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671.
Ravindar K Reddy MS Lindqvist L Pelletier J Deslongchamps P 《The Journal of organic chemistry》2011,76(5):1269-1284
A full account of the synthesis of hippuristanol and its analogues is described. Hecogenin acetate was identified as a suitable and economical starting material for this work, and substrate-controlled stereoselection was obtained throughout the construction of the key spiroketal unit. Suárez cyclization was first used, but Hg(II)-catalyzed spiroketalization of the 3-alkyne-1,7-diol motif was finally identified as the most convenient strategy. 相似文献
672.
K. Sridhar ReddyB. Venkateswara Rao 《Tetrahedron: Asymmetry》2011,22(2):190-194
A short, simple and efficient synthesis of the C-2 epimer of (+)-deacetylanisomycin starting from d-mannitol, utilizing an epoxide opening with a Grignard reagent and acid catalysed unusual intramolecular 5-endo-tet cyclization as key steps has been reported. 相似文献
673.
S. Naveen Sridhar M. Anandalwar J. Shashidhara Prasad Dinesh Manvar Arun Mishra Anamik Shah 《Journal of chemical crystallography》2008,38(4):315-319
Abstract 2,6-Dimethyl-5-(phenylcarbamoyl)-4-(3-nitrophenyl)-1,4-dihydropyridine-2-carboxylate was synthesized in two steps and was
characterized spectroscopically and confirmed by X-ray diffraction studies. The molecule crystallizes in the monoclinic crystal
class in the spacegroup P21/c with cell parameters a = 10.5960(6) ?, b = 10.2450(7) ?, c = 19.5790(11) ?, β = 107.448(3)° and Z = 4. The 1,4-dihydropyridine ring in the structure adopts a flattened boat conformation.
Graphical Abstract 2,6-Dimethyl-5-(phenylcarbamoyl)-4-(3-nitrophenyl)-1,4-dihydropyridine-2-carboxylate was synthesized in two steps and was
characterized spectroscopically and confirmed by X-ray diffraction studies. The molecule crystallizes in the monoclinic crystal
class in the spacegroup P21/c with cell parameters a = 10.5960(6) ?, b = 10.2450(7) ?, c = 19.5790(11) ?, β = 107.448(3)° and Z = 4. The 1,4-dihydropyridine ring in the structure adopts a flattened boat conformation.
相似文献
674.
Ramu Pasupathi Sugavaneshwar Thang Duy Dao Takahiro Yokoyama Satoshi Ishii 《辐射效应与固体损伤》2018,173(1-2):112-117
In this work, we have fabricated lead selenide (PbSe) thin films by the pulsed laser deposition method on Si/SiO2 substrates and investigated the effect of oxygen annealing (sensitization) in these films. The oxygen-sensitized films show high responsivity in the visible (VIS) and the near-infrared (NIR) region at room temperature without cooling. We also demonstrate the effective surface oxidation of PbSe thin films during the oxygen annealing process without treated with commonly used halogens that leads to a better photoresponse in these PbSe films. 相似文献
675.
Quanchi Chen Jordi-Amat Cuello-Garibo Ludovic Bretin Liyan Zhang Vadde Ramu Yasmin Aydar Yevhen Batsiun Sharon Bronkhorst Yurii Husiev Nataliia Beztsinna Lanpeng Chen Xue-Quan Zhou Claudia Schmidt Ingo Ott Martine J. Jager Albert M. Brouwer B. Ewa Snaar-Jagalska Sylvestre Bonnet 《Chemical science》2022,13(23):6899
In vivo data are rare but essential for establishing the clinical potential of ruthenium-based photoactivated chemotherapy (PACT) compounds, a new family of phototherapeutic drugs that are activated via ligand photosubstitution. Here a novel trisheteroleptic ruthenium complex [Ru(dpp)(bpy)(mtmp)](PF6)2 ([2](PF6)2, dpp = 4,7-diphenyl-1,10-phenanthroline, bpy = 2,2′-bipyridine, mtmp = 2-methylthiomethylpyridine) was synthesized and its light-activated anticancer properties were validated in cancer cell monolayers, 3D tumor spheroids, and in embryonic zebrafish cancer models. Upon green light irradiation, the non-toxic mtmp ligand is selectively cleaved off, thereby releasing a phototoxic ruthenium-based photoproduct capable notably of binding to nuclear DNA and triggering DNA damage and apoptosis within 24–48 h. In vitro, fifteen minutes of green light irradiation (21 mW cm−2, 19 J cm−2, 520 nm) were sufficient to generate high phototherapeutic indexes (PI) for this compound in a range of cancer cell lines including lung (A549), prostate (PC3Pro4), conjunctival melanoma (CRMM1, CRMM2, CM2005.1) and uveal melanoma (OMM1, OMM2.5, Mel270) cancer cell lines. The therapeutic potential of [2](PF6)2 was further evaluated in zebrafish embryo ectopic (PC3Pro4) or orthotopic (CRMM1, CRMM2) tumour models. The ectopic model consisted of red fluorescent PC3Pro4-mCherry cells injected intravenously (IV) into zebrafish, that formed perivascular metastatic lesions at the posterior ventral end of caudal hematopoietic tissue (CHT). By contrast, in the orthotopic model, CRMM1- and CRMM2-mCherry cells were injected behind the eye where they developed primary lesions. The maximally-tolerated dose (MTD) of [2](PF6)2 was first determined for three different modes of compound administration: (i) incubating the fish in prodrug-containing water (WA); (ii) injecting the prodrug intravenously (IV) into the fish; or (iii) injecting the prodrug retro-orbitally (RO) into the fish. To test the anticancer efficiency of [2](PF6)2, the embryos were treated 24 h after engraftment at the MTD. Optimally, four consecutive PACT treatments were performed on engrafted embryos using 60 min drug-to-light intervals and 90 min green light irradiation (21 mW cm−2, 114 J cm−2, 520 nm). Most importantly, this PACT protocol was not toxic to the zebrafish. In the ectopic prostate tumour models, where [2](PF6)2 showed the highest photoindex in vitro (PI > 31), the PACT treatment did not significantly diminish the growth of primary lesions, while in both conjunctival melanoma orthotopic tumour models, where [2](PF6)2 showed more modest photoindexes (PI ∼ 9), retro-orbitally administered PACT treatment significantly inhibited growth of the engrafted tumors. Overall, this study represents the first demonstration in zebrafish cancer models of the clinical potential of ruthenium-based PACT, here against conjunctival melanoma.A new tris-heteroleptic photoactivated chemotherapy ruthenium complex induces apoptosis upon green light activation in a zebrafish orthothopic conjunctival melanoma xenograft model. 相似文献
676.
Piyush Kashyap Mamta Thakur Nidhi Singh Deep Shikha Shiv Kumar Poonam Baniwal Yogender Singh Yadav Minaxi Sharma Kandi Sridhar Baskaran Stephen Inbaraj 《Molecules (Basel, Switzerland)》2022,27(19)
The recent coronavirus disease (COVID-19) outbreak in Wuhan, China, has led to millions of infections and the death of approximately one million people. No targeted therapeutics are currently available, and only a few efficient treatment options are accessible. Many researchers are investigating active compounds from natural plant sources that may inhibit COVID-19 proliferation. Flavonoids are generally present in our diet, as well as traditional medicines and are effective against various diseases. Thus, here, we reviewed the potential of flavonoids against crucial proteins involved in the coronavirus infectious cycle. The fundamentals of coronaviruses, the structures of SARS-CoV-2, and the mechanism of its entry into the host’s body have also been discussed. In silico studies have been successfully employed to study the interaction of flavonoids against COVID-19 Mpro, spike protein PLpro, and other interactive sites for its possible inhibition. Recent studies showed that many flavonoids such as hesperidin, amentoflavone, rutin, diosmin, apiin, and many other flavonoids have a higher affinity with Mpro and lower binding energy than currently used drugs such as hydroxylchloroquine, nelfinavir, ritonavir, and lopinavir. Thus, these compounds can be developed as specific therapeutic agents against COVID-19, but need further in vitro and in vivo studies to validate these compounds and pave the way for drug discovery. 相似文献
677.
Dr. Elke Duchardt-Ferner Dr. Jan Ferner Dr. Boris Fürtig Dr. Martin Hengesbach Dr. Christian Richter Dr. Andreas Schlundt Dr. Sridhar Sreeramulu Dr. Anna Wacker Prof. Dr. Julia E. Weigand Dr. Julia Wirmer-Bartoschek Prof. Dr. Harald Schwalbe 《Angewandte Chemie (International ed. in English)》2023,62(14):e202217171
The outbreak of COVID-19 in December 2019 required the formation of international consortia for a coordinated scientific effort to understand and combat the virus. In this Viewpoint Article, we discuss how the NMR community has gathered to investigate the genome and proteome of SARS-CoV-2 and tested them for binding to low-molecular-weight binders. External factors including extended lockdowns due to the global pandemic character of the viral infection triggered the transition from locally focused collaborative research conducted within individual research groups to digital exchange formats for immediate discussion of unpublished results and data analysis, sample sharing, and coordinated research between more than 50 groups from 18 countries simultaneously. We discuss key lessons that might pertain after the end of the pandemic and challenges that we need to address. 相似文献