66040-54-8Relevant articles and documents
Alkaloids of the Ant Chelaner antarcticus
Jones, Tappey H.,Highet, Robert J.,Don, Warwick A.,Blum, Murray S.
, p. 2712 - 2716 (1986)
The major alkaloidal component from the ant Chelaner antarcticus (White) was found to be (5E,8Z)-3-(1-non-8-enyl)-5-((E)-1-prop-1-enyl)pyrrolizidine (1).The structure was suggested by spectral data and confirmed by a nonstereoselective synthesis, which also permitted the assignment of its stereochemistry.A minor component was the known compound trans-2-(1-hex-5-enyl)-5-(1-non-8-enyl)pyrrolidine (2), previously reported in Monomorium species.
Nonactin biosynthesis: Setting limits on what can be achieved with precursor-directed biosynthesis
Kusche, Brian R.,Phillips, Joshua B.,Priestley, Nigel D.
, p. 1233 - 1235 (2009)
Nonactin, produced by Streptomyces griseus ETH A7796, is a macrotetrolide assembled from nonactic acid. It is an effective inhibitor of drug efflux in multidrug resistant erythroleukemia K562 cells at sub-toxic concentrations and has been shown to possess both antibacterial and antitumor activity. As total synthesis is impractical for the generation of nonactin analogs we have studied precursor-directed biosynthesis as an alternative as it is known that nonactic acid can serve as a nonactin precursor in vivo. To determine the scope of the approach we prepared and evaluated a furan-based nonactic acid derivative, 11. Although no new nonactin analogs were detected when 11 was administered to S. griseus fermentative cultures, a significant inhibition of nonactin biosynthesis was noted (IC50 ～ 100 μM). Cell mass, nonactic acid production and the generation of other secondary metabolites in the culture were unaffected by 11 demonstrating that 11 selectively inhibited the assembly of nonactin from nonactic acid. While we were unable to generate new nonactin analogs we have discovered, however, a useful inhibitor that we can use to probe the mechanism of nonactin assembly with the ultimate goal of developing more successful precursor-directed biosynthesis transformations.
Diethylsilane as a Powerful Reagent in Au Nanoparticle-Catalyzed Reductive Transformations
Louka, Anastasia,Kidonakis, Marios,Saridakis, Iakovos,Zantioti-Chatzouda, Elisavet-Maria,Stratakis, Manolis
, p. 3508 - 3514 (2020/06/02)
Diethylsilane (Et2SiH2), a simple and readily available dihydrosilane, that exhibits superior reactivity, as compared to monohydrosilanes, in a series of reductive transformations catalyzed by recyclable and reusable Au nanoparticles (1 mol-%) supported on TiO2. It reduces aldehydes or ketones almost instantaneously at ambient conditions. It can be used in a one pot rapid reductive amination procedure, in which premixing of aldehyde and amine is required prior to the addition of the reducing agent and the catalyst, even in a protic solvent. An unprecedented method for the synthesis of N-arylisoindolines is also shown in the reductive amination between o-phthalaldehyde and anilines. In this transformation, it is proposed that the intermediate N,2-diphenylisoindolin-1-imines are reduced stepwise to the isoindolines. Finally, Et2SiH2 readily reduces amides into amines in excellent yields and shorter reaction times relative to previously known analogous nano Au(0)-catalyzed protocols.
Tuning lipase-catalysed kinetic resolution of 2-substituted thiophenes and furans: A scalable chemoenzymatic route to masked γ-bis-oxo-alcohols
Ferreira, Dartagnan S.P.,Ferreira, Jeiely G.,Filho, Everaldo F.S.,Princival, Jefferson L.
, p. 37 - 45 (2016/02/18)
The demand for greener and applicable approaches aiming at the synthesis of optically active compounds as single enantiomers has seen a significant growth worldwide. Since most of the chemically synthesized compounds are produced as racemates their kinetic resolution has been of great interest. For this purpose a number of chemo-enzymatic approaches were proposed. One of such approaches, the use of isolated lipases, is a well-established alternative. Herein we report the kinetic resolutions of 2-Substituted five-membered heteroaromatic rings. By optimizing the reaction conditions it was possible to produce (2-hydroxy)-2-substituted furans and thiophenes in high enantiomeric ratio (E > 200). Thus, racemic mixtures of compounds with slight structural differences were resolved. The current chemo-enzymatic strategy has been applied to a scalable approach leading to the formation of the enantiopure (S)-2i a well-known building block used for the synthesis of bioactive natural compounds.
