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Koichi Takeya

Koichi Takeya

D-Index & Metrics

Discipline name D-Index World Ranking Current World Ranking National Ranking Current National Ranking Publications Citations
Chemistry 65 7779 7057 518 486 414 13036

Koichi Takeya publications per year

The chart shows the history of publications by Koichi Takeya between 1975 and 2025, highlighting the no. of papers published in each year and offering an overview of the publication velocity of this scholar. Koichi Takeya published across 51 years, from 1975 to 2025, averaging 8.3 papers a year. Output peaked at 34 publications in 1997. 2 of the 422 publications appeared in the last two years.

No. of publications
10 20 30
Bar chart. Horizontal axis: year, 1975 to 2025. Vertical axis: number of publications, 0 to 34. Peak 34 publications in 1997. 1975: 1 publication 1976: 1 publication 1977: 1 publication 1978: 0 publications 1979: 1 publication 1980: 1 publication 1981: 4 publications 1982: 2 publications 1983: 2 publications 1984: 4 publications 1985: 1 publication 1986: 2 publications 1987: 9 publications 1988: 7 publications 1989: 9 publications 1990: 9 publications 1991: 12 publications 1992: 17 publications 1993: 28 publications 1994: 25 publications 1995: 33 publications 1996: 30 publications 1997: 34 publications 1998: 11 publications 1999: 8 publications 2000: 9 publications 2001: 8 publications 2002: 6 publications 2003: 7 publications 2004: 20 publications 2005: 7 publications 2006: 15 publications 2007: 11 publications 2008: 17 publications 2009: 9 publications 2010: 12 publications 2011: 9 publications 2012: 6 publications 2013: 11 publications 2014: 5 publications 2015: 1 publication 2016: 1 publication 2017: 1 publication 2018: 4 publications 2019: 2 publications 2020: 1 publication 2021: 2 publications 2022: 2 publications 2023: 2 publications 2024: 1 publication 2025: 1 publication
1975 2025

422 publications in total across all disciplines

View publications per year as a table
Koichi Takeya: publications per year, 1975 to 2025
Year Publications
1975 1
1976 1
1977 1
1978 0
1979 1
1980 1
1981 4
1982 2
1983 2
1984 4
1985 1
1986 2
1987 9
1988 7
1989 9
1990 9
1991 12
1992 17
1993 28
1994 25
1995 33
1996 30
1997 34
1998 11
1999 8
2000 9
2001 8
2002 6
2003 7
2004 20
2005 7
2006 15
2007 11
2008 17
2009 9
2010 12
2011 9
2012 6
2013 11
2014 5
2015 1
2016 1
2017 1
2018 4
2019 2
2020 1
2021 2
2022 2
2023 2
2024 1
2025 1
Total 422
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Koichi Takeya publication distribution in Chemistry in 2026

The chart shows the distribution of publications by all Research.com ranked scientists in the field of Chemistry in 2026. The highlighted bar marks where Koichi Takeya sits on this spectrum.

No. of scientists
250 500 750 1,000 1,250
Bar chart with 63 bars. Horizontal axis: publications, 61–80 to 1,295+. Vertical axis: number of scientists, 0 to 1,350. Most scientists, 1,350, have 161–180 publications. The last bar groups every scientist with 1,295 publications or more. The highlighted bar, 401–420 publications, is where this scientist sits. 61–80 publications: 66 scientists 81–100 publications: 302 scientists 101–120 publications: 623 scientists 121–140 publications: 918 scientists 141–160 publications: 1,218 scientists 161–180 publications: 1,350 scientists 181–200 publications: 1,344 scientists 201–220 publications: 1,281 scientists 221–240 publications: 1,216 scientists 241–260 publications: 1,100 scientists 261–280 publications: 979 scientists 281–300 publications: 939 scientists 301–320 publications: 764 scientists 321–340 publications: 643 scientists 341–360 publications: 628 scientists 361–380 publications: 522 scientists 381–400 publications: 459 scientists 401–420 publications: 397 scientists 421–440 publications: 327 scientists 441–460 publications: 270 scientists 461–480 publications: 265 scientists 481–500 publications: 252 scientists 501–520 publications: 201 scientists 521–540 publications: 185 scientists 541–560 publications: 148 scientists 561–580 publications: 148 scientists 581–600 publications: 132 scientists 601–620 publications: 114 scientists 621–640 publications: 104 scientists 641–660 publications: 91 scientists 661–680 publications: 92 scientists 681–700 publications: 73 scientists 701–720 publications: 57 scientists 721–740 publications: 54 scientists 741–760 publications: 67 scientists 761–780 publications: 45 scientists 781–800 publications: 46 scientists 801–820 publications: 39 scientists 821–840 publications: 32 scientists 841–860 publications: 36 scientists 861–880 publications: 29 scientists 881–900 publications: 26 scientists 901–920 publications: 24 scientists 921–940 publications: 14 scientists 941–960 publications: 23 scientists 961–980 publications: 28 scientists 981–1,000 publications: 15 scientists 1,001–1,020 publications: 29 scientists 1,021–1,040 publications: 12 scientists 1,041–1,060 publications: 19 scientists 1,061–1,080 publications: 12 scientists 1,081–1,100 publications: 6 scientists 1,101–1,120 publications: 8 scientists 1,121–1,140 publications: 12 scientists 1,141–1,160 publications: 5 scientists 1,161–1,180 publications: 6 scientists 1,181–1,200 publications: 14 scientists 1,201–1,220 publications: 7 scientists 1,221–1,240 publications: 2 scientists 1,241–1,260 publications: 6 scientists 1,261–1,280 publications: 4 scientists 1,281–1,294 publications: 6 scientists 1,295+ publications: 100 scientists
61–80 publications 1,295+

This scientist: 414 publications — 82nd percentile

82% of scientists in this discipline score the same or lower.

The last bar groups every scientist with 1,295 publications or more.

View publications distribution as a table
Number of Chemistry scientists by publication count, Research.com 2026 ranking edition. Based on 17,934 ranked scientists.
Publications Scientists This scientist
61–80 66
81–100 302
101–120 623
121–140 918
141–160 1,218
161–180 1,350
181–200 1,344
201–220 1,281
221–240 1,216
241–260 1,100
261–280 979
281–300 939
301–320 764
321–340 643
341–360 628
361–380 522
381–400 459
401–420 397 414
421–440 327
441–460 270
461–480 265
481–500 252
501–520 201
521–540 185
541–560 148
561–580 148
581–600 132
601–620 114
621–640 104
641–660 91
661–680 92
681–700 73
701–720 57
721–740 54
741–760 67
761–780 45
781–800 46
801–820 39
821–840 32
841–860 36
861–880 29
881–900 26
901–920 24
921–940 14
941–960 23
961–980 28
981–1,000 15
1,001–1,020 29
1,021–1,040 12
1,041–1,060 19
1,061–1,080 12
1,081–1,100 6
1,101–1,120 8
1,121–1,140 12
1,141–1,160 5
1,161–1,180 6
1,181–1,200 14
1,201–1,220 7
1,221–1,240 2
1,241–1,260 6
1,261–1,280 4
1,281–1,294 6
1,295+ 100
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Koichi Takeya D-index placement in Chemistry in 2026

The chart shows the D-index (discipline H-index) distribution of Chemistry scientists ranked by Research.com in 2026. The highlighted bar marks where Koichi Takeya sits on this spectrum.

No. of scientists
250 500 750 1,000
Bar chart with 61 bars. Horizontal axis: D-Index, 40–41 to 159+. Vertical axis: number of scientists, 0 to 1,051. Most scientists, 1,051, have 56–57 D-Index. The last bar groups every scientist with 159 D-Index or more. The highlighted bar, 64–65 D-Index, is where this scientist sits. 40–41 D-Index: 289 scientists 42–43 D-Index: 612 scientists 44–45 D-Index: 808 scientists 46–47 D-Index: 776 scientists 48–49 D-Index: 835 scientists 50–51 D-Index: 861 scientists 52–53 D-Index: 872 scientists 54–55 D-Index: 933 scientists 56–57 D-Index: 1,051 scientists 58–59 D-Index: 930 scientists 60–61 D-Index: 882 scientists 62–63 D-Index: 834 scientists 64–65 D-Index: 731 scientists 66–67 D-Index: 775 scientists 68–69 D-Index: 683 scientists 70–71 D-Index: 646 scientists 72–73 D-Index: 561 scientists 74–75 D-Index: 501 scientists 76–77 D-Index: 437 scientists 78–79 D-Index: 388 scientists 80–81 D-Index: 354 scientists 82–83 D-Index: 292 scientists 84–85 D-Index: 275 scientists 86–87 D-Index: 254 scientists 88–89 D-Index: 235 scientists 90–91 D-Index: 185 scientists 92–93 D-Index: 192 scientists 94–95 D-Index: 155 scientists 96–97 D-Index: 163 scientists 98–99 D-Index: 125 scientists 100–101 D-Index: 105 scientists 102–103 D-Index: 105 scientists 104–105 D-Index: 112 scientists 106–107 D-Index: 88 scientists 108–109 D-Index: 68 scientists 110–111 D-Index: 69 scientists 112–113 D-Index: 65 scientists 114–115 D-Index: 79 scientists 116–117 D-Index: 61 scientists 118–119 D-Index: 44 scientists 120–121 D-Index: 37 scientists 122–123 D-Index: 40 scientists 124–125 D-Index: 33 scientists 126–127 D-Index: 26 scientists 128–129 D-Index: 34 scientists 130–131 D-Index: 35 scientists 132–133 D-Index: 25 scientists 134–135 D-Index: 27 scientists 136–137 D-Index: 17 scientists 138–139 D-Index: 16 scientists 140–141 D-Index: 20 scientists 142–143 D-Index: 20 scientists 144–145 D-Index: 15 scientists 146–147 D-Index: 9 scientists 148–149 D-Index: 9 scientists 150–151 D-Index: 16 scientists 152–153 D-Index: 11 scientists 154–155 D-Index: 9 scientists 156–157 D-Index: 3 scientists 158 D-Index: 3 scientists 159+ D-Index: 98 scientists
40–41 D-Index 159+

This scientist: 65 D-Index — 58th percentile

58% of scientists in this discipline score the same or lower.

The last bar groups every scientist with 159 D-Index or more.

View D-Index distribution as a table
Number of Chemistry scientists by D-index, Research.com 2026 ranking edition. Based on 17,934 ranked scientists.
D-Index Scientists This scientist
40–41 289
42–43 612
44–45 808
46–47 776
48–49 835
50–51 861
52–53 872
54–55 933
56–57 1,051
58–59 930
60–61 882
62–63 834
64–65 731 65
66–67 775
68–69 683
70–71 646
72–73 561
74–75 501
76–77 437
78–79 388
80–81 354
82–83 292
84–85 275
86–87 254
88–89 235
90–91 185
92–93 192
94–95 155
96–97 163
98–99 125
100–101 105
102–103 105
104–105 112
106–107 88
108–109 68
110–111 69
112–113 65
114–115 79
116–117 61
118–119 44
120–121 37
122–123 40
124–125 33
126–127 26
128–129 34
130–131 35
132–133 25
134–135 27
136–137 17
138–139 16
140–141 20
142–143 20
144–145 15
146–147 9
148–149 9
150–151 16
152–153 11
154–155 9
156–157 3
158 3
159+ 98
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Overview

Koichi Takeya is affiliated with the University of Tokyo in Japan. Their research primarily spans the fields of biochemistry, genetics, molecular biology, and medicine. Within these domains, Takeya has contributed to studies in molecular biology, pharmacology, biochemistry, plant science, and complementary and alternative medicine.

The scientist's work focuses on various topics related to natural compounds and their biological properties. Key research themes include the biological activity of diterpenoids and biflavonoids, synthesis of organic compounds, traditional and medicinal uses of Annonaceae plants, natural compound pharmacology studies, traditional Chinese medicine analysis, phytochemistry and biological activities, and natural product bioactivities and synthesis.

Takeya has authored publications in a range of scientific journals, with frequent appearances in:

  • Tetrahedron Letters
  • Bioorganic & Medicinal Chemistry Letters
  • Molecules
  • Heterocycles
  • Chemical and Pharmaceutical Bulletin

Recent published works by Takeya include:

  • "Structures of bicyclic hexapeptides RA-XXVII and RA-XXVIII from Rubia cordifolia L." (2024, Tetrahedron Letters)
  • "Garcinielliptone G from Garcinia subelliptica Induces Apoptosis in Acute Leukemia Cells" (2021, Molecules)
  • "Five New Highly Oxidized Neoclerodane Diterpenes, Salvileucalins E-I from Salvia leucantha" (2020, Heterocycles)
  • "Semisynthesis of Antitrypanosomal p-Quinone Analog Possesing the Komaroviquinone Pharmacophore" (2022, Chemical and Pharmaceutical Bulletin)
  • "Antitumor Agents. 282. 2'-(R)-O-Acetylglaucarubinone, a Quassinoid from Odyendyea gabonensis As a Potential Anti-Breast and Anti-Ovarian Cancer Agent" (2020, UNC Libraries)

Takeya frequently collaborates with several researchers, including Yukio Hitotsuyanagi, Yutaka Aoyagi, Reiko Yano, Haruhiko Fukaya, and Tomoyo Hasuda. The collaboration network indicates sustained partnerships within the field.

Best Publications

  • Structure–cytotoxic activity relationship for the toad poison bufadienolides

    Yoshiaki Kamano;Ayano Kotake;Hirofumi Hashima;Masuo Inoue

  • Studies on a Novel Anthraquinone and Its Glycosides isolated from Rubia cordifolia and R. akane

    Hideji Itokawa;Kazuhiko Mihara;Koichi Takeya

  • Antitumor principles from Ginkgo biloba L.

    Hider Itokawa;Nobuo Totsuka;Keisuke Nakahara;Koichi Takeya

  • Anthraquinones, Naphthohydroquinones and Naphthohydroquinone Dimers from Rubia cordifolia and Their Cytotoxic Activity

    Hideji Itokawa;Zedan Z. Ibraheim;Ya-Fang Qiao;Koichi Takeya

  • Isoflavanones from the heartwood of Swartzia polyphylla and their antibacterial activity against cariogenic bacteria.

    Kenji Osawa;Hideyuki Yasuda;Takashi Maruyama;Hiroshi Morita

  • Cytotoxic Quassinoids and Tirucallane-Type Triterpenes from the Woods of Eurycoma longifolia.

    Hideji Itokawa;Etsuko Kishi;Hiroshi Morita;Koichi Takeya

  • QSAR evaluation of the Ch'an Su and related bufadienolides against the colchicine-resistant primary liver carcinoma cell line PLC/PRF/5(1).

    Yoshiaki Kamano;Ayano Yamashita;Toshihiko Nogawa;Hiroshi Morita

  • Studies on the antitumor cyclic hexapeptides obtained from Rubiae radix.

    Hideji Itokawa;Koichi Takeya;Kazuhiko Mihara;Noboru Mori

  • Cytotoxic flavonoids from Vitex agnus-castus

    Chieko Hirobe;Zhi-Sheng Qiao;Koichi Takeya;Hideji Itokawa

  • Structural and conformational studies of [Ile7] and [Leu7]surfactins from Bacillus subtilis natto.

    Hideji Itokawa;Toshihiko Miyashita;Hiroshi Morita;Koichi Takeya

  • Cytotoxic aromatic triterpenes from Maytenus ilicifolia and Maytenus chuchuhuasca.

    O Shirota;H Morita;K Takeya;H Itokawa

  • Diarylheptanoids from the Rhizomes of Curcuma xanthorrhiza and Alpinia officinarum

    Shin-Ichi Uehara;Ichiro Yasuda;Kazuyuki Akiyama;Hiroshi Morita

  • Cytotoxic diterpenes from the rhizomes of Hedychium coronarium.

    H. Itokawa;H. Morita;I. Katou;K. Takeya

  • Studies on the Antitumor Bisabolane Sesquiterpenoids Isolated from Curcuma xanthorrhiza

    Hideji Itokawa;Fusayoshi Hirayama;Kazuko Funakoshi;Koichi Takeya

  • Cyclolinopeptides B - E, new cyclic peptides from Linum usitatissimum

    Hiroshi Morita;Akira Shishido;Teruki Matsumoto;Hideji Itokawa

  • Triterpenes fromMaytenus ilicifolia

    Hideji Itokawa;Osamu Shirota;Hiroshi Ikuta;Hiroshi Morita

  • Antitumour principles from Alpinia galanga.

    Hideji Itokawa;Hiroshi Morita;Takayoshi Sumitomo;Nobuo Totsuka

  • Squalene derivatives from Eurycoma longifolia

    Hiroshi Morita;Etsuko Kishi;Koichi Takeya;Hideji Itokawa

  • 4-Aza-2,3-dehydro-4-deoxypodophyllotoxins: simple aza-podophyllotoxin analogues possessing potent cytotoxicity.

    Yukio Hitotsuyanagi;Masamoto Fukuyo;Kyoko Tsuda;Masatsugu Kobayashi

  • Structures of Amides from Asiasarum heterotropoides MAEK. var. mandshuricum MAEK.

    Ichiro Yasuda;Koichi Takeya;Hideji Itokawa

Frequent Co-Authors

Hideji Itokawa
Hideji Itokawa University of Tokyo
Hiroshi Morita
Hiroshi Morita Hoshi University
Yoichi Iitaka
Yoichi Iitaka University of Tokyo
Khalijah Awang
Khalijah Awang University of Malaya
Yuji Matsumoto
Yuji Matsumoto Nara Institute of Science and Technology
Kentaro Yamaguchi
Kentaro Yamaguchi Tokushima Bunri University
George R. Pettit
George R. Pettit Arizona State University
Jun'ichi Kobayashi
Jun'ichi Kobayashi Hokkaido University
Hiroaki Saito
Hiroaki Saito University of Tokyo
David E. Minnikin
David E. Minnikin University of Birmingham

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