Yasuko Hikino

Inokosterone, an insect metamorphosing substance from Achyranthes fauriei : Absolute configuration and synthesis☆

Abstract Inokosterone, a phytoecdysone isolated from Achyranthes fauriei (Amaranthaceae), has been partially acetylated to give the 2,26-diacetate (4) which has been converted into methyl 5 - acetoxy - 4 - methylpentanoate (7), showing no apparent [α]D, and 2β - acetoxy - 3β,14α - dihydroxy - 5β - pregn - 7 - ene - 6,20 - dione (8). Chemical and physiochemical studies have shown the configurations at C-20 and C-22 to be R. Inokosterone has thus been concluded to be a mixture of C-25 epimers of (20R,22R) - 2β,3β,14α,20,22,26 - hexahydroxy - 5β - cholest - 7 - en - 6 - one (1). After the synthesis of the model compound, a C-25 epimeric mixture of (20R,22R) - 3β,20,22,26 - tetrahydroxy - 5α - cholestane (23), inokosterone has been synthesized via (20R) - 2β,3β,14α,20 - tetrahydroxy - 20 - formyl - 5β - pregn - 7 - en - 6 - one (25) by Grignard reaction with 4 - (tetrahydrofuran - 2 - yloxy) - 3 - methylbutynylmagnesium bromide (15) followed by hydrogenation and hydrolysis. The use of an NMR shift reagent with the inokosterone acetates (9, 29) and the optical activity measurement of α - methylglutaric acid (3) derived from inokosterone have established that inokosterone is a 1:2 mixture of the C-25 R and S epimers.

Rubrosterone, a metabolite of insect metamorphosing substance from Achyranthes rubrofusca: Synthesis

Abstract Rubrosterone, a metabolite of ecdysterols isolated from Achyranthes spp. (Amaranthaceae), has been synthesized by two routes from ecdysterone.

Rubrosterone, a metabolite of insect metamorphosing substance from Achyranthes rubrofusca: structure and absolute configuration.

Abstract A novel C 19 steroid, nibrosterone, isolated first from Achyranthes rubrofusca and later from A. fauriei (Amaranthaceae), has the stereostructure I on the basis of the chemical and physico-chemical properties of the steroid and its diacetate.

Structure and absolute configuration of narchinol A

Abstract From Chinese spikenard, Nardostachys chinensis (Valerianaceae), a new trisnorsesquiterpenic diketo-alcohol, narchinol A has been isolated and its stereostructure deduced as I on the basis of chemical, and physical data.

Arthropod molting hormones.

While much is known about the hormones of vertebrates, knowledge of the hormones of invertebrates is far less complete. However, the chemistry of the molting hormones and the juvenile hormones of insects has made surprisingly rapid advances during the past few years and has now become a subject of research which is attracting the interest of both chemists and biologists. This review article is an attempt to summarize recent developments in our knowledge regarding the chemistry, synthesis and metabolism of the arthropod molting hormones, but will in the main exclude consideration of biological properties which have been frequently the object of excellent reviews (71).

Structure and absolute configuration of α-kessyl alcohol and kessyl glycol

Abstract The structures and absolute configuration of α-kessyl alcohol (I) and kessyl glycol (II), sesquiterpenic constituents of Japanese valerian roots, have been established on the basis of chemical and spectroscopic data.

Structure of cyclokessyl acetate, a sesquiterpenoid of Valeriana fauriei ‘hokkai-kisso’ roots☆

Abstract A new sesquiterpenoid, cyclokessyl acetate, was isolated from the roots of Valeriana fauriei ‘hokkai-kisso’ (Valerianaceae), and its structure was determined by chemical and spectroscopic evidence, especially by means of two-dimensional NMR correlations, to have a novel carbon skeleton.

Biochemical syntheses—I : Microbial transformation of α-kessyl alcohol to kessyl glycol and kessane-2β,7-diol

Abstract The microbiological attack of Cunninghamella blakesleeana, Corticium sasakii, Corticium centrifugum, and Streptomyces aurofaciens on α-kessyl alcohol (I), a constituent of valerian roots, has resulted in the selective hydroxylation at two positions (8α and 7) yielding kessyl glycol (II), another constituent of valerian, and kessane-2β,7-diol (III).