Synthesis of xestobergsterol A from dehydroepiandrosterone

Nakamura, Atsuko; Kaji, Yuko; Saida, Kaname; Ito, Michiko; Nagatoshi, Yumi; Hara, Noriyuki; Fujimoto, Yoshinori

doi:10.1016/j.tetlet.2005.07.042

Cited by 15 publications

(7 citation statements)

References 18 publications

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“…Xestobergsterol A (249) was synthesized from dehydroepiandrosterone in Fujimoto's laboratory (Scheme 76). 110 In their synthesis, oxidation of the allylic C7 position of intermediate 260 was carried out by an N-hydroxyphthalimide-catalyzed air oxidation. 111 That is, olefin 260 was treated with dibenzoyl peroxide and a catalytic amount of N-hydroxyphthalimide under an oxygen atmosphere.…”

Section: Scheme 75 Total Synthesis Of Fomitellic Acid B (259) By Kobamentioning

confidence: 99%

Allylic Oxidations in Natural Product Synthesis

2013

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Although C-H oxidation of hydrocarbons is generally difficult, allylic C-H oxidation is relatively simple and predictable, even on a preparative scale, because active species generated at the allylic position are stabilized by the double bond. Therefore, allylic oxidation has been employed in natural product synthesis, and a variety of reagents and conditions for allylic oxidation have been reported. However, reagents and conditions suitable for natural product synthesis are limited in terms of efficiency and chemo-, regio-, and stereoselectivity, owing to the structural and characteristic diversity of natural products. This review addresses allylic oxidations, highlighting reagents and conditions that meet the requirements for natural product synthesis.

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Section: Scheme 75 Total Synthesis Of Fomitellic Acid B (259) By Kobamentioning

confidence: 99%

Allylic Oxidations in Natural Product Synthesis

2013

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“…(367) A number of synthetic applications of the palladiumcatalyzed formation of ␣,␤-unsaturated carbonyl compounds from silylenol ethers (Saegusa oxidation) were published. For example, applications toward kainoids [1515], gymnocin A [205], fumagalone analogs [503], guanacastepenes [1516], GKK1032s [138,1517], the ABCD ring system of manzamine [1176], xestobergsterol A [1518] and (+)-solanascone, (+)-dehydrosolanascone, and (+)-anhydro-␤-rotunol [1519] were described. Palladium hydroxide on carbon using tbutylhydrogen peroxide as the reoxidant was used in Saegusa-type oxidations [1520].…”

Section: Oxidationsmentioning

confidence: 99%

Transition metals in organic synthesis: Highlights for the year 2005

Söderberg

2008

Coordination Chemistry Reviews

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“…Xestobergsterol is pentacyclic polyhydroxylated steroid, isolated in 1992 from the Okinawan marine sponge, Xestospongia bergquisita [ 38 ]. It inhibits IgE-mediated histamine release from activated mast cells [ 39 ], with an inhibitory effect that resulted in being even stronger than some anti-allergy drugs, such as disodium cromoglycate [ 33 ]. In detail, xestobergsterol A blocks the generation of inositol triphosphate (IP3) and phospholipase C (PLC) activity in a dose-dependent way and inhibits early events in IgE-dependent mediator release, such as Ca 2+ -mobilization from intracellular stores [ 38 , 39 ].…”

Section: Marine Natural Products: a Potential Immunomodulating Andmentioning

confidence: 99%

“…It inhibits IgE-mediated histamine release from activated mast cells [ 39 ], with an inhibitory effect that resulted in being even stronger than some anti-allergy drugs, such as disodium cromoglycate [ 33 ]. In detail, xestobergsterol A blocks the generation of inositol triphosphate (IP3) and phospholipase C (PLC) activity in a dose-dependent way and inhibits early events in IgE-dependent mediator release, such as Ca 2+ -mobilization from intracellular stores [ 38 , 39 ]. Therefore, like contignasterol, it could be considered as a potential anti-asthma agent with a promising pharmacological potential [ 31 ].…”

Section: Marine Natural Products: a Potential Immunomodulating Andmentioning

confidence: 99%

Marine Bioactives and Potential Application in Sports

et al. 2014

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An enriched diet with antioxidants, such as vitamin E, vitamin C, β-carotene and phenolic compounds, has always been suggested to improve oxidative stress, preventing related diseases. In this respect, marine natural product (MNP), such as COX inhibitors, marine steroids, molecules interfering with factors involved in the modulation of gene expression (such as NF-κB), macrolides, many antioxidant agents, thermogenic substances and even substances that could help the immune system and that result in the protection of cartilage, have been recently gaining attention. The marine world represents a reserve of bioactive ingredients, with considerable potential as functional food. Substances, such as chitin, chitosan, n-3 oils, carotenoids, vitamins, minerals and bioactive peptides, can provide several health benefits, such as the reduction of cardiovascular diseases, anti-inflammatory and anticarcinogenic activities. In addition, new marine bioactive substances with potential anti-inflammatory, antioxidant and thermogenic capacity may provide health benefits and performance improvement, especially in those who practice physical activity, because of their increased free radical and Reacting Oxygen Species (ROS) production during exercise, and, particularly, in athletes. The aim of this review is to examine the potential pharmacological properties and application of many marine bioactive substances in sports.

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Synthesis of xestobergsterol A from dehydroepiandrosterone

Cited by 15 publications

References 18 publications

Allylic Oxidations in Natural Product Synthesis

Allylic Oxidations in Natural Product Synthesis

Transition metals in organic synthesis: Highlights for the year 2005

Marine Bioactives and Potential Application in Sports

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