Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Koichi Hayakawa is active.

Publication


Featured researches published by Koichi Hayakawa.


Journal of Molecular Catalysis B-enzymatic | 1996

Regiospecific hydroxylation of 3-(methylaminomethyl) pyridine to 5-(methylaminomethyl) -2 (1H) -pyridinone byArthrobacter ureafaciens

Takahiro Ishikawa; Kasumi Maeda; Koichi Hayakawa; Takakazu Kojima

Abstract Microbial production of a 6-hydroxy-3-pyridylmethyl compound from 3-pyridylmethyl compound was investigated. The hydroxylation of 3-(methylaminomethyl)pyridine to 5-(methylaminomethyl)-2(1 H )-pyridinone, tautomer of 2-hydroxy-5(methylaminomethyl)pyridine, by resting cells of Arthrobacter ureafaciens JCM3873 was found to proceed regio- and chemo-selectively with an almost quantitative yield. The addition of molybdate ion and nicotine as an inducer to the culture medium was required for the preparation of cells containing high hydroxylation activity. The optimal temperature and pH for the hydroxylation by using resting cells were 35°C and around 7, respectively. This hydroxylation enzyme does undergo inhibition by the substrate. The inhibitory effect could be eliminated by stepwise feeding of the substrate. Under adequate conditions, 23 mg/ml of 5-(methylaminomethyl)-2(1 H )-pyridinone was produced with a molar yield of nearly 100% from 3-(methylaminomethyl)pyridine.


Archive | 1997

Process for preparing free α-hydroxy acids from ammonium salts thereof

Koichi Hayakawa


Archive | 1997

Process for preparing α-hydroxy acids using microorganism and novel microorganism

Yoichi Kobayashi; Ken Watabe; Mahito Ohira; Koichi Hayakawa


Archive | 1988

Amidine derivative, production thereof and acaricide, agricultural and horticultural germicide

Akira Hashimoto; Koichi Hayakawa; Hiroyasu Hosokawa; Takashi Kishimoto; Akira Nakayama; Shinsuke Sano; Eiko Takahashi; Tomio Yamada


Archive | 1985

Formamidoxime derivatives with fungicidal and insecticidal activity.

Koichi Hayakawa; Hiroaki Nishikawa; Sho Hashimoto


Japanese Journal of Phytopathology | 1987

Negatively Correlated Cross-Resistance to N-phenylformamidoximes in Benzimidazole-Resistant Phytopathogenic Fungi

Akira Nakata; Shinsuke Sano; Sho Hashimoto; Koichi Hayakawa; Hiroaki Nishikawa; Yasushi Yasuda


Bioscience, Biotechnology, and Biochemistry | 1994

N-Phenyl-N′-alkoxyformamidines and Alkanamidines as Potent Flower-inducing Compounds in Asparagus Seedlings and Their Effects on Microsomal t-Cinnamic Acid 4-Hydroxylase

Masashi Kusukawa; Naoko Wada; Koichi Hayakawa; Hajime Iwamura


Archive | 2003

Process for the production of methionine

Yoichi Kobayashi; Ippei Ono; Koichi Hayakawa; Ryousuke Mizui; Takahiro Ishikawa


Archive | 2001

Process for the preparation of 2-amino acids

Yoichi Kobayashi; Koichi Hayakawa


Archive | 1998

Production of calcium 2-hydroxy-4-methylthiobutanoate

Masaji Hatayama; Koichi Hayakawa; Takahiro Ishikawa; Yoichi Kobayashi; Takeshi Watabe; 洋一 小林; 公一 早川; 健 渡部; 正次 畑山; 高広 石川

Collaboration


Dive into the Koichi Hayakawa's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge