- Effective gene-silencing of siRNAs that contain functionalized spacer linkages within the central region
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Short-interfering RNAs containing a variety of functional groups at the central region of the sense strand were synthesized and evaluated. The gene-silencing data suggest that these siRNAs are biocompatible and are very effective in cell-based assays.
- Desaulniers, Jean-Paul,Hagen, Gordon,Anderson, Jocelyn,McKim, Chris,Roberts, Blake
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Read Online
- Synthesis and acetylcholinesterase inhibitory activity of 2β,3α-disulfoxy-5α-cholestan-6-one
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Disodium 2β,3α-dihydroxy-5α-cholestan-6-one disulfate (8) has been synthesized using cholesterol (1) as starting material. Sulfation was performed using trimethylamine-sulfur trioxide complex in dimethylformamide as the sulfating agent. The acetylcholinesterase inhibitory activity of compound 8 was evaluated and compared to that of disodium 2β,3α-dihydroxy- 5α-cholestane disulfate (10) and diols 7 and 9. Compounds 8 and 10 were active with IC50 values of 14.59 and 59.65 μM, respectively. Diols 7 and 9 showed no inhibitory activity (IC50 > 500 μM).
- Richmond, Victoria,Santos, Gustavo A. Garrido,Murray, Ana P.,Maier, Marta S.
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Read Online
- A Simple Synthesis of Steroidal 3α,5-Cyclo-6-ones and their Efficient Transformation to Steroidal 2-En-6-ones
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Sterols 1 were converted to 3α-5-cyclo-6-ones 4 via their mesylates and subsequent oxidation.Refluxing 4 with sodium bromide/p-toluene sulfonic acid in dimethylformamide gave steroidal 2-en-6-ones 5, among which 5 is an important brassinolide intermediate.
- Aburatani, Masakazu,Takeuchi, Tadashi,Mori, Kenji
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Read Online
- Synthesis of a carborane-containing cholesterol derivative and evaluation as a potential dual agent for MRI/BNCT applications
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In this study the synthesis and characterization of a new dual, imaging and therapeutic, agent is proposed with the aim of improving the efficacy of Boron Neutron Capture Therapy (BNCT) in cancer treatment. The agent (Gd-B-AC01) consists of a carborane un
- Alberti, Diego,Toppino, Antonio,Geninatti Crich, Simonetta,Meraldi, Chiara,Prandi, Cristina,Protti, Nicoletta,Bortolussi, Silva,Altieri, Saverio,Aime, Silvio,Deagostino, Annamaria
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Read Online
- Synthesis and antitumor activity of novel steroidal imidazolium salt derivatives
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Sixty-one novel steroidal imidazolium salt derivatives were synthesized and evaluated in vitro against a panel of human tumor cell lines. The results showed that diosgenin?imidazolium salt derivatives displayed much higher cytotoxic activities than choles
- Deng, Guogang,Zhou, Bei,Wang, Jing,Chen, Zhuo,Gong, Liang,Gong, Yaxiao,Wu, Dongmei,Li, Yan,Zhang, Hongbin,Yang, Xiaodong
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Read Online
- Cyclic Diaryl λ3-Bromanes: A Rapid Access to Molecular Complexity via Cycloaddition Reactions
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Biaryls have widespread applications in organic synthesis. However, sequentially polysubstituted biaryls are underdeveloped due to their challenging preparation. Herein, we report the synthesis of dissymetric 2,3,2′,3′,4-substituted biaryls via pericyclic reactions of cyclic diaryl λ3-bromanes. The functional groups tolerance and atom economy allow access to molecular complexity in a single reaction step. Continuous flow protocol has been designed for the scale-up of the reaction, while postfunctionalizations have been developed taking advantage of the residual Br-atom.
- Lanzi, Matteo,Ali Abdine, Racha Abed,De Abreu, Maxime,Wencel-Delord, Joanna
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supporting information
p. 9047 - 9052
(2021/12/06)
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- Apoptosis inducing properties of 3-biotinylate-6-benzimidazole B-nor-cholesterol analogues
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In this work, a series of Biotin-substituted B-nor-cholesteryl benzimidazole compounds were synthesized. The antiproliferative activities of these compounds were evaluated in vitro using a series of human cancer cell lines, including HeLa (cervical cancer), SKOV3 (ovarian cancer), T-47D (thymus gland cancer), MCF-7 (human breast cancer) and HEK293T (normal renal epithelial) cells. These compounds displayed distinct antiproliferative activities against the currently tested cancer cells. The apoptotic properties induced by compound 6d were further investigated. Our results showed that compound 6d could induce the apoptosis of SKOV3 cells, blocking the cell growth in S-phase. Western blotting analyses revealed that compound 6d can induce cell apoptosis via the mitochondria-dependent pathway.
- Zhu, Zhiling,Liu, Zhiping,Cui, Jianguo,Huang, Yanmin,Chen, Hualong,Wu, Yulan,Huang, Xiaotong,Gan, Chunfang
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- 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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- Steroid compound 3-site hydroxyl configuration inversion method
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The invention discloses a steroid compound 3-site hydroxyl configuration inversion method. The method specifically comprises the following steps that (1) a steroid compound containing a 3-site hydroxyl reacts with an acyl chloride compound; (2) the product obtained in the step (1) and a substituting agent are subjected to SN2 nucleophilic substitution reaction under existing of a phase transfer catalyst; and (3) the product obtained in the step (2) is subjected to a hydrolysis reaction. Compared with a Mitsunobu method, the method does not need to use triphenylphosphine and azodiformate pricedhigher, and accordingly the production cost is greatly lowered; meanwhile, a p-nitrobenzoic acid derivative which seriously affects the water environment does not need to be used, and therefore the method is more environmentally friendly. The method adopts cesium acetate/18-crown ether-6 system to conduct 3-site hydroxyl configuration inversion, can remarkably reduce occurrence of side reactions,accordingly a higher reaction yield is obtained, and the method is finally applicable to industrialized production.
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Paragraph 0086; 0087; 0088
(2018/12/14)
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- Ti-Catalyzed Radical Alkylation of Secondary and Tertiary Alkyl Chlorides Using Michael Acceptors
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Alkyl chlorides are common functional groups in synthetic organic chemistry. However, the engagement of unactivated alkyl chlorides, especially tertiary alkyl chlorides, in transition-metal-catalyzed C-C bond formation remains challenging. Herein, we describe the development of a TiIII-catalyzed radical addition of 2° and 3° alkyl chlorides to electron-deficient alkenes. Mechanistic data are consistent with inner-sphere activation of the C-Cl bond featuring TiIII-mediated Cl atom abstraction. Evidence suggests that the active TiIII catalyst is generated from the TiIV precursor in a Lewis-acid-assisted electron transfer process.
- Wu, Xiangyu,Hao, Wei,Ye, Ke-Yin,Jiang, Binyang,Pombar, Gisselle,Song, Zhidong,Lin, Song
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supporting information
p. 14836 - 14843
(2018/11/10)
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- 3-biotin ether ester-B reduction-cholesteric benzimidazole compound and preparation method and application thereof
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The invention discloses a 3-biotin ether ester-B reduction-cholesteric benzimidazole compound and a preparation method and application thereof. The 3-biotin ether ester-B reduction-cholesteric benzimidazole compound is characterized in that the chemical structure formula refers to the description, wherein n is an even number which is more than or equal to 2; R1 is H or CH3; R2 is H or OCH3. The 3-biotin ether ester-B reduction-cholesteric benzimidazole compound is obvious in effect on inhibiting cells of various tumor cell strains such as human uterine cervix cancer cell strains, ovarian carcinoma cell strains and human breast carcinoma cell lines; and meanwhile, the 3-biotin ether ester-B reduction-cholesteric benzimidazole compound is nontoxic to human renal epithelial cells and can be applicable to preparation of drugs for treating cancers.
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Paragraph 0043; 0047; 0052; 0056
(2019/01/16)
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- Carboxylate-Assisted Iridium-Catalyzed C-H Amination of Arenes with Biologically Relevant Alkyl Azides
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An iridium-catalyzed C-H amination of arenes with a wide substrate scope is reported. Benzamides with electron-donating and -withdrawing groups and linear, branched, and cyclic alkyl azides are all applicable. Cesium carboxylate is crucial for both reactivity and regioselectivity of the reactions. Many biologically relevant molecules, such as amino acid, peptide, steroid, sugar, and thymidine derivatives can be introduced to arenes with high yields and 100 % chiral retention. Ir responsible! A direct C-H amination between benzamide derivatives and various alkyl azides was achieved using iridium catalysis (see scheme; NTf=trifluoromethanesulfonyl amide). Cesium carboxylate was found to be the promoter and regiocontroller of this reaction. By this method, many biological active molecules can be introduced to benzamide components with high yields and 100 % chiral retention.
- Zhang, Tao,Hu, Xuejiao,Wang, Zhen,Yang, Tiantian,Sun, Hao,Li, Guigen,Lu, Hongjian
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supporting information
p. 2920 - 2924
(2016/03/23)
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- POLYMER-CYCLODEXTRIN-LIPID CONJUGATES
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The invention comprises compounds, methods of making, and methods of using. A group of polymer-cyclodextrin-lipid conjugates having a center backbone and three or four appended functional groups are disclosed, wherein one of the hydrophilic components is cyclodextrin. The compounds may have a backbone with three or four appended functional groups: one or two lipophilic compounds including sterols or "fat soluble" vitamins or fatty acids, one or two hydrophilic polymer and one cyclodextrin. Specific functional groups may be selected for specific applications in formulating pharmaceuticals, cosmetics, nutriceuticals, and the like. Typical coupling reaction of the conjugates may involve one or more or combinations or in series of alkylation including N-alkylation or O-alkylation, etherification, esterification and amidation chemical processes. A variety of linkers between the center backbone and functional groups may also be selected to modify the carriers or center backbones for the coupling reactions and optimize performance of the conjugates.
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Paragraph 00148; 00149
(2017/01/09)
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- POLYMER-CARBOHYDRATE CONJUGATES FOR DRUG DELIVERY TECHNOLOGY
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The invention comprises compounds, methods of making, and methods of using. The compounds may have a linear or cylic backbone and three or four appended functional groups: one or two lipohilic compounds including sterols or “fat soluble” vitamins, one or two hydrophilic polymer, and one or two carbohydrate. A group of polymer-carbohydrate conjugates having a central backbone and three appended functional groups are disclosed wherein one lipophilic compound is void of both steroid acids. The conjugate may have fatty acids as the primary lipophilic carrier, one hydrophilic polymer, and one carbohydrate. Specific functional groups may be selected for specific applications in formulating pharmaceuticals, cosmetics, nutriceuticals, and the like. Typical coupling reaction of the conjugates may involve one or more or combinations or in series of alkylation including N-alkylation or O-alkylation, etherification, esterification and amidation chemical processes. A variety of linkers between the backbone and functional groups may also be selected to modify the carriers or center backbones for the coupling reactions and optimize performance of the conjugates.
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Paragraph 0115
(2015/06/17)
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- ANTIMICROBIAL CATIONIC POLYCARBONATES
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Antimicrobial cationic polymers having one or two cationic polycarbonate chains were prepared by organocatalyzed ring opening polymerization. One antimicrobial cationic polymer has a polymer chain consisting essentially of cationic carbonate repeat units
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Paragraph 0459; 0460
(2014/10/16)
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- Iron(III)-catalyzed halogenations by substitution of sulfonate esters
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A novel halogenation reaction from sulfonates catalyzed by iron(III) is described. The reaction can be performed as a stoichiometric or a catalytic version. This reaction provides a convenient strategy for the efficient access to structurally diverse secondary chlorides, bromides and iodides. The stereochemical course of the reaction is governed by the substrate and the experimental conditions. Secondary alcohols modified as quisylates or pysylates are substantially more reactive. Aliphatic quisylates proceed with overall inversion of configuration under catalytic conditions. Chemoselectivity in bismesylates was observed in favour of the secondary mesylate. Additionally, based on the experimental results, a possible catalytic cycle for the halogenation has been proposed.
- Ortega, Nuria,Feher-Voelger, Andres,Brovetto, Margarita,Padron, Juan I.,Martin, Victor S.,Martin, Tomas
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supporting information; experimental part
p. 963 - 972
(2011/06/20)
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- Click chemistry: An efficient synthesis of heterocycles substituted with steroids, saponins, and digitalis analogues
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The copper-catalyzed azide-alkyne cycloaddition (CuAAC) has been used for the construction of 1,2,3-triazole containing steroids in good to excellent yields. Combination of propargylic glycosides and steroidal azides as reaction partner allowed the synthesis of a privileged class of natural product analogues. The versatility of this protocol makes this chemistry a useful attractive approach for the synthesis of target molecules. Georg Thieme Verlag Stuttgart · New York.
- Deobald, Anna M.,Camargo, Leandro R. S.,Alves, Diego,Zukerman-Schpector, Julio,Correa, Arlene G.,Paixao, Marcio W.
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supporting information; scheme or table
p. 4003 - 4010
(2012/01/05)
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- Inversion of secondary chiral alcohols in toluene with the tunable complex of R3N{single bond}R′COOH
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The SN2 reaction of enantiomerically pure sulfonates with the tunable complex of R3N-R′COOH in toluene has been extensively studied. It was revealed that the molar ratio of the tertiary amines and carboxylic acids in the complex of R3NR′COOH is crucial for the SN2 reaction, and should be tuned for each sulfonate to give the best yield. Fifteen sulfonates 1 and 3-13 (Scheme 2) were prepared and transformed into 22 corresponding inverted esters 2 and 14-24 (Scheme 2) in good to high yields.
- Shi, Xiao-Xin,Shen, Chun-Li,Yao, Jian-Zhong,Nie, Liang-Deng,Quan, Na
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experimental part
p. 277 - 284
(2010/05/18)
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- Practical synthesis of 3β-amino-5-cholestene and related 3β-halides involving i-steroid and retro-i-steroid rearrangements
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(Equation Presented) Derivatives of 3β-amino-5-cholestene (3β-cholesterylamine) are of substantial interest as cellular probes and have potential medicinal applications. However, existing syntheses of 3β-amino-5-cholestene are of limited preparative utility. We report here a practical method for the stereoselective preparation of 3β-amino-5- cholestene, 3β-chloro-5-cholestene, 3β-bromo-5-cholestene, and 3β-iodo-5-cholestene from inexpensive cholesterol. A sequential i-steroid/retro-i-steroid rearrangement promoted by boron trifluoride etherate and trimethylsilyl azide converted cholest-5-en-3β-ol methanesulfonate to 3β-azido-cholest-5-ene with retention of configuration in 93% yield.
- Sun, Qi,Cai, Sutang,Peterson, Blake R.
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supporting information; experimental part
p. 567 - 570
(2009/07/18)
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- CHOLESTERYLAMINES FOR THE TREATMENT AND PREVENTION OF INFECTIOUS DISEASES
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The present invention relates to the use of cholesterylamines in the preparation of pharmaceutical compositions. These pharmaceutical compositions are to be used in the medical intervention of infectious diseases, in particular diseases caused by a virus or a bacterium.
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Page/Page column 22
(2008/12/06)
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- Synthetic mimics of mammalian cell surface receptors: method and compositions
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The present invention relates to new synthetic receptors. More particularly, the present invention relates to the use of the synthetic receptors for delivering a protein, peptide, drug, prodrug, lipid, nucleic acid, carbohydrate or small molecule into a t
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Page/Page column 23; 25
(2008/06/13)
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- Synthesis of solid-phase bound sulfonate esters
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p-Pivaloyloxybenzenesulfonyl and methylsulfonyl residues were used as linkers to attach secondary alcohols to Wang resin and to Merrifield resin, respectively. p-Pivaloyloxybenzenesulfonates of alcohols were deprotected at the phenolic group and coupled with Wang resin by Mitsunobu reaction whereas mesylates were lithiated at the methyl group and subsequently connected with chloromethyl residues of Merrifield resin.
- Furman,Lysek,Matyjasek,Wojtkielewicz,Chmielewski
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p. 2795 - 2802
(2007/10/03)
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- Syntheses and structures of 3-stannylcholest-5-ene species
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The compounds, 3α- and 3β-triphenylstannylcholest-5-ene, 1 and 2 respectively, have been prepared stereospecifically in reactions of Ph3SnLi with cholesteryl methane- or toluene-p-sulfonates, and of Ph3SnCl with the Grignard reagent from cholesteryl chloride, respectively. Complete 1H and 13C NMR spectral assignments for 1 have been obtained using HMBC and HMQC techniques: these have been used to aid the 13C NMR spectral assignments for 2 and 3α- and 3β-(InPh3-nSn)cholest-5-enes (n = 1-2) (9-12). Crystal structure determinations of 3α-(IPh2Sn)cholest-5-ene 9 and 3α-(I2PhSn)cholest-5-ene 10 indicate distorted tetrahedral geometries about the tin centres in both compounds. The Sn-I bond lengths are 2.731(5) A in 9 and between 2.6979(12) and 2.7173(12) A in 10. Despite the similarity in the values (ca. 60°) of the dihedral angles, Sn-C(3)-C(2)-C(1) [C(1) aliphatic carbon] and Sn-C(3)-C(4)-C(5) [C(5) olefinic carbon], the values of 3J[119Sn-13C(1)] are about twice the 3J[119Sn-13C(5)] values in each of 1, 9 and 10; in contrast, 3J[119Sn-13C(1)] and 3J[119Sn-13C(5)] values are essentially the same in each of 2, 11 and 12 [Sn-C(3)-C(2)-C(1) and Sn-C(3)-C(4)-C(5) ca. 180°].
- Buchanan, Heather J.,Cox, Philip J.,Doidge-Harrison, Solange M. S. V.,Howie, R. Alan,Jaspars, Marcel,Wardell, James L.
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p. 3657 - 3664
(2007/10/03)
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- Selektive Blockierung von primaeren oder sekundaeren Hydroxylgruppen mit elektroaktiven Schutzgruppen
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In a diol such as 17, at first the primary OH-group is blocked with an electroactive protecting group (18).Then the secondary OH-group is protected with a second group (19), that is reduced at more negative potentials.Controlled potential electrolysis selectively deblocks the primary OH-group.As protecting groups the tritylone (= 9,10-dihydro-10-oxo-9-phenyl-9-anthracenyl-) and 4-cyanobenzyl residue were suitable.With the help of a combination of these groups 1-dodecyloxy-3-octadecyloxy-2-propanol (27) was prepared starting with 1,2-O-isopropylideneglycerol (21).
- Stouwe, Claus van der,Schaefer, Hans J.
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p. 946 - 958
(2007/10/02)
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