMURA2000 Volume 48 Issue 5 Pages 603-609
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo types of distamycin-linked hydroxamic acids (DHA), which contain various lengths of polymethylene chains (PM-DHA) and relatively rigid phenylene ones (Ph-DHA), have been synthesized for the first time. Their DNA cleavage specificities were investigated by an end-labeled fragment cleavage experiment in the presence of vanadyl ion and hydrogen peroxide. The DNA cleavage by the PM-DHA·VO(II) complexes was shown to be very dependent on the length of the chain and the AT sequences. The tetramethylene DHA (1b) complex exhibited highly specific cleavage patterns flanking the 8 and 10 AT sites. Interestingly, the Ph-DHA complexes selectively cleaved the 5' end-labeled strand at the AT sites, but did not cleave the 3' end-labeled strand. The vanadyl complexing moieties and the local sequence conformation of the AT tract are suggested to contribute significantly to the DNA recognition of the PM-DHA·VO(II) complexes.View full abstractDownload PDF (1503K) -
Kazunori MURAMATSU, Toshiki MASUMIZU, Yoshie MAITANI, Sung Hee HWANG, ...2000 Volume 48 Issue 5 Pages 610-613
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe effects of soybean-derived sterylglucoside (SG) on the fluidity of liposomal membrane composed of dipalmitoylphosphatidylcholine (DPPC) were investigated compared with those of soybean-derived sterol (SS) and cholesterol (Ch) using an electron spin resonance spectrometer. Three kinds of liposomes were prepared in the molar ratio of DPPC/X=7/4, where X is SS, Ch or SG. The fluidity close to the polar head groups increased with an increase of temperature in the DPPC membrane containing SS, Ch and SG in the range 35 to 45°C. Those near the hydrophobic end changed with an increase in temperature in liposomes containing SS, Ch and SG, which had a fluidizing effect on the DPPC membrane below the transition temperature (Tm, 41.9°C) and a condensing effect over the Tm. The fluidizing effects of these compounds around 37°C near the polar head group and the hydrophobic end increased in the following order : Ch<SG≤SS and SS<Ch<SG, respectively. SG increased the fluidity of liposomal membrane dramatically above the Tm (35.4°C). These results suggest that the high fluidity close to the hydrophobic end of the liposomal membranes around 37°C, the decrease of Tm, and the sigmoidal nature of fluidity vs. temperature are important factors in the effectiveness of liposomes containing SG as a carrier of drugs.View full abstractDownload PDF (653K) -
Hak Cheol KWON, Nam In BAEK, Sang Un CHOI, Kang Ro LEE2000 Volume 48 Issue 5 Pages 614-616
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThree new butanolides, 2-(1-methoxy-11-dodecenyl)-penta-2, 4-dien-4-olide (1), (2Z, 3S, 4S)-2-(11-dodecenylidene)-3-hydroxy-4-methylbutanolide (2) and (2E, 3R, 4R)-2-(11-dodecenylidene)-3-hydroxy-4-methoxy-4-methyl-butanolide (3), were isolated from the stems of Lindera obtusiloba BLUME. Their chemical structures were assigned by spectroscopic evidence. They exhibited cytotoxicity against cultured human tumor cell lines with their ED50 values ranging from 3.19 to 14.63 μg/ml.View full abstractDownload PDF (517K) -
Masato SHIGEYAMA, Toyoaki OHGAYA, Yoshiaki KAWASHIMA, Hirofumi TAKEUCH ...2000 Volume 48 Issue 5 Pages 617-622
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSModification to find the best physicochemical properties of minocycilne hydrochloride ointment for optimum treatment of bedsore was investigated by coformulating various types of cyclodextrins (CyD) in the ointment base. It was found that the drug release rate from the ointment base was modified according to the preparation method of ointment base and the type of CyD admixed. The physicochemical properties, such as viscosity, elution volume, water absorption of ointment bas were also modified by those factors. The mechanism of physicochemical modification with CyD was explanied by the structural change of ointment base and the change of surface tension of emulsifying agent solution with the CyD. The stability of ointment was investigated by confirming the reproducibility of drug release rate after storage at ambient and cooled temperature conditions. In conclusion, a fused mixed ointment with β-CyD was found to be preferable for treatment of bedstore, because of the improved drug release rate, lowered viscosity and increased elution volunme of the resultant ointment.View full abstractDownload PDF (1227K) -
Akira MIZUNO, Atsto OGATA, Tomoe KAMEI, Makoto SHIBATA, Tetsuo SHIMAMO ...2000 Volume 48 Issue 5 Pages 623-635
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of 5-aminoalkylpyrrolo[3, 2-c]azepine derivatives was synthesized and their serotonin 2 (5-HT2) receptor antagonist and antiplatelet aggregation activities were evaluated. 5-HT2 receptor antagonist activity was largely determined by the nature of the substituent at the 8-position as well as aminoalkyl group at the 5-position of the pyrrolo[3, 2-c]azepine ring.Compound 18a, 5-[3-]4-(4-fluorophenyl)piperazin-1-yl]propyl]-8-hydroxy-1-methyl-1, 4, 5, 6, 7, 8, -hexahydropyrrolo[3, 2-c]azepin-4-one, was recognized as having potent 5-HT2 receptor antagonist activity with weak α1 adrenoceptor blocking activity and no significant D2 receptor binding affinity, while the corresponding isomeric pyrrolo[3, 4-c]azepine derivative (22) displayed only weak 5-HT2 receptor antagonist activity. After racemic 18a was resolved directly via diastereomeric salt formation, each enantiomer was evaluated precisely. The 5-HT2 receptor antagonist activity of 18a was found to reside primarily in (-)-18a (which was about 14-fold more potent than (+)-18a in isolated guinea pig arteries). Consequently, (S)-(-)-18a (SUN C5174) displayed the overall best profile with potent 5-HT2 receptor antagonist activity (pA2=8.98±0.06) and high selectivity versus other receptors.SUN C5174 showed a marked inhibitory effect on the platelet aggregation induced by serotonin in combination with collagen and adenosine diphosphate (ADP) in canine or human platelet-rich plasma (IC50=6.5 to 16 nM). Moreover, this compound significantly inhibited the mortality rate in mouse acute pulmonary thromboembolitic death induced by collagen and serotonin at oral doses of 0.3 mg/kg or higher.View full abstractDownload PDF (1852K) -
A. S. FOUDA, M. M. GOUDA, S. I. Abd EL-RAHMAN2000 Volume 48 Issue 5 Pages 636-640
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe effect of benzaldehyde, 2-hydroxybenzoyl hydrazone derivatives on the corrosion of aluminium in hydrochloric acid has been investigated using themometric and polarization techniques. The inhibitive efficiency ranking of these compounds from both techniques was found to be : 2>3>1>4. The inhibitors acted as mixed-type inhibitors but the cathode is more polarized. The relative inhititive efficiency of these compounds has been explained on the basis of structure of the inhibitors and their mode of interaction at the surface. Results show that these additive are adsorbed on an aluminium surface according to the Langmuir isotherm. Polarization measurements indicated that the rate of corrosion of aluminium rapidly increases with temperature over the range 30-55°C both in the absence and in the presence of inhibitors. Some thermodynamic data of the adsorption process are calculated and discussed.View full abstractDownload PDF (613K) -
Yong-Hong WANG, Jia-Shi LI, Ze-Rong JIANG, Hajime KUBO, Kimio HIGASHIY ...2000 Volume 48 Issue 5 Pages 641-645
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo new alkaloids were isolated together with 16 known lupin alkaloids from the leaves and stems of Chinese Maackia amurensis. Their structures were determined by spectroscopic methods to be (-)-6α-methoxylupanine and (-)-5α-(12-cytisinylmethyl)-6α-hydroxylupanine and identified by comparison with synthetic samples.The structures of lupin alkaloids were also related to the geographical distributions of the Maackia plants.View full abstractDownload PDF (731K) -
Kenya KIMURA, Fumitoshi HIRAYAMA, Hidetoshi ARIMA, Kaneto UEKAMA2000 Volume 48 Issue 5 Pages 646-650
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe effects of storage on the crystallization, dissolution and absorption of tolbutamide from amorphous tolbutamide-2-hydroxypropyl-β-cyclodextrin (HP-β-CyD) complex were investigated, in comparison with those of polyvinylpyrrolidone (PVP) solid dispersion. The amorphous solid complex of tolbutamide with HP-β-CyD and the solid dispersion of tolbutamide with PVP were prepared by a spray-drying method. During storage, a stable form of tolbutamide (form I) was crystallized from the amorphous PVP dispersion, whereas a metastable form of tolbutamide (form II) was crystallized from the HP-β-CyD complex. The dissolution rate of tolbutamide from both HP-β-CyD complex and PVP dispersion was significantly faster than that of tolbutamide alone. However, the dissolution rate from the PVP dispersion markedly decreased with storage, because of the formation of slow dissolving from I crystals. On the other hand, the dissolution rate from the HP-β-CyD complex was only slightly decreased due to the formation of fast dissolving formII crystals. These in vitro dissolution characteristics were clearly reflected in the in vivo absorption of tolbutamide and the glucose plasma level after oral administration in dogs. The results suggested that HP-β-CyD is useful not only for converting crystalline tolbutamide to an amorphous substance, but also for maintaining the fast dissolution rate of the drug over a long period. Furthermore, the crystallization of drugs from CyD complexes, with storage, seemed to be different from that involving polymer excipients such as PVP.View full abstractDownload PDF (774K) -
Masayuki YOSHIKAWA, Toshio MORIKAWA, Iwao TOGUCHIDA, Shoichi HARIMA, H ...2000 Volume 48 Issue 5 Pages 651-656
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe methanolic extract and ethyl acetate-soluble portion from the flowers of Chrysanthemum indicum L., Chrysanthemi Indici Flos, were found to show inhibitory activity against nitric oxide (NO) production in lipopolysaccharide-activated macrophages. Five new germacrane-type sesquiterpenes, kikkanols D, D monoacetate, E, F, and F monoacetate, were isolated from the ethyl acetate-soluble portion. Their absolute stereostructuers were elucidated on the basis of chemical and physicochemical evidence, which included application of the modified Mosher's method. The effects of fifteen principal components from the ethyl acetate-soluble portion of this medicinal flower against NO production were examined and, among them, a cetylenic compounds and flavonoids were found to show potent inhibitory activity.View full abstractDownload PDF (1026K) -
Jian-mei HUANG, Yoshiyasu FUKUYAMA, Chun-shu YANG, Hiroyuki MINAMI, Ma ...2000 Volume 48 Issue 5 Pages 657-659
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSStructures of three new sesquiterpene lactones 1-3, isolated from the pericarps of Illicium merrillianum, have been assigned as 14-O-benzoylfloridanolide, 2, 10-epoxy-3-dehydroxypseudoanisatin and 7-O-methylpseudo-majucin on the basis of spectroscopic data and chemical transformation. The structure of 2, having an ether linkage between C-2 and C-10, has been confirmed by X-ray crystallographic analysis.View full abstractDownload PDF (572K) -
Koji WADA, Takao MORI, Norio KAWAHARA2000 Volume 48 Issue 5 Pages 660-668
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSHigh-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (HPLC-APCI-MS) was successfully applied to stereoisomeric C19-norditerpenoid alkaloids at position 1. APCIMS allowed the easy and precise control of the energy deposition by varying the drift voltage. Comparison of the breakdown curves, observed by changing the potential difference between the first electrode and the second electrode of the APCI ion source, revealed stereochemical dependence of different fragmentations. The APCI spectra of alkaloids were predominantly the [M+H]+ ion and major fragment ion, corresponding to the [M+H-H 2O] + ion or the [M+H-CH3COOH]+ ion, and comparison of the spectra showed that the abundance of fragment ions was significantly higher for C-1 β-form alkaloids than for C-1 α-form alkaloids. The characteristic fragment ions were formed by the loss of a water, acetic acid or methanol molecule at position 8. The fragmentation mechanisms depending on the stereochemistry of the precursor ion could be discerned by recording the spectra in a deuterated solvent system of 0.05 M ammonium acetate in D2O-acetonitrile-tetrahydrofuran. Loss of D2O from the precursor ion gave the fragment ion. This result indicated that the proton of protonation was included in the leaving water molecule. The peak intensity ratio R=[M+H]+/[M+H-H2O]+ manifested the stereochemical differentiation of alkaloids at position 1.View full abstractDownload PDF (1307K) -
Takao SAKAMOTO, Atsushi NUMATA, Yoshinori KONDO2000 Volume 48 Issue 5 Pages 669-672
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn order to elucidate the reaction mechanism of the cyclization between an ethynyl group and an imino group at the ortho-position on an aromatic ring to afford isoquinolines, reaction of 2-ethynylbenzaldehydes under various conditions was examined. It is concluded that reaction proceeds via an ionic process and the isoquinoline 4-hydrogen atom derives from the solvent. In addition, it was found taht 2-ethynylbenzaldehyde O-methyloximes underwent cycliazation in the presence of primary and secondary alcohols to give 3-substituted isoquinolines.View full abstractDownload PDF (721K) -
Shinji OHMORI, Tadashi MAKINO2000 Volume 48 Issue 5 Pages 673-677
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe purpose of this study was to develop a new sustained-release phenylpropanolamine hydrochloride (PPA) bilayer caplets that consists of an immediate-release portion and a prolonged-release portion containing a hydroxypropylmethylcellulose 2208 (HPMC2208) matrix. Since PPA is a highly water-soluble drug, incorporation of 60% HPMC2208 level in the matrix was required for giving the product a PPA-slow releasing property. Difference in the viscosity grade of HPMC2208 in the matrices did not greatly influence the PPA dissolution characteristics from the matrices. Therefore, we formulated the prolonged-release portion consisting of 10% PPA, 30% excipients, and 60% HPMC2208 (Metolose 90SH4000) into the sustained-release PPA bilayer caplets. The PPA dissolution characterisitcs from the formulated bilayer caplets showed the prolonged dissolution profile after rapid dissolution and was close to the targeted profile calculated from PPA pharmacokinetics study. The manufacturing methods of the prolonged-release portion and the filling order of the prolonged-release portion in bilayer compression did not significantly affect the PPA dissolution characteristics from the bilayer caplets. The PPA dissolution characteristics from the bilayer caplets was pH independent. Moreover, the PPA dissolution characteristics from the bilayer caplets was not affected by mechanical shear. The sustained-release PPA bilayer caplets is expected to present constant prolonged-release of PPA after rapid dissolution in vivo without dissolution change due to pH and mechanical shear.View full abstractDownload PDF (917K) -
Shinji OHMORI, Tadashi MAKINO2000 Volume 48 Issue 5 Pages 678-682
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe purpose of this study was to establish the manufacturing method of the formulated bilayer caplets containing the hydroxypropylmethylcellulose 2208 (HPMC2208) matrix without lamination. In manufacturing the bilayer caplets containing the HPMC2208 (Metolose 90SH4000) matrix, some bilayer caplets were cracked. We found that cracing of bilayer caplets is not the separation of two layers, but lamination of the prolonged-release layer. It was assumed that Metolose 90SH4000 causes lamination of the prolonged-release layer.Two factors, roller compaction pressure on dry granulation of the prolonged-release layer and filling order of the prolonged-releas layer in bilayer compression, were related to lamination of bilayer caplets. The compactibility of the prolonged-release layer decrease with an increase in roller compaction pressure on dry granulation. The compactibility of the prolonged-release layer manufactured by direct compression is superior to that manufactured by dry granulation. The compactibility of the prolonged-release layer in the shape of the second layer, convexo-concave, is superior to that in the shape of the first layer, convexo-convex. This is due to the fact that the density distribution inside the compact in the shape of convexo-concave was more uniform than that in the shape of convexo-convex.The manufacturing method of the formulated bilayer caplets having the prolonged-release layer whose Metolose 90SH4000 content is 60% without lamination is as follows : the prolonged-release layer manufactured by direct compression is fed as the second layer in bilayer compression.View full abstractDownload PDF (1440K) -
Makoto KATO, Kensuke MAEDA, Kazuyuki SATO, Masaaki OMOTE, Akira ANDO, ...2000 Volume 48 Issue 5 Pages 683-686
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTo develop new synthons for the syntheses of organofluorine compounds, the treatment of Halothane, 2-bromo-2-chloro-1, 1, 1-trifluoroethane, (1) with 4-methylbenzenethiol (2) in the presnce of sodium hydride gave 1-chloro-2, 2, 2-trifluoroethyl 4-methylphenyl sulfide (3), which was oxidized with m-chloroperbenzoic acid (m-CPBA) to the corresponding sulfoxide (4) and sulfone (5). Reaction of 3 and 5 with allyltributyltin in the presence of 2, 2'-azobis(isobutyronitrile) (AIBN) gave 1-(trifluoromethyl)-3-butenyl compounds (9, 11). Sulfoxide 4 was decomposed in this condition. The treatment of 3 with allyltrimethylsilane in the presence of Lewis acids gave 1-(trifluoromethyl)-3-butenyl compounds (9) in good yield. This result suggests taht 4-methylphenylthio substituent stabilizes the α-carbocation effectively, though the trifluoromethyl group destabilizes it strongly. Aromatic compounds similarly reacted with 3 in the presence of titanium(IV) chloride to give 2-aryl-1, 1, 1-trifluoro-2-(4-methylphenylthio)ethanes. Thus, sulfur compounds derived from Halothane were found to be useful new synthons for organofluorine compounds.View full abstractDownload PDF (811K) -
Hideyuki ITO, Eri KOBAYASHI, Yoshie TAKAMATSU, Shu-Hua LI, Tsutomu HAT ...2000 Volume 48 Issue 5 Pages 687-693
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThree new flavonoid glycosides, togethr with 15 known flavonoids, have been isolated from the leaves of Eriobotrya japonica, and characterized as (2S)- and (2R)-naringenin 8-C-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosides, and cinchonain Id 7-O-β-D-glucopyranoside, respectively, based on spectral analyses including two dimensional (2D) NMR techniques. Higher proanthocyanidin fraction in the water-soluble portion of the extract was characterized as a procyanidin oligomer mixture mainly composed of undecameric procyanidin. These polyphenols have also been assessed for cytotoxic activity against two human oral tumor (human squamous cell carcinoma and human salivary gland tumor) cell lines. Selective cytotoxicity of the procyanidin oligomer between tumor and normal gingival fibroblast cells, and its possible mechanism, were also described.View full abstractDownload PDF (1371K) -
Sadao OIDA, Yawara TAJIMA, Toshiyuki KONOSU, Yoshie NAKAMURA, Atsushi ...2000 Volume 48 Issue 5 Pages 694-707
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNovel triazole compounds with a dioxane ring were synthesized. Condensation of the diol precursor 10 with various aromatic aldehydes 11-13 under acidic conditions afforded a series of dioxane-triazole compounds 14-16. The antifungal activities of the compounds 14-16 were evaluated in vivo in mice infection models against Candida and Aspergillus species. High activities were seen for the derivatives with one or two double bond(s) and an aromatic ring substituted with an electron-withdrawing group in th side chain. Among the derivatives, R-102557 (16R : Ar=4-(2, 2, 3, 3)-tetrafluoropropoxy)phenyl)showed excellent in vivo activities against Candida, As-pergillus and Cryptococcus species. It also showed high tolerance in a preliminary toxicity study in rats.View full abstractDownload PDF (1873K) -
Kazuyoshi EBISAWA, Nobuya NAGASHIMA, Ken-ichi FUKUHARA, Satoshi KUMON, ...2000 Volume 48 Issue 5 Pages 708-715
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAspartame (L-α-aspartyl-L-phenylalanine methyl ester) is a dipeptide sweetener about 200 tims as sweet as sugar. It exists in crystal forms such as IA, IB, IIA, and IIB, which differ in crystal structure and in the degree of hydration. Among these, IIA is the most stable crystal form, and its crystal structure has been well determined (Hatada et al., J. Am. Chem. Soc., 107, 4279-4282 (1985)). To elucidate the structral factors of thermal stability in the IIA form of aspartame and to examine the physical process in the crystal transformation between the IIA and IIB forms, we performed a thermal analysis and solid-state NMR measurements. We found that a quasi-stable intermediate state exists in the transformation, and it has the same crystal lattice as the usual IIA from, despite the dehydration from 1/2 mol to 1/3 mol per 1 mol of aspartame. The results of the energy component analysis and the molecular dynamics simulation suggest that the entropic effect promotes the generation of the intermediate state, which is presumably caused by the evaporation of the water of crystallization and the increase of molecular motion in aspartame. Thus, the thermal stability of the IIA form is attributable to a structural property, i.e., the crystal lattice itself is retained during the above dehydration. Moreover, the molecular dynamics simulations suggest that the aspartame molecules have two kinds of conformational frexibility in the intermediate state.View full abstractDownload PDF (1297K) -
Makoto MORI, Atsushi SOMADA, Sadao OIDA2000 Volume 48 Issue 5 Pages 716-728
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSStereocontrolled synthesis of tricyclic carbapenem (5-azatrinem) derivatives 4, in which a piperidine ring is condensed to the carbapenem skeleton, was achieved. The pivotal tricyclic intermediate 2, allyl (8S, 9R, 10S)-5-(tert-butoxycarbonyl)-10-[(R)-1-(tert-butyldimethylsilyloxy)ethyl]-11-oxo-1, 5-diazatricyclo[7.2.0.03.8]undec-2-ene-2-carboxylate, was synthesized starting from an acetoxyazetidinone chiron 6 in a practical manner based on a C-C bond formaiton reaction between 6 and piperidinone-ester 5, palladium-catalyzed de(allyloxy)carbonylation of 7b and Wittig-type cyclization via an oxalimide 9. Selective deprotection of the N-Boc group of 2 was found to proceed smoothly by treatment with trimethylsilyl trifluoromethanesulfonate and 2, 6-lutidine to give the amino compound 3, whose functionalization on the nitrogen atom to derivatives 10 followed by deprotection led to various 5-azatrinem acids 4. These compounds showed potent in vitro activities against gram-positive and gram-negative bacteria.View full abstractDownload PDF (2361K) -
Jean Chang FONG, Khalid BENAMOUR, Barbara SZYMONSKI, Francois THOMASSO ...2000 Volume 48 Issue 5 Pages 729-733
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn order to obtain possible veinotonic drugs acting through α2 receptor activation, we prepared clonidine analogues in which the 2-imino-imidazolidine was attached to various aliphatic or aromatic heterocycles. Among them, the two benzopyranic derivatives 16 and 22 exhibited interesting affinities (19 and 95 nM respectively on [3H]rauwolscine binding, compared to 35 nM for clonidine). Their affinity for α1 receptors was found to be much lower : 7570 and 5030 nM for 16 and 22 respectively, suggesting 16 to be 400 times more selective for α2 than for α1-adrenoceptors.View full abstractDownload PDF (859K) -
Anthony A. ATTAMA, Michael U. ADIKWU, Ngozi D. OKOLI2000 Volume 48 Issue 5 Pages 734-737
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSProsopis gum (PG) extracted from Prosopis africana was investigated for bioadhesive delivery of theophylline (TPL). Bioadhesive granules containing TPL were formulated and the bioadhesive properties evaluated using adhesion of the granules onto a porcine intestinal mucus surface. The bioadhesion of the gum dispersion was also evaluated using coated glass beads and the strength of the films formulated from the gums was also determined. The release properties of the TPL-containing granuls were assessed by diffusion of TPL from the granules through porcine intestianal wall into a sink solution. Sodium carboxymethylcellulose (SCMC) was used as the standard bioadhesive polymer. Results indicated that PG is highly bioadhesive compared to SCMC. The result of the release studies also showed that PG could be used to deliver TPL in a bioadhesive dosage form.View full abstractDownload PDF (642K) -
Atta-ur RAHMAN, M. Iqbal CHOUDHARY, M. Nur-e ALAM, Purev O. NDOGNII, T ...2000 Volume 48 Issue 5 Pages 738-739
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo new benzoquinone derivatives, bungequinone (1) and dihydrobungeiquinone (2), and two known derivatives, 3-hydroxyirisquinone (3) and 3-hydroxydihydroirisquinone (4), were isolated from the roots of Iris bungei.The structures of the new compounds were established on the basis of spectroscopic methods.View full abstractDownload PDF (423K) -
Celeste E. O'CONNELL, Ceryl A. ROWELL, Karen ACKERMANN, Ana Maria GARC ...2000 Volume 48 Issue 5 Pages 740-742
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSCA1A2X peptidomimetics containing a modified proline at position A2 were prepared and evaluated for their ability to inhibit farnesyltransferase (FTase) and geranylgeranyltransferase I (GGTase I) in enzymatic and cellbased assays. These compounds inhibited farnesylation of H-ras in vitro in the high nanomolar to low micromolar IC50 range.View full abstractDownload PDF (491K) -
Maria STEFANIDOU, Sotiris ATHANASELIS, Giorgos ALEVISOPOULOS, John PAP ...2000 Volume 48 Issue 5 Pages 743-745
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe Δ9-tetrahydrocannabinol (Δ9-THC) content was identified and determined quantitatively using a Gas Chromatography Detector (Gas Chromatography - Electron Ion Detector) instrument in samples of illicit herbal cannabis. Law enforcement authorities sent the samples to the Department of Forensic Medicine and Toxicology, University of Athens, for toxicological analysis. The concentrations of Δ9-THC in these samples ranged from 0.08% to 4.41%. Such concentrations suggest that Greece might be at high risk, as an area for the illicit cultivation of "pedigree" cannabis plants. The forensic aspects of cannabis classificaiton are discussed.View full abstractDownload PDF (455K) -
Koichi MACHIDA, Kazumi OYAMA, Mutsumi ISHII, Rie KAKUDA, Yasunori YAOI ...2000 Volume 48 Issue 5 Pages 746-748
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFour new terpenoids, gardenate A (1), 2-hydroxyethyl gardenamide A (2), (1R, 7R, 8S, 10R)-7, 8, 11-trihydroxyguai-4-en-3-one 8-O-β-D-glucopyranoside (3) and Jasminosie F (4), were isolated from Gardeniae Fructus. Their structures were established on the basis of spectral analysisView full abstractDownload PDF (589K) -
Naoko OHNUMA, Keiko AMEMIYA, Rie KAKUDA, Yasunori YAOITA, Koichi MACHI ...2000 Volume 48 Issue 5 Pages 749-751
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo new sterols, (22E)-23-methylergosta-5, 7-22-trien-3β-ol (1) and 5α, 6α-epoxy-(22E)-ergosta-8, 14, 22-triene-3β, 7α-diol (2), have been isolated from two edible mushrooms, Lentinula edodes and Tricholoma matsutake, respectively, together with twelve known ones (3-14). The structures of the new compounds were elucidated on the basis of their spectral data.View full abstractDownload PDF (543K) -
Yoshio TAKEDA, Yoshihiro OKADA, Toshiya MASUDA, Eiji HIRATA, Takakazu ...2000 Volume 48 Issue 5 Pages 752-754
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNew megastigmane (1) and tetraketide (2) were isolated from the leaves of Euscaphis japonica and the structures were elucidated by means of spectroscopic and chemical evidence.View full abstractDownload PDF (578K) -
Hisao MATSUZAKI, Isao TAKEUCHI, Yoshiki HAMADA, Keiichiro HATANO2000 Volume 48 Issue 5 Pages 755-756
Published: May 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS1, 4-Oxazepine formation reactions of 1, 8-naphthyridine derivatives (1-4) with peroxy acid have been studied using a semiempirical MO method (AM1) and an ab initio molecular orbital method (Gaussian 94). The energies of molecules involved in the reaction paths were calculated and the transition states related to experimental products were obtained. For the reactions of 1-3, the calculated energies of the transition states predicted the previously obtained products. However, the calculated values for the reaction of 4 suggested a different type of oxazepine compound, which was verified in further experiments.View full abstractDownload PDF (460K)
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