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Atsutoshi OTA, Yoichi KAWASHIMA, Hirofumi OHISHI, Toshimasa ISHIDA
1993 Volume 41 Issue 10 Pages
1681-1685
Published: October 15, 1993
Released on J-STAGE: March 31, 2008
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The stereochemistry of a novel Ca
2+ antagonist, semotiadil, 1, was investigated using X-ray crystallography and CD. The X-ray structure was analyzed using its diastereomeric salt with (S)-(+)-mandelic acid (2); 1 (mandelate). The R absolute configuration of 1, which was previously determined by chemical transformation of the optically-active synthetic precursor, was directly confirmed by this analysis. The hydrogen bonding, electrostatic and the hydrophobic interactions, which stabilize the crystal structure, were observed in the crystal. CD spectra of 1 (mandelate) and the hydrogen fumarate of 1 (SD-3211; 1 (fumarate)) in ethanolic solution exhibited similar spectral patterns. The CD bands from each chromophore were unambiguously assigned and the conformation of the benzothiazine ring was determined using the helicity rule. The X-ray and CD data confirmed the P-conformation of the benzothiazine ring and the existence of the 2-phenyl ring in an equatorial position in both of the crystal and ethanolic solution states. These findings were in good agreement with our previous results regarding the conformational analysis of 2-arylbenzothiazine derivatives.
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Yasuko IN, Mitsunobu DOI, Masatoshi INOUE, Toshimasa ISHIDA, Yasumasa ...
1993 Volume 41 Issue 10 Pages
1686-1690
Published: October 15, 1993
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As part of a series of investigations into the conformational stability of a C
2-symmetric or related cyclic peptide isolated from the ascidian Lissoclinum patella, the molecular conformation of patellamide A, the chemical structure of which deviates slightly for C
2-symmetry, was determined by X-ray crystal analysis. Patellamide A took on a saddle-shaped rectangular form and wrapped around the water and methanol solvents. This conformation which is very similar to that of C
2-symmetric ascidiacyclamide would be proposed as a possible candidate for biologically "active" conformation.
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Hiroko NAKAGAWA, Junko CHIKUMA, Chun-Guang LI, Koh-ichi YAMADA, Hirosh ...
1993 Volume 41 Issue 10 Pages
1691-1694
Published: October 15, 1993
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The synthesis and characterization of Co(II)CI
2 and Cu(II)Cl
2 complexes with 2-chloro-10-(3-dimethylaminopropyl)phenothiazine-5-oxide hydrochloride (cpz(O)HCl) and three related compounds are described. The crystal structures of the complexes [CoCl
3cpz(O)H] (1) and [CuCl
3 cpz(O)H] (2) were determined by single-crystal X-ray diffraction analyses. 1 crystallizes in the monoclinic space group P2
1/c with a=8.150(1), b=17.763(2), c=14.630(2) Å, β=103.93(1)°, V=2055.8(3) Å
3, and Z=4. 2 crystallizes in the monoclinic space group P2
1/c with a=8.141(1), b=17.175(4), c=14.810(3) Å, β=103.27(1)°, V=2015.5(7) Å
3, and Z=4. The metal atoms in both complexes are coordinated in a tetrahedral geometry and the two complexes are arranged in a head-to-tail manner to form a dimer.
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Takeshi IMANISHI, Masayuki YAMASHITA, Yoshimi HIROKAWA, Tetsuaki TANAK ...
1993 Volume 41 Issue 10 Pages
1695-1697
Published: October 15, 1993
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(±)-Isogymnomitrol (1b) and (±)-O-methylgymnomitrol (1c) were synthesized starting from the 1, 2, 6-trimethyltricyclo[5.3.1.0
2, 6]undecan-9-one derivative 4 via 1, 2-carbonyl transposition from C(9) to C(8) as a key step.
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Ken YASUI, Kenji KAWADA, Kiyomi KAGAWA, Katsuya TOKURA, Kengo KITADOKO ...
1993 Volume 41 Issue 10 Pages
1698-1707
Published: October 15, 1993
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Enantioselective total synthesis of the labdane diterpene (-)-1, was achieved starting from the R-(-)-enantiomer of the Wieland-Miescher ketone (3). The enantiomer (+)-1 was obtained by partial synthesis via microbial transformation of sclareol (24). These results established that the natural compound (+)-1, a platelet aggregation inhibitor, has a normal absolute stereochemistry like that of manool (2). The B-norlabdane-related compound 44 was also synthesized using a novel ring contraction reaction.
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Takashi TANAKA, Shinji KIRIHARA, Gen-ichiro NONAKA, Itsuo NISHIOKA
1993 Volume 41 Issue 10 Pages
1708-1716
Published: October 15, 1993
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Five new ellagitannins, platycaryanins A (27), B (26), C (30), and D (25), and platycariin (31), and a new complex tannin, strobilanin (32), have been isolated from the fruits and bark of Platycarya strobilacea SIEB. et ZUCC. (Juglandaceae), together with twenty-six known compounds. On the basis of spectroscopic and chemical evidence, platycaryanins A, B and C, and platycariin have been characterized as the ellagitannins having a tergalloyl ester group, while platycaryanin D was found to be an unusual ellagitannin possessing (R)-hexahydroxydiphenoyl esters at the glucopyranose 2, 3- and 4, 6-positions. During these chemical studies, re-examination of the similar ellagitannins, alnusnins A and B, which were previously reported from Alnus sieboldiana, led us to revise their structures to 29 and 28, respectively, in which the tergalloyl group forms a lactone ring. Furthermore, biomimetic conversion of ellagitannins having a glucopyranose core into C-glycosidic ellagitannins was successfully achieved for the first time, and the reaction was applied to the structure elucidation of platycariin (31).
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Nobuo IKOTA
1993 Volume 41 Issue 10 Pages
1717-1721
Published: October 15, 1993
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(+)-1, 8-Di-epi-swainsonine (15) and (-)-1-epi-swainsonine (17) were synthesized stereoselectively from an (S)-pyroglutamic acid derivative (1a). A (2R, 3R, 4R)-3, 4-dihydroxy-2-hydroxymethylpyrrolidine derivative (6a) was prepared by cis-dihydroxylation of an α, β-unsaturated lactam (2) followed by epimerization of the di-O-benzyl derivative (3b) as the key reactions. The diastereoselective allylation of the aldehyde 6b obtained from 6a and subsequent cyclization of 13 and 16 gave 15 and 17, respectively. It proved that 1, 8-di-epi-swainsonine (15) is dextrorotatory.
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Kazuko YOSHIKAWA, Yasuhiro NAGAI, Masaya YOSHIDA, Shigenobu ARIHARA
1993 Volume 41 Issue 10 Pages
1722-1725
Published: October 15, 1993
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From the Fresh leaves of Hovenia dulcis THUNB. var. tomentella MAKINO, five new dammarane glycosides named hodulosides VI-X (1-5) were isolated. Their structures were determined on the basis of chemical and spectral evidence. Hodulosides VII-X showed antisweet activities.
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Akira TAKAHASHI, Tsutomu AGATSUMA, Tomihisa OHTA, Tetsuji NUNOZAWA, Ta ...
1993 Volume 41 Issue 10 Pages
1726-1729
Published: October 15, 1993
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Five new chlorinated phenyl ethers, russuphelins B (2), C (3), D (4), E (5) and F (6) have been isolated from the mushroom Russula subnigricans HONGO, and their structures were elucidated by spectroscopic and chemical means. Russuphelins B (2), C (3) and D (4) exhibited cytotoxic activity in vitro against P388 leukemia cells.
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Kazuko YOSHIKAWA, Yuuji KONDO, Shigenobu ARIHARA, Kouji MATSUURA
1993 Volume 41 Issue 10 Pages
1730-1732
Published: October 15, 1993
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Systematic separation of the saponin fraction of the leaves of Gymnema sylvestre has led to the isolation of four new saponins, gymnemic acids XV-XVIII, as antisweet substances. The structures were elucidated by spectral and chemical studies. Gymnemic acids XV-XVIII, are 21-O-2-methylbutyryl-22-O-2-methylcrotonoyl, 16, 22-O-bis-2-methylcrotonoyl, 21-O-benzoyl, and 28-O-benzoyl gymnemagenin 3-O-gluculonides, respectively. Gymnemic acids VIII and IX that we had named in the previous paper were renamed gymnemic acids XV and XVI, respectively.
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Naoki NODA, Ryuichiro TANAKA, Kazumoto MIYAHARA, Toshio KAWASAKI
1993 Volume 41 Issue 10 Pages
1733-1737
Published: October 15, 1993
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Three glycosphingolipids were isolated in the pure state from the crude drug, "Jiryu" (the earthworm, Pheretima asiatica). Their structures were determined as N-docosanoyl-1-O-[6-O-(2-trimethylammonioethoxy)phosphinato-β-D-galactopyranosyl]-(4E)-16-methylheptadecasphingenine (1), N-docosanoyl-1-O-[6-O-(2-trimethylammonioethoxy)-phosphinato-β-D-galactopyranosyl]-(4E)-sphingenine (2) and N-tetracosanoyl-1-O-[6-O-(2-trimethylammonioethoxy)-phosphinato-β-D-galactopyranosyl]-(4E)-sphingenine (3). They are zwitterionic glycosphingolipids having a phosphocholine group attached to the sugar moiety, resembling those obtained from two kinds of marine annelid, and one has a branched long-chain base.
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Shigeo NOZOE, Akira TAKAHASHI, Tomihisa OHTA
1993 Volume 41 Issue 10 Pages
1738-1742
Published: October 15, 1993
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The chirality of the 3-hydroxy-3-methylglutaric acid (HMGA) moiety of fasciculic acid A (1), a calmodulin antagonist isolated from Naematoloma fasciculare, was established to be S by comparing the
1H-NMR spectrum of the L-alanylamide of HMGA derived from 1 with those of its diastereomer and the diastereomeric mixture.
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Toshiko SATAKE, Kazuyuki HORI, Kohei KAMIYA, Yasuhisa SAIKI, Yasuo FUJ ...
1993 Volume 41 Issue 10 Pages
1743-1745
Published: October 15, 1993
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Two new flavonol glycosides have been isolated from the fruit of Turkish Rhamnus thymifolius (Rhamnaceae) and their structures were elucidated as kaempferol-3-O-α-L-rhamnopyranosyl(1→3)-(4-O-acetyl)-O-α-L-rhamnopyranosyl-(1→6)-O-β-D-galactopyranoside and kaempferol-4'-O-α-L-rhamnopyranosyl(1→3)-O-α-L-rhamnopyranosyl(1→6)-O-β-D-galactopyranoside based on spectral and chemical evidence.
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Tohru SAITO, Shigeji MORI, Jun CHIKAZAWA, Tae KANAI, Tozo FUJII
1993 Volume 41 Issue 10 Pages
1746-1752
Published: October 15, 1993
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The first total synthesis of caissarone hydrochloride (1), a constituent of the sea anemone Bunodosoma caissarum, has been accomplished via a two-step route starting from N
6, 9-dimethyl-8-oxoadenine (3), which is obtainable from 9-methyladenine (5) through a four-step route. The key step in the synthesis is the regioselective methylation of 3 at N(3), which has been designed on the basis of a methylation study of N
6-benzyl-9-methyl-8-oxoadenine (11). Some positional isomers (19, 24, and 31) and analogues (8, 26, and 32) of 1 have also been synthesized. A
1H-NMR spectroscopic study has suggested that the free base (23) of caissarone is capable of forming a hetero-base pair (such as 41) with 2', 3', 5'-tri-O-acetylguanosine (40) in Me
2SO-d
6.
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Akikazu KAKEHI, Suketaka ITO, Tatsuya UEDA, Satoshi TAKANO
1993 Volume 41 Issue 10 Pages
1753-1756
Published: October 15, 1993
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The treatment of 2-iminothieno[3, 2-α]indolizine derivatives with potassium tert-butoxide generated exclusively potassium 1-(2-cyanovinyl)indolizine-2-thiolates through the ring opening of the initially formed thiin-2-imide ions. These 2-indolizinethiolates reacted with various alkylating agents to give the corresponding S-alkylated 1-vinylindolizine derivatives, and 2-acetonylthio- and 2-phenacylthio-1-(2-cyanovinyl)indolizines of these products smoothly underwent intramolecular Michael addition under the conditions employed here to afford the corresponding 2-acetyl- and 2-aroylthieno[3, 2-α]indolizines in high yields with the elimination of a methylene compound.
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Yuko TAKEMURA, Tomoko KUROZUMI, Motoharu JU-ICHI, Masayoshi OKANO, Nar ...
1993 Volume 41 Issue 10 Pages
1757-1759
Published: October 15, 1993
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Two new acridone-coumarin dimers, named neoacrimarine-C (1) and -D (2), were isolated from the root of Citrus hassaku. Their structures were elucidated on the basis of spectroscopic data.
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Takeshi HASEGAWA, Tomohiro NIGO, Takao KAKITA, Hiromu TOYODA, Harumasa ...
1993 Volume 41 Issue 10 Pages
1760-1768
Published: October 15, 1993
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The synthesis and antiulcer activity of highly strained cage compounds such as pentacyclo[4.2.0.0
2, 5.0
3, 8.0
4, 7]-octane (cubane), pentacyclo[4.3.0.0
2, 5.0
3, 8.0
4, 7]nonane (homocubane) and pentacyclo[5.3.0.0
2, 4.0
3, 6.0<5, 8>]decane are described. Of the compounds obtained, N-[3-(3-piperidinomethylphenoxy)propyl]-4-piperidinocarbonylpentacyclo[4.2.0.0
2, 5.0
3, 8.0<4, 7>]octane carboxamide (26a) and N-[3'-(3'-piperidinomethylphenoxy)propyl]-1-bromo-9, 9-ethylenedioxypentacyclo[4.3.0.0
2, 5.0
3, 8.0
4, 7]nonane]-4-carboxamide (26q) showed more potent antiulcer activity with very good cytoprotective ability in the HCl·ethanol-treated rat model. Compounds 26a and 26q exhibited H
2-receptor antagonist potency (in vitro) comparable to that of ranitidine, but did not inhibit histamine-stimulated acid secretion (in vivo) in the gastric fistula rat model, when orally administered in the dose range at which antiulcer and cytoprotective activities were seen. The structure-activity relationships are discussed.
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Nobuyuki NAKAMURA, Hiroko NAGAI, Makiko YONEDA, Hisashi SUGA, Masanori ...
1993 Volume 41 Issue 10 Pages
1769-1773
Published: October 15, 1993
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The first chemical synthesis of thromboxane B
3 starting with the Corey lactone is described. A reversed-phase high-performance liquid chromatographic method was developed for the direct determination without derivatization, of thromboxane B
3 in the presence of thromboxane B
2.
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Kaoru UMEHARA, Ariko SUGAWA, Masanori KUROYANAGI, Akira UENO, Takao TA ...
1993 Volume 41 Issue 10 Pages
1774-1779
Published: October 15, 1993
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In the course of studying differentiation-inducers from plants, their isolation was performed from the methanolic extract of Arctium Fructus (the fruits of Arctium lappa L., Compositae), and then their phagocytic activity on differentiated mouse myeloid leukemia cells (M1) was monitered. Thirteen compounds, including five new ones, were isolated as differentiation-inducers toward M1 cells. These consisted of two lignans, eight sesquilignans and three dilignans. Arctigenin (2) was the most effective compound of all those isolated, and it induced differentiation of M1 cells at a concentration 0.5 μM. Sesquilignans were less effective than lignans and dilignans showed even weaker activity. These lignoids were inactive towards a human acute promyelocytic leukemia cell line (HL-60).
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Atsushi YAMAMOTO, Toshio MIYASE, Akira UENO, Toshio MAEDA
1993 Volume 41 Issue 10 Pages
1780-1783
Published: October 15, 1993
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From the whole plants of Scrophularia kakudensis, three new saikosaponin homologs, named scrophulasaponins II-IV, were isolated, together with six known and four artifact saponins; their structures were elucidated by spectroscopic data and chemical evidence.
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Osamu NAKAMURA, Yoshihiro MIMAKI, Yutaka SASHIDA, Tamotsu NIKAIDO, Tai ...
1993 Volume 41 Issue 10 Pages
1784-1789
Published: October 15, 1993
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The saponin fraction prepared from the methanolic extract of the underground parts of Agapanthus inapertus was found to exhibit inhibitory activity on cAMP phosphodiesterase (55.2%) at a concentration of 100 μg/ml. From this fraction, four new steroidal saponins, designated as agapanthussaponin A (1), B (2), C (3) and D (4), were isolated as the active principles, along with an inactive new furostanol saponin (5). The structures of 1-5 were determined by spectroscopic data and hydrolysis. The IC
50 of 1-4 on cAMP phosphodiesterase were 0.7, 1.2, 1.1 and 2.0 (×10
-5M), respectively, which are more potent than that of papaverine (IC
50 3.0×10
-5M).
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Purusotam BASNET, Shigetoshi KADOTA, Mineo SHIMIZU, Hong-Xi XU, Tsuneo ...
1993 Volume 41 Issue 10 Pages
1790-1795
Published: October 15, 1993
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The CHCl
3 extract of Matteccia orientalis showed very strong hypoglycemic activity in streptozotocin (STZ)-induced diabetic rats. A new C-methyl flavanone derivative, 2'-hydroxymatteucinol (3) was isolated from the hypoglycemic activity bearing fraction, along with two known compounds, demethoxymatteucinol (1) and matteucinol (2). The structures of these isolated compounds were elucidated by spectroscopic methods. One of the compounds isolated from CHCl
3 extract, 2'-hydroxymatteucinol (3), showed dose-dependent hypoglycemic activity, and a blood sugar lowering effect was observed even at the dose of 10 mg/kg (p.o.) in STZ-induced diabetic rats.
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Meselhy R. MESELHY, Shigetoshi KADOTA, Yasunori MOMOSE, Noboru HATAKEY ...
1993 Volume 41 Issue 10 Pages
1796-1802
Published: October 15, 1993
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Two new quinochalcone C-glycosides, hydroxysafflor yellow A (1a) and tinctormine (2a), were isolated from Carthamus tinctorius L. (Compositae) together with carthamin, safflor yellow B and safflomin C. The structures of 1a and 2a have been determined by spectroscopic methods including heteronuclear multiple-bond multiple-quantum coherence and linked scan FAB-MS. The latter compound (2a) was demonstrated to have potent Ca
2+ antagonistic action.
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Hong-Xi XU, Shigetoshi KADOTA, Masahiko KUROKAWA, Kimiyasu SHIRAKI, Ta ...
1993 Volume 41 Issue 10 Pages
1803-1806
Published: October 15, 1993
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Hot aqueous and methanol extracts of the rhizomes of Woodwardia orientalis were tested for their in vitro antiviral activity against herpes simplex virus type 1 (HSV-1), poliovirus type 1, and measles virus by plaque reduction assay. The aqueous extract of W. orientalis reduced the plaque forming ability of HSV-1 and poliovirus more strongly than did the methanol extract. By bioassay-directed fractionation of the aqueous extract, a new glucoside, woodorien (1), along with five known compounds were isolated from an EtO Ac-soluble fraction that had antiviral activity. The structures of these compounds were determined by the use of two dimensional (2D) NMR techniques (
1H-
1H correlation spectroscopy (COSY),
1H-
13C COSY and heteronuclear multiple-bond multiple-quantum coherence (HMBC)). Woodorien (1) was the most potent inhibitor against HSV-1 among the isolated compounds.
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Hong-Yu LI, Kazuo KOIKE, Taichi OHMOTO
1993 Volume 41 Issue 10 Pages
1807-1811
Published: October 15, 1993
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Three new alkaloids, picrasidines W (1), X (2) and Y (3), were isolated from the wood of Picrasma quassioides BENNET (Simaroubaceae). Their structures were determined by spectral and chemical evidence. Previously isolated picrasidine Q (4) was unambiguously determined by X-ray crystallographic analysis.
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Toshio YAMAGUCHI, Masami NISHIMURA, Rokuro OKAMOTO, Tomio TAKEUCHI, Ke ...
1993 Volume 41 Issue 10 Pages
1812-1816
Published: October 15, 1993
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Amorphous 16-membered macrolide compounds were prepared by spray drying, and the physicochemical stability of the amorphous states has been investigated. Josamycin, rokitamycin, midecamycin, 3-O-acetyl-4"-O-isovaleryltylosin, miocamycin and 4"-O-(4-methoxyphenyl)acetyltylosin were used as macrolide compounds. From X-ray powder diffractometry and differential scanning calorimetric (DSC) measurements, all the spray dried compounds were recognized to be in a glassy state. Miocamycin and 4"-O-(4-methoxyphenyl)acetyltylosin glasses showed crystallization and fusion peaks on DSC thermograms, and were crystallized after 6 months of storage at 313 K and 75% relative humidity. Other compounds showed only a glass transition peak on each DSC thermogram, and the glassy state was maintained stably against humidity. It was found that the physicochemical stability of the glassy state of miocamycin was closely related to the inlet temperature of the spray drying process.
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Shoko YOKOYAMA, Keiko SHINOZAKI, Masaaki SUNOHARA, Tadao FUJIE
1993 Volume 41 Issue 10 Pages
1817-1821
Published: October 15, 1993
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The rates of release of 3-aminopyridine (3AP) from fatty acid (FA)-3AP complexes, FA-3AP, were determined at various temperatures, and the thermodynamic quantities of the release of 3AP were estimated. The results were compared with previous results obtained for FA-nicotinamide (NAA) complexes, FA-NAA.The values of activation enthalpy (ΔH
〓) and activation entropy (ΔS
〓) for the release of 3AP from FA-3AP were positive and negative, respectively, indicating that the release of 3AP is disadvantageous from not only enthalpic but also entropic viewpoints. The plots of ΔH
〓 against the carbon number (n) in the constituent FA showed a zig-zag line with an upward convex at odd-numbered positions and the plots of the absolute values of |-ΔS
〓| showed a zig-zag line with a downward convex at odd-numbered positions, though the positive value of ΔH
〓 increased and the negative ralue of ΔS
〓 decreased with an increasing n for either even-numbered or odd-numbered FA. It was found that the release of 3AP from RA-3AP formed with odd-numbered FA is more disadvantageous enthalpically but more advantageous entropically as compared with that from FA-3AP formed with even-numbered FA. Furthermore, it is suggested that FA-3AP is formed by at least van der Waals forces and hydrophobic interactions.It was found that FA-3AP has similar physicochemical properties to FA-NAA and that the variation in physico-chemical properties of FA-3AP owing to the difference in n is smaller than that of FA-NAA. This is considered to be due to the fact that the packing of 3AP into the FA host cavity is looser than that of NAA.
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Zheng WANG, Fumitoshi HIRAYAMA, Kengo IKEGAMI, Kaneto UEKAMA
1993 Volume 41 Issue 10 Pages
1822-1826
Published: October 15, 1993
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Amorphous nifedipine powders were prepared by spray-drying with 2-hydroxypropyl-β-cyclodextrin (HP-β-CyD) or polyvinylpyrrolidone K-30 (PVP). Upon storage of the products at a high temperature and humidity, nifedipine crystallized in matrices, yielding both bigger crystals (>50 μm) in a PVP matrix and smaller crystals (about 5 μm) in a HP-β-CyD matrix. The release of nifedipine from tablets containing the HP-β-CyD complex was accelerated upon storage, whereas that from the PVP solid dispersion was decelerated. The deceleration of the release rate was attributable to the growth of nifedipine crystals with a larger size in the PVP matrix. The release of nifedipine from the HP-β-CyD complex at the early stage of storage was rather slow due to the low wettability and high compressibility of the tablets. However, over a longer period of storage, the inhibitory effect of HP-β-CyD on the crystal growth of nifedipine took effect, leading to the release acceleration. To maintain the improved release of nifedipine over a long period of storage, a possible combination of HP-β-CyD and PVP was investigated to act as a hybridizing drug carrier. Among various compositions, the 1 : 3 : 1 (nifedipine : PVP : HP-β-CyD, weight ratio) product gave the most appropriate release profile without any decreased release of nifedipine at the early and late stages of storage.
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Yoshiaki KAWASHIMA, Hirofumi TAKEUCHI, Tomoaki HINO, Toshiyuki NIWA, T ...
1993 Volume 41 Issue 10 Pages
1827-1831
Published: October 15, 1993
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Pulverized L-HPC (low-substituted hydroxypropylcellulose, LH41) can be used as a sustained-release matrix filler. In previous papers, we had reported that the flowability and packability of LH41 powder with or without acetaminophen was improved by wet granulation for practical uses. In the present report, dry granulation via slugging was employed to avoid the use of an organic solvent (e.g. ethanol). The sustained-releasing functions of the original LH41 were maintained during granulation with lower slugging pressures (≤10MPa), whereas they were lost with higher slugging pressures (≥20MPa). The sustained-releasing function of the tablet prepared with the granules of LH41 and the drug (acetaminophen) was determined by a function of internal pore size distribution and the swelling property of the tablet. The granules of LH41 and the drug prepared by a roller compactor were applied practically to prepare a controlled-release matrix tablet using a single-punch tabletting machine. It was possible to widely control the drug release of the resultant tablets (i.e. rapid- to sustained-release) by changing the roller compaction pressure.
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Manabu HORI, Kenji SUZUKI, Takeshi YAMAMOTO, Fumio NAKAJIMA, Akio OZAK ...
1993 Volume 41 Issue 10 Pages
1832-1841
Published: October 15, 1993
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From a structural comparison study between serotonin and serotonin
3 (5-HT
3) antagonists using a two-dimensional grid template composed of regular hexagons, we deduced structural modification patterns from agonists to antagonists, and designed new 5-HT
3 antagonist prototypes. Among them, 2-(4-methyl-1-piperazinyl)-1-butylbenzimidazole (6) was identified as a lead compound which has potent 5-HT
3 antagonistic activity comparable to that of granisetron. Using a quantitative structure-activity relationships method, we optimized the structure of 6 and selected 6-amino-5-chloro-1-isopropyl-2-(4-methyl-1-piperazinyl)benzimidazole dimaleate (69, KB-6933), one of the most potent and long-acting 5-HT
3 antagonists, as a candidate drug.
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Noriko MOTOHASHI, Yutaka SAITO
1993 Volume 41 Issue 10 Pages
1842-1845
Published: October 15, 1993
Released on J-STAGE: March 31, 2008
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Hydroxyl radicals were generated from N
2O-saturated phosphate-buffered saline solution (pH 7.5) by irradiation with a 3.7 TBq
137Cs source. The radicals attacked benzoate to form highly fluorescent products. The induction of fluorescence was tested in 0.002 to 2mM of benzoate solution; the fluorescence intensity was approximately constant at benzoate concentrations more than 0.1 mM during irradiation, and increased linearly with irradiation dose up to 53 Gy tested. The major primary products detected by high-performance liquid chromatography were three monohydroxybenzoates, 2-, 3- and 4-hydroxybenzoate (HOBZ). The G-values obtained from γ-irradiation for 60 min of a 0.2 mM benzoate solution were G(2-HOBZ)=0.97, G(3-HOBZ)=0.48 and G(4-HOBZ)=0.45. As the fluorescence of irradiated benzoate solution arose mostly from 2- and 3-HOBZ and the intensity of 2-HOBZ is 30 times that of 3-HOBZ, 98% of the fluorescence intensity induced was ascribed to 2-HOBZ. A hydroxyl radical scavenger competed with benzoate for hydroxyl radicals produced, and diminished the fluorescent products. A rate constant for the reaction of a scavenger with hydroxyl radical could be determined from the reduction in fluorescence intensity, using 0.2 mM benzoate and various concentrations of the scavenger. The fluorescence intensity was detectable down to 0.15 μM of 2-HOBZ produced. For various compounds, rate constants obtained in this way were similar to those measured by pulse-radiolysis.
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Rika OBATA, Takeshi OHNUMA
1993 Volume 41 Issue 10 Pages
1846-1847
Published: October 15, 1993
Released on J-STAGE: March 31, 2008
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As part of a search for new potent derivatives, electrochemical oxidation of etoposide (1) was carried out under controlled potential (500mV) to yield 1, 2-dehydroetoposide (4), 4'-O-demethyl-1, 2, 3, 4-tetradehydro-4-dehydroxy-podophyllotoxin (5) and 1, 2, 3, 4-tetradehydroetoposide (6). They showed no cytotoxicity against B16-melanoma.
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Kazuho HARADA, Yuko SHIMOZONO, Eisuke KAJI, Shonosuke ZEN
1993 Volume 41 Issue 10 Pages
1848-1849
Published: October 15, 1993
Released on J-STAGE: March 31, 2008
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4-Substituted 5-hydroxymethyl-3-methoxycarbonyl-2-isoxazoline 2-oxides (1) reacted with an excess of titanium tetrachloride in dichloromethane to yield a new type of functionalized heterocycle, benzofuro[2, 3-c]tetrahydropyran-3, 4-dione 4-oximes (2). The structure of the 7-chloro derivative (2a) was determined by single crystal X-ray analysis and a mechanism is proposed for the formation of 2 from 1.
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Yoshinori TOMINAGA, Raymond N. CASTLE, Milton L. LEE
1993 Volume 41 Issue 10 Pages
1853-1855
Published: October 15, 1993
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Aminochrysene derivatives were synthesized by the oxidative photocyclization of acetylaminostilbenes in the presence of iodine and air, followed by hydrolysis.
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Taiko ODA, Yoshihiro SATO
1993 Volume 41 Issue 10 Pages
1856-1859
Published: October 15, 1993
Released on J-STAGE: March 31, 2008
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In order to evaluate the contribution of the two phenolic hydroxyl groups to the biological activities of indenestrols A (IA) and B (IB), monomethyl ether derivatives of IA and IB were prepared and each enantiomer was separated to >99% purity by high-pressure liquid chromatography using a chiral column. The structures of the enantiomers were confirmed by proton and carbon-13 nuclear magnetic resonance and circular dichroism spectroscopic studies.
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Hideaki OTSUKA, Masaru KIDO, Tomitake TSUKIHARA, Kumiko TSUKIHARA, Yas ...
1993 Volume 41 Issue 10 Pages
1860-1862
Published: October 15, 1993
Released on J-STAGE: March 31, 2008
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By means of single crystal X-ray analysis of dendranthemoside A pentaacetate, the absolute configuration of the asymmetric center at the 9-position was determined to be R. The configurations of three other positions, which had been determined to be 3S, 5R and 6S by application of β-D-glucosylation induced shift trends, were verified.
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Naoki YAMADA, Nobutoshi MURAKAMI, Takashi MORIMOTO, Jinsaku SAKAKIBARA
1993 Volume 41 Issue 10 Pages
1863-1865
Published: October 15, 1993
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An extract of the cyanobacterium P. tenue showed a significant inhibitory effect on its own growth. Bioassay-directed fractionation has led to the identification of the auto-growth inhibitory substance as a mixture of fatty acids. Unsaturated fatty acids such as linoleic and linolenic acids appear to be predominantly responsible for the auto-growth inhibitory effect.
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Shu-Min HU, Sui-Xu XU, Xin-Sheng YAO, Cheng-Bin CUI, Yasuhiro TEZUKA, ...
1993 Volume 41 Issue 10 Pages
1866-1868
Published: October 15, 1993
Released on J-STAGE: March 31, 2008
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Dauricoside (1), a new glycosidal alkaloid, was ioslated from the rhizomes of Menispermum dauricum DC. along with dauricine (2), daurisoline (3), dauriporphine (4), menisporphine (5), and 6-O-demethylmenisporphine (6), and its structure was determined by means of spectroscopic methods. Compounds 1, 2, and 3 inhibited blood-platelet aggregation induced by adenosine 5'-diphosphate (ADP).
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Hideji ITOKAWA, Zedan Z. IBRAHEIM, Ya-Fang QIAO, Koichi TAKEYA
1993 Volume 41 Issue 10 Pages
1869-1872
Published: October 15, 1993
Released on J-STAGE: March 31, 2008
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Further investigation of the roots of Rubia cordifolia resulted in the isolation of four new naphthohydroquinones and two naphthohydroquinone dimers, and one known naphthohydroquinone, one naphthoquinone, two anthraquinones and one naphthohydroquinone dimer. The structures of these compounds were established by various chemical and spectroscopic methods including two dimensional NMR techniques. Also, the isolated compounds were submitted to a bio-assay for cytotoxic and antitumor activity.
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Kazushi SHINGU, Mariko MIYAGAWA, Shoji YAHARA, Toshihiro NOHARA
1993 Volume 41 Issue 10 Pages
1873-1875
Published: October 15, 1993
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Two new withanolides, physapruins A and B, were isolated from the methanolic extract of the fresh aerial parts of Physalis pruinosa (Solanaceae), and their structures have been determined to be 4β, 14α, 17β, 20β-tetrahydroxy-1-oxo-20S, 22R-witha-2, 5, 24-trienolide (1) and 6β-acetoxy-5α-butoxy-14α-17β-20β-trihydroxy-1-oxo-20S, 22R-witha-2, 24-dienolide (2) on the basis of spectral evidence.
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Shoko YOKOYAMA, Masaaki SUNOHARA, Tadao FUJIE
1993 Volume 41 Issue 10 Pages
1876-1878
Published: October 15, 1993
Released on J-STAGE: March 31, 2008
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The hygroscopicity of 3-aminopyridine (3AP) and fatty acids complexes (FA-3AP) was measured under various levels of humidity at 30°C, where the carbon number (n) of the constituent fatty acid (FA) was 14-18. The release behavior of 3AP from FA-3AP was then examined in a JP XII dissolution test apparatus using JP XII disintegration test medium No. 1 (pH 1.2) at 37°C.3AP was extremely hygroscopic : 3AP was completely deliquesced during storage at relative humidity levels above 80%.In contrast, FA-3AP did not absorb moisture even at 100% relative humidity during at least one month of storage.3AP was released speedily from FA-3AP in the aqueous test medium. The values of T
50 and T
80, which represent the time required for 50% and 80% of 3AP to release, were 1-3 and 2-6min, respectively for five different types of FA-3AP. The values of T
50 or T
80 for FA-3AP formed with odd-numbered FA were larger than those for FA-3AP formed with even-numbered FA, which has an alkyl chain lengh one carbon number longer, though the values of T
50 or T
80 increased rather regularly with an increase in alkyl chain lengh for only even-numbered or odd-numbered FA. This was the same tendency as previously observed for the FA-nicotinamide complex.
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Kiyoshi IKEDA, Tsuyoshi ASAHARA, Kazuo ACHIWA
1993 Volume 41 Issue 10 Pages
1879-1881
Published: October 15, 1993
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New N-acylated L-serine-containing non-phosphorylated and phosphorylated D-glucosamine derivatives structurally corresponding to lipid A disaccharide backbone were synthesized. Compound 4, 5 showed mitogenic activity.
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Norio AIMI, Hideo SEKI, Shin-ichiro SAKAI, Joju HAGINIWA
1993 Volume 41 Issue 10 Pages
1882-1884
Published: October 15, 1993
Released on J-STAGE: March 31, 2008
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A new iridoid glycoside, kinginoside, was isolated from Lonicera morrowii (Caprifoliaceae). Its structure was deduced to be sweroside-6'-O-(4"-O-feruloyl-α-L-rhamnoside mainly by spectroscopic analysis. The structure was confirmed by chemical synthesis of the corresponding acetate from sweroside of known structure.
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Hiroto NAKANO, Hiroshi HONGO
1993 Volume 41 Issue 10 Pages
1885-1887
Published: October 15, 1993
Released on J-STAGE: March 31, 2008
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The efficient photochemical synthesis of photopyridone having an electron-withdrawing group and its high-pressure Diels-Alder cycloaddition, the first examples of an application of the technique relating to photopyridone, are reported.
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