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Koichi Takeya

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TOP 3
Tomoyo Hasuda; Yukio Hitotsuyanagi; Mitsuyuki Shinada; Koichi Takeya
Synthesis of [Tyr-5-Ψ(CH2NMe)-Tyr-6]RA-VII, a reduced peptide bond analogue of RA-VII, an antitumor bicyclic hexapeptide.
Yukio Hitotsuyanagi; Saori Kato; Jun-ichi Kusano; Masumi Odagiri; Haruhiko Fukaya; Tomoyo Hasuda; Koichi Takeya
Isolation, structure determination, and synthesis of allo-RA-V and neo-RA-V, RA-series bicyclic peptides from Rubia cordifolia L.
Tomoyo Hasuda; Yukio Hitotsuyanagi; Koichi Takeya
Monoclonal antibodies from Rubia cordifolia against antitumor cyclohexapeptide deoxybouvardin and their use in immunoassay.

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All Publications

2012: Tomoyo Hasuda; Yukio Hitotsuyanagi; Mitsuyuki Shinada; Koichi Takeya
Synthesis of [Tyr-5-Ψ(CH2NMe)-Tyr-6]RA-VII, a reduced peptide bond analogue of RA-VII, an antitumor bicyclic hexapeptide.
Bioorganic & medicinal chemistry letters 2012;22(8):2757-9.
2012: Yukio Hitotsuyanagi; Saori Kato; Jun-ichi Kusano; Masumi Odagiri; Haruhiko Fukaya; Tomoyo Hasuda; Koichi Takeya
Isolation, structure determination, and synthesis of allo-RA-V and neo-RA-V, RA-series bicyclic peptides from Rubia cordifolia L.
Chemistry (Weinheim an der Bergstrasse, Germany) 2012;18(10):2839-46.
2012: Tomoyo Hasuda; Yukio Hitotsuyanagi; Koichi Takeya
Monoclonal antibodies from Rubia cordifolia against antitumor cyclohexapeptide deoxybouvardin and their use in immunoassay.
Hybridoma (2005) 2012;31(1):20-4.
2011: Tomoyo Hasuda; Yukio Hitotsuyanagi; Koichi Takeya
Production of monoclonal antibodies against antitumor cyclohexapeptide RA-VII from Rubia cordifolia and their characterization.
Journal of natural medicines 2011;65(3-4):588-93.
2011: Yutaka Aoyagi; Yukio Hitotsuyanagi; Tomoyo Hasuda; Haruhiko Fukaya; Koichi Takeya; Ritsuo Aiyama; Takeshi Matsuzaki; Shusuke Hashimoto
Semisynthesis of triptolide analogues: effect of γ-lactone and C-14 substituents on cytotoxic activities.
Bioorganic & medicinal chemistry letters 2011;21(10):3046-9.
2011: Yutaka Aoyagi; Yoshiyuki Adachi; Kei Ozawa; Chihiro Yokomizo; Ming-Yu Gui; Yong-Ri Jin; Xu-Wen Li; Naohito Ohno; Koichi Takeya
Synthesis of rabdokunmin C analogues and their inhibitory effect on NF-κB activation.
Bioorganic & medicinal chemistry 2011;19(7):2450-7.
2011: Yukio Hitotsuyanagi; Ji-Ean Lee; Saori Kato; Ik Hwi Kim; Hideyuki Kohashi; Haruhiko Fukaya; Koichi Takeya
Per-N-methylated analogues of an antitumor bicyclic hexapeptide RA-VII.
Bioorganic & medicinal chemistry 2011;19(7):2458-63.
2011: Chin Hui Kee; Chuan Gee Lim; Hiroshi Morita; Ibrahim Noorbatcha; Koichi Takeya; Azhar Ariffin; Khalijah Awang; Noel Francis Thomas
Cyclization vs. cyclization/dimerization in o-amidostilbene radical cation cascade reactions: the amide question.
Molecules (Basel, Switzerland) 2011;16(9):7267-87.
2010: Chin Hui Kee; Azhar Ariffin; Khalijah Awang; Koichi Takeya; Hiroshi Morita; Salmaan Inayat Hussain; Kok Meng Chan; Pauline J Wood; Michael D Threadgill; Chuan Gee Lim; Seikweng Ng; Jean Frédéric F Weber; Noel F Thomas
Challenges associated with the synthesis of unusual o-carboxamido stilbenes by the Heck protocol: Intriguing substituent effects, their toxicological and chemopreventive implications.
Organic & biomolecular chemistry 2010;8(24):5646-60.
2010: Kartini Ahmad; Noel F Thomas; A Hamid A Hadi; Mat Ropi Mukhtar; Khalit Mohamad; Mohd Azlan Nafiah; Koichi Takeya; Hiroshi Morita; Marc Litaudon; Hiroko Arai; Khalijah Awang
Oppositinines A and B: new vasorelaxant beta-carboline alkaloids from Neisosperma oppositifolia.
Chemical & pharmaceutical bulletin 2010;58(8):1085-7.
2010: Masumi Villeneuve; Mizuo Kawai; Motoko Watanabe; Yutaka Aoyagi; Yukio Hitotsuyanagi; Koichi Takeya; Hiroaki Gouda; Shuichi Hirono; David E Minnikin; Hiroo Nakahara
Differential conformational behaviors of alpha-mycolic acids in Langmuir monolayers and computer simulations.
Chemistry and physics of lipids 2010;163(6):569-79.
2009: Kimihiko Sato; Yasunori Inaba; Hyun-Sun Park; Toshiyuki Akiyama; Tetsuo Koyama; Haruhiko Fukaya; Yutaka Aoyagi; Koichi Takeya
Cytotoxic bisnor- and norditerpene dilactones having 7alpha,8alpha-epoxy-9,11-enolide substructure from Podocarpus macrophyllus D. DON.
Chemical & pharmaceutical bulletin 2009;57(7):668-79.
2009: Khalit Mohamad; Yusuke Hirasawa; Marc Litaudon; Khalijah Awang; A Hamid A Hadi; Koichi Takeya; Wiwied Ekasari; Aty Widyawaruyanti; Noor Cholies Zaini; Hiroshi Morita
Ceramicines B-D, new antiplasmodial limonoids from Chisocheton ceramicus.
Bioorganic & medicinal chemistry 2009;17(2):727-30.
2008: Ji-Ean Lee; Yukio Hitotsuyanagi; Yoshie Nakagawa; Saori Kato; Haruhiko Fukaya; Koichi Takeya
Design and synthesis of a bis(cycloisodityrosine) analogue of RA-VII, an antitumor bicyclic hexapeptide.
Bioorganic & medicinal chemistry letters 2008;18(24):6458-61.
2008: Kimihiko Sato; Keito Sugawara; Hirono Takeuchi; Hyun-Sun Park; Toshiyuki Akiyama; Tetsuo Koyama; Yutaka Aoyagi; Koichi Takeya; Takanori Tsugane; Susumu Shimura
Antibacterial novel phenolic diterpenes from Podocarpus macrophyllus D. Don.
Chemical & pharmaceutical bulletin 2008;56(12):1691-7.
2008: Yutaka Aoyagi; Akira Yamazaki; Chihiro Nakatsugawa; Haruhiko Fukaya; Koichi Takeya; Susumu Kawauchi; Hiroshi Izumi
Salvileucalin B, a novel diterpenoid with an unprecedented rearranged neoclerodane skeleton from Salvia leucantha Cav.
Organic letters 2008;10(20):4429-32.
2008: Ji-Ean Lee; Yukio Hitotsuyanagi; Haruhiko Fukaya; Kazuyuki Kondo; Koichi Takeya
New cytotoxic bicyclic hexapeptides, RA-XXIII and RA-XXIV, from Rubia cordifolia L.
Chemical & pharmaceutical bulletin 2008;56(5):730-3.
2008: Yutaka Aoyagi; Yukio Hitotsuyanagi; Tomoyo Hasuda; Saki Matsuyama; Haruhiko Fukaya; Koichi Takeya; Ritsuo Aiyama; Takeshi Matsuzaki; Shusuke Hashimoto
Fluorination of triptolide and its analogues and their cytotoxicity.
Bioorganic & medicinal chemistry letters 2008;18(7):2459-63.
2008: Ji-Ean Lee; Yukio Hitotsuyanagi; Ik Hwi Kim; Tomoyo Hasuda; Koichi Takeya
A novel bicyclic hexapeptide, RA-XVIII, from Rubia cordifolia: structure, semi-synthesis, and cytotoxicity.
Bioorganic & medicinal chemistry letters 2008;18(2):808-11.
2007: Kumiko Mitsui; Hiroaki Saito; Ryota Yamamura; Haruhiko Fukaya; Yukio Hitotsuyanagi; Koichi Takeya
Apotirucallane and tirucallane triterpenoids from Cedrela sinensis.
Chemical & pharmaceutical bulletin 2007;55(10):1442-7.
2007: Hiroshi Morita; Maiko Enomoto; Yusuke Hirasawa; Toru Iizuka; Kazunori Ogawa; Nobuo Kawahara; Yukihiro Goda; Teruki Matsumoto; Koichi Takeya
Cyclonatsudamine A, a new vasodilator cyclic peptide from Citrus natsudaidai.
Bioorganic & medicinal chemistry letters 2007;17(19):5410-3.
2007: Khalijah Awang; Chong Soon Lim; Khalit Mohamad; Hiroshi Morita; Yusuke Hirasawa; Koichi Takeya; Odile Thoison; A Hamid A Hadi
Erythrocarpines A-E, new cytotoxic limonoids from Chisocheton erythrocarpus.
Bioorganic & medicinal chemistry 2007;15(17):5997-6002.
2007: Masumi Villeneuve; Mizuo Kawai; Motoko Watanabe; Yutaka Aoyagi; Yukio Hitotsuyanagi; Koichi Takeya; Hiroaki Gouda; Shuichi Hirono; David E Minnikin; Hiromichi Nakahara
Conformational behavior of oxygenated mycobacterial mycolic acids from Mycobacterium bovis BCG.
Biochimica et biophysica acta 2007;1768(7):1717-26.
2007: Koichi Nishimura; Yukio Hitotsuyanagi; Noriko Sugeta; Haruhiko Fukaya; Yutaka Aoyagi; Tomoyo Hasuda; Takeshi Kinoshita; Koichi Takeya
Tricalysiamides A-D, diterpenoid alkaloids from Tricalysia dubia.
Journal of natural products 2007;70(5):758-62.
2006: Yutaka Aoyagi; Yoshinao Takahashi; Haruhiko Fukaya; Koichi Takeya; Ritsuo Aiyama; Takeshi Matsuzaki; Shusuke Hashimoto; Teruo Kurihara
Semisynthesis of isetexane diterpenoid analogues and their cytotoxic activity.
Chemical & pharmaceutical bulletin 2006;54(11):1602-4.
2006: Kumiko Mitsui; Hiroaki Saito; Ryota Yamamura; Haruhiko Fukaya; Yukio Hitotsuyanagi; Koichi Takeya
Hydroxylated gedunin derivatives from Cedrela sinensis.
Journal of natural products 2006;69(9):1310-4.
2006: Hiroshi Morita; Michiko Eda; Toru Iizuka; Yusuke Hirasawa; Mitsuhiro Sekiguchi; Young Sook Yun; Hideji Itokawa; Koichi Takeya
Structure of a new cyclic nonapeptide, segetalin F, and vasorelaxant activity of segetalins from Vaccaria segetalis.
Bioorganic & medicinal chemistry letters 2006;16(17):4458-61.
2006: Yutaka Aoyagi; Yumi Nishioka; Fukuya Tobe; Tomoyo Hasuda; Koichi Takeya; Ming-Yu Gui; Yong-Ri Jin; Xu-Wen Li
Synthesis of 1-O-monoacyl or 12-O-monoacyl, 1-,12-O-diacyl-, and 11,12-dehydrated excisanin A 7,14-acetonides and their cytotoxic activity.
Bioorganic & medicinal chemistry 2006;14(17):5802-11.
2006: Hiroshi Morita; Toru Iizuka; Chee Yan Choo; Kit-Lam Chan; Koichi Takeya; Jun'ichi Kobayashi
Vasorelaxant activity of cyclic peptide, cyclosquamosin B, from Annona squamosa.
Bioorganic & medicinal chemistry letters 2006;16(17):4609-11.
2006: Yutaka Aoyagi; Yoshinao Takahashi; Yudai Satake; Koichi Takeya; Ritsuo Aiyama; Takeshi Matsuzaki; Shusuke Hashimoto; Teruo Kurihara
Cytotoxicity of abietane diterpenoids from Perovskia abrotanoides and of their semisynthetic analogues.
Bioorganic & medicinal chemistry 2006;14(15):5285-91.
2006: Takayuki Koizumi; Mayumi Abe; Tohru Yamakuni; Yasushi Ohizumi; Yukio Hitotsuyanagi; Koichi Takeya; Yasufumi Sato
Metronomic scheduling of a cyclic hexapeptide Ra-VII for anti-angiogenesis, tumor vessel maturation and anti-tumor activity.
Cancer science 2006;97(7):665-74.
2006: Hiroshi Morita; Toru Iizuka; Akira Gonda; Hideji Itokawa; Koichi Takeya
Cycloleonuripeptides E and F, cyclic nonapeptides from Leonurus heterophyllus.
Journal of natural products 2006;69(5):839-41.
2006: Yutaka Aoyagi; Yukio Hitotsuyanagi; Tomoyo Hasuda; Haruhiko Fukaya; Koichi Takeya; Ritsuo Aiyama; Takeshi Matsuzaki; Shusuke Hashimoto
Semisynthesis of C-ring modified triptolide analogues and their cytotoxic activities.
Bioorganic & medicinal chemistry letters 2006;16(7):1947-9.
2006: Ik Hwi Kim; Noriko Kaneko; Nahoko Uchiyama; Ji Ean Lee; Koichi Takeya; Nobuo Kawahara; Yukihiro Goda
Two phenylpropanoid glycosides from Neopicrorhiza scrophulariiflora.
Chemical & pharmaceutical bulletin 2006;54(2):275-7.
2005: Hiroshi Morita; Toru Iizuka; Chee Yan Choo; Kit-Lam Chan; Hideji Itokawa; Koichi Takeya
Dichotomins J and K, vasodilator cyclic peptides from Stellaria dichotoma.
Journal of natural products 2005;68(11):1686-8.
2005: Takeshi Kinoshita; Nao Itaki; Maho Hikita; Yutaka Aoyagi; Yukio Hitotsuyanagi; Koichi Takeya
The isolation and structure elucidation of a new sesquiterpene lactone from the poisonous plant Coriaria japonica (Coriariaceae).
Chemical & pharmaceutical bulletin 2005;53(8):1040-2.
2005: Hiroshi Morita; Khalijah Awang; A Hamid A Hadi; Koichi Takeya; Hideji Itokawa; Jun'ichi Kobayashi
Conformational analysis of rhazinilam and three-dimensional quantitative structure-activity relationships of rhazinilam analogues.
Bioorganic & medicinal chemistry letters 2005;15(4):1045-50.
2004: Ik Hwi Kim; Yukio Hitotsuyanagi; Koichi Takeya
Quassinoid glucosides from seeds of Brucea amarissima.
Phytochemistry 2004;65(23):3167-73.
2004: Kumiko Mitsui; Masato Maejima; Haruhiko Fukaya; Yukio Hitotsuyanagi; Koichi Takeya
Limonoids from Cedrela sinensis.
Phytochemistry 2004;65(23):3075-81.
2004: Osamu Shirota; Setsuko Sekita; Motoyoshi Satake; Hiroshi Morita; Koichi Takeya; Hideji Itokawa
Nine new isoxuxuarine-type triterpene dimers from Maytenus chuchuhuasca.
Chemistry & biodiversity 2004;1(9):1296-307.
2004: Osamu Shirota; Setsuko Sekita; Motoyoshi Satake; Hiroshi Morita; Koichi Takeya; Hideji Itokawa
Two cangorosin A type triterpene dimers from Maytenus chuchuhuasca.
Chemical & pharmaceutical bulletin 2004;52(9):1148-50.
2004: Hironori Fujiwara; Shin-ya Saito; Yukio Hitotsuyanagi; Koichi Takeya; Yasushi Ohizumi
RA-VII, a cyclic depsipeptide, changes the conformational structure of actin to cause G2 arrest by the inhibition of cytokinesis.
Cancer letters 2004;209(2):223-9.
2004: Osamu Shirota; Setsuko Sekita; Motoyoshi Satake; Hiroshi Morita; Koichi Takeya; Hideji Itokawa
Nine regioisomeric and stereoisomeric triterpene dimers from Maytenus chuchuhuasca.
Chemical & pharmaceutical bulletin 2004;52(6):739-46.
2004: Ik Hwi Kim; Satoru Takashima; Yukio Hitotsuyanagi; Tomoyo Hasuda; Koichi Takeya
New quassinoids, javanicolides C and D and javanicosides B--F, from seeds of Brucea javanica.
Journal of natural products 2004;67(5):863-8.
2004: Yukio Hitotsuyanagi; Shuichi Motegi; Tomoyo Hasuda; Koichi Takeya
Semisynthesis of an analogue of antitumor bicyclic hexapeptide RA-VII by fixing the Ala-2/Tyr-3 bond to Cis by incorporating a triazole cis-amide bond surrogate.
Organic letters 2004;6(7):1111-4.
2004: Yukio Hitotsuyanagi; Tomoyo Hasuda; Takayuki Aihara; Hiroshi Ishikawa; Kentaro Yamaguchi; Hideji Itokawa; Koichi Takeya
Synthesis of [Gly-1]RA-VII, [Gly-2]RA-VII, and [Gly-4]RA-VII. Glycine-containing analogues of RA-VII, an antitumor bicyclic hexapeptide from Rubia plants.
The Journal of organic chemistry 2004;69(5):1481-6.
2004: Ming-Yu Gui; Yutaka Aoyagi; Yong-Ri Jin; Xu-Wen Li; Tomoyo Hasuda; Koichi Takeya
Excisanin H, a novel cytotoxic 14,20-epoxy-ent-kaurene diterpenoid, and three new ent-kaurene diterpenoids from Rabdosia excisa.
Journal of natural products 2004;67(3):373-6.
2003: Yutaka Aoyagi; Yoshihiro Saitoh; Tasuku Ueno; Mai Horiguchi; Koichi Takeya; Robert M Williams
Lipase TL-mediated kinetic tesolution of 5-benzyloxy-1-tert-butyldimethylsilyloxy-2-pentanol at low temperature: concise asymmetric synthesis of both enantiomers of a piperazic acid derivative.
The Journal of organic chemistry 2003;68(18):6899-904.
2003: Yukio Hitotsuyanagi; Shin-Ichi Sasaki; Yuji Matsumoto; Kentaro Yamaguchi; Hideji Itokawa; Koichi Takeya
Synthesis of [L-Ala-1]RA-VII, [D-Ala-2]RA-VII, and [D-Ala-4]RA-VII by epimerization of RA-VII, an antitumor bicyclic hexapeptide from Rubia plants, through oxazoles.
Journal of the American Chemical Society 2003;125(24):7284-90.
2003: Hyun-Sun Park; Yoshinao Takahashi; Haruhiko Fukaya; Yutaka Aoyagi; Koichi Takeya
S(R)-podolactone D, a new sulfoxide-containing norditerpene dilactone from Podocarpus macrophyllus var. maki.
Journal of natural products 2003;66(2):282-4.
2002: Yoshiaki Kamano; Ayano Yamashita; Toshihiko Nogawa; Hiroshi Morita; Koichi Takeya; Hideji Itokawa; Toshiaki Segawa; Ayako Yukita; Kyoko Saito; Mariko Katsuyama; George R Pettit
QSAR evaluation of the Ch'an Su and related bufadienolides against the colchicine-resistant primary liver carcinoma cell line PLC/PRF/5(1).
Journal of medicinal chemistry 2002;45(25):5440-7.
2002: Teruki Matsumoto; Koichi Nishimura; Koichi Takeya
New cyclic peptides from Citrus medica var. sarcodactylis SWINGLE.
Chemical & pharmaceutical bulletin 2002;50(6):857-60.
2002: Yukio Hitotsuyanagi; Shuichi Motegi; Haruhiko Fukaya; Koichi Takeya
A cis amide bond surrogate incorporating 1,2,4-triazole.
The Journal of organic chemistry 2002;67(10):3266-71.
2002: Hooi Hoon Ang; Yukio Hitotsuyanagi; Haruhiko Fukaya; Koichi Takeya
Quassinoids from Eurycoma longifolia.
Phytochemistry 2002;59(8):833-7.
2001: Yukio Hitotsuyanagi; A Ozeki; Hideji Itokawa; S de Mello Alves; Koichi Takeya
Cedronolactone E, a novel C(19) quassinoid from Simaba cedron.
Journal of natural products 2001;64(12):1583-4.
2001: Jun'ichi Kobayashi; H Suzuki; Kazutaka Shimbo; Koichi Takeya; Hiroshi Morita
Celogentins A-C, new antimitotic bicyclic peptides from the seeds of Celosia argentea.
The Journal of organic chemistry 2001;66(20):6626-33.
2001: Chee Yan Choo; K L Chan; T W Sam; Yukio Hitotsuyanagi; Koichi Takeya
The cytotoxicity and chemical constituents of the hexane fraction of Typhonium flagelliforme (Araceace).
Journal of ethnopharmacology 2001;77(1):129-31.
2001: T Matsumoto; A Shishido; H Morita; Hideji Itokawa; Koichi Takeya
Cyclolinopeptides F-I, cyclic peptides from linseed.
Phytochemistry 2001;57(2):251-60.
2001: Chee Yan Choo; Kit-Lam Chan; Koichi Takeya; Hideji Itokawa
Cytotoxic activity of Typhonium flagelliforme (Araceae).
Phytotherapy research : PTR 2001;15(3):260-2.
2000: M Haraguchi; Y Mimaki; M Motidome; H Morita; Koichi Takeya; Hideji Itokawa; A Yokosuka; Y Sashida
Steroidal saponins from the leaves of Cestrum sendtenerianum.
Phytochemistry 2000;55(7):715-20.
2000: Hiroshi Morita; Yoshihiro Sato; Kit-Lam Chan; Chee Yan Choo; Hideji Itokawa; Koichi Takeya; Jun'ichi Kobayashi
Samoquasine A, a benzoquinazoline alkaloid from the seeds of Annona squamosa.
Journal of natural products 2000;63(12):1707-8.
2000: Yukio Hitotsuyanagi; M Fukuyo; K Tsuda; M Kobayashi; A Ozeki; Hideji Itokawa; Koichi Takeya
4-Aza-2,3-dehydro-4-deoxypodophyllotoxins: simple aza-podophyllotoxin analogues possessing potent cytotoxicity.
Bioorganic & medicinal chemistry letters 2000;10(4):315-7.
1999: Hideji Itokawa; Koichi Takeya; Yukio Hitotsuyanagi; H Morita
[Antitumor compounds isolated from higher plants].
Yakugaku zasshi : Journal of the Pharmaceutical Society of Japan 1999;119(8):529-83.
1998: Yoshiaki Kamano; A Kotake; H Hashima; M Inoue; H Morita; Koichi Takeya; Hideji Itokawa; N Nandachi; T Segawa; A Yukita; K Saitou; M Katsuyama; George R Pettit
Structure-cytotoxic activity relationship for the toad poison bufadienolides.
Bioorganic & medicinal chemistry 1998;6(7):1103-15.
1998: A Ozeki; Yukio Hitotsuyanagi; E Hashimoto; Hideji Itokawa; Koichi Takeya; S de Mello Alves
Cytotoxic quassinoids from Simaba cedron.
Journal of natural products 1998;61(6):776-80.
1998: Y S Yun; K Shimizu; H Morita; Koichi Takeya; Hideji Itokawa; Osamu Shirota
Triterpenoid saponin from Vaccaria segetalis.
Phytochemistry 1998;47(1):143-4.
1997: H Morita; Y S Yun; Koichi Takeya; Hideji Itokawa
Conformational preference for segetalins G and H, cyclic peptides with estrogen-like activity from seeds of Vaccaria segetalis.
Bioorganic & medicinal chemistry 1997;5(11):2063-7.
1997: C Hirobe; Z S Qiao; Koichi Takeya; Hideji Itokawa
Cytotoxic flavonoids from Vitex agnus-castus.
Phytochemistry 1997;46(3):521-4.
1997: H Morita; Koichi Takeya; Hideji Itokawa
Cyclic octapeptides from Stellaria dichotoma var. lanceolata.
Phytochemistry 1997;45(4):841-5.
1997: Hiroshi Morita; Akira Gonda; L Wei; Y Yamamura; Koichi Takeya; Hideji Itokawa
Taxuspinananes A and B, new taxoids from Taxus cuspidata var. nana.
Journal of natural products 1997;60(4):390-2.
1997: Y S Yun; Hiroshi Morita; Koichi Takeya; Hideji Itokawa
Cyclic peptides from higher plants. 34. Segetalins G and H, structures and estrogen-like activity of cyclic pentapeptides from Vaccaria segetalis.
Journal of natural products 1997;60(3):216-8.
1997: H Morita; Y S Yun; Koichi Takeya; Hideji Itokawa; Osamu Shirota
Thionation of segetalins A and B, cyclic peptides with estrogen-like activity from seeds of Vaccaria segetalis.
Bioorganic & medicinal chemistry 1997;5(3):631-6.
1997: Hidekazu Nagaya; Yoneko Tobita; T Nagae; Hideji Itokawa; Koichi Takeya; A F Halim; Osama B Abdel-Halim
Cytotoxic triterpenes from Cleome africana.
Phytochemistry 1997;44(6):1115-9.
1997: Ichiro Takano; Ichiro Yasuda; M Nishijima; Y Yanagi; Koichi Takeya; Hideji Itokawa
Ester-type cephalotaxus alkaloids from Cephalotaxus harringtonia var. drupacea.
Phytochemistry 1997;44(4):735-8.
1996: H Morita; T Kayashita; Koichi Takeya; Hideji Itokawa
Conformational analysis of a cyclic heptapeptide, pseudostellarin D by molecular dynamics and Monte Carlo simulations.
Chemical & pharmaceutical bulletin 1996;44(11):2177-80.
1996: Koichi Takeya; Z S Quio; C Hirobe; Hideji Itokawa
Cytotoxic trichilin-type limonoids from Melia azedarach.
Bioorganic & medicinal chemistry 1996;4(8):1355-9.
1996: A A el-Gamal; Koichi Takeya; Hideji Itokawa; A F Halim; M M Amer; H E Saad; S A Awad
Anthraquinones from the polar fractions of Galium sinaicum.
Phytochemistry 1996;42(4):1149-55.
1996: Koichi Takeya; Z S Qiao; C Hirobe; Hideji Itokawa
Cytotoxic azadirachtin-type limonoids from Melia azedarach.
Phytochemistry 1996;42(3):709-12.
1996: H Morita; S Nagashima; Y Uchiumi; O Kuroki; Koichi Takeya; Hideji Itokawa
Cyclic peptides from higher plants. XXVIII. Antitumor activity and hepatic microsomal biotransformation of cyclic pentapeptides, astins, from Aster tataricus.
Chemical & pharmaceutical bulletin 1996;44(5):1026-32.
1996: H Morita; Y S Yun; Koichi Takeya; Hideji Itokawa; Osamu Shirota
A cyclic heptapeptide from Vaccaria segetalis.
Phytochemistry 1996;42(2):439-41.
1996: Hiroshi Morita; T Kayashita; M Shimomura; Koichi Takeya; Hideji Itokawa
Cyclic peptides from higher plants. 24.1 yunnanin C, a novel cyclic heptapeptide from Stellaria yunnanensis.
Journal of natural products 1996;59(3):280-2.
1995: Hideji Itokawa; Y Yun; H Morita; Koichi Takeya; K Yamada
Estrogen-like activity of cyclic peptides from Vaccaria segetalis extracts.
Planta medica 1995;61(6):561-2.
1995: H Morita; S Nagashima; Koichi Takeya; Hideji Itokawa
Solution forms of antitumor cyclic pentapeptides with 3,4-dichlorinated proline residues, astins A and C, from Aster tataricus.
Chemical & pharmaceutical bulletin 1995;43(8):1395-7.
1995: Hideji Itokawa; Z S Qiao; C Hirobe; Koichi Takeya
Cytotoxic limonoids and tetranortriterpenoids from Melia azedarach.
Chemical & pharmaceutical bulletin 1995;43(7):1171-5.
1995: Hiroshi Morita; T Kayashita; Koichi Takeya; Hideji Itokawa
Cyclic peptides from higher plants, Part 15. Pseudostellarin H, a new cyclic octapeptide from Pseudostellaria heterophylla.
Journal of natural products 1995;58(6):943-7.
1995: H Morita; S Nagashima; Koichi Takeya; Hideji Itokawa
Structure of a new peptide, astin J, from Aster tataricus.
Chemical & pharmaceutical bulletin 1995;43(2):271-3.
1994: Osamu Shirota; H Morita; Koichi Takeya; Hideji Itokawa
Cytotoxic aromatic triterpenes from Maytenus ilicifolia and Maytenus chuchuhuasca.
Journal of natural products 1994;57(12):1675-81.
1994: Hideji Itokawa; T Miyashita; H Morita; Koichi Takeya; T Hirano; M Homma; K Oka
Structural and conformational studies of [Ile7] and [Leu7]surfactins from Bacillus subtilis natto.
Chemical & pharmaceutical bulletin 1994;42(3):604-7.
1993: Hideji Itokawa; Z Z Ibraheim; Y F Qiao; Koichi Takeya
Anthraquinones, naphthohydroquinones and naphthohydroquinone dimers from Rubia cordifolia and their cytotoxic activity.
Chemical & pharmaceutical bulletin 1993;41(10):1869-72.
1993: H Morita; K Matsumoto; Koichi Takeya; Hideji Itokawa
Conformation of tropolone ring in antileukemic tropoloisoquinoline alkaloids.
Chemical & pharmaceutical bulletin 1993;41(8):1478-80.
1993: H Morita; K Matsumoto; Koichi Takeya; Hideji Itokawa; Y Iitaka
Structures and solid state tautomeric forms of two novel antileukemic tropoloisoquinoline alkaloids, pareirubrines A and B, from Cissampelos pareira.
Chemical & pharmaceutical bulletin 1993;41(8):1418-22.
1993: Hideji Itokawa; K Kondo; Yukio Hitotsuyanagi; M Isomura; Koichi Takeya
Studies on RA derivatives. V. Synthesis and antitumor activity of Ala2-modified RA-VII derivatives.
Chemical & pharmaceutical bulletin 1993;41(8):1402-10.
1993: Hideji Itokawa; K Kondo; Yukio Hitotsuyanagi; A Nakamura; H Morita; Koichi Takeya
Preparation and cytotoxicity of cyclic hexapeptides, RA derivatives.
Chemical & pharmaceutical bulletin 1993;41(7):1266-9.
1993: Hideji Itokawa; K Masuyama; H Morita; Koichi Takeya
Cytotoxic sesquiterpenes from Nardostachys chinensis.
Chemical & pharmaceutical bulletin 1993;41(6):1183-4.
1993: Koichi Takeya; T Yamamiya; H Morita; Hideji Itokawa
Two antitumour bicyclic hexapeptides from Rubia cordifolia.
Phytochemistry 1993;33(3):613-5.
1993: H Morita; S Nagashima; Koichi Takeya; Hideji Itokawa
Astins A and B, antitumor cyclic pentapeptides from Aster tataricus.
Chemical & pharmaceutical bulletin 1993;41(5):992-3.
1993: K Oka; T Hirano; M Homma; H Ishii; K Murakami; S Mogami; A Motizuki; H Morita; Koichi Takeya; Hideji Itokawa
Satisfactory separation and MS-MS spectrometry of six surfactins isolated from Bacillus subtilis natto.
Chemical & pharmaceutical bulletin 1993;41(5):1000-2.
1993: H Morita; T Yamamiya; Koichi Takeya; Hideji Itokawa; Chiseko Sakuma; J Yamada; T Suga
Conformational recognition of RA-XII by 80S ribosomes: a differential line broadening study in 1H NMR spectroscopy.
Chemical & pharmaceutical bulletin 1993;41(4):781-3.
1992: Y Ichihara; Koichi Takeya; Yukio Hitotsuyanagi; H Morita; S Okuyama; M Suganuma; H Fujiki; M Motidome; Hideji Itokawa
Cajucarinolide and isocajucarinolide: anti-inflammatory diterpenes from Croton cajucara.
Planta medica 1992;58(6):549-51.
1992: Hideji Itokawa; K Saitou; H Morita; Koichi Takeya; K Yamada
Structures and conformations of metabolites of antitumor cyclic hexapeptides, RA-VII and RA-X.
Chemical & pharmaceutical bulletin 1992;40(11):2984-9.
1992: H Morita; T Yamamiya; Koichi Takeya; Hideji Itokawa
New antitumor bicyclic hexapeptides, RA-XI, -XII, -XIII and -XIV from Rubia cordifolia.
Chemical & pharmaceutical bulletin 1992;40(5):1352-4.
1992: Hideji Itokawa; H Morita; Koichi Takeya
Solution forms of an antitumor cyclic hexapeptide, RA-VII in dimethyl sulfoxide-d6 from nuclear magnetic resonance studies.
Chemical & pharmaceutical bulletin 1992;40(4):1050-2.
1991: Hideji Itokawa; K Saitou; H Morita; Koichi Takeya
Conformational analysis of [n-demethyl-Tyr(OCH3)-3]RA-VII, conformationally restricted model approach.
Chemical & pharmaceutical bulletin 1991;39(8):2161-3.
1991: Hideji Itokawa; Y Ichihara; M Mochizuki; T Enomori; H Morita; Osamu Shirota; M Inamatsu; Koichi Takeya
A cytotoxic substance from Sangre de Grado.
Chemical & pharmaceutical bulletin 1991;39(4):1041-2.
1991: H Morita; M Nakayama; H Kojima; Koichi Takeya; Hideji Itokawa; E P Schenkel; M Motidome
Structures and cytotoxic activity relationship of casearins, new clerodane diterpenes from Casearia sylvestris Sw.
Chemical & pharmaceutical bulletin 1991;39(3):693-7.
1990: Hideji Itokawa; N Totsuka; H Morita; Koichi Takeya; Y Iitaka; E P Schenkel; M Motidome
New antitumor principles, casearins A-F, for Casearia sylvestris Sw. (Flacourtiaceae).
Chemical & pharmaceutical bulletin 1990;38(12):3384-8.
1989: Hideji Itokawa; N Totsuka; K Nakahara; M Maezuru; Koichi Takeya; M Kondo; M Inamatsu; H Morita
A quantitative structure-activity relationship for antitumor activity of long-chain phenols from Ginkgo biloba L.
Chemical & pharmaceutical bulletin 1989;37(6):1619-21.
1988: Hideji Itokawa; H Morita; I Katou; Koichi Takeya; A J Cavalheiro; R C de Oliveira; M Ishige; M Motidome
Cytotoxic diterpenes from the rhizomes of Hedychium coronarium.
Planta medica 1988;54(4):311-5.
1988: Hideji Itokawa; H Morita; Koichi Takeya; M Motidome
Diterpenes from rhizomes of Hedychium coronarium.
Chemical & pharmaceutical bulletin 1988;36(7):2682-4.
1988: Hideji Itokawa; N Totsuka; Koichi Takeya; K Watanabe; E Obata
Antitumor principles from Casearia sylvestris Sw. (Flacourtiaceae), structure elucidation of new clerodane diterpenes by 2-D NMR spectroscopy.
Chemical & pharmaceutical bulletin 1988;36(4):1585-8.
1987: Hideji Itokawa; N Totsuka; K Nakahara; Koichi Takeya; Jean-Pierre Lepoittevin; Y Asakawa
Antitumor principles from Ginkgo biloba L.
Chemical & pharmaceutical bulletin 1987;35(7):3016-20.
1987: Hideji Itokawa; H Morita; T Sumitomo; N Totsuka; Koichi Takeya
Antitumour principles from Alpinia galanga.
Planta medica 1987;53(1):32-3.