Masayuki Kuniyoshi

University of the Ryukyus

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Halogenated Monoterpenes Having a Cyclohexadienone from the Red Alga Portieria Hornemanni

Journal of the Chinese Chemical Society (2003)

Masayuki Kuniyoshi Naomasa Oshiro Takayuki Miono Tatsuo Higa

Abstract Five new ochtodane class monoterpenes have been isolated from two collections of the red alga Portieria hornemanni and their structures elucidated by spectroscopic analysis. These compounds contained 4,4‐dimethylcyclohexa‐2,5‐dienone in common and differed in the C 2 side chain structure. Some of them showed mild cytotoxicity. Also discussed is the mechanism of the transformation of 2‐chloro‐1‐hydroxyochtoda‐3(8),5‐dien‐4‐one, a related labile compound reported previously, into 4,5‐dimethylbenzo[ b ]furan.

Furan

Monoterpene

10.1002/jccs.200300023

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Citations (6)

Stereoinversion of 1-arylethanols by Cyanidioschyzon merolae NEIS-1332

Journal of Molecular Catalysis B Enzymatic (2007)

Takamitsu Utsukihara Osami Misumi Kôichi Nakajima Masahiro Koshimura Masayuki Kuniyoshi

Biotransformation

10.1016/j.molcatb.2007.10.002

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Citations (15)

Reaction of Styrene Derivatives with Lithium Naphthalene

Yukagaku (1969)

Kyoichi SUGA Shôji Watanabe Tsutomu Fujita Masayuki Kuniyoshi

The reaction of styrene derivatives with lithium naphthalene was studied. 2, 3-Dimethyl-1, 4-diphenyl butane was obtained from ω-methyl styrene and allyl benzene, 1, 4-diphenyl-2-butene from ω-bromostyrene, 2, 3-diphenyl adipic acid from cinnamic acid, 1, 1, 4, 4-tetraphenyl butane from 1, 1-diphenyl ethylene, and 1, 4-diphenyl butane from phenylacetylene. Reactions of lithium naphthalene with 1, 2-disubstituted ethylenes gave the reduction products.

Phenylacetylene

Butane

10.5650/jos1956.18.878

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Thermal condensation of formaldehyde with 3-p-menthene, 1-p-menthene, and cyclooctene

Canadian Journal of Chemistry (1968)

Shôji Watanabe Kyoichi SUGA Masayuki Kuniyoshi

When a mixture of 3-p-menthene, paraformaldehyde, and acetic anhydride was heated at 200 °C in an autoclave, an acetate was obtained. By saponification of the acetate with alcoholic potassium hydroxide, 3-hydroxylmethyl-4-p-menthene was obtained. Similarly, 2-hydroxymethyl-6-p-menthene was produced from 1-p-menthene, and 1-hydroxylmethyl-2-cyclooctene was produced from cyclooctene.

Cyclooctene

Potassium hydroxide

Hydroxymethyl

Paraformaldehyde

Diazomethane

10.1139/v68-322

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Citations (1)

The chlorination of 5α- and 5β-cholestan-3-one and dechlorination of 2,2,4α-trichloro-5α-cholestan-3-one and 2β,4,4-trichloro-5β-cholestan-3-one

Australian Journal of Chemistry (1983)

Masayuki Kuniyoshi Y. Satoh

Chlorination of Sα- and 5β-cholestan-3-one (l) and (7) proceeds sequentially to give the α-monochloro (2) and (8), α,α-dichloro (3) and (9), and α, α, α'-trichloro (4) and (10) derivatives; the nature of the product mainly depends on the reaction conditions. The α, α'-dichloro ketones (5) and (11) could be prepared by dechlorination of the corresponding trichloro ketones (4) and (10) with chromium(II) acetate. Further dechlorination of the dichloro ketones (5) and (11) with the same reagent furnished the α-monochloro ketones (6) and (12) which cannot be obtained by the direct chlorination of 5α- and 5β-cholestan-3-one.

Biocatalysis

10.1071/ch9831073

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Citations (1)

Studies on the constituents of brown alga Sargassum crassifolium J. Agardh.

正之国吉 Masayuki Kuniyoshi

We have continuously investigated on the secondary metabolites, especially on the structurally interesting and/or biologically active constituents, from many kinds of sea weeds growing in Okinawan sea. In this paper, we would like to report the isolation and the structural elucidation of some interesting constituents from the title alga. From the ethanolic extract of the brown alga Sargassum crassi/olium (Japanese name Atsubamoku) collected at Sesoko-jima island area, a new tetraterpene which containes two terminal diene system of double bonds in its chemical structure has been isolated as a major component accompanying by (-)-loliolide, (+)-loliolide and palmitic acid. The structural determinations of these compounds were carried out on the basis of chemical and spectral analysis using IR, UV, 1H- NMR, 13C NMR, and Mass spectroscopies. 11?I 7 '/ J ~.:c ~ (Sargassum crassi/olium J. Agardh) (J)PX?t~~ 1$ El ~=i~~;t1tP5lItl fj~;:~t ~ f.il!k (J)rmNl~;: -:>1.-) l, .f(J)~Jmmttp.x;7 to)~;W~§~ t l,lWf~ ~tT~?-C 1.-) 0 1J~, ~@mmt7 'Y J ~~ .:c ~ ~ w'*~ 0 =, '=:'(J)1~ft4o/.} 1JUt!m-c ~ t.:. 0)-C~~T

Sargassum

Spectral Analysis

Chemical structure

Source

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Reaction of 5$\alpha$-Cholest-2-ene with Iodine-Copper (2) Acetate

Takamitsu Utsukihara Yuuya Yokoyama Katsuo Kaneko Isao Yoshino T Miyasaka

Ene reaction

Alpha (finance)

Source

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Hydroxylation of steroid compounds by Gelasinospora retispora

Journal of Molecular Catalysis B Enzymatic (2010)

Masahiro Koshimura Takamitsu Utsukihara Asako Hara Syuhei Mizobuchi C. Akira Horiuchi

Hydroxylation

10.1016/j.molcatb.2010.07.008

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Citations (23)

The Probability of Intramolecular Hydrogen Bonding in Some Terpenic Cyclic, Unsaturated Alcohols.

Yukagaku (1970)

Kyoichi SUGA Shôji Watanabe Masayuki Kuniyoshi

Intramolecular hydrogen bonding of the some terpenic cyclic unsaturated alcohols, such as 2-hydroxymethyl-6 (1) -p-menthene, 3-hydroxylmethyl-4 (5) -p-menthene, nopol, 1, 3, 6, 10, 10-pentamethyl-4-hydroxymethylbicyclo [4, 4, 0] decene-2, 3-hydroxymethyl-5-tert-butylcyclohexene and 3-hydroxym-ethylcyclooctene was measured by infrared absorption and nuclear magnetic resonance spectra.

Hydroxymethyl

10.5650/jos1956.19.33

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ChemInform Abstract: THE CHLORINATION OF 5α‐ AND 5β‐CHOLESTAN‐3‐ONE AND DECHLORINATION OF 2,2,4α‐TRICHLORO‐5α‐CHOLESTAN‐3‐ONE AND 2β,4,4‐TRICHLORO‐5β‐CHOLESTAN‐3‐ONE

Chemischer Informationsdienst (1983)

Masayuki Kuniyoshi Yurie Satoh

10.1002/chin.198346323

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