Fucosterol-24,28-epoxide, as a probable intermediate in the conversion of β-sitosterol to cholesterol in the silkworm

Morisaki, Masuo; Ohtaka, Hiroshi; Okubayashi, Mari; Ikekawa, Nobuo; Horie, Yoshinori; Nakasone, Shoichi

doi:10.1039/c39720001275

Cited by 31 publications

(14 citation statements)

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“…Our result is in agreement with that of a nutritional experiment effected in Bombyx mori, the larvae of which died when reared on a semi-synthetic diet containing stigmast-5-ene-3fl,28-diol (VI) as a sole sterol source (Morisaki et al, 1974).…”

Section: Resultssupporting

confidence: 91%

“…It is generally accepted that a major route of dealkylation of 16-sitosterol (I) proceeds through the formation of fucosterol (II), followed by epoxidation of the 24(28)-double bond, rearrangement to desmosterol (III) and a C2 unit, and reduction of the 24(25)double bond (Scheme 1) (Svoboda et al, 1971(Svoboda et al, , 1975Allais & Barbier, 1971;Morisaki et al, 1974;Chen et al, 1975).…”

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confidence: 99%

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Role of 24- and 28-hydroxylated intermediates in the metabolism of β-sitosterol in the insect Tenebrio molitor

Nicotra¹,

Ronchetti²,

Russo³

et al. 1979

Biochemical Journal

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1. [28-3H]Stigmast-5-ene-3 beta, 28-diol and [23,23,25-3H]stigmast-5-ene-3 beta, 24-diol were synthesized. 2. Each of the samples was mixed with beta-[4-14C]sitosterol and administered to Tenebrio molitor larvae. 3. The former compound is not utilized by the insect; the latter, although metabolized to 24(28)-ethylidene sterols and cholesterol, is not a beta-sitosterol metabolite. 4. The above results are discussed in relation to the mechanism of formation of the 24(28)-double bond in beta-sitosterol metabolism in T. molitor.

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Section: Resultssupporting

confidence: 91%

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confidence: 99%

Role of 24- and 28-hydroxylated intermediates in the metabolism of β-sitosterol in the insect Tenebrio molitor

Nicotra¹,

Ronchetti²,

Russo³

et al. 1979

Biochemical Journal

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“…However, it should be more rigorously confirmed by tracer experiments that the dealkylation of sitosterol to cholesterol in the prawn proceeds via 24-methyl enecholesterol or fucosterol-24, 28-epoxide as pro posed in insects. 13,14) The low body retention rates of sitosterol in prawn juvenile (Table 6) suggest that sitosterol, even if absorbed from the guts, is excreted faster from the body than chole sterol, as also demonstrated previously in the metabolic studies of the prawn using radioactive sterols.15) These results indicate that sitosterol is probably utilized as a sterol source after being converted to cholesterol and the bioconversion may not proceed in a fast rate in P. japonicus juveniles. The irreplaceable cholesterol require ment in diets supplies a strict metabolic need for cholesterol as a precursor of steroid hormones16) and possibly a constituent of cellular membranes17,18) in this prawn.…”

Section: Discussionsupporting

confidence: 55%

Nutritive value of sitosterol for the prawn Penaeus japonicus.

Teshima¹,

Kanazawa²,

Koshio³

et al. 1989

NIPPON SUISAN GAKKAISHI

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The larval and juvenile prawns Penaeus japonicus were maintained on purified diets with cholesterol alone and mixtures of cholesterol-sitosterol (1:1, 1:3, 1:10, 1:30, 1:100) to evaluate a cholesterol-sparing effect of sitosterol. The juvenile prawns had the highest weight gain (%), feed conversion efficiency (FCE) and protein efficiency ratio (PER) on the diet containing 0.5% cholesterol alone. The partial replacement of cholesterol with sitosterol reduced the weight gain, FCE, and PER inversely with increasing proportions of sitosterol. The body retention rates (%) of dietary proteins, lipids, total sterols, and cholesterol were lowered when dietary cholesterol was partially replaced with sitosterol. The larval prawns also grew best with the highest survival rate on the diet containing 1.0% cholesterol alone. The partial replacement of cholesterol with sitosterol (cholesterol/sitosterol ratios of 1:1, 1:3, 1:10, and 1:30) did not decrease the survival rates markedly but slightly retarded the larval development with increasing proportions of sitosterol. These results indicated that sitosterol had the cholesterol-sparing effect in terms of survival rates for the larvae but not for the juveniles, suggesting the change in sterol metabolism during the life cycle of the prawn.

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“…First, 3 H-label of fucosterol administered to larva was trapped in FE and 3 H-label of FE was incorporated into cholesterol. 14 ) Secondly, hydrogen migration from C-25 to C-24 was verified by feeding [25- 3 H]-24-ethylcholesterol followed by determining chemically the position of the label of the resulting desmosterol. 15 ) Thirdly, the 24,28-imine analogue of FE was shown to be a potent inhibitor of the enzyme termed fucosterol epoxide lyase that catalyzes the conversion.…”

Section: Sterol Metabolism In Insectsmentioning

confidence: 99%

Reminiscences of research on the chemistry and biology of natural sterols in insects, plants and humans

Ikekawa

Fujimoto

Ishiguro

2013

Proceedings of the Japan Academy. Ser. B: Physical and Biologic

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Natural sterols often occur as a heterogeneous mixture of homologs, which had disturbed the progress of steroid research. Development and application of GC methodology overcame this difficulty and enabled us to obtain detailed sterol profiles. Together, fine synthesis of stereo-defined isomers and homologs of steroids having oxygenated side chains allowed us to compare them with natural samples as well as to investigate structure-activity relationship. Advance of HPLC technology also facilitated the determination of the stereochemical structure of naturally occurring steroidal compounds, which were obtained only in minute amounts. This review highlights three topics out of our steroid research that have been performed mainly at Tokyo Institute of Technology around 1970–1990. These are sterol metabolism in insects focusing on the mechanism of the conversion of plant sterols to cholesterol and ecdysone biosynthesis, the synthesis and biochemical research of active forms of vitamin D3 derivatives, and the synthesis and microanalysis of plant hormone brassinosteroids.

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Fucosterol-24,28-epoxide, as a probable intermediate in the conversion of β-sitosterol to cholesterol in the silkworm

Cited by 31 publications

References 0 publications

Role of 24- and 28-hydroxylated intermediates in the metabolism of β-sitosterol in the insect Tenebrio molitor

Role of 24- and 28-hydroxylated intermediates in the metabolism of β-sitosterol in the insect Tenebrio molitor

Nutritive value of sitosterol for the prawn Penaeus japonicus.

Reminiscences of research on the chemistry and biology of natural sterols in insects, plants and humans

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