6997-41-7Relevant academic research and scientific papers
Construction of Cholesterol Oxime Ether Derivatives Containing Isoxazoline/Isoxazole Fragments and Their Agricultural Bioactive Properties/Control Efficiency
Xu, Hui,Zhang, Kong,Lv, Min,Hao, Meng
, p. 8098 - 8109 (2021/08/03)
To explore natural-product-based pesticidal candidates and high value-added application of cholesterol in agriculture, oximinoether derivatives of cholesterol-containing isoxazoline/isoxazole fragments (I-1～I-16 and II-1～II-18) were semiprepared by structural optimization of cholesterol. Their structures were characterized by optical rotation, high-resolution mass spectrometry (HRMS), IR, and 1H NMR spectroscopy. Particularly, the Z configurations of oxime fragments at the C-7 position of target compounds were undoubtedly determined by X-ray crystallography. Against Mythimna separata Walker, compounds 3e, I-8, I-14, and II-3 showed 2.4-2.7-fold growth inhibitory activity of the precursor cholesterol. Against Plutella xylostella Linnaeus, compounds I-6, I-7, and I-9 showed 2.4-2.7-fold oral toxicity of cholesterol. Against Aphis citricola Van der Goot, compounds 2e and II-15 exhibited 4.9 and 5.8-fold aphicidal activity of cholesterol, respectively. Notably, they showed good control effects (3.0-5.0-fold promising control efficiency of 1) against A. citricola in the greenhouse. Structure-activity relationships (SARs) suggested that the C-3 hydroxyl group and the C-7 position of cholesterol are two important modification sites. It will pave the way for future structural optimization and application of cholesterol derivatives as potential pesticidal agents in agriculture.
Natural-product-based pesticides: Semisynthesis, structural elucidation, and evaluation of new cholesterol–matrine conjugates as pesticidal agents
Hao, Meng,Li, Tianze,Lv, Min,Xu, Hui,Xu, Jianwei,Zhang, Shaoyong
, (2021/09/07)
To develop new potential pesticide candidates from low value-added natural bioactive products, a series of new cholesterol–matrine conjugates (I(a–e)–IV(a–e)) were prepared from two lead compounds cholesterol and matrine. Against Mythimna separata Walker, compound IVa exhibited 3.0 and 2.6 folds promising insecticidal activity of cholesterol and matrine, respectively; against Aphis citricola Van der Goot, compound IVd showed 4.3 and 2.2 folds potent aphicidal activity of their precursors; notably, it also showed good control effects in the greenhouse; against Plutella xylostella Linnaeus at a dose of 20 μg/nymph, compound IIIe exhibited 2.8 and 2.0 folds oral toxicity of cholesterol and matrine, respectively. Compounds IIIe, IVd and IVe can be used as the leads for further structural optimization as the insecticidal and aphicidal agents.
Preparation method of obeticholic acid and intermediate thereof
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Paragraph 0290; 0291, (2018/07/30)
The invention discloses a preparation method of obeticholic acid and an intermediate thereof. The invention provides a preparation method of a compound V. The preparation method of the compound V comprises the following steps: carrying out hydroxyl protective reaction on a compound VI and a hydroxyl protective reagent to obtain the compound V. The preparation method is simple and convenient to operate, low in cost, gentle in condition, environmentally friendly and suitable for industrialization.
Preparation method of obeticholic acid and intermediate thereof
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Paragraph 0291; 0292, (2018/07/30)
The invention discloses a preparation method of obeticholic acid and an intermediate thereof. The provided preparation method of the obeticholic acid comprises the following step: carrying out oxidizing reaction on a compound V and an oxidizing agent in an organic solvent to obtain a compound IV so as to obtain the final product. PG1 is a carboxyl protecting group, PG2 is a hydroxyl protecting group, and a component as shown in specification in the compound V and the compound IV independently shows that the ethidine is an E configuration, a Z configuration or a mixture of the E configuration and the Z configuration. The preparation method is simple and convenient to operate, low in cost, gentle in condition, environmentally friendly and suitable for industrialization.
Metal-Free Allylic Oxidation of Steroids Using TBAI/TBHP Organocatalytic Protocol
Lam, Ying-Pong,Yeung, Ying-Yeung
supporting information, p. 2369 - 2372 (2018/04/19)
A mild, efficient and organocatalytic allylic oxidation of steroids using a TBAI/TBHP protocol has been developed. A range of bioactive Δ5-en-7-ones can be easily prepared from the corresponding Δ5-steroids. The methodology features several advantages, including readily available starting materials, environmentally benign oxidant, high functional group compatibility, and metal-free catalysis.
Multiple Enone-Directed Reactivity Modes Lead to the Selective Photochemical Fluorination of Polycyclic Terpenoid Derivatives
Pitts, Cody Ross,Bume, Desta Doro,Harry, Stefan Andrew,Siegler, Maxime A.,Lectka, Thomas
, p. 2208 - 2211 (2017/02/23)
In the realm of aliphatic fluorination, the problem of reactivity has been very successfully addressed in recent years. In contrast, the associated problem of selectivity, that is, directing fluorination to specific sites in complex molecules, remains a great, fundamental challenge. In this report, we show that the enone functional group, upon photoexcitation, provides a solution. Based solely on orientation of the oxygen atom, site-selective photochemical fluorination is achieved on steroids and bioactive polycycles with up to 65 different sp3 C-H bonds. We have also found that γ-, β-, homoallylic, and allylic fluorination are all possible and predictable through the theoretical modes reported herein. Lastly, we present a preliminary mechanistic hypothesis characterized by intramolecular hydrogen atom transfer, radical fluorination, and ultimate restoration of the enone. In all, these results provide a leap forward in the design of selective fluorination of complex substrates that should be relevant to drug discovery, where fluorine plays a prominent role.
Allylic oxidation of steroidal olefins by vanadyl acetylacetonate and tert-butyl hydroperoxide
Grainger, Wendell S.,Parish, Edward J.
, p. 103 - 109 (2015/06/30)
Abstract Readily available vanadyl acetylacetonate was found to oxidize the allylic sites of Δ5 steroidal alcohols without protection of hydroxyl groups. Cholesterol, dehydroepiandrosterone, cholesterol benzoate, cholesterol acetate, pregnenolone, and 5-pregnen-3,20-diene were oxidized to 7-keto products using vanadyl acetylacetonate in one pot reactions at room temperature in the presence of oxygen and water.
STEROL DERIVATIVES AND USE THEREOF FOR TREATING DISEASES INVOLVING TRANSFORMED ASTROCYTE CELLS OR FOR TREATING MALIGNANT HAEMOPATHIES
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Page/Page column 14; 15, (2013/12/03)
The invention relates to novel sterol derivatives, the preparation method thereof, pharmaceutical compositions containing them and use thereof for treating diseases involving transformed astrocyte cells or for treating malignant haemopathies. The inventio
An unprecedented method for the generation of tert -butylperoxy radical using DIB/TBHP protocol: Solvent effect and application on allylic oxidation
Zhao, Yi,Yeung, Ying-Yeung
supporting information; experimental part, p. 2128 - 2131 (2010/08/05)
Figure presented Tert-Butylperoxy radical was generated with PhI(OAc) 2 and tBuOOH. Ester solvent was found to be critical and the protocol was applied in the allylic oxidation of various olefinic substrates, which gave the corresponding α,β-unsaturated enones in good yield and regioselectivity.
An environmentally benign catalytic oxidation of cholesteryl acetate with molecular oxygen by using N-hydroxyphthalimide
Yao, Zhen,Hu, Xingbang,Mao, Jianyong,Li, Haoran
scheme or table, p. 2013 - 2017 (2010/06/19)
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.
