G Koyama

649 total citations
21 papers, 462 citations indexed

About

G Koyama is a scholar working on Molecular Biology, Organic Chemistry and Pharmacology. According to data from OpenAlex, G Koyama has authored 21 papers receiving a total of 462 indexed citations (citations by other indexed papers that have themselves been cited), including 8 papers in Molecular Biology, 7 papers in Organic Chemistry and 5 papers in Pharmacology. Recurrent topics in G Koyama's work include Microbial Natural Products and Biosynthesis (5 papers), Cancer therapeutics and mechanisms (3 papers) and Synthesis and Reactions of Organic Compounds (3 papers). G Koyama is often cited by papers focused on Microbial Natural Products and Biosynthesis (5 papers), Cancer therapeutics and mechanisms (3 papers) and Synthesis and Reactions of Organic Compounds (3 papers). G Koyama collaborates with scholars based in Japan. G Koyama's co-authors include Yöichi Iitaka, HAMAO UMEZAWA, Kenji Maeda, Hitoshi Umezawa, H. Nakamura, Masaji Ohno, Shinichi Kondo, Toru Takita, Mikio Hori and Kenji Maeda and has published in prestigious journals such as Journal of the American Chemical Society, Tetrahedron Letters and Helvetica Chimica Acta.

In The Last Decade

G Koyama

21 papers receiving 417 citations

Peers

G Koyama
Henry W. Dion United States
Bunji Shimizu United Kingdom
K. Ramasamy India
Donald W. Visser United States
Mikio Honjo Japan
W. Werner Zorbach United States
John A. Beisler United States
Joseph P. Joseph
J. A. Stock United Kingdom
Seiji Shibahara Japan
Henry W. Dion United States
G Koyama
Citations per year, relative to G Koyama G Koyama (= 1×) peers Henry W. Dion

Countries citing papers authored by G Koyama

Since Specialization
Citations

This map shows the geographic impact of G Koyama's research. It shows the number of citations coming from papers published by authors working in each country. You can also color the map by specialization and compare the number of citations received by G Koyama with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites G Koyama more than expected).

Fields of papers citing papers by G Koyama

Since Specialization
Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by G Koyama. Nodes represent research fields, and links connect fields that are likely to share authors. Colored nodes show fields that tend to cite the papers produced by G Koyama. The network helps show where G Koyama may publish in the future.

Co-authorship network of co-authors of G Koyama

This figure shows the co-authorship network connecting the top 25 collaborators of G Koyama. A scholar is included among the top collaborators of G Koyama based on the total number of citations received by their joint publications. Widths of edges represent the number of papers authors have co-authored together. Node borders signify the number of papers an author published with G Koyama. G Koyama is excluded from the visualization to improve readability, since they are connected to all nodes in the network.

All Works

20 of 20 papers shown
1.
Koyama, G, Hiroaki Nakamura, Hitoshi Umezawa, & Yöichi Iitaka. (1976). The crystal and molecular structures of oxoformycin B and formycin, B. Acta Crystallographica Section B. 32(3). 813–820. 23 indexed citations
2.
Nakamura, Hiroaki, G Koyama, Hitoshi Umezawa, & Yöichi Iitaka. (1976). The crystal and molecular structure of coformycin. Acta Crystallographica Section B. 32(4). 1206–1212. 8 indexed citations
3.
Nakamura, H., G Koyama, Yöichi Iitaka, et al.. (1974). Structure of coformycin, an unusual nucleoside of microbial origin. Journal of the American Chemical Society. 96(13). 4327–4328. 100 indexed citations
4.
Koyama, G. (1974). The Crystal and Molecular Structure of 3‐Oxo‐17β‐acetoxy‐Δ4‐14α‐methyl‐8α, 9β, 10α, 13α‐estrene. Helvetica Chimica Acta. 57(2). 370–375. 3 indexed citations
5.
Koyama, G. (1974). Metabolites of Microorganisms. 144th communication. The Crystal and Molecular Structure of 3‐Hydroxy‐4‐methylproline. Helvetica Chimica Acta. 57(8). 2477–2483. 19 indexed citations
6.
Koyama, G, Hitoshi Umezawa, & Yöichi Iitaka. (1974). The crystal structure of formycin hydrobromide monohydrate. Acta Crystallographica Section B. 30(6). 1511–1516. 16 indexed citations
7.
Koyama, G, H. Nakamura, YASUHIKO MURAOKA, et al.. (1973). THE CHEMISTRY OF BLEOMYGIN. X. The Journal of Antibiotics. 26(2). 109–111. 2 indexed citations
8.
Suhara, Yoshitomo, et al.. (1972). Total synthesis of kasugamycin. Journal of the American Chemical Society. 94(18). 6501–6507. 20 indexed citations
9.
Koyama, G, H. Nakamura, SHOJI OMOTO, et al.. (1969). THE MOLECULAR AND CRYSTAL STRUCTURE OF VIOMYCIDINE. The Journal of Antibiotics. 22(1). 34–35. 7 indexed citations
10.
Ishizuka, Masaaki, TSUTOMU SAWA, G Koyama, TOMIO TAKEUCHI, & HAMAO UMEZAWA. (1968). METABOLISM OF FORMYCIN AND FORMYCIN B IN VIVO. The Journal of Antibiotics. 21(1). 1–4. 18 indexed citations
11.
Maeda, Kenji, et al.. (1968). The Chemistry of Pyridomycin. Chemical and Pharmaceutical Bulletin. 16(4). 679–687. 10 indexed citations
12.
Koyama, G, H. Nakamura, YASUHIKO MURAOKA, et al.. (1968). The chemistry of bleomycin. II the molecular and crystal structure of a sulfur-containing chromophoric amino acid. Tetrahedron Letters. 9(44). 4635–4638. 28 indexed citations
13.
Koyama, G, Yöichi Iitaka, Kenji Maeda, & HAMAO UMEZAWA. (1968). The crystal structure of kanamycin. Tetrahedron Letters. 9(15). 1875–1879. 21 indexed citations
14.
Murase, Masayuki, et al.. (1966). The studies on the degradation products of formycin and formycin B.. PubMed. 19(2). 91–2. 5 indexed citations
15.
Koyama, G, Kenji Maeda, HAMAO UMEZAWA, & Yöichi Iitaka. (1966). The structural studies of formycin and formycin b. Tetrahedron Letters. 7(6). 597–602. 90 indexed citations
16.
Watanabe, Seiji, et al.. (1966). The studies on the chemical derivations of formycin and formycin B.. PubMed. 19(2). 93–6. 3 indexed citations
17.
Umezawa, Hitoshi, et al.. (1965). Transformation of formycin to formycin B and their biological activities.. PubMed. 18(4). 178–81. 10 indexed citations
18.
Koyama, G, et al.. (1965). Formycin B and its relation to formycin.. PubMed. 18(4). 175–7. 18 indexed citations
19.
Takeuchi, Takumi, et al.. (1964). ANTITUMOR ACTIVITIES OF FORMYCIN AND LABILOMYCIN.. PubMed. 17. 124–6. 7 indexed citations
20.
Hori, Mikio, et al.. (1964). A NEW ANTIBIOTIC, FORMYCIN.. PubMed. 17. 96–9. 49 indexed citations

Rankless uses publication and citation data sourced from OpenAlex, an open and comprehensive bibliographic database. While OpenAlex provides broad and valuable coverage of the global research landscape, it—like all bibliographic datasets—has inherent limitations. These include incomplete records, variations in author disambiguation, differences in journal indexing, and delays in data updates. As a result, some metrics and network relationships displayed in Rankless may not fully capture the entirety of a scholar's output or impact.

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