- Synthesis and search for 3β,3′β-disteryl ethers after high-temperature treatment of sterol-rich samples
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It has been proven that at increased temperature, sterols can undergo various chemical reactions e.g., oxidation, dehydrogenation, dehydration and polymerisation. The objectives of this study are to prove the existence of dimers and to quantitatively analyse the dimers (3β,3′β-disteryl ethers). Sterol-rich samples were heated at 180 °C, 200 °C and 220 °C for 1 to 5 h. Quantitative analyses of the 3β,3′β-disteryl ethers were conducted using liquid extraction, solid-phase extraction and gas chromatography coupled with mass spectrometry. Additionally, for the analyses, suitable standards were synthetized from native sterols. To identify the mechanism of 3β,3′β-disteryl ether formation at high temperatures, an attempt was made to use the proposed synthesis method. Additionally, due to the association of sterols and sterol derivatives with atherosclerosis, preliminary studies with synthetized 3β,3′β-disteryl ethers on endothelial cells were conducted.
- Bus, Katarzyna,Ofiara, Karol,Sitkowski, Jerzy,Szterk, Arkadiusz,Zmys?owski, Adam
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- A metal-free approach to access ketones, amides, and nitriles employing TBAI/TBHP oxidative system in water
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Hydrocarbons, benzylamines, and heteroaromatic-bearing amines have been efficiently employed as substrates in allylic and benzylic oxidations via C(sp3)–H bond activation by TBAI/TBHP in water. This operationally simple method allows access to ketones, nitriles, and amides in moderate to high yields and a regio- and chemoselective late-stage functionalization.
- Gomes, Suzane Quintana,Salles, Airton G.
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supporting information
p. 3389 - 3399
(2019/11/05)
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- Oxyphytosterols as active ingredients in wheat bran suppress human colon cancer cell growth: Identification, chemical synthesis, and biological evaluation
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Consumption of whole grains has been reported to be associated with a lower risk of colorectal cancer. Recent studies illustrated that phytochemicals in wheat bran (WB) may protect against colorectal cancer. There is a growing interest in the phytosterol contents of foods as either intrinsic or added components due to their beneficial health effects. However, little is known whether phytosterols in WB contribute the observed chemopreventative activity of the grain. In the present study, we directly purified and identified four oxyphytosterols 1-4 from sterol-enriched fraction of WB, and also successfully synthesized five sterol oxides 5-8 and 13. Using these nine compounds as references, we outlined a comprehensive profile of steroids in WB using tandem liquid chromatography mass spectrometry with electrospray ionization (LC-ESI/MSn, n = 2-3) techniques for the first time. Among them, three sterol oxides 13, 14, and 18 are novel compounds, and 14 compounds 3, 4, 6-11, 13, 14, 16, and 18-20 were reported in WB for the first time. Our results on the inhibitory effects of available sterol oxides 1-8 and 13 against the growth of human colon cancer cells HCT-116 and HT-29 showed that compounds 2-8 exerted significant antiproliferative effects, with oxysterol 8 being the most active one in both cells. We further demonstrated that four most active sterol oxides 5-8 could induce cell death through the apoptosis pathway. Our results showed that phytosterols, particularly oxyphytosterols, in WB possess significant antiproliferative properties, and thereby may greatly contribute the observed chemoprevention of the whole grain wheat.
- Zhu, Yingdong,Soroka, Dominique,Sang, Shengmin
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p. 2267 - 2276
(2015/03/14)
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- An expeditious synthesis of spinasterol and schottenol, two phytosterols present in argan oil and in cactus pear seed oil, and evaluation of their biological activities on cells of the central nervous system
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Abstract Spinasterol and schottenol, two phytosterols present in argan oil and in cactus pear seed oil, were synthesized from commercially available stigmasterol by a four steps reactions. In addition, the effects of these phytosterols on cell growth and
- Badreddine, Asmaa,Karym, El Mostafa,Zarrouk, Amira,Nury, Thomas,El Kharrassi, Youssef,Nasser, Boubker,Cherkaoui Malki, Mustapha,Lizard, Gérard,Samadi, Mohammad
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p. 119 - 124
(2015/08/03)
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- Sterols as anticancer agents: Synthesis of ring-B oxygenated steroids, cytotoxic profile, and comprehensive SAR analysis
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The cytotoxicity of oxysterols was systematically studied in tumor and normal cells. Synthetic strategies to prepare this library included oxidations at ring B and a new method to yield 6β-hemiphthalates directly from Δ5-steroids. Most oxysterols were cytotoxic and showed selectivity toward cancer cells, LAMA-84 cells (leukemia) being particularly sensitive to 4, 8, 22, and 27 (IC50 5.6 μM). The structural requirements to induce selective toxicity are discussed to shed light on the development of new anticancer drugs.
- Carvalho, Jo?o F. S.,Silva, M. Manuel Cruz,Moreira, Jo?o N.,Sim?es, Sérgio,Sá E Melo, M. Luisa
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supporting information; experimental part
p. 7632 - 7638
(2011/02/21)
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- An environmentally benign catalytic oxidation of cholesteryl acetate with molecular oxygen by using N-hydroxyphthalimide
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A green and effective method is reported for the oxidation of cholesteryl acetate to 7-keto-cholesteryl acetate with O2 in the presence of catalytic amounts of N-hydroxyphthalimide (NHPI) under mild conditions. It was found that Co(OAc)2 could cooperate with Mn(OAc)2 to enhance the catalytic ability of NHPI resulting in better yields. This economical and environmentally-friendly method provides a potentially new way for the synthesis of the intermediate product of vitamin D3 in industry, which eliminates the use of large amounts of bromine in present route and overcomes the drawbacks of the known oxidation methods.
- Yao, Zhen,Hu, Xingbang,Mao, Jianyong,Li, Haoran
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scheme or table
p. 2013 - 2017
(2010/06/19)
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- Synthesis of highly pure oxyphytosterols and (oxy)phytosterol esters. Part I. Regioselective hydrogenation of stigmasterol: An easy access to oxyphytosterols
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The synthesis of several oxyphytosterols is described starting from stigmasterol, the key step being the regioselective hydrogenation of the 22-23 double bond of the latter.
- Geoffroy, Philippe,Julien-David, Diane,Marchioni, Eric,Raul, Francis,Aoude-Werner, Dalal,Miesch, Michel
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p. 702 - 707
(2008/09/21)
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- Synthesis, isolation and characterisation of β-sitosterol and β-sitosterol oxide derivatives
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β-Sitosterol is the most prevalent plant cholesterol derivative (phytosterol) and can undergo similar oxidation to cholesterol, leading to β-sitosterol oxides. The biological impact of phytosterol oxides has only been evaluated in a phytosterol blend (usually of β-sitosterol, campesterol, stigmasterol and dihydrobrassicasterol). The lack of pure phytosterols, including β-sitosterol, hinders the collection of significant toxicity data on the individual β-sitosterol oxides. An efficient synthetic route to multi-gram quantities of pure β-sitosterol is described here, together with the first syntheses and characterisation of pure β-sitosterol oxides. The Royal Society of Chemistry 2005.
- McCarthy, Florence O.,Chopra, Jay,Ford, Alan,Hogan, Sean A.,Kerry, Joe P.,O'Brien, Nora M.,Ryan, Eileen,Maguire, Anita R.
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p. 3059 - 3065
(2007/10/03)
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- Gram-scale chromatographic purification of β-sitosterol: Synthesis and characterization of β-sitosterol oxides
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An effective purification method for β-sitosterol was developed starting from a commercial source of a phytosterol mixture using preparative adsorption column chromatography. β-Sitosterol (≥95% purity) was obtained on a gram-scale. Thus, the synthesis of six β-sitosterol oxides, including 7α-hydroxy, 7β-hydroxy, 5,6α-epoxy, 5,6β-epoxy, 7-keto, and 5α,6β-dihydroxysitosterol, were successfully carried out. The spectral characteristics of all the synthetic intermediates and target compounds (~95% purity) were well-documented.
- Zhang, Xin,Geoffroy, Philippe,Miesch, Michel,Julien-David, Diane,Raul, Francis,Aoude-Werner, Dalal,Marchioni, Eric
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p. 886 - 895
(2007/10/03)
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- Synthesis of (24R)-3β-hydroxystigmast-5-en-7-one
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The natural compound (24R)-3β-hydroxystigmast-5-en-7-one has been synthesized from β-sitosterol.
- Kovganko,Kashkan
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p. 433 - 436
(2007/10/03)
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- Inhibitory effect of some oxygenated stigmastane-type sterols on 12-O- tetradecanoylphorbol-13-acetate-induced inflammation in mice
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The oxygenated stigmastane-type sterols stigmastane-3β,6α-diol, stigmastane-3β,6α-diol, 7α-hydroxysitosterol and its diacetyl derivative, 7β-hydroxysitosterol and its diacetyl derivative, 7-oxositosterol, 4β- hydroxysitosterol, and stigmast-4-ene-3β,6β-diol were evaluated with respect to their anti-inflammatory activity against 12-O- tetradecanoylphorbol-13-acetate (TPA)-induced inflammation in mice. All of the sterols, with the exception of 7α-hydroxysitosterol and its diacetyl derivative, were found to possess marked inhibitory activity. The 50% inhibitory dose of these compounds for TPA-inflammation (1 μg) was 0.5-1.0 mg/ear.
- Kimura,Yasukawa,Takido,Akihisa,Tamura
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p. 1617 - 1619
(2007/10/03)
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