1228547-52-1Relevant academic research and scientific papers
A mild and selective method for the N-Boc deprotection by sodium carbonate
El Kazzouli, Sa?d,Koubachi, Jamal,Berteina-Raboin, Sabine,Mouaddib, Abderrahim,Guillaumet, Gérald
, p. 8575 - 8577 (2006)
A cleavage of N-tert-butyloxycarbonyl protection by Na2CO3 is reported. The N-free products are obtained in excellent yields. The compatibility of the method with the presence of acidic or basic groups is demonstrated. The reactions were performed on indole, azaindole, indazole, pyrazole, indolinone, quinolinone, and oxazolone.
DNA-Templated [2+2] Photocycloaddition: A Straightforward Entry into the Aplysinopsin Family of Natural Products
Duchemin, Nicolas,Skiredj, Adam,Mansot, Justine,Leblanc, Karine,Vasseur, Jean-Jacques,Beniddir, Mehdi A.,Evanno, Laurent,Poupon, Erwan,Smietana, Michael,Arseniyadis, Stellios
, p. 11786 - 11791 (2018)
Biosynthetic considerations inspired us to harness the templating properties offered by DNA to promote a [2+2] photoinduced cycloaddition. The method was developed based on the dimerization of (E)-aplysinopsin, which was previously shown to be unproductive in solution. In sharp contrast, exposure of this tryptophan-derived olefin to light in the presence of salmon testes DNA (st-DNA) reproducibly afforded the corresponding homo-dimerized spiro-fused cyclobutane in excellent yields. DNA provides unique templating interactions enabling a singular mimic of the solid-state aggregation necessary for the [2+2] photocycloaddition to occur. This method was ultimately used to promote the prerequisite dimerizations leading to both dictazole B and tubastrindole B, thus constituting the first example of a DNA-mediated transformation to be applied to the total synthesis of a natural product.
Synthesis of Camalexin and Related Analogues
Stremski, Yordan,Statkova-Abeghe, Stela,Angelov, Plamen,Ivanov, Iliyan
, p. 1589 - 1595 (2018)
Camalexin is synthesized on a gram scale by coupling of thiazole and indole in an amidoalkylation–oxidation sequence. Several high-yielding implementations of this two-step approach are demonstrated with variation of either the intermediate acyliminium reagent or the oxidation conditions. Benzo-analogues and aza-analogues of the natural product are also obtained by this method. As a side result, a new formylation of indole is demonstrated.
Brassinin oxidase mediated transformation of the phytoalexin brassinin: Structure of the elusive co-product, deuterium isotope effect and stereoselectivity
Pedras, M. Soledade C.,Minic, Zoran,Sarma-Mamillapalle, Vijay K.
, p. 1390 - 1399 (2011)
Brassinin oxidase, a fungal detoxifying enzyme that mediates the conversion of the phytoalexin brassinin into indole-3-carboxaldehyde, is the first enzyme described to date that catalyzes the transformation of a dithiocarbamate group into an aldehyde equivalent. Brassinin is an essential phytoalexin due to its antifungal activity and its role as biosynthetic precursor of other phytoalexins produced in plants of the family Brassicaceae (common name crucifer). In this report, the isolation, structure determination and synthesis of the elusive co-product of brassinin transformation by brassinin oxidase, S-methyl dithiocarbamate, the syntheses of dideuterated and (R) and (S) monodeuterated brassinins, kinetic analyses of isotope effects and chemical modifications of brassinin oxidase are described. The reaction of [1′-2H 2]brassinin was found to be slowed by a kinetic isotope effect of 5.3 on the value of kcat/Km. This result indicates that the hydride/hydrogen transfer step preceding brassinin transformation is rate determining in the overall reaction. In addition, the use of (R) and (S)-[1′-2H]brassinins as substrates indicated that the hydride/hydrogen transfer step is ca. 88% stereoselective for the pro-R hydrogen. A detailed chemical mechanism of the enzymatic transformation of brassinin is proposed.
Chemical structures of novel maillard reaction products under hyperglycemic conditions
Imahori, Daisuke,Matsumoto, Takahiro,Kojima, Naoto,Hasei, Tomohiro,Sumii, Megumi,Sumida, Taishi,Yamashita, Masayuki,Watanabe, Tetsushi
, p. 363 - 367 (2018)
Two novel and two known compounds, 4-quinolylaldoxime and indole-3-aldehyde, were isolated from a reaction mixture consisting of D-glucose and L-tryptophan at physiological temperature and pH. The chemical structures of the two novel compounds were elucidated by spectroscopic analysis such as X-ray crystallography. One of the novel compound and the indole-3-aldehyde showed mutagenicity toward Salmonella typhimurium YG1024 with S9 mix. Furthermore, 4-quinolylaldoxime was detected from streptozotocin-induced diabetic rat plasma by LC-MS/MS analysis; however, the isolated compounds were not detected in rat diet extracts. To our knowledge, this is the first report in which 4-quinolylaldoxime was detected in rat plasma. These results suggest that amino-carbonyl reaction products may be formed in diabetic condition and induce genetic damage.
Synthesis, antiproliferative and apoptosis induction potential activities of novel bis(indolyl)hydrazide-hydrazone derivatives
Sreenivasulu, Reddymasu,Reddy, Kotthireddy Thirumal,Sujitha, Pombala,Kumar, C. Ganesh,Raju, Rudraraju Ramesh
, p. 1043 - 1055 (2019)
In recent years, indole-indazolyl hydrazide-hydrazone derivatives with strong cell growth inhibition and apoptosis induction characteristics are being strongly screened for their cancer chemo-preventive potential. In the present study, N-methyl and N,N-dimethyl bis(indolyl)hydrazide-hydrazone analog derivatives were designed, synthesized and allowed to evaluate for their anti-proliferative and apoptosis induction potential against cervical (HeLa), breast (MCF-7 and MDA-MB-231) and lung (A549) cancer cell lines relative to normal HEK293 cells. The MTT assay in conjunction with mitochondrial potential assays and the trypan blue dye exclusion were employed to ascertain the effects of the derivatives on the cancer cells. Further, mechanistic studies were conducted on compound 14a to understand the biochemical mechanisms and functional interactions with various signaling pathways triggered in HeLa and MCF-7 cells. Compound 14a induced apoptosis via caspase independent pathway through the participation of mitogen-activated protein kinases (MAPK) such as extracellular signal related kinase (ERK) and p38 as well as p53 pathways. It originates the activation of pro-apoptotic proteins such as Bak and Mcl-1s and also strongly induced the generation of reactive oxygen species. In downstream signaling pathway, activated p53 protein interacted with MAPK pathways, including SAPK/c-Jun N-terminal protein kinase (JNK), p38 and ERK kinases resulting in apoptotic cell death. The involvement of MAPK cascades such as p38, ERK and p38 on compound 14a induced apoptotic cell death was evidenced by the fact that the inclusion of specific inhibitors of p38, ERK1/2 and JNK MAPK (SB2035809, PD98059 and SP600125) prevented the compound 14a towards induced apoptosis. The results clearly showed that MAP kinase cascades were crucial for apoptotic response in compound 14a induced cellular killing and were dependent on p53 activity. Based on the results, compound 14a was identified as a promising candidate for cancer therapeutics and these findings furnish a basis for further in vivo experiments on anti-proliferative activity.
WCl6/DMF as a new reagent system for the phosphine-free Pd(0)-catalyzed aminocarbonylation of aryl halides
Iranpoor, Nasser,Firouzabadi, Habib,Rizi, Zeinab Tavangar,Erfan, Soodabeh
, p. 43178 - 43182 (2014)
WCl6 in dimethyl formamide (DMF) is introduced as a new reagent system for aminocarbonylation of aryl halides in the presence of PdCl2 as pre-catalyst without any phosphorous ligand. Aryl iodides, bromides as well as chlorides were efficiently converted to their corresponding N,N-dimethyl amides in good to high yields. In this protocol, WCl6/DMF is responsible for the generation of both Pd(0) catalyst as well as the formation of a Vilsmeier imminium type intermediate.
Discovery of inhibitors of brassinin oxidase based on the scaffolds of the phytoalexins brassilexin and wasalexin
Pedras, M. Soledade C.,Minic, Zoran,Sarma-Mamillapalle, Vijay K.,Suchy, Mojmir
, p. 2456 - 2463 (2010)
Inhibitors of brassinin oxidase (BOLm), a unique phytoalexin detoxifying enzyme produced by the plant pathogenic fungus Leptosphaeria maculans (asexual stage Phoma lingam), were designed based on scaffolds of the phytoalexins brassilexin and wasalexin. Evaluation of these compounds using purified BOLm established that the inhibitory effect of brassilexin and derivatives decreased as follows: 6-chlorobrassilexin ≈ 6-bromobrassilexin > 5-bromobrassilexin ≈ 5-chlorobrassilexin ≈ 6-fluorobrassilexin > 8-methylbrassilexin > brassilexin ≈ 5-fluorobrassilexin. 6-Chlorobrassilexin was determined to be the best competitive inhibitor of BOLm discovered to date, with a Ki = 31 μM. Importantly, brassilexin and derivatives did not appear to induce BOLm in fungal cultures. Overall, these results suggest that the brassilexin scaffold is a good lead for further development of paldoxins against L. maculans, as it inhibits competitively BOLm without apparent induction.
A Modular Formal Total Synthesis of (±)-Cycloclavine
Netz, Natalie,Opatz, Till
, p. 1723 - 1730 (2016)
Cycloclavine is a clavine-type Ergot alkaloid noteworthy for its unique pentacyclic skeleton featuring a 3-azabicyclo[3.1.0]hexane substructure. A short convergent route to the racemic alkaloid is described which comprises only eight linear steps and requires only four chromatographic purifications. The two key building blocks can be prepared in high yield from commercially available starting materials. Two consecutive coupling reactions, namely a selective alkylation of a dienolate and a Heck reaction, are the key steps of the reaction sequence. (Chemical Equation Presented).
Indole - based distinctive chemosensors for 'naked-eye' detection of CN- and HSO4-, associated with hydrogen-bonded complex and their DFT study
Sain, Dibyendu,Kumari, Chanda,Kumar, Ashish,Dey, Swapan
, p. 239 - 248 (2016)
Colorimetric detection of anions (HSO4- and CN-) was achieved via analyte triggered colour changing of the dipodal and tripodal sensors in CH3CN-H2O (1:1). The sensors exhibited very sharp visual colo
