113931-96-7Relevant articles and documents
A simple and Highly Chemoselective Desilylation of tert-Butyldimethylsilyl Ethers
Lee, Adam Shih-Yuan,Yeh, Hsiu-Chih,Tsai, Ming-Hung
, p. 6891 - 6894 (1995)
The use of a 0.25M CH3OH/CCl4 (1:1) solvent mixture under ultrasound for the selective deprotection of tert-butyldimethylsilyl ethers of benzyl alcohols is described.This method enables to deprotect tert-butyldimethylsilyl ethers of primary alcohols, whereas tert-butyldimethylsilyl ethers of secondery and tertiary alcohols were stable under the reaction condition.
Synthesis of a Photo-Caged DOPA Derivative by Selective Alkylation of 3,4-Dihydroxybenzaldehyde
Schneider, Tobias,Kubyshkin, Vladimir,Budisa, Nediljko
, p. 2053 - 2063 (2018)
Natural and synthetic polymers containing the catechol moiety of noncoded amino acid 3,4-dihydroxyphenylalanine (DOPA) are capable of metal-coordination and adhesion under wet conditions. Masking the catechol subunit with a photo-cleavable group would provide an opportunity to design tunable adhesion properties that are especially important for biomaterial and biomedicine applications. Herein, we report the regioselective synthesis of a photo-caged DOPA bearing an ortho-nitrobenzyl (oNB) group that is capable of undergoing cleavage upon irradiation with UV light. We developed a selective synthetic route towards a 3-O-oNB alkylated DOPA regioisomer that can be readily incorporated into proteins by using a previously developed bio-expression platform. The synthesis is based on a regioselectivity switch in 3,4-dihydrozybenzaldehyde alkylation upon application of different equivalents of deprotonating base. The enantiomerically pure 3-O-oNB-DOPA was prepared on a gram scale and proved to be generally compatible with the solid-phase peptide synthesis conditions. We also demonstrate the general applicability of the developed synthetic strategy by providing the synthesis of 3-O-methyl-DOPA.
Free-radical-scavenging and xanthine oxidase inhibitory constituents from Stereospermum personatum
Sampath Kumar,Tiwari, Ashok K.,Venkat Reddy,Aparna,Jagadeeshwar Rao,Zehra Ali,Madhusudana Rao
, p. 1615 - 1621 (2005)
Bioassay-guided fractionation of different extracts of both stem and stem bark of Stereospermum personatum led to the isolation of free-radical-scavenging and xanthine oxidase inhibitory molecules along with three new anthraquinones, sterequinones F-H (1-3), a new naphthoquinone, sterequinone I (4), two new phenethyl esters, 2(4′-hydroxyphenyl)ethyl undecanoate (14) and 2(4′-hydroxyphenyl)ethyl nonacosanoate (15), and a new 3,4,5-trimethoxycinnamyl ether, 2-methoxy-4-[3′-(3″,4″, 5″trimethoxyphenyl)allyloxymethyl]phenol (16), together with known compounds. The antioxidant and xanthine oxidase inhibitory potentials of the isolated compounds are reported.
Biological evaluation of natural and synthesized homovanillic acid esters as inhibitors of intestinal fatty acid uptake in differentiated Caco-2 cells
Lieder, Barbara,Hans, Joachim,Hentschel, Fabia,Geissler, Katrin,Ley, Jakob
, (2019)
With raising prevalence of obesity, the regulation of human body fat is increasingly relevant. The modulation of fatty acid uptake by enterocytes represents a promising target for body weight maintenance. Recent results demonstrated that the trigeminal active compounds capsaicin, nonivamide, and trans-pellitorine dose-dependently reduce fatty acid uptake in differentiated Caco-2 cells as a model for the intestinal barrier. However, non-pungent alternatives have not been investigated and structural determinants for the modulation of intestinal fatty acid uptake have not been identified so far. Thus, based on the previous results, we synthesized 23 homovanillic acid esters in addition to the naturally occurring capsiate and screened them for their potential to reduce intestinal fatty acid uptake using the fluorescent fatty acid analog Bodipy-C12 in differentiated Caco-2 cells as an enterocyte model. Whereas pre-incubation with 100 μM capsiate did not change fatty acid uptake by Caco-2 enterocytes, a maximum inhibition of ?47% was reached using 100 μM 1-methylpentyl-2-(4-hydroxy-3-methoxy-phenyl)acetate. Structural analysis of the 24 structural analogues tested in the present study revealed that a branched fatty acid side chain, independent of the chain length, is one of the most important structural motifs associated with inhibition of fatty acid uptake in Caco-2 enterocytes. The results of the present study may serve as an important basis for designing potent dietary inhibitors of fatty acid uptake.
Chromium-Salen Complex/Nitroxyl Radical Cooperative Catalysis: A Combination for Aerobic Intramolecular Dearomative Coupling of Phenols
Nagasawa, Shota,Fujiki, Shogo,Sasano, Yusuke,Iwabuchi, Yoshiharu
, p. 6952 - 6968 (2021/05/29)
We describe an aerobic intramolecular dearomative coupling reaction of tethered phenols using a catalytic system consisting of a chromium-salen (Cr-salen) complex combined with a nitroxyl radical. This novel catalytic system enables formation of various spirocyclic dienone products including those unable to be accessed by previously reported methods efficiently under mild reaction conditions.
PHOTOPROXIMITY PROFILING OF PROTEIN-PROTEIN INTERACTIONS IN CELLS
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, (2021/04/01)
Photoactive probes and probe systems for detecting biological interactions are described. The photoactive probes include probes that combine both photocleavable and photoreactive moieties. The photoactive probe systems can include a first probe comprising a photocatalytic group and a second probe comprising a group that can act as a substrate for the reaction catalyzed by the photocatalytic group. The probes and probe systems can also include groups that can specifically bind to a binding partner on a biological entity of interest and a detectable group or a precursor thereof. The probes and probe systems can detect spatiotemporal interactions of proteins or cells. In some embodiments, the interactions can be detected in live cells. Also described are methods of detecting the biological interactions.
A mild, efficient, and selective deprotection of tert-butyldimethylsilyl (TBDMS) ethers using dicationic ionic liquid as a catalyst
Jadhav, Arvind H.,Kim, Hern
, p. 5338 - 5342 (2012/11/07)
Selective deprotection of alkyl TBDMS ether in the presence of phenolic TBDMS ether using dicationic ionic liquid [tetraEG(mim)2][OMs] 2 as a homogeneous catalyst showed significant catalytic activity in methanol at ambient temperature to produce respective alcohol in excellent yield. The present environmentally benign catalytic system is found to be very convenient, fast, high yielding, and clean method for selective desilylation of alkyl silyl ethers even in the existence of other sensitive organic functional groups such as aldehyde, methoxy, and acetate were also achieved.
Application of hansch's model to capsaicinoids and capsinoids: A study using the quantitative structure-activity relationship. A novel method for the synthesis of capsinoids
Barbero, Gerardo F.,Molinillo, Jose M. G.,Varela, Rosa M.,Palma, Miguel,MacIas, Francisco A.,Barroso, Carmelo G.
, p. 3342 - 3349 (2011/07/30)
We describe a synthetic approach for two families of compounds, the capsaicinoids and capsinoids, as part of a study of the quantitative relationship between structure and activity. A total of 14 capsaicinoids of increasing lateral chain lengths, from 2 to 16 carbon atoms, were synthesized. In addition, 14 capsinoids with identical lateral chains, as well as capsiate and dihydrocapsiate, have been synthesized, and a new method for the synthesis of these compounds has been developed. The yields range from 48.35 to 98.98%. It has been found that the synthetic capsaicinoids and capsinoids present a lipophilia similar to those of the natural compounds and present similar biological activity. The bioactivity of the synthetic capsaicinoids and capsinoids decreases proportionally to the degree of difference in lipophilia (higher or lower) compared to the natural compounds. Biological activity was determined using the etiolated wheat (Triticum aestlvum L.) coleoptiles bioassay and by comparing results of the synthesis with those presented by their counterpart natural compounds. The bioactivities found correlated directly to the lipophilic properties of the synthesized compounds.
METHOD FOR THE CHEMICAL SYNTHESIS OF CAPSINOIDS
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Page/Page column 3-4, (2010/03/02)
Method for the chemical synthesis of capsinoids, natural compounds with proven biological activity, from vanillin, comprising the protection of the alcohol group thereof, reduction of the aldehyde to alcohol, esterification of same and deprotection of the first protected alcohol group. In this way, the desired compounds are generated with high purity and said compounds can be easily separated with no mixing owing to the competitive esterification on the aromatic ring.
Highly Efficient and Convenient Deprotection of Methoxymethyl Ethers and Esters Using Bismuth Triflate in an Aqueous Medium
Venkat Reddy,Jagadeeshwar Rao,Sampath Kumar,Madhusudana Rao
, p. 1038 - 1039 (2007/10/03)
A simple and efficient method has been developed for the hydrolysis of methoxymethyl (MOM) ethers and esters to the corresponding alcohols and acids employing a catalytic amount of bismuth triflate in an aqueous medium. The conversions occur at ambient temperature and the yields of the deprotected alcohols are very good. The reaction was highly selective in the presence of other protecting groups such as TBDMS, TBDPS, benzyl, and allyl ethers.
