- A quinoline alkaloid rich Quisqualis indica floral extract enhances the bioactivity
-
A volatile alkaloid quinoline-4-carbonitrile (QCN) was isolated from the floral extract of Quisqualis indica. Major compounds were trans-linalool oxide (1.0, 4.5%), methyl benzoate (1.0, 4.0%), 2,2,6-trimethyl-6-vinyl-tetrahydropyran-3-one (7.4, 17.8%), 2,2,6-trimethyl-6-vinyl-tetrahydropyran-3-ol (1.0, 1.2%), (E,E)-α-farnesene (29.1, 16.1%), QCN (5.7, 1.3%) in live and picked flowers, respectively. Flower compositions were altered due to change in enzymatic reaction at the time of picking. Some rearrangements of oxygenated terpenoids occurred in the process of hydrodistillation to obtain essential oil. Chemical synthesis of QCN and its selectively reduced products derived from QCN were prepared through green reaction process. The catalytic modification of QCN has produced quinoline-4-methylamine; the later compound has shown enhanced bio-activities. QCN and floral extract (absolute) have shown potential anti-inflammatory and antioxidant activities. Besides, floral absolute has shown significant anti-inflammatory and antioxidant activities due to improved QCN (19.7%) content to synergize amongst terpenoids and benzenoids as compared to the essential oil with 1.1% of QCN.
- Rout, Prasant Kumar,Kumar, Prashant,Rao, Y. Ramachandra,Kumar, Anant,Bawankule, Dnyaneshwar U.,Singh, Ruchi,Singh, Kijay Bahadur,Chanotiya, Chandan Singh,Naik
-
p. 1632 - 1638
(2019/07/12)
-
- Heterogeneous Hydrogenation of Quinoline Derivatives Effected by a Granular Cobalt Catalyst
-
We communicate a convenient method for the pressure hydrogenation of quinolines in aqueous solution by using a particulate cobalt-based catalyst that is prepared in situ from simple Co(OAc)2 4H2O through reduction with abundant zinc powder. This catalytic protocol permits a brisk and atom-efficient access to a variety of 1,2,3,4-tetrahydroquinolines thereby relying solely on easy-to-handle reagents that are all readily obtained from commercial sources. Both the reaction setup assembly and the autoclave charging procedure are conducted on the bench outside an inert-gas-operated containment system, thus rendering the overall synthesis time-saving and operationally very simple.
- Timelthaler, Daniel,Topf, Christoph
-
p. 629 - 642
(2021/11/22)
-
- Cobalt-bridged secondary building units in a titanium metal-organic framework catalyze cascade reduction of N-heteroarenes
-
We report here a novel Ti3-BPDC metal-organic framework (MOF) constructed from biphenyl-4,4′-dicarboxylate (BPDC) linkers and Ti3(OH)2 secondary building units (SBUs) with permanent porosity and large 1D channels. Ti-OH groups from neighboring SBUs point toward each other with an O-O distance of 2 ?, and upon deprotonation, act as the first bidentate SBU-based ligands to support CoII-hydride species for effective cascade reduction of N-heteroarenes (such as pyridines and quinolines) via sequential dearomative hydroboration and hydrogenation, affording piperidine and 1,2,3,4-tetrahydroquinoline derivatives with excellent activity (turnover number ~ 1980) and chemoselectivity.
- Feng, Xuanyu,Song, Yang,Chen, Justin S.,Li, Zhe,Chen, Emily Y.,Kaufmann, Michael,Wang, Cheng,Lin, Wenbin
-
p. 2193 - 2198
(2019/02/20)
-
- Selective Catalytic Hydrogenation of Heteroarenes with N-Graphene-Modified Cobalt Nanoparticles (Co3O4-Co/NGratα-Al2O3)
-
Cobalt oxide/cobalt-based nanoparticles featuring a core-shell structure and nitrogen-doped graphene layers on alumina are obtained by pyrolysis of Co(OAc)2/phenanthroline. The resulting core-shell material (Co3O4-Co/NGratα-Al2O3) was successfully applied in the catalytic hydrogenation of a variety of N-heteroarenes including quinolines, acridines, benzo[h], and 1,5-naphthyridine as well as unprotected indoles. The peculiar structure of the novel heterogeneous catalyst enables activation of molecular hydrogen at comparably low temperature. Both high activity and selectivity were achieved in these hydrogenation processes, to give important building blocks for bioactive compounds as well as the pharmaceutical industry.
- Chen, Feng,Surkus, Annette-Enrica,He, Lin,Pohl, Marga-Martina,Radnik, J?rg,Topf, Christoph,Junge, Kathrin,Beller, Matthias
-
supporting information
p. 11718 - 11724
(2015/09/28)
-
- Solvent dependent regioselective hydrogenation of substituted quinolines
-
Various substituted quinolines have been reduced under H2 using Rh/Al2O3. Using methanol as solvent leads selectively to the 1,2,3,4-tetrahydroquinoline derivatives whereas in hexafluoroisopropanol the decahydro compounds are obtained.
- Fache, Fabienne
-
p. 2827 - 2829
(2007/10/03)
-
- Regiospecific Hydrogenation of Quinolines and Indoles in the Heterocyclic Ring
-
Quinolines, indoles, acridine and carbazole were hydrogenated using a large variety of heterogeneous catalysts in hydrocarbon solvents in an effort to achieve selective hydrogenation of the heterocyclic ring.When quinolines were hydrogenated using supported platinum, palladium, rhodium, ruthenium, or nickel metal catalysts in the presence of hydrogen sulfide, carbon disulfide, or carbon monoxide, there was exclusive hydrogenation of the heterocyclic ring to give only 1,2,3,4-tetrahydroquinolines.Use of iridium, rhenium, molybdenum(VI) oxide, tungsten(VI) oxide, chromium(III) oxide, iron(III) oxide, cobalt(II) oxide-molybdenum(VI) oxide, or copper chromite catalysts also caused exclusive hydrogenation of the heterocyclic ring even without addition of sulfur compounds or carbon monoxide.Hydrogenation of indoles using platinum, rhenium, or, in some cases, nickel catalysts (with or without sulfur compounds) occurred exclusively in the heterocyclic ring to give indolines, but conversions were affected by indole-indoline equilibria.
- Shaw, J.E.,Stapp, P.R.
-
p. 1477 - 1483
(2007/10/02)
-