World's Best Scientists 2026 revealed!
Hiromitsu Takayama

Hiromitsu Takayama

D-Index & Metrics

Discipline name D-Index World Ranking Current World Ranking National Ranking Current National Ranking Publications Citations
Chemistry 68 6572 5957 429 402 403 15463

Hiromitsu Takayama publications per year

The chart shows the history of publications by Hiromitsu Takayama between 1979 and 2025, highlighting the no. of papers published in each year and offering an overview of the publication velocity of this scholar. Hiromitsu Takayama published across 47 years, from 1979 to 2025, averaging 8.9 papers a year. Output peaked at 26 publications in 2008. 5 of the 419 publications appeared in the last two years.

No. of publications
5 10 15 20 25
Bar chart. Horizontal axis: year, 1979 to 2025. Vertical axis: number of publications, 0 to 26. Peak 26 publications in 2008. 1979: 1 publication 1980: 1 publication 1981: 2 publications 1982: 4 publications 1983: 0 publications 1984: 2 publications 1985: 0 publications 1986: 4 publications 1987: 9 publications 1988: 3 publications 1989: 7 publications 1990: 6 publications 1991: 8 publications 1992: 11 publications 1993: 7 publications 1994: 18 publications 1995: 15 publications 1996: 14 publications 1997: 20 publications 1998: 18 publications 1999: 12 publications 2000: 12 publications 2001: 11 publications 2002: 21 publications 2003: 14 publications 2004: 16 publications 2005: 12 publications 2006: 16 publications 2007: 12 publications 2008: 26 publications 2009: 17 publications 2010: 14 publications 2011: 14 publications 2012: 10 publications 2013: 2 publications 2014: 14 publications 2015: 6 publications 2016: 7 publications 2017: 4 publications 2018: 5 publications 2019: 9 publications 2020: 3 publications 2021: 4 publications 2022: 2 publications 2023: 1 publication 2024: 1 publication 2025: 4 publications
1979 2025

419 publications in total across all disciplines

View publications per year as a table
Hiromitsu Takayama: publications per year, 1979 to 2025
Year Publications
1979 1
1980 1
1981 2
1982 4
1983 0
1984 2
1985 0
1986 4
1987 9
1988 3
1989 7
1990 6
1991 8
1992 11
1993 7
1994 18
1995 15
1996 14
1997 20
1998 18
1999 12
2000 12
2001 11
2002 21
2003 14
2004 16
2005 12
2006 16
2007 12
2008 26
2009 17
2010 14
2011 14
2012 10
2013 2
2014 14
2015 6
2016 7
2017 4
2018 5
2019 9
2020 3
2021 4
2022 2
2023 1
2024 1
2025 4
Total 419
Download as CSV

Hiromitsu Takayama 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 Hiromitsu Takayama 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: 403 publications — 80th percentile

80% 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
401–420 397 403
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
Download as CSV

Hiromitsu Takayama 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 Hiromitsu Takayama 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, 68–69 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: 68 D-Index — 64th percentile

64% 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
66–67 775
68–69 683 68
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
Download as CSV

Overview

Hiromitsu Takayama is affiliated with Chiba University in Japan and is active in research areas spanning biochemistry, genetics, molecular biology, and chemistry. Their publications reflect a focus on molecular biology and organic chemistry, with notable involvement also in pharmacology, biochemistry, and materials chemistry.

The scientist's research topics concentrate on various aspects of chemical synthesis and alkaloids, cholinesterase and neurodegenerative diseases, as well as alkaloids' synthesis and pharmacology. Other topics include traditional and medicinal uses of Annonaceae, sulfur compounds in biology, redox biology and oxidative stress, and glutathione transferases and polymorphisms.

Frequent collaborators include Mariko Kitajima, Hayato Ishikawa, Shinya Shiomi, Noriyuki Kogure, and Wilailak Kaewsri.

Key publication venues in which Takayama has contributed include:

  • The Journal of Organic Chemistry (2 publications)
  • Journal of Synthetic Organic Chemistry Japan (2 publications)
  • Analytical Methods (1 publication)
  • Chemical and Pharmaceutical Bulletin (1 publication)
  • Journal of the American Chemical Society (1 publication)

Recent significant publications by Takayama include:

  • Total Syntheses of Lycopodium and Monoterpenoid Indole Alkaloids Based on Biosynthesis-Inspired Strategies, 2020, Chemical and Pharmaceutical Bulletin

Other notable papers connected with their research field or coauthors but authored by different primary authors include:

  • Simultaneous determination of intracellular reduced and oxidized glutathiones by the König reaction, 2023, Analytical Methods
  • Asymmetric Total Synthesis and Structure Elucidation of Huperzine H, 2022, The Journal of Organic Chemistry
  • New monoterpenoid indole alkaloids from Gelsemium elegans seeds, 2021, Tetrahedron
  • Elucidation of Absolute Configuration of Ophiorrhiside A by Comparison of ECD Spectra with That of Model Chiral Compound Having a 1,2,3,4-Tetrahydro-β-carbolin-3-one Skeleton, 2020, Heterocycles

Takayama's research integrates synthetic chemical approaches to biologically relevant alkaloids, studying both their chemical and pharmacological properties. The scientific output suggests significant intersections with neurodegenerative disease-related biochemical pathways through cholinesterase-related studies and redox biology.

Best Publications

  • Pteropodine and isopteropodine positively modulate the function of rat muscarinic M1 and 5-HT2 receptors expressed in Xenopus oocyte

    Tai-Hyun Kang;Kinzo Matsumoto;Michihisa Tohda;Yukihisa Murakami

  • Chemistry and pharmacology of analgesic indole alkaloids from the rubiaceous plant, Mitragyna speciosa

    Hiromitsu Takayama

  • Selenosugars are key and urinary metabolites for selenium excretion within the required to low-toxic range.

    Yayoi Kobayashi;Yasumitsu Ogra;Kazuya Ishiwata;Hiromitsu Takayama

  • Studies on the synthesis and opioid agonistic activities of mitragynine-related indole alkaloids: discovery of opioid agonists structurally different from other opioid ligands.

    Hiromitsu Takayama;Hayato Ishikawa;Mika Kurihara;Mariko Kitajima

  • Antinociceptive effect of 7-hydroxymitragynine in mice: Discovery of an orally active opioid analgesic from the Thai medicinal herb Mitragyna speciosa.

    Kenjiro Matsumoto;Syunji Horie;Hayato Ishikawa;Hiromitsu Takayama

  • Rhynchophylline and isorhynchophylline inhibit NMDA receptors expressed in Xenopus oocytes.

    Tai-Hyun Kang;Yukihisa Murakami;Kinzo Matsumoto;Hiromitsu Takayama

  • A New Indole Alkaloid, 7 alpha-Hydroxy-7H-mitragynine, from Mitragyna speciosa in Thailand.

    Dhavadee Ponglux;Sumphan Wongseripipatana;Hiromitsu Takayama;Masae Kikuchi

  • Characterization of a recently evolved flavonol-phenylacyltransferase gene provides signatures of natural light selection in Brassicaceae

    Takayuki Tohge;Regina Wendenburg;Hirofumi Ishihara;Ryo Nakabayashi

  • Two new tryptamine-derived alkaloids from Chimonanthus praecox f. concolor

    Mariko Kitajima;Ikue Mori;Kazumichi Arai;Noriyuki Kogure

  • Feasible production of camptothecin by hairy root culture of Ophiorrhiza pumila

    K. Saito;H. Sudo;M. Yamazaki;M. Koseki-Nakamura

  • Identification of a novel selenium metabolite, Se-methyl-N-acetylselenohexosamine, in rat urine by high-performance liquid chromatography-inductively coupled plasma mass spectrometry and -electrospray ionization tandem mass spectrometry

    Yasumitsu Ogra;Kazuya Ishiwata;Hiromitsu Takayama;Norio Aimi

  • Protective effect of rhynchophylline and isorhynchophylline on in vitro ischemia-induced neuronal damage in the hippocampus: putative neurotransmitter receptors involved in their action

    Tai-Hyun Kang;Yukihisa Murakami;Hiromitsu Takayama;Mariko Kitajima

  • Metabolite profiling of alkaloids and strictosidine synthase activity in camptothecin producing plants.

    Yasuyo Yamazaki;Akiko Urano;Hiroshi Sudo;Mariko Kitajima

  • New type of trimeric and pentameric indole alkaloids from Psychotria rostrata.

    Hiromitsu Takayama;Ikue Mori;Mariko Kitajima;Norio Aimi

  • Prenylated flavonoids and related compounds of the Indonesian Artocarpus (Moraceae)

    Euis H. Hakim;Sjamsul A. Achmad;Lia D. Juliawaty;Lukman Makmur

  • Simultaneous analysis of mitragynine, 7-hydroxymitragynine, and other alkaloids in the psychotropic plant “kratom” ( Mitragyna speciosa ) by LC-ESI-MS

    Ruri Kikura-Hanajiri;Maiko Kawamura;Takuro Maruyama;Mariko Kitajima

  • Dimerization of indole derivatives with hypervalent iodines(III): a new entry for the concise total synthesis of rac- and meso-chimonanthines

    Hayato Ishikawa;Hiromitsu Takayama;Norio Aimi

  • First total synthesis of trimeric indole alkaloid, psychotrimine.

    Yohei Matsuda;Mariko Kitajima;Hiromitsu Takayama

  • Isolation of gelsedine-type indole alkaloids from Gelsemium elegans and evaluation of the cytotoxic activity of gelsemium alkaloids for A431 epidermoid carcinoma cells.

    Mariko Kitajima;Tomonori Nakamura;Noriyuki Kogure;Mio Ogawa

  • Total Synthesis Guided Structure Elucidation of (+)‐Psychotetramine

    Klement Foo;Timothy Newhouse;Ikue Mori;Hiromitsu Takayama

  • Metabolomics-oriented isolation and structure elucidation of 37 compounds including two anthocyanins from Arabidopsis thaliana.

    Ryo Nakabayashi;Miyako Kusano;Makoto Kobayashi;Takayuki Tohge

Frequent Co-Authors

Mariko Kitajima
Mariko Kitajima Chiba University
Hayato Ishikawa
Hayato Ishikawa Kumamoto University
Kentaro Yamaguchi
Kentaro Yamaguchi Tokushima Bunri University
Kazuei Igarashi
Kazuei Igarashi Chiba University
Hiroshi Watanabe
Hiroshi Watanabe Niigata University
Mami Yamazaki
Mami Yamazaki Chiba University
Keiko Kashiwagi
Keiko Kashiwagi Chiba Institute of Science
Kazuo T. Suzuki
Kazuo T. Suzuki Chiba University
Elaine Holmes
Elaine Holmes Imperial College London

If you think any of the details on this page are incorrect, let us know.

Report an issue

We appreciate your kind effort to assist us to improve this page, it would be helpful providing us with as much detail as possible in the text box below:

Related Online Degrees & Career Pathways

For students studying Chemistry in the USA, exploring related online degrees and career pathways can open diverse opportunities. Many programs offer flexibility, such as affordable options that demonstrate how much does it cost to get a criminal justice degree, which may help prospective students budget their education effectively.

Associate degrees are a popular starting point, with offerings like criminal justice associate programs online providing foundational knowledge that can complement chemical expertise, especially in forensics or regulatory careers.

Additionally, career paths such as becoming a paralegal associate degree holder can combine legal skills with scientific understanding, enhancing job prospects in intellectual property or compliance sectors.

For those interested in applying their chemistry background commercially, learning how to get into pharmaceutical sales can be a lucrative option. This path leverages scientific knowledge while developing communication and sales expertise.

Exploring these related degrees and career pathways can help Chemistry students find versatile roles that match their skills and interests.

Best Scientists Citing Hiromitsu Takayama

Trending Scientists

Recently Published Articles