1895-98-3Relevant academic research and scientific papers
Evaluation of thioamides, thiolactams and thioureas as hydrogen sulfide (H2S)donors for lowering blood pressure
Zaorska, Ewelina,Hutsch, Tomasz,Gawry?-Kopczyńska, Marta,Ostaszewski, Ryszard,Ufnal, Marcin,Koszelewski, Dominik
supporting information, (2019/04/29)
Hydrogen sulfide (H2S)is a biologically important gaseous molecule that exhibits promising protective effects against a variety of pathological processes. For example, it was recognized as a blood pressure lowering agent. Aligned with the need for easily modifiable platforms for the H2S supply, we report here the preparation and the H2S release kinetics from a series of structurally diversified thioamides, thiolactams and thioureas. Three different thionation methods based on the usage of a phosphorus pentasulfide and Lawesson reagent were applied to prepare the target thioamides and thiolactams. Furthermore, obtained H2S donors were evaluated both in in vivo and in vitro studies. The kinetic parameters of the liberating H2S was determined and compared with NaHS and GYY4137 using two different detection technics i.e.; fluorescence labeling 7-azido-4-methyl-2H-chromen-2-one and 5,5‘-dithiobis (2-nitrobenzoic acid), sulfhydryl probe, also known as the Ellman's reagent. We have proved that the amount of releasing H2S from these compounds is controllable through structural modifications. Finally, the present study shows a hypotensive response to an intravenous administration of the developed donors in the anesthetized rats.
Synthesis and tyrosinase inhibition activity of trans-stilbene derivatives
Ismail, Tabasum,Shafi, Syed,Srinivas, Jada,Sarkar, Dhiman,Qurishi, Yasrib,Khazir, Jabeena,Alam, Mohammad Sarwar,Kumar, Halmuthur Mahabalarao Sampath
, p. 97 - 102 (2016/01/25)
Synthesis of a focussed library of trans-stilbene compounds through Wittig and other base catalysed condensation reactions is presented. The synthesized stilbenes were screened for their inhibitory potential against murine tyrosinase activity to explore the structure activity relationship (SAR). Presence of electron withdrawing group (-CN) at the double bond and hydroxyl group or halogen atom especially at para-position on the aromatic rings was found to significantly elevate the inhibitory activity. Among all the compounds screened, compounds 2, 6, 8, 10, 11, 15 and 21 were found to exhibit appreciable inhibitory activity. Compound 21 ((E)-2,3-bis(4-Hydroxyphenyl)acryonitrile) was found to be the most active with an IC50 value of 5.06 μM which is less than half of the value 10.78 μM observed for resveratrol (common standard used in murine tyrosinase activity studies) under similar conditions. The results obtained from the present study reveal structural/functional group sensitivity for the tyrosinase inhibitory activity of stilbenoid moieties and are expected to be very helpful for the design and synthesis of novel, selective and effective tyrosinase inhibitors.
Synthesis and photochemical transformations of a few olefin-appended 11,12-dibenzoyldibenzobarrelenes
Jacob, Ambily Mary,George, Gisha,Jacob, Jomon P.,Mathew, Eason M.
, p. 199 - 202 (2015/06/02)
Several olefin-appended dibenzobarrelenes have been synthesised by Diels-Alder reaction between 9-alkenylanthracenes and dibenzoylacetylene under carefully controlled conditions and their photochemistry was examined. Olefin appendages acted as efficient quenchers of the triplet state of these barrelenes.
Synthesis and characterization of para-pyridine linked NHC palladium complexes and their studies for the Heck-Mizoroki coupling reaction
Liu, Ya-Ming,Lin, Yi-Chun,Chen, Wen-Ching,Cheng, Jen-Hao,Chen, Yi-Lin,Yap, Glenn P. A.,Sun, Shih-Sheng,Ong, Tiow-Gan
experimental part, p. 7382 - 7389 (2012/07/31)
This paper describes the synthesis of 1-(pyridine-4-ylmethyl) NHC and their Pd(ii) and Ag(i) complexes, which are fully characterized. Interestingly, we have also synthesized a Pd complex 3a-CO3 using a more direct treatment of K2CO3 with PdCl2. 3a-CO 3 represents the first reported solid structure of a Pd η2-carbonato complex stabilized by an NHC framework. 3a-CO 3 can be easily converted to a PdCl2 derivative by treating it with chloroform. We have found these palladium complexes mediate the Heck-Mizoroki coupling with a low catalyst loading. Furthermore, we also expand such catalytic manifold toward constructing fused polyaromatic substrates, a highly useful class of compounds in optoelectronic chemistry.
Novel reduction of isothiocyanates to thioformamides with SmI2 and tert-butyl alcohol in the presence of HMPA
Park, Heui Sul,Lee, In Sang,Kim, Yong Hae
, p. 1805 - 1806 (2007/10/03)
Isocyanates react with SmI2 and tert-butyl alcohol in the presence of HMPA to give thioformamides in excellent yields under mild conditions.
Approaches to Chemically Modified Enzymes As Synthetic Catalysts
Aitken, David J.,Alijah, Renate,Onyiriuka, Samuel O.,Suckling, Colin J.,Wood, Hamish C. S.,Zhu, Limin
, p. 597 - 608 (2007/10/02)
Attempts to introduce new catalytic activities of potential use in synthetic transformations into enzyme active sites are described.Substitution of the naturally occurring zinc in carboxypeptidase A by several metals known to catalyse hydrogenation was investigated; a new protein characterised as a rhodium carboxypeptidase was isolated but it failed to show activity as a hydrogenation catalyst for the reduction of a series of dehydroamino acid amides.Horse liver alcohol dehydrogenase was investigated for its potential to act as an oxygen transferase via Lewis acid catalysis.A series of cyclohexenyl and phenylribosides together with new alkenyl(arenyl)oxymethylenoxyethanols was prepared for evaluation as substrates; in the course of this study, novel neighbouring group participation by the oxygen atom of a chloromethyl ether was observed.Although the binding of potential oxygen acceptors (alkenes and aromatic compounds) and oxygen donors (hydrogen peroxide and alkyl hydroperoxides) was demonstrated, oxygen transfer did not occur with the combinations investigated.In contrast to the failure of the above metalloenzymes to catalyse new reactions, papain modified at the active site sulfhydryl group by thiazolium salts and pyridinium salts was shown to exhibit reactions characteristic of the covalently attached cofactor.Thus the thiazolopapains acted as decarboxylation catalysts for pyruvate and the pyridinopapains could be reduced to dihydropyridines which reduced electrophilic carbonyl substrates with small enantiomeric excess.
PHASE TRANSFER CATALYSED POLYMER-SUPPORTED WITTIG REACTIONS
Clarke, Stephen D.,Harrison, Charles R.,Hodge, Philip
, p. 1375 - 1378 (2007/10/02)
Arylsubstituted olefins can be prepared in high yield using phase transfer catalysed polymer-supported Wittig reactions.
